Fitting higher flowing Garrett turbos - what's involved

[Caveman]

Guys,

As you know my car has gone as far as it can on the stock turbos, so like many I've decided that bigger turbos is the next logical step.

I understand that TD04s are the cheapest route, but the amount of relocation and general faffing around required really puts me off.

What I'm looking to do is find turbos that will give me a safe 400-450 bhp, whilst only requiring adapter plates, downpipe modification and revised plumbing. Some people have mentioned the GT2554R as a good bet, but the rated power is way more than I need and they do still look quite a bit bigger than the std TD03, so I'm concerned about clearance isues. I was wondering if the GT1548 would be a better bet?

Ultimately I want to know if there are any turbos that will fit and offer good power without requiring relocation or removal of stuff. I've heard of aircon units being removed, thinner radiator fans and all measure of messing about to get turbos in.

Does anyone know what will fit with minimal messing around?

Answers on a postcard! :)

Cheers,

Mart.

[Kieran]

Unfortunately, the "Easiest" option is TD04s. It's not really as simple as you'd like it to be. TBH I don't think it'll be too long before the TD04 route is 'Cracked' and it's offered as a kit... It's been done now and I know several others are looking at doing it.

Looking at the compressor maps, I doubt the GT15 series flows enough anyway.

Search around for posts by Valmes - One's called 'Let's think bigger turbos' as I recall, lots of info in there.

[Caveman]

Hi Kieran,

thanks for your reply. I thought the TD04 route required relocation of things such as the aircon pump, smaller radiator fans and bulkhead hammering?

Are you saying TD04s will fit with just adapter plates, plumbing and modded downpipes?

Cheers,

Mart.

[Nutter_John]

There are different TD04's , the ones K reffer's to are from a scooby

[Nick Mann]

I am working on a kit. It is no-where near ready yet, so if you are in a rush, don't wait! I am hoping to have costs ready by spring, with the kit being available soon after.

I will obviously let everyone know when I have some news!

[djb160]

what sort of kit is it Nick? Is there a link to a thread for it somewhere?

[Nick Mann]

It doesn't exist yet, but it will include the minimum amount of stuff to fit a pair of subaru WRX turbos.

Taking an abstract guess it will include:
2 exhaust elbows.
A few nuts & bolts.
A few lengths of hose.
A few Samco style couplers.
A few Banjo bolt fittings.
A thinner radiator fan.
An oil filter relocation kit.
A couple of actuator brackets.

The turbos will need clocking and the exhaust manifold flange on the turbo will need drilling ant tapping.

I can't guarantee that any of this is spot on yet, or that any other issues will be found on the way, so like I said - if you are in a hurry then don't wait!

[Caveman]

Hi Nick,

Thanks for the tip.

I have been looking further into similarly sized turbos and I still think the Garrett GT1548 could be a good bet. It's both oil and water cooled and flows up to 200bhp in standard trim. A bit of hybridising can easily get it to 250bhp or more.

The real beauty is that the GT15 is the same size nearly to the TD03 so it will require the most minimal mods to fit.

Here's a comparison pic between our TD03 and the GT15:

uploaded/2162/1227611382.jpg

uploaded/2162/1227611649.jpg

Cheers,

Mart.

[Nick Mann]

Sorry to be a pain, but neither of those turbos is a standard VR4 fitment. The VR4 uses a TD03, not a TC.

Having said that, I am still wishing you luck with your project - I guess we could help each other out whilst we are both looking at similar stuff! :D

[Kieran]

I have been looking further into similarly sized turbos and I still think the Garrett GT1548 could be a good bet. It's both oil and water cooled and flows up to 200bhp in standard trim. A bit of hybridising can easily get it to 250bhp or more.

To say a turbo will 'Flow' a certain amount of BHP is a risky business. It really depends on what engine it's on.

If you look at the compressor map here:

http://www.turbobygarrett.com/turbobygarrett/images/catalog/Turbochargers/gt15_images/GT1548_466755_3_comp_e.gif

You can see that the GT1548 flows 15lb/min at a Pressure Ratio of two (Effectively 1 bar of boost). Now whilst on the Garret GT1548 map doesn't show the air density or temperature, in the past Garret maps have been based on a temperature and air pressure that one would see in real life. Rather than reproduce a lot of info, have a read of this:

http://www.stealth316.com/2-3s-compflowmaps.htm

The paragraph beneath the very first compressor map shows what garrett have used in the past and how to convert lb/min into CFM. For the purposes of conversion, I think it is a reasonably safe assumption to use the same calculation (10lb/min = 144.7178CFM).

So, at 1 bar boost, the GT15 is flowing 15lb/min and it's in the 70% efficiency zone - not too bad but you wouldn't want to get much worse than that. 15lbs/min = 217.0 CFM x 2 = 434CFM.

Somewhere on here, someone worked out the CFM requirements for our engines and as I recall the flow rate was something like 450ish in standard form at 0.9bar - So I still say you need to be thinking bigger.

[SGHOM]

basically Mart...... If you want to go faster in a VR4....... then buy a skyline. :happy:

[scientist]

basically Mart...... If you want to go faster in a VR4....... then buy a skyline. :happy:
Wheres the fun in that? Its because hardly anybody is taking the plunge why parts are so scarce for these cars. Stick with the MHI variants, they will not fail you or be as problematic. Atleast u can rebuild them when they fail unlike the GT series ball bearing turbos.

So far its been proven that twin TD04s from the subarus are very compatible bolt ons with very minimal modifications. That in it own opens up a lot of options for WRX compatible turbos, since there are many bolt on turbo options for the WRX.

[Turbo_Steve]

I'm in the MHI camp too: whilst they may not be as good turbos as Garrett GT series, they are damn good turbos, and represent excellent value for money. More importantly, they are incredibly easy to hybridise...again for very little expenditure. A properly specced GT is going to have equivalent spool and more eventual power than an MHI unit, and cost more. Whilst that is brilliant for those of us who want uber-huge power and normal driveability, it would appear we're not there yet: TD04s and TD05s seem to be able to deliver enough power to damage drivetrain and possibly engine components, whilst spooling early enough to remain civilised. A TD05 turbine is probably about on the limit, I would suggest, but there may be margins in the map for more.
A pair of TD05-16Gs should just see you into 600bhp territory.

[Caveman]

Hi Nick,

Thanks for your comments, collaboration would indeed be worthwhile. I do have to correct you on the turbo designation though, the VR4 definitely has a pair of TD03-07G turbos, not TD03s. If you look back through past threads from Valmes etc, they have had them out and rebuilt and have recorded the model numbers. The ones in the fotos are the same as ours!

Kieran, if you look at the foto of the GT15 you can see that both the thickness of the turbo wheel area and the outlet are much larger, whilst maintaining similar overall dimensions, surely this should allow for greater flow compared with ours??

As for comments on Skylines over Legnums, they're two different cars. I always wanted a fast , 4WD, good handling, yet roomy estate and the only other car in this league would be the RS4/6 or Legact STI, none of which I can afford. So Leggie it is!

Mart. :)

[Nick Mann]

I do have to correct you on the turbo designation though, the VR4 definitely has a pair of TC03-06A turbos, not TD03s. If you look back through past threads from Valmes etc, they have had them out and rebuilt and have recorded the model numbers. The ones in the fotos are the same as ours!

All good collaborations should start with a row!

I'll bet you whatever you want that neither of the turbos from your photo is from a standard 8th gen VR4. :scholar: I am 100% sure that neither is the correct fitment. The one on the left appears to have an extra hole in it (some sort of external wastegate thing?) and the one on the right has a square exhaust manifold flange. Both incorrect for our cars.

I'll do some double checking on the model number, but I'm 95% sure I'm right.

[Caveman]

Hi Nick, the ones in the fotos are TC03s, but not the exact same version as ours, but still the same size, just different fittings. I'm sure we have TD03, happy to be proven wrong though!

Mart. :)

[Nick Mann]

Looking closer at the TC03 above, the compressor and turbine housings are wrong and the actuator is different. I'll see if I can get any numbers off the turbos in my garage tomorrow. :thumbsup:

[mpau009]

Yes, the turbos are definately TD-03's, i have mine i a box, and the numbers confirm the info on the list attached. They come with the 7g compressor wheel, and it is steel not ceramic as some people on OZVR4 thought for a while.

[Caveman]

I stand corrected! :D

Cheers,

Mart.

[Gowf]

Yep definately TD03, i have 04's from a gto. They have almost the same flange as the 03's, but its orientated differently. I am fairly confident that you can get the tdo4hl's on the stock manifold with some modification, but what i found was that the oil filter was a huge problem and required a sandwich plate. Not too much of an issue, but even the sandwich plate was too large. Im talking td05's now, but in the end the original filer housing was cut down, and tapped for some s/s braid pipe to go off to a filter relocation kit.
At the end of the day there is no cheap option available, you cant just bolton, if you do manage to provide a cost effective kit Nick, my hat is off to you.

Or caveman, you could just buy mine!

[scientist]

I'm in the MHI camp too: whilst they may not be as good turbos as Garrett GT series, they are damn good turbos, and represent excellent value for money. More importantly, they are incredibly easy to hybridise...again for very little expenditure. A properly specced GT is going to have equivalent spool and more eventual power than an MHI unit, and cost more. Whilst that is brilliant for those of us who want uber-huge power and normal driveability, it would appear we're not there yet: TD04s and TD05s seem to be able to deliver enough power to damage drivetrain and possibly engine components, whilst spooling early enough to remain civilised. A TD05 turbine is probably about on the limit, I would suggest, but there may be margins in the map for more.
A pair of TD05-16Gs should just see you into 600bhp territory.

I would tend to disagree on the power potential part. Problem is, most people compare OEM MHIs against aftermarket Garretts.

Take for example, the TD05H-16G7 on the evo 3. The record on that turbo is 490whp @ 31psi boost. true it was pushing it well beyond its efficiency, but unlike some of the garretts it HELD up with such heavy abuse for a few racing seasons.

I definitely wouldn't go garrett route on most of these cars, since there are bolt on MHIs...which can be rebuilt. Just look at the prefered set of turbos on 300ZXs and 3000GTs in the US....there are quite a few running 9s on a pair of Evo 3 turbos. Even JUN opted for a TD05-18G for the 900whp 350Z

[Turbo_Steve]

er....presumably that's a PAIR of TD05-18Gs? :)

And whilst I agree with your comments pertaining to the T series turbos, the GTs are a ball bearing cartridge and really do spool earlier for the same power.

[Davezj]

Yes, the turbos are definately TD-03's, i have mine i a box, and the numbers confirm the info on the list attached. They come with the 7g compressor wheel, and it is steel not ceramic as some people on OZVR4 thought for a while.


i don't mean to put a spanner in the works, but hasn't everybody just said the impretza has TD-04 as standard and these are goodone to go for.

That is all well and good.

However the table posted up shows TD05H-16G-7 for the WRX/STI/Forester.

where did this info come from and is it reliable?

Is the standard Impretza turbo TD-04 and WRX/STI TD-05 or are we all wrong about the TD-04.

just an observation, i am not having a go at anyone, i appiciate all the effort that goes into finding all this info and at some point hope to make use of it.

[bradc]

early ones came with td05's, most of them however came with td04's

[Turbo_Steve]

er....and some of the later ones....Subaru turbo choices were complicated dependant on model, target market and vehicle shape / gearbox.

The later ones that aren't a WRX generally have an IHI turbo. Technically, this should fit an work well (pair of VF34s anyone?) but they generally cost a lot more money!

[Davezj]

I will get my coat this to LA LA LA LA LA!!!!

i will just read!

[Madhav]

Also don't overlook the kkr 280 turbo, good for an easy 300kw atw and spool up time is as good as the standard turbos (or so i hope). My car is currently in the workshop getting a pair fitted, they need an adapter plate and a new thermo fan, but otherwise it seems to be ok. They will be in within 3 weeks max, I'll keep everyone posted.

[Eurospec]

The scooby td04 13t turbo is what people are normally refering to right? It came on quite a few versions and you want the one without the rotated entry.

I agree that these tubs will go on to stock manifolds, since they have very large hotside foot plates , meaning you can get the space to drill them and get them to bolt up. I dont think of it as a straight forward mod though!

Wierdly the front one will be harder than the rear, but i would think it will go with a thinner fan, or maybe a push fan etc.

Now Gowf has genuine td04 13g's on his and that makes lets say ball park 400 bhp. Since they are mitsubishi turbos it required the custom construction of manifolds, but i guess you could get a td04hl15g and drop those on to the same manifolds. the physical size is very similar. I've pushed over 550bhp out of a set of those on a 6g72.

The scooby turbo way will give rod bending ability in a 6a13 i would think. We use hybred 13T's ont gtos all the time and pretty much i can say that at 1 bar boost, on stock intercoolers, warlbro pump, 550s, pressure reg, fuel lines, and map2 i can make 400bhp. small increases in boost increase the power quite a bit. 1.5 bar will make nearly 500, but you run into charge cooling issues and resultant knock before getting there. 450 really needs a front mount etc on those.

So what i'm still not too sure about is just how far stock rods will go before they are getting pushed to their limits. Look at a 6g72 bottom end, its huge compared to a 6a13, and for daily driven cars above 450bhp, we reccomend forged in those.

Cheers,

Ben.

[Mante]

I can understand why you may want to stick with twin setup but why?? its harder to tune a twin, cost more and requires alot more space..

the trick is finding a setup (compressor size/hotside-cold side) that takes everything you want to achieve and go from there. Mine, literally instant boost, great mid range and holds way past redline.

Twin?? why bother. Put it this way all the "big boys" i.e supra's...skylines.. etc use single, YES I know they have inlines vs the v6 but its all done for a reason.

[djb160]

I think it's more of a keeping the car as it "is" sort of thing. I mean lets face it if actually cared about power efficiency that much we wouldn't be driving VR4s

[Turbo_Steve]

Twins spool better. It's that simple.

If you were talking about a sequential setup, Mante, I'd agree with you.
But Parallel twin turbos will always spool earlier than a single large one, even with twin scroll housings.

That said, there is a grey area, where a single turbo that is slightly larger than a pair of twins will spool roughly the same but tend to make more power.

However, for a daily driver, a single TD05 turbo delivers roughly the same performance as a pair of TD04s on these engines, but goes on to make less eventual power. A TD06 will spool significantly later.

Big single conversions are all about ultimate power: I've driven many (many many) big single conversions, and whilst they are fantastic drag cars, and work well on the highway, they are totally unsuited to driving on European roads (hence why they are so unusual over here) as you are forever changing gear trying to keep it in the power band. Of course, a smaller turbo could be fitted.....but then you lose out on top end power.

Manufacturers go to the expense of fitting paralell turbos because it makes a better drivers car.
Most VR-4 owners are in love with the sheer responsiveness of the engine (which is excellent) and don't want to sacrifice that for more power.

Valmes has a pair of TD05s on his, and after watching his videos posted, I wouldn't want to go that large: they are definitely slower to spool than the factory turbos, and it's right on the threshold of being "noticeable" whilst driving normally.

That said, the factory turbos do seem to be too small: Mitsubishi were trying for a small engine that felt like a much bigger one - instant throttle response throughout the rev range and effortless power with no thump in the back.
Which they achieved. Most owners want to retain this, and the TD04s or GT2554Rs seem the best way...marginally slower spoolu up but with much higher eventual flow.


As for being harder to tune....how?
Quick comparison to get to 400bhp.

Both setups need:
Intercooler
Fuelling
Inlet
coolant and oil lines
Boost control.
ECU Remap / piggyback / similar
Exhaust.

However, whilst the twin turbo setup will just require the turbos 'bolting into place' the single turbo will require:

Extensive manifold fabrication (transverse V6, so lots of piping)
Longer runnels leading to increased under bonnet temps
Longer runnels leading to increased spool times
Longer runnels increasing likelihood of cracked piping (seen this lots)
Completely reworked inlet piping
Most people find they have to change the throttle body to the other side of the inlet manifold to make room.

Assuming you go for MORE than 400bhp (and risk the rods which are an unknown): So lets say 600bhp.

Pair of TD05-18Gs will fit with some persuasion (radiator / fan changes).
Still using factory manifolds.
Will spool roughly the same as TD05-16Gs....which are about the limit of spool for a daily driver IMO. So gearing & rev limt need be unaffected.


Single turbo will be...hm...we're looking at a GT40R here, or an MHI TD06/07.
That's a big turbo to find room for.
Significant increase in oil flow & cooling required for one of these.
Much later spool as this is a big turbine to turn: on a 2.5L we're looking at 4000rpms at least.
Later spool means being caught "off boost" on gear changes. Rev limit needs to be raised (effectively doubling the risk of damage to the internals with every 500rpm it is raised) or the gear ratios need to be changed (expensive, boring).
You also now have a single turbo spooling up hard as soon as sufficient load is available, which generally increases the shock loading on all components.



There are also the efficiency arguments:
A pair of larger (but not huge) turbos will remain in their efficiency band, and at lower temperatures, than a single turbo that spools as early and flows the same. So two turbos need less intercooling, and potentially less fuel to soak up heat in the bores.


So I am going to have to strongly disagree that a single conversion is the way to go unless you're building a car purely for the out-and-out power.
In which case, I wouldn't start with a VR-4 LOL!


I hate to say this, but the i6 vs v6 thing is a big deal as well.....i6 can do a single turbo with minimal (even less!) pipework. V6 (especially transverse in a cramped engine bay) means a LOT of fabrication work.
That said, once you have converted to single, upgrading the turbo is a much simpler task, but that assumes you will keep changing it?

[Turbo_Steve]

In fact:
http://en.wikipedia.org/wiki/Twin-turbo


We're all trying to stay with:


use a light pressure set up where the turbos are designed to output less boost but spool earlier, however, this set up sacrifices top end power

Trying to stay towards the lower / middle efficiency band of smaller turbos will give a significant increase in power with marginal sacrifice in spool charecteristics, especially if the transition is mapped smoothly.


A big single turbo goes from NA to +ve pressure and is difficult to hide the spool up without sacrificing power until quite late in the rev range.

[Mante]

So I am going to have to strongly disagree that a single conversion is the way to go unless you're building a car purely for the out-and-out power.
In which case, I wouldn't start with a VR-4 LOL!




Sequential setup is even more of a hassle for tuning purposes but like you said it is GREAT once it is all completed.

It is ironic you mentioned 400 bhp, how about 368 awhp and 363 lb :) That was accomplished on crappy 93 octane or 98 MON as I've been told with a single Gt35R (not off the shelf made specifically for the 6a13) that spools around 3500 making it extremely driver friendly. Limited to those numbers because the internals are stock 100%) I've seen and read about Valmes setup, the shop that did my setup wasnt impressed (nothing against his car) with the power or overal layout. FTOLTD?? ( if I misspell it sorry) did a single conversion years ago, same overal dislike for the outcome.

Full explination of my setup dyno sheet, 1/4 runs etc etc..
My Vr4 site (http://www.bernardhill.net/vr4.html)

I want to touch on the myths you mentioned..


Extensive manifold fabrication (transverse V6, so lots of piping)
Longer runnels leading to increased under bonnet temps
Longer runnels leading to increased spool times
Longer runnels increasing likelihood of cracked piping (seen this lots)
Completely reworked inlet piping
Most people find they have to change the throttle body to the other side of the inlet manifold to make room.

-manifold fabrication: true but these cars are 10 years old there are hairline cracks all throughout the manifolds SO why not replace them all while everything is apart ? I intended in using my factory ones but they were cracked pretty badly.

-longer runners= increased heat underhood: Ok any tuner should have a vented hood at this point. With a single setup it can (and should) be positioned under that vent to allow proper cooling

-increased spool: Not if research is done and you dont just toss out turbos. Alot of people walk in saying "I want a GT958359453245R to fit in my honda civic" /pan lol Ive seen I've driven some cars with setups just like this flat out scary.

-cracking runners: same as stated above, there are methods to combat this. heat coating treatments and the BEST WAY. Finding a fabricator that can actually weld!! Alot of people think they can weld but there beads are an eyesore which leads to premature cracking.


-the last two (reworked piping and changind inlet direction) All I have to say I will let this photo speak. I honestly havent seen a setup as clean and makes as much power then mine (not braggnig going by numbers)

Single conversion photo (http://www.bernardhill.net/photos/2008/07_16_Arfab/images/11.jpg)

As for expense, well with a single turbo you dont have to buy two but that money you save will be used on piping so it works out to be EVEN!!

Now to play devils advocate, you were right that a twin setup should spool sooner BUT again that is if you grab something off the shelf.. "Lets take two evo turbos and use them.. wait lets rebuild them first" or scooby turbo's or 3000gt turbos. You will accomplish getting power but the setup was originally made for another car in mind.

Nothing is more appealing then seeing two turbo's when you pop the hood, you will always get the "ooooooH" factor for onlookers lol

[Mante]

I think it's more of a keeping the car as it "is" sort of thing. I mean lets face it if actually cared about power efficiency that much we wouldn't be driving VR4s


If someone wanted to keep a car as it is then no modifications would be done, routine maintance and drive it..

[djb160]

after stock turbo boost characteristics 3500 feels real slow and doesn't feel like a daily driver at all. You'd probably get used to it in time, WRX owners don't seem to mind that sort of lag.

[Mante]

after stock turbo boost characteristics 3500 feels real slow and doesn't feel like a daily driver at all. You'd probably get used to it in time, WRX owners don't seem to mind that sort of lag.


Do you even know when the stock 9c's are full boost?? 2200 ish so 2200 is acceptable but 3500 is slow?

[mpau009]

Do you even know when the stock 9c's are full boost?? 2200 ish so 2200 is acceptable but 3500 is slow?

I think DJB is referring to another single conversion from NZ, which has a GT3540 mounted. I would doubt that his setup would be on 'full' boost at 3500, but it is making some really good power for the early stages of its tuning.

I decided to go for the TD-05-16g from an Evo6 for my conversion, but with longer headers than your setup from what i can see. Not quite the extent or intent of your build, and i havent had it properly wound up yet, but i am happy with the compromise between spool and boost at 10 psi.

I reckon the main difference in feel is the way a single comes on boost. It is easy to take the td-03/7s for granted for that kick in the back off the line..

Still i would love a ride in yours or Tylers single setups.

Mante is there a decent build thread of your car? i was aware of it, but i would love to see some photos of the ideas you used. Heres a pic of mine, cobbled together from ideas kicking around here and personalised a bit. Im hoping to get some numbers back before christmas.

[djb160]

Yeah thanks mike that was what I was meaning, sorry if I confused you there, I should have explained a bit better.

[mpau009]

i don't mean to put a spanner in the works, but hasn't everybody just said the impretza has TD-04 as standard and these are goodone to go for.

That is all well and good.

However the table posted up shows TD05H-16G-7 for the WRX/STI/Forester.

where did this info come from and is it reliable?

Is the standard Impretza turbo TD-04 and WRX/STI TD-05 or are we all wrong about the TD-04.

just an observation, i am not having a go at anyone, i appiciate all the effort that goes into finding all this info and at some point hope to make use of it.


Oh yeah? weird, i dont know much about the subaru stuff..

I just had my turbos out, and i put the numbers off them into google to see what i could find out, and that came up. It may be BS, but i am pretty sure the VR4 info is correct, the numbers match up anyway..

Were there some single turbo STI subarus? or are they an aftermarket kit:thinking: maybe it could be something to do with that. Otherwise with TD-05s there would be some formidable forresters out there :P

[Goku]

You just get the TD04 turbo's off the 98- WRX's and they preyy much bolt right up, with a little adaption.

[Mante]

Mante is there a decent build thread of your car? i was aware of it, but i would love to see some photos of the ideas you used. Heres a pic of mine, cobbled together from ideas kicking around here and personalised a bit. Im hoping to get some numbers back before christmas.

My build (http://bernardhill.net/photos/2007/09_18_Arfab/)
in the developmental stages. I would like to take credit for the layout BUT I saw a 3000gt with roughly the same layout, once I drafted that idea the shop did the testing and let there imagination run wild.

After my recent trip to the drag strip I need larger injectors, even upgrading to the sard 550's isnt going to be enough :( Found the sard 1000cc's that will supply the fuel demands for now as well as handle the demand after the motor is built..

[pitslayer]

havnt read the whole thread, fact is im lazy and its late and my pizza is going cold....but the oil filter relocation, i was curious, but would a bypass filtration kit work instead of relocating the oil filter. I mean does a bypass filtration kit get rid of the need for the oil filter on the block? if so would that be an easier avenue than getting adapator and sandwhich plates made up......mmmm plates of sandwhichs nom nom nom

[Turbo_Steve]

Mante,

I definitely can't fault your welding or pipework, it looks gorgeous! :)

I want to address a few of your points:


manifold fabrication: true but these cars are 10 years old there are hairline cracks all throughout the manifolds SO why not replace them all while everything is apart ? I intended in using my factory ones but they were cracked pretty badly.
Fair comment: old parts do need to be changed. But imagine picking up a cheap set from the Mitsubishi parts specialist, bolting them on, and then bolting on two slightly modified TD04s. Maybe a days work? Now contrast that against having the car off the road for at least two days, nearer to a week, whilst someone fabricates a long and complicated manifold. If that manifold cracks, it has to be a bespoke repair. If the "off the shelf" ones crack, I claim on my warranty and another set arrives to be fitted.



-longer runners= increased heat underhood: Ok any tuner should have a vented hood at this point. With a single setup it can (and should) be positioned under that vent to allow proper cooling

But most of us don't want one: it utterly removes any stealth aspect of having a VR-4! And, your point was that it's less hassle to tune single turbo...but now we're modifying the bodywork!!! It's more hassle, more expense and at least half of people think they look ugly.
A pair of sensibly sized small turbos will not generate as much heat as a single large one for the same output. They will be lower in the efficiency map.






-increased spool: Not if research is done and you dont just toss out turbos. Alot of people walk in saying "I want a GT958359453245R to fit in my honda civic" lol Ive seen I've driven some cars with setups just like this flat out scary.
I'm sorry but I really can't agree with this one. I do agree with the fact that a correctly selected turbo will minimze lag: this is not in dispute. However longer runnels will ALWAYS increase lag. The longer the manifold, the longer it takes to build pressure at the turbine inlet, as it has a larger space to fill. Longer runnels also mean increased likelihood of uneven gasflow, as the pulse timings vary with the pipe resonance at different RPMs. We're deep into fluid dynamics here, but it's essentially the organ pipe effect: how adding a 1" extension in the middle of a car exhaust can totally change how it sounds.
I've spent so much time messing around with manifolds on the EJ20T and EJ257T to know what a massively significant effect they have, and how difficult it is to get them working optimally. Again, big power is relatively simple, but getting big power AND good low down response is the holy grail.





-cracking runners: same as stated above, there are methods to combat this. heat coating treatments and the BEST WAY. Finding a fabricator that can actually weld!! Alot of people think they can weld but there beads are an eyesore which leads to premature cracking.
That I 100% agree with. There are methods of managing heat and cracking, and there are good welders who make great manifolds, which is fantastic if you happen to know one. However most of us here will be asking a shop to fabricate this for us, and as such it will cost a lot of money, and be a lot of hassle. Machining a "fitment adaptor" to the existing manifolds, even if you're fitting brand new ones from Mitsubishi, is going to be cheaper and definitely easier.




-the last two (reworked piping and changind inlet direction) All I have to say I will let this photo speak. I honestly havent seen a setup as clean and makes as much power then mine (not braggnig going by numbers)

It looks truly awesome! Very neat. How long did it take you to put it togther? Bearing in mind that the TDO4 conversion will simply need a samco adaptor hose from the existing inlet pipes (by my reckoning less than an hours messing about, and about £35 each).

You clearly know what you're talking about Mante, and have built an awesome car.
But you can't rule out the twins based on expense. GT35Rs are a lot of money in the UK, even used, as they are a popular upgrade. TD04s go for peanuts in comparison.

To give you an idea: I could buy 6 used TD04s (all with very low mileage) for the price a high mileage GT35R changes hands for over here. (genuine Garrett).
The adaptor plates / drilling the turbine plate is cheaper than new manifolds.
Inlet pipework could simply use an inline adaptor, though I accept most people will replace the pipework.
They will be at decent boost levels by 2800rpms...possibly even earlier.
Not sure what gear ratios you have, sir, but on mine 3500rpms is about 200rpms above the gearboxes natural shift point..so you have that "pause"..albeit only momentary, on every gearchange. Maybe you don't? or Maybe you don't care?
Again, I've drive 2.5s with GT35Rs and GT40Rs on, and it's not hopelessly laggy...but it IS enough to be an irritation on a car my wife expects to drive the kids around in....these are big, practical cars that most people want to retain as a daily driver.

I'm not having a go at you, Mante, because what you have built is brilliant, and will turn an awesome drag time. But by the same token, what you've built is the first step to being a "race" version of the car. Most people want more power, with no (or little) increase in noise, and absoloutely no compromises on the driveability.

[bradc]

I do like Mante's build too, as Steve said, the quality of the work is top notch, but I'm a lover of twins :)

My technical reasoning is due to the much shorter pipework. I've have a good look around Mpau's car while the work was being done and the pipework in it is very long, I much prefer the more elegant solution of hanging a turbo just off each head. I also like the fact that a pair of GT2554R's will make 500hp with less lag than any single setup able to make the same amount of power.

Lastly, and most importantly, I have a twin turbo V6 with 4wd in a station wagon body. How bloody awesome does that sound? There are tons of 4 cylinder single turbo cars out there, I've got more cylinders and I want the car to be unique, so sticking with the twin setup just adds to that :)

[Mante]

sorry to cut this short but I am on my phone....

One thing I want to make perfectly clear I love having a twin setup. I would have preferred to keep a twin setup but to many limitations got in the way. Alot of important things came in pairs. Breast's... ok one important thing came in pairs :)

to be continued later

[djb160]

... Breast's... ok one important thing came in pairs :)


Aaaaaaaaand that wins the argument. Case closed.

[mpau009]

I love this thread :)

This is why cars are so appealing to me, there is so much theory and science in it, but it comes down to people making it happen.

I am looking forward to seeing the few td-04 cars that will be coming together in the next 6 months, to see how they compare. I personally dont think that one format is going to be more than a few % better than another, but it is interesting starting to see some feedback from the single setups.

I thought i might as well chuck out some of my opinions to keep the debate rolling /pan

1) Simplicity.
Provided you dont have to cut anything structural, or bash the firewall, i dont think fitting twins would be any harder than single. Some of the most irritating hassles i had have come from blocking unused oil and coolant lines, and splicing wires to keep them away from heat. If i was doing it over, i would have made new manifolds like Mante, i had already gone to the trouble of getting the other flanges drawn, it would have been very little extra work or cost to have 42mm pipe from each. But i also dont think that i would have lost too much by sticking with the cast..

2) Piping Length.
I think it is splitting hairs a bit with this type of argument.. not having a go, but i just think that it will make such a slight difference in the long run. And i still need to be convinced that twins can really justify the complicated (and more expensive to fabricate) intercooler and intake pipings.. I still cant really see how Mantes gets to the cooler and back - which is what i was hoping to see, but it is probably similar length to mine. I think if we are talking about affecting lag it is such a small issue that it cant be the deriding factor for me.. I would really like to read some about where the piping length affects performance in different ways. Ie, my manifold would be 20-ish% longer than Mante, but more even in length, and my dump pipe to the exhaust has 4 less bends in it. And both our intercooler piping setups are easily a meter or so shorter than stock VR4.

There may be a bit of an argument for the heat thing, but i dont know enough to really say.

As far as my overall experience so far.. i think that for me a single was the way to go. If the VR4 had a different engine configuration i would love to see something like the nissans run, but it just didnt make enough sense to me. In hindsight, i dont think that fitting upgraded twins was as daunting as it sounds, but it would be more work, and i would say more cost.. assuming you dont go for an expensive turbo like Mante or Tyler.. mine cost $650nz ($340 US these days) Probably the most expensive part of the exercise was the HPC coating on the manifolds, whether you would be able to do away with that with twins?

The Td-04 adaptor plate seems like a great idea, cheap and effective, but like brad with the twins, i just love the difference of the single on this car for 'rediculousness' value as much as the rest of it, hence the top mount (amongst other reasons). I think all in all i have a car that is simpler, easier to work on and further upgrade.

So you boys, hurry up and build something for me to have a ride in :P i am waiting to be converted back to the twins :afro:

[bradc]

Well you've been in my car with it's instant boost response and power :)

[valmes]

what's going on in here...

[Mante]

Fair comment: old parts do need to be changed. But imagine picking up a cheap set from the Mitsubishi parts specialist, bolting them on, and then bolting on two slightly modified TD04s.



Yea, that is true if you can find them. I personally spent 6 weeks waiting for used manifolds (used parts suppliers think the parts are new so its way overpriced) I even went the special order route directly through mitsu jap only to find out the parts are no longer available. Last resort was to get the manifolds fabricated, more costly BUT it seems to be worth it.






But most of us don't want one: it utterly removes any stealth aspect of having a VR-4! And, your point was that it's less hassle to tune single turbo...but now we're modifying the bodywork!!! It's more hassle, more expense and at least half of people think they look ugly.



Yes CF hoods get alot more attention, other drivers as well as law enforcement but the functionality of the hood makes up for it. Shedding 25lbs as well as cooling was worth it to me. I can no longer "blend" into traffic :( Good point!


However longer runnels will ALWAYS increase lag. The longer the manifold, the longer it takes to build pressure at the turbine inlet, as it has a larger space to fill. Longer runnels also mean increased likelihood of uneven gasflow, as the pulse timings vary with the pipe resonance at different RPMs.

Yes longer runners of the same diameter piping will increase lag, that is why I am proud that they did flow test's and found a diameter that would not cause an increase in lag. Like you I've seen many inefficient setups where the same diameter was used all the way around.. hot side as well as cold side which left me scratching my head like "oh that isnt going to work"




I've spent so much time messing around with manifolds on the EJ20T and EJ257T to know what a massively significant effect they have,

A scooby fan?? cool makes me miss my 90 legacy :)



It looks truly awesome! Very neat. How long did it take you to put it togther?

The piping took about 3 months, delays occured due to parts being available. Finding the Vband took 2 months alone. They worked on a similar setup and finished it over a weekend becuase they had everything in hand before starting the work. The overall stage took 12 months.. Ooh yea 6 months for Garrett to put together my housing itself. Had to send data from the factory ecu so they could see everything, the overhead cost wasnt bad for the research but honestly it is living up to everything I wanted it to do. Quick response, longevity and holds power all the way past my redline (expect it to be raised to 9k... details later that process just started yesturday)



But you can't rule out the twins based on expense.

I would never rule out a twin setup becuase like you said getting the turbo's is usually cheaper, hell everything you said was accurate :scholar:


I havent changed the gearing at all, I do plan on doing it after the spare motor is built. Under normal driving conditions I can leave it in 2nd or 3rd and go for miles... I know your feeling about turbo lag BUT in my case I found that grey area!

[Mante]

There may be a bit of an argument for the heat thing, but i dont know enough to really say.


Heat is always a problem under the hood, they wrapped the key components which after a hard drive cool enough to touch. Track days I will use the turbo blanket on the housing but its ugly as all hell!!

The td04 plate is a damn good idea, and frankly I can get any used turbo pretty cheap.. benefit of being here in the states :)

What I have noticed is alot of dealers over there take the same item sold here copy the price that is sold here (USD to EURO/GBP etc) say its sold here for 290 USD they then list it over there for 290 EURO/GPB.. wth that sucks for you guys.

For example I found this on ebay..MITSUBISHI LEGNUM VR4 Tappets - Lash Adjusters x 24 (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=250277603234) took EVERYTHING from a site here in the states even the damn price... 3sx.com (http://www.3sx.com/store/comersus_viewItemBundle.asp?idProduct=12153) its crazy honestly!! The dollar conversion is what and how this store is making over on you guys.

[Turbo_Steve]

LOL Well, you're painfully right on the pricing, which is why people generally try and do things the cheapest way over here. Fair point on the manifolds: I haven't tried to get any yet, I was basing this on my experiences with other cars.
I hate you for your turbo prices: it's just unfair. GT42Rs, even tweaked, are sensible money. And you look at the price of something like an FPGreen out there, and it makes me want to cry.

Mine needs a new hood, and I was considering CF, actually...but I can't possibly go with a vent...nononono.

If you've done a proper flow-tested manifold, then I salute you: I can't even begin to imagine how much that would cost in the UK.

I think the interesting point here is that modifying a car in the US really is a different process to the UK.
Even in as much as I've seen ultra-high power cars come over from the states (a good example was a twin tubo'd mustang that came over to run at Santa Pod) and get dyno'd in this country and make as much as 15% less power.
Which is just weird...is it the fuel? The air? Do you guys actually secretly breathe methane or something? LOL

I keep looking at your dynograph and scratching my head...I'll have to have a proper drive in ours tomorrow and see where the shifts are.
But hey, it sounds like it's working for you, and that's the main thing: you obviously have a pretty godo idea what you're doing (investing money in the right places i.e. the turbocharger and research) and it sounds like it paid off. I have to be a bit nasty and suggest that either your Garrett researchers are truly amazing (which is a distinct possibility, but surely bery very expensive?) or that there may have been a teeny bit of luck involved if you've landed in the "sweet spot" for lag on the first go!

But congratulations again, sir...a fantastic piece of machinery, either way. Now, if I can just find an extra day in each week to concentrate on the cars, I can start on my own LOL

[Mante]

Pricing over here for that FPgreen isnt bad at all, found a reputable site for roughly the same price as my Gt35R (before the options). I made sure to use one of the more common flanges on mine so I "could" go up to the Gt40/42R or anything else but I seriously doubt it, my target of 550 to 600 awhp is attainable with everything I have already.

I went with this shop in particular because they do almost everything in house, and the shop owner is brilliant I spent some time researching his work before I went spoke with him the first time..


I think the interesting point here is that modifying a car in the US really is a different process to the UK.
Even in as much as I've seen ultra-high power cars come over from the states (a good example was a twin tubo'd mustang that came over to run at Santa Pod) and get dyno'd in this country and make as much as 15% less power.
Which is just weird...is it the fuel? The air? Do you guys actually secretly breathe methane or something? LOL

Our air quality sucks, we can only get higher octane fuel at tracks so we are stuck with 87, 89 and 93 for daily street use. The only thing I can think of that would cause that mustang to perform that way is air density..elevation?

All in all Thanks.. Once the injectors come in another tune will be done, maybe I can gain 10 or 20 hp :) *wishful thinking*

[Turbo_Steve]

It's an oft held debate, Mante: nobody knows what Dynos in the US always read more than they do here, but it seems fairly certain it's the cars and not the dynos.

I can't work out US fuel ratings....you're talking about octane, but US guys have MON and not RON octane assessment....and 93MON seems equivalent to 95RON over here?

[Kenneth]

Another interesting point is that the cars in NZ tend to make more power than in the UK also.

Not only that, we get better fuel economy which supports the idea that there must be SOMETHING different.

[scientist]

Dynos in the UK take whp, work it out to BHP then work it back to whp. Which involves a lot of calculation (speculation as to what transmission loss is) to give the figure. there is a lot of room for misjudgement in that method.

In the US they only measure whp as it is read from the dyno, with only SAE corrections involved which is more of a direct formula.

[Turbo_Steve]

So these big power cars are coming over and performing the same, but losing numbers because of the mathematics? It's possible....but in that case who is right? LOL

Yah, Ken, I've noticed you guys seem to go further on a tank. I put it down to different tarmac?

[djb160]

Nah our roads couldn't possibly be better.....?

[Kenneth]

No, it isn't the roads. If anything, England has better roads on average.

Has to be something else.

[scientist]

So these big power cars are coming over and performing the same, but losing numbers because of the mathematics? It's possible....but in that case who is right? LOL

Yah, Ken, I've noticed you guys seem to go further on a tank. I put it down to different tarmac?
I would consider the WHP reading that the rest of the world recieves to be more accurate. Remember in the UK they dyno records whp, converts it to BHP and then BACK to wheel hp. whereas the rest of the world relies on the WHP the dyno recorded. Less guessing going on

[Turbo_Steve]

Great....so when I take mine to a Dyno operator using a well know US brand Dyno, how do I persuade them to use the US method and not the UK one?

More to the point, if this IS true, then a US car on a british dyno with a lower power reading will still run the 9.5 second times it ran in the US.... but they don't? They're always shocked by how slow they are over here. And they usually end up going bang!

I do totally agree that the more factoring you do with the results, the more innacurate they're going to get (just look at the differences between the same dyno on different runs) but I think there is more to it than just this.
Like the big-power jap cars that are imported with Dyno graphs showing 1000hp or more, but on their first run here just won't break the 800bhp barrier.

[Mante]

The only thing left that I can think of is altitude and air density which is "basically" the same thing. That is probrably the reason you guys get higher octane fuel to compensate :)

[scientist]

Great....so when I take mine to a Dyno operator using a well know US brand Dyno, how do I persuade them to use the US method and not the UK one?

More to the point, if this IS true, then a US car on a british dyno with a lower power reading will still run the 9.5 second times it ran in the US.... but they don't? They're always shocked by how slow they are over here. And they usually end up going bang!

I do totally agree that the more factoring you do with the results, the more innacurate they're going to get (just look at the differences between the same dyno on different runs) but I think there is more to it than just this.
Like the big-power jap cars that are imported with Dyno graphs showing 1000hp or more, but on their first run here just won't break the 800bhp barrier.

That happens in the caribbean also, they import cars claiming to be making over 1000hp but fall short when dynoed, and a lot of them fall flat on their face when raced (blown engines). But with regards to times on the track, a lot of factors are to be considered, like track preperations, tire choices etc. Its like this example, some cars left trinidad running 9s, went to grenada to race for the caribbean championship but had a hard time breaking 10s because of how the track was prepped and how much track bite was laid down. Even some of the record breaking cars in the US have a hard time being consistent going from one track to the other.

As for the rolling road request, ask for the raw dyno data or ask him to produce the results without factoring BHP calculations.


Dynojet offers their winpep viewer
http://www.dynojet.com/downloads/zip/7.5.2_Install_.zip (Winpep Download)


http://www.mustangdyne.com/downloads/PowerDynePC%20v143%20No%20Docs%20DEMO.EXE (Mustang Dyno Power Dyne)

[Turbo_Steve]

And that'll be some rep.

Mante, are you sure US fuel is actually worse?
I was led to believe that it's a completely different ratings system, so that your 91MON was equivalent to our 95RON, and 93MON was our 98RON?

[Mante]

And that'll be some rep.

Mante, are you sure US fuel is actually worse?
I was led to believe that it's a completely different ratings system, so that your 91MON was equivalent to our 95RON, and 93MON was our 98RON?

I have not done the research myself but 91 mon (here in the us)is equivelant to 98 ROM over there.. Our EPA (environment protection agency), dot..nhtsa well put it this way several agencies regulate the fuel here in the states..

[Nutter_John]

The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing these results with those for mixtures of isooctane and n-heptane.

There is another type of octane rating, called Motor Octane Number (MON) or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, a higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON. Normally fuel specifications require both a minimum RON and a minimum MON.

In most countries (including all of Europe and Australia) the "headline" octane that would be shown on the pump is the RON, but in the United States, Canada and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, would be 91-92 in Europe. However most European pumps deliver 95 (RON) as "regular", equivalent to 90-91 US (R+M)/2, and even deliver 98 (RON) or 100 (RON).

[Turbo_Steve]

:iloveyou:

Fan-flippin-tastic, John!!

So, Mante, your "rubbish" fuel isn't all that rubbish after all, just "conservatively rated" against ours LOL

[Mante]

I have noticed (R+M)/2 on quite a few pumps. I still call it rubbish because if I want to use pump 93 I have to use a fuel additive. My practice is having a 5 gallon tank having it filled at tracks or shops to add one gallon of 118 to a tank of 93.

[Nutter_John]

:iloveyou:

Fan-flippin-tastic, John!!

So, Mante, your "rubbish" fuel isn't all that rubbish after all, just "conservatively rated" against ours LOL

wikipedia is great ain't it :D

I did know all that but could not think of a better way to say it

[Turbo_Steve]

LOL Yeah Yeah.... :D