Fitting higher flowing Garrett turbos - what's involved

[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
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

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 i am waiting to be converted back to the twins

[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


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 took EVERYTHING from a site here in the states even the damn price... 3sx.com 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