supercharger on a 6A13TT

[Davezj]

this is just a concept thought.

has anyone fitted a superchager to a vr4?
it would have to be a centrifugal type like the rotrex ones below, it would be about the size of a C30-64
http://www.tts-performance.co.uk/#!r...ercharger/cur7

it would be as an addition and not as a instead of. if you get a supercharger cheap enough would it be worth it, rather than going for a td04 conversion.

where would you fit it?

could it fit where the expansion tank, power steering resovior is, or at the back by the alternator?

space is probably the limiting factor.

[Nick Mann]

Are we going back to this thread?:
http://www.clubvr4.com/forum/showthread.php?63136

[Davezj]

cheers nick, yes it has been discussed before.

i am bored i am recovering from an ACL knee operation so my mind is working overtime.

[Nick Mann]

No worries dude. That thread was an interesting read which is why I remembered it. Hope you are recovering well!

[Davezj]

yeh not to bad, i have just read the thread you linked to again and watched the videos as well, and it is a good read,.

and put me off the idea. even if i can get a cheap supercharger. in the reagin of 100hp-200hp for less than £300 delivered.
i am still tempped to buy it but maybe for a different project or resale to maybe a glanza boy.

[Adam.Findlay]

it would have to be a centrifugal type like the rotrex ones below

Uhh V engines are perfect for the use of roots or screw type blowers.
if anything a centrifugal one would be much more difficult to mount as you have to mount it in such a way where it can be driven by the belt.

A roots/screw type blower could be mounted just like this
http://s354.photobucket.com/user/Cyo...N1077.jpg.html

or in the valley of the V like they do with V8's.

pulling the turbos off an engine to supercharge it is a complete and utter waste of time, unless you keep the turbos on so it is twin (or compound depending on how its setup) charged

and then with the kind of boost levels you can acheive with compound charging would see the stock 6a13tt internals up to or past their capabilitys.

[Badger_01]

https://www.youtube.com/watch?v=bCocbmg34mQ

[Davezj]

all the info needed on compound charging is in the linked thread by nick mann.

no this is purely hypathetical,
has anyone put an extra supercharger or turbocharger in parallel with the twin turbos we already have on the car.

my gut feeling would be a turbo would not work very well, but a supercharger would.

[SEAN-NZ]

i doubt putting a supercharger post turbos would have very good gains as the turbos probably wouldnt be able to supply enough air, happy to be corrected if im wrong though

[Adam.Findlay]

superchargers are more mechanical compared to turbos with the exception of a centrifugal which I am ignoring as it would be almost impossible to mount on a VR4 without deleting one or many ancillarys such as A/C and P/S
Anyway...
Ignoring efficiencies and other calculations for simplicity
If you have a for examples sake 2:1 compression supercharger it will take 1.0 bar (atmospheric) pressure and double it to 2.0 bar (atmospheric pressure x2 so 1 Bar boost) for a given pulley ratio and engine speed

So, if you have a turbo feeding 1 bar boost (2 bar absolute) into the intake side of that same supercharger it will double it again leaving you with 3 Bar boost (4 Bar absolute)

where as compound charging with a second (or in our case third) turbo can be controlled by three wastegates. one on each of the factory twin turbos, then the outlet exhaust gasses of the stock twins, AND their wastegate gas collect together and feed into the secondary bigger turbo, this way the big turbo still sees full exhaust gas flow from the engine so the only detriment to its spool will be the exhaust gas cooling between the valve and the secondary turbo and therefore loosing velocity.

The secondary turbo is again controlled by a wastegate which can be electronically controlled to limit or raise the boost.

Either way they are both complex soloutions
the "twin charged" way seems like the easier way to do it to me. just use a Eaton M90 supercharger which is a roots type blower with the intake in the back of the body.
http://i5.photobucket.com/albums/y19...e/_MG_8901.jpg
This will let you blow boost into the back of it from the stock twin turbos as the intake of the supercharger will be on the flywheel end of the motor much like this

http://i206.photobucket.com/albums/b...A/IMG_0867.jpg

then connect the pulley to an ancillary belt with a bit of tensioner and bracket trickery. the hardest part will be getting a intake manifold made to sit between the V so the supercharger could bolt on and supply air to all 6 cylinders evenly.


compound charging with a 3rd turbo the 3rd turbo will have to be mounted ontop of the gearbox to fit, which means that the stock turbos are around the wrong way, as the exhaust housings of the td03's face the cambelt end, so you would have to either have a pipe off each turbine housing which does a full 180 and heads back the other way to the big secondary turbo. Or make custom manifolds to flip the turbos 180 so the exhaust housings are facing the right way, but then how do you get air into the front of them as The MAF needs to meter air for both turbos!
and either way you still need to then find somewhere to jam in a downpipe off the back of the secondary turbo.

LONG story short. just buy two used TD04L or TD04HL turbos and put 19t compressor housings and wheels on to them and fit them on to your 6a, no twin charging, no compound charging. super simple and a pair of 19t td04's will blow enough air to make 600hp+ which is more than enough to blow the pants off a stock 6a13 bottom end or give you serious driveline issues.

[Adam.Findlay]

i doubt putting a supercharger post turbos would have very good gains as the turbos probably wouldnt be able to supply enough air, happy to be corrected if im wrong though

yep correct. stock turbos are the limiting factor. raising the pressure with a supercharger will mainly just add heat. not flow.
as I said, best to just slap some big ol TD04's on and go for gold

[Davezj]

thanks for your input adam, but i don't think you are understanding what i am suggesting in the hyperthetical world,
i was suggesting, effectively having a tripple parrallel system, 2 turbos and one supercharger all running in parellel.
the supercharger would have its own air pipes from the inlet behind the MAF and to the input of the intercooler.
as you say the supercharger would give say 1 bar of boost and the combined output boost from the stack turbos would give 1 bar, 2 bar total, which is why i awas talking about using a centrifugal supercharger.

as i say this is just hyperthetical and i am try to figure out what would happen if you did it.

[Adam.Findlay]

thanks for your input adam, but i don't think you are understanding what i am suggesting in the hyperthetical world,
i was suggesting, effectively having a tripple parrallel system, 2 turbos and one supercharger all running in parellel.
the supercharger would have its own air pipes from the inlet behind the MAF and to the input of the intercooler.
as you say the supercharger would give say 1 bar of boost and the combined output boost from the stack turbos would give 1 bar, 2 bar total, which is why i awas talking about using a centrifugal supercharger.

as i say this is just hyperthetical and i am try to figure out what would happen if you did it.

right'o. I just didnt get why you would ask such a quesion if you had no intention of seeing the idea out to some degree.

also 1 bar from a supercharger added to 1 bar from turbos does not give 2 bar. both the turbos and the supercharger will have to push against that same 1 bar of pressure which will be in the plenum. the flow will just increase if you catch my drift

[Davezj]

ah yes, i think i do.
you will get no more boost as both of the compressors are only capable of compressing on a ratio of 1:2. Just more potential flow as long as there are no other bottle neck in the system.

so can i extrapolate what you have said and produce the following system.

so can i say, if can produce say 1.5bar which mine can at certain conditions with the standard turbos, which is outside there range of efficiency if i used a supercharger as well it would not produce any more boost but it would effectively give more air flow which would possibley make the turbos work less hard to produce that 1.5 bar and bring them back into a more efficient range of operation and give a cooler air charge temp in the inlet manifold, and as the rpm increases the system would be able to hold that level of boost to a much higher rpm, as the system can flow more air.

[Adam.Findlay]

yes that is right to a certain extent.
the turbos are the bottle neck on our engines so if you are running out of flow with the turbos adding a supercharger, which is not in a compound setup will feed the engine more air. however the turbos will still be pushing that same 1.5 bar so they will still be compressing the air the same ammount and be spinning at the same speed therefore still heating the air up to un-desirable temps.

If you are running a supercharger "in parallel" as you say, if the turbo pressure drops, which it will as the stock td03's can only support ~1 bar to redline. the pressure of the whole system will drop. if the system was to maintain a constant 1.5 bar pressure as the rpm rises, the supercharger pressure would have to rise at the same rate the turbo pressure drops in correlation with rpm. and this is not possible as superchargers cannot accelerate faster than the crankshaft as they are driven off the crankshaft at a set ratio.. Follow?

also 1.5 bar would be the very upper most limit I would ever run a stock bottom end 6a13 to and even then you are running a decent risk of bending a rod, not to mention the detonation issues you would have.
I would say the intake temps at 1.5bar would be so high with td03's regardless of supercharger or not you would probably have to wind out so much timing to avoid detonation it would probably make the car slower

the stock turbos can only flow what they can flow. supplementing them with a supercharger will increase flow but its not going to make life easier for the wee TD03's they still have to fight the same back pressure from the plenum.
this is why compound charging is a better solution as you can run the turbos at a much lower boost pressure, feed that low pressure boost into the supercharger and then let the supercharger "multiply" the pressure that is fed into it. however is is quite uncommon on mass manufactured cars as it is complex to implement and service.
not to mention if the supercharger is a big step up in pressure from inlet to outlet, a small variation in inlet pressure, ie boost spikes. will give a huge variation in outlet pressures.

Hence why I said earlier that a pair of TD04's isa much better option, It will remove the bottleneck of the stock td03s whilst proving more air to the engine without the need for a supercharger.

TL;DR supercharging whilst retaining the stock turbos, although different and i guess cool. would be expensive and not much of a gain compared to other options

[Davezj]

i am with you on this, i follow what you are saying, and that makes sense.

thanks for your perserverance and effort you have put in on the subject, it is most appreciated.

OK heres another thought i was having,
is it possible to swap the compressor housing and compressor wheel from a TD04L subaru turbo and fit it to the CHAR of the TD03 turbos we use.
i know there will be an issue going from a 7G to a 13T compressor with regard spool up, but is this possible and do you know if anyone has done it.

i believe there could be an issue with back pressure due to the larger compressor wheel producing to much flow.
and an issue with the small exhaust turbine actually getting slowed down massively if the compressor wheel is to big.
is 7G to 13T to much of a jump.

[Adam.Findlay]

Cool thats good sometimes it can be hard to explain via forums. as you can well understand

the cores (CHRA) of the td03 and td04 are different sizes so its not as easy as just putting the 13t wheel and td04 front cover onto the TD03 core and turbine shaft. you would have to machine out the front TD03 cover to accept the 13t wheel, but it is highly unlikely that the TD03 cover has enough meat in it to go quite that large.
GTO 9B's might be possible but then thats not much of an upgrade.

although im by no means a turbo expert I can imagine just upgrading the compressor side of a turbo will lead to surge problems as it would severly mess with the efficency/flow maps and then you still have the problem of the tiny TD03 exhaust housings and wheels being a restriction.

[Davezj]

yes that is kind of what i was thinking about, i could not remeber the "surging" word.

i had a suspistion that it might be a machining issue to fit the compressor wheel, i was looking at a turbo upgrade video for a TD04L 13T to a 19T, and the company doing it had machined the commpressor wheel to fit the original CHAR and housing of the TD04L, i presume this would impact the overall upgrade preformance but still be an upgrade.

this is the video for the compressor wheel modification from ARD.
http://www.youtube.com/watch?v=xTOjEBaRUc0

[Adam.Findlay]

CHAR

CHRA
Center Housing Rotating Assembly just FYI

if you have td04l/hl's you can buy the new 19t wheels and compressor housings.
http://www.ebay.com/itm/Turbo-Compre...ef9392&vxp=mtr
this means its just a matter of bolting the new 19t wheel on sending it away to get balanced then putting the new compressor cover on. no machining needed.

or if you buy some cheap 2nd hand td04's you can buy this kit

http://www.ebay.com/itm/Turbo-Compre...3bf8a9&vxp=mtr

which is the same as above but includes the rebuild kit.

cheap as chips, for ~350USD for 2x kits + cost of the second hand turbos (which in NZ you can pick up for ~100NZD each) that will give you turbos capable of up to and over 600hp

[Davezj]

cheers adam,

yes the a pair of turbos TD04L can be bought cheap, but it si all the fabrication that is going to be the pair in the backside.

i know i am try to get the unobtainable, a bolt on upgrade, but you can't blame me for trying.