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Thread: GTIR Turbo Manifolds

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Posts: 101-110 of 231
2008-12-30 05:37:19
#101
Ok, so i am still confused on which housing to get .64 or the .86??? I want streetable power, but also want to be able to run 11's @ 20psi and track down most any car dwn on the highway, which I am assuming both can do, but which is better for the street and everyday driveability???What is the lag difference? Miko it seems you keep saying that s4's are needed for this turbo to reach 400whp, but I don't have that option, so what cams would you recommend for my GTi-r with the gt2871r with either the 64 or 86 housing??

Thanks
2008-12-30 05:58:30
#102
.86 gt2871r on a gtir manifold with s4's is a great all around set up, you will have a quick spooling all around fun car, and destroy almost anyone from a roll. I have had this set up on my nx and it was a riot to drive. I have also had the .64 gt2871r which was also a great turbo, as far as spool i didnt notice a whole lot of difference in lag between the 2, i was running both turbos on a uk 10:1 engine and had the .86 on a usdm 9.5:1 with stock cams as well. I would say get which ever cas jwt makes for your car like the s3m's.

Also i agree with miko, you shouldnt need to rev that high at all, i dont think i took mine over 7k, i have a 7k pill in my shift light. I never got to the dyno to tune at anything over 10psi, but with conservative timing a stock ecu and an emanage i had 250 or so whp at 9 psi, and 270whp at 10psi, again this is with the base timing backed down quite a bit around 13 deg. with a 2.5" exhaust, so i could run pump gas on the 10:1 engine. we basicaly set the car up for all around driveability which was focused on alot more than peak whp, the car drove awesome and i got 35+mpg on the hwy when not in boost. i only ran it at 20-21psi for a short period of time, until one of my injectors failed and i melted a piston. Atp and also precision sell nice units and are pretty decent to deal with.
2008-12-30 06:10:12
#103
Originally Posted by insane
.86 gt2871r on a gtir manifold with s4's is a great all around set up, you will have a quick spooling all around fun car, and destroy almost anyone from a roll. I have had this set up on my nx and it was a riot to drive. I have also had the .64 gt2871r which was also a great turbo, as far as spool i didnt notice a whole lot of difference in lag between the 2, i was running both turbos on a uk 10:1 engine and had the .86 on a usdm 9.5:1 with stock cams as well. I would say get which ever cas jwt makes for your car like the s3m's.

Also i agree with miko, you shouldnt need to rev that high at all, i dont think i took mine over 7k, i have a 7k pill in my shift light. I never got to the dyno to tune at anything over 10psi, but with conservative timing a stock ecu and an emanage i had 250 or so whp at 9 psi, and 270whp at 10psi, again this is with the base timing backed down quite a bit around 13 deg. with a 2.5" exhaust, so i could run pump gas on the 10:1 engine. we basicaly set the car up for all around driveability which was focused on alot more than peak whp, the car drove awesome and i got 35+mpg on the hwy when not in boost. i only ran it at 20-21psi for a short period of time, until one of my injectors failed and i melted a piston. Atp and also precision sell nice units and are pretty decent to deal with.


I am running 72lb msd's , so fueling shouldn't be a issue and remmeber my timing is set at 20* as per the base timing for the gtir. I plan on running 20-24 psi with some nice high octane at the track and will be looking for mid 11's@118+ with either the 64 or the 86.

I really think I am going to need cams so I will probably get the jwt s3m's, but would like to see some before and after numbers on them to see what they can do.
2008-12-30 06:45:17
#104
yeah i was running hrc 625cc's at 3 bar, it was an internal injector problem. This is why if i ever buy used injectors from anyone i will have them cleaned tested and flowed at rc. I bought them from my friend and his car ran fine with them, he upgraded to 1000cc and they sat a bit until i purchased them, i installed them figuring what the hell his car always ran great and after a short wile i have a nice holy 10:1 piston. I will have to dig up the flow chart but basicly my car was a 3cyl with the little ammount of fuel being flowed and the injector itself not physically opening and closing correctly, it would occasionally piss into the cylinder. Also that piston was hella white and the other 3 were black so it definately went lean, i should post some pics of it, its pretty cool. I forgot about the gtir's timing.

I would say on your engine with the itb's i would run the larger a/r. i havent personally seen dyno charts of the s3m's.

Anyway a little off topic lol, is there any updates on the quality of the manifold, is it going to fit with minor mods? If the gt28 turbo doesnt fit with it what is it made for?
2008-12-30 11:39:32
#105
Originally Posted by jonwepa
I really think I am going to need cams.


just for info, the dyno i put up was done on a standard gtir head and cams
2008-12-30 11:49:59
#106
What would the hp be at 1.5 bar = 22.05 roughly and are the numbers you listed WHP or just CHP
2008-12-30 12:38:27
#107
andreas, on a stock gtir, roughly, we'd expect to see 420-430ish. This set up that made 463, really wasn't all that, it was pretty much just a set of pistons and a turbo, mappable standard ecu. With a better set up ed and allen would've been able to push a little more, maybe almost the limits of that turbo

the graph shown is corrected at the fly, measured at the wheels was 370bhp, just found the wheel graph, it actually peaked at 2bar, then drops off to 1.8-1.7



our awd system just eats power, almost definately another reason why our figures are so much different for the same turbo, what sort of losses do you see ?
2008-12-30 12:52:16
#108
OK so 26 PSI making 370 WHP.

I know if you were to get a set of cams like the JWT GTIR cams you should pick up about 40-45 more WHP. I love these cams by the way.

That would put you at about 410 WHP @ 26 PSI.
add another 5-7% for drivetrail loss over the FWD and you are at 430-440 WHP. Which is where the turbo should be.

I belive in making the engine as efficent as possible instead of raising the boost. So I generally work around 15 PSI untill I am happy then we go up on boost.


Here is what I found about the turbos listed below with .86 AR turbine housing.

GT28RS seems to do best around 16-18 PSI
GT2871R seems to do best around 20-23 PSI
GT3071 seem to do best around 22-25 PSI
GT3076-GTBB37 seems to best around 24-28 PSI.

This means anything over those boost levels the turbo does not realy make any good gains to make it worth raising the boost or this means the efficency of the turbo has been reached and there starts to be an increase in heat.
2008-12-30 13:12:39
#109
Originally Posted by Andreas
OK so 26 PSI making 370 WHP.


the peak was 29.4 psi

it was really done just to see how far they could push a pretty much basic rebuilt gtir engine with just a bolt on turbo, injectors, intercooler etc.
2008-12-30 13:23:10
#110
Originally Posted by kieron
the peak was 29.4 psi

it was really done just to see how far they could push a pretty much basic rebuilt gtir engine with just a bolt on turbo, injectors, intercooler etc.


What is a basic rebuilt motor.

I feel once you have put aftermarket pistons in a motor you have gone past the basic rebuild.

GTIR rods ars so good that changing them is almost silly, so I figure you guys left them alone.

The true diffrence from a stock motor and a motor with " pistons " and rods Pistons being the big change is much higher boost more saftly as you know.

I know a stock GTIR motor will shake off 25 PSI of boost with no problem. So you put pistons in one of them and leave the rods alone 30 plus psi is no problem. I have seen GTIR rods take upwards of 600 plus WHP on some cars I have seen run on the dyno.

With these T28 based turbos head ports dont see much of a gain.

Cams show the big gain as the head is not going to be a restriction especially for a GTIR head that has god flow potential.

You runn something like a GT35R and porting of the head will show some nice numbers.
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