Andrew Wojteczko

well, we are looking for decent spool but for our purposes, the motor will never be below 3500 as long as I'm doing my job behind the wheel. Would the increase in VE from switching to the .82 A/R be worth while? I see on the compressor map that the higher the A/R, the higher the efficiency, so will a .82 A/R make 18lbs at 3500 RPM on our motor? Peak power is important to us as our series is only limited by success ballast, so the more room to roll the boost on, the better. Thanks guys.
I found out our supplier is sourcing from both Precision and ATP turbo. Precision claims the 4" inlet is not available, still trying to sort that out.

Thanks,

Andrew Wojteczko

Edman951

JChen, I send you another non zip file this morning from my work. It a very big file over 10MB.

Andrew,
A 0.82 A/R may only give you 18psi at 4000rpm.
With my 0.63 i get 18psi by 3600 or so.
But you are right that you may get better VE with the .82.
And have more top end.
The .63 really work for the street. Its not a super fast spooler but it aint laggy.
You can get a good idea from my video i posted.

The thing you should do is start with the .63 and then later buy just a spare .82 housing. So you will be able to try both.
I actually wanted to get a .48 spare housing made to see if it spooled sooner. But i'm happy with the .63.

The last secret thing, is that you could probably get a KKK housing bored to fit on the GT turbo.
It almost fit on my spare #6 housing but the GT wheel was to big.
But it won'T get you out of the wood from custom work.
Because the GT is not as long as the K26 turbo so you need to extend the Xoverpipe anyways.
Check out the picture on my install post to see the diference in lenght.
https://rennlist.com/forums/showthre...ighlight=gt30R

Andrew Wojteczko

Thanks Edman, as far as custom fabbing, we are fully equipped with inhouse tig, CNC, and anything else we need, I'm just worried about getting the best turbo for our needs. Does anyone know what the output diameter of the .82 A/R housing is? is it 3"? I am not sure what the GT30R diagram in the catalogue is actually referring to.
Again, I believe for our race application, 18lbs at 4000 RPM is plenty, does this more closely compare with a T4 turbine housing?

Thanks again,

Andrew Wojteczko

Andrew Wojteczko

If the .82 housing is 3" outlet, I will use the Vband discharge adapter and do a full 3" V band downpipe, this should inturn help the VE's and bring the compressor into it's higher efficiency sooner and limit the reduction in spool up while still keeping our top end.

Chris Prack

I have been watching this thread with interest. You guys are getting closer!!

Remeber this thread? http://fourums.rennlist.com/rennfour...d.php?t=124737

Andrew Wojteczko

Chris, Can't open that link

Edman951

Chris, the link doesn't work

Andrew,
the .82 has the 3'' outlet check it out here.
http://store.yahoo.com/cheapturbo/gagt56tr.html

Going to a 3'' with V band is probably the best all in all.
Specially for a track car.

It doesn'T compare to the T4.
The T4 is bigger.

Andrew Wojteczko

Ok,

So then 3071R with a .82 A/R on the hotside, and 3" Vband adapter and then 3" all the way back for our dedicated 2.5l track motor. If anyone has any objections please speak up, I am going to get this on its way tomorrow, looks like it's coming from precision or atp.

-Wheel: 60mm w/ 84 trim
-Housing: .82 ar (3" 4 bolt outlet i believe)

Compressor
-Wheel: 71mm w/ 56 trim
-Housing: .50 ar
- 4" inlet
This compressor seems to be the perfect match, 77% efficiency at 7000RPM and 18-22 psi, never crosses the surge line on the left end.

Thanks so much to everyone for all the info and input.
Here are some pics of what we've been doing
www.voytechco.com/IMGP0248.jpg
www.voytechco.com/engine.jpg
www.voytechco.com/engine2.jpg
www.voytechco.com/dash.jpg
www.voytechco.com/ducts.jpg
www.voytechco.com/car.jpg
www.voytechco.com/rear.jpg
www.voytechco.com/rear2.jpg
www.voytechco.com/rods.jpg
www.voytechco.com/rods2.jpg
www.voytechco.com/bottom.jpg

Parts not fabricated in house listed below,
TEC3R from Tim at SFR (Thanks for the extensive support at all hours)
Leda suspension thanks to Racer's Edge
Aluminum pressure plate, injectors and first turbo (Huntley)
Thanks to everyone who made this possible. Car is now complete waiting on replacement turbo. (Many pictures taken during fabrication)

Andrew Wojteczko

Corleone

I still think that .82 is to big. Why dont you go for the HKS hot side that have .73 in A/R with the same wheels/trim? Se the HKS list.

Corleone

This cam, (not at his website) has its best pb from 36-3700 to 7000. I will say once again that I dont normally drive at wot from lower rpm so in practice you have to gear down to make the car go fast. When I wot from 1500 and up and get 20 psi at 32-3300 the boost is forced up like in the dynos. But 4-7000 works really great and I think the cam is moore important than many thinks. I also really dont think that the Swedish redone cam by Enem works near as the Millegde one.

NZ951

How much was the cam?

J Chen

Andrew,
Me too think it's a bad idea to go with .82.
I've seen the housing, it's big. Why not give
the .63 a shot. Yes you're working above 4000
rpm but let's not forget that you want as quick
a response when coming put of turns. Besides
since it's a track car, you've got to play with
different AR's for different track right ?

Duke

That's one of the good things about a full Garret turbo, easy/cheap to try different hothousings.

This is the thread Chris was trying to link to:
https://rennlist.com/forums//showthread.php?t=124737

mrfixit951

Pauerman,

It seems that each Garrett disty has their own housings............

I spent a considerable amount of time on the phone with one of the guys from Precision.

He stated that the smallest hotside A/R is 0.82 with the 100mm bolt spacing (GT type) turbine exit. The inlet is a stock T3 inlet flange. ATP offers a GT style to V-band discharge adater at a reasonable price...

Many different Garrett retailers offer a GT30 combatible turbine housing with stock T3 inlet and outlet flanges with a smaller A/R of 0.63 or 0.48.

Chris I studied that thread some time ago. Maybe we are getting close = use the 0.82 A/R ???

The coldside is getting just as confusing with the 3" versus 4" inlet issue. Either way the 71 mm 56 trim 0.5 A/R compressor side looks like a winner.

Ben

Duke

Judging by the torque curves he's definatly using big hot housings.
I've always found it strange how scared the 951-crowd seems to be of bigger hot housings. Then finally someone posts dynocharts of something different (bigger hot housings amongst other things) and everyone are so amazed and can't stop talking about how they want the same kind of power.
But look at where peak tq is...it's well over 5000rpm. So the strange thing is when the same people starts asking for that kind of power levels but at the same time asks for tq peak around 3000rpm...
Nothing's for free.