NZ951

Just want to poll this and get some feedback if ANYONE is running a GT53R... I am thinking .82 exhaust housing at this stage with a T04S cover.

J Chen

Do you know how Biggg .82AR is on the GT30/35s ?
Wrong choice my friend.

NZ951

Yeah I know .82 is big... I think .63 may be on the small side though. Ideally I want around .75. I think the #8 is around .57... I want to be able to efficiently run low - mid 20 psi and have a theoretical HP capability of 550WHP.

J Chen

.63AR should be o.k though still a little laggy.
Why don't you start form .63 & take it from there ?
Better choice would be to go for an HKS hot housing.
I think Corleone is running one & you can ask Edman 951
too as he's running a .63AR hot housing.

NZ951

Yeah I think the HKS housing is a .7 something, I have been looking for it but cant find it yet... I may have to give SFR a call.

Markus951

Gt30R with 0.63ar will take you to 450-480 crank hp, thats wiht 98 ron. But it spools up pretty fast, if you ask me. With stock head NA cam and 3" exhaust, maybesome 400 + hp and with right cam better cooler, ported head adjustable cam gear, maybe some extra 70-80 hp. GT30R is on of the best high-boost turbos IMO. I am using the same turbo, and I think I am pretty close to max efficency of that compressor map. running 26-28 psi overboost.

If I would be facing the same issue, id go for one of the custom dual BB units from Innovative Turbo. Give them a call, tell them what you want, They will make you a custom ballbearing turbo what will spool fast and at the same time is big enough to get you 500+ hp.

NZ951

Are you sure its only a 480 crank turbo with a .63?

DanG

I'd go with a GT12.



Well, maybe 4 of them.

NZ951

lol one for each cylinder?

DanG

You got it. Although, that might actually be the right multiple for this turbo. Its just barely small enough for a 600cc restricted motor.

Packaging/plumbing 4 turbos would be a treat.

NZ951

Looks like GT30R with an HKS housing may be the way to go...

NZ951

Ok, I found the HKS .73 housing. So maybe the GT30R with HKS .73 housing would be good... Corlene?

Markus951

It is in my case. Max what I could get out of that turbo is 470-480 crank. At least on that Bosch dyno what I used when I got 402 crank hp. I also checked with specialist who had use both Bosch and Dynojet with same car and the diffence is approx Bosch crank hp equals dynojet rear wheel hp. If your car is being dynod on dynojet you should gain at least extra 130hp

Go for innovative. GT35R is low boost turbo IMO, and not suitable for our cars.

NZ951

I will have to go with the HKS .73 housing by the look of it... I will see it Tim can build one.

Corleone

Yes with the HKS .73 housing you will have moore top end power in expense of earlier boost compared to .61. As Im using E85 (Ethanol) nowdays (it runs a lot cooler) I have changed from my .73 back to my old HKS .61 A/R housing and the change really feels. A lot stronger in lower rpms and earlier spool. The difference between these two houses is about 350-500 rpm in spool. Maybe it dont sounds much but in practice 500 rpm is very much.

My opinion is that if you feels satisfied with just around or just under 500 hp you should choose the .61, as a street car it will be faster. If you drive moost at strip or at the highway I would choose the bigger .73.

About the compressor... I have some guys here in my town that tunes SAAB and they also have a Rototest. One of them had the GT30R with a .82 house and he dynoed moore than 580 hp at crank, of course with some less compressor efficiency but it still says that it will be enough. Using a bigger than 76/57 mm wheel in a A/R .60 C house in our 2,5 liter this is overkill.

I think moost of the guys here around is talking most hp number but it isnt the hole truth, I think moost of us want a car with best accelerating numbers and then it seems wise to let some top hp go for a earlier spool and qicker boostbuildup. Look at Jons (Vitesse) setups, they have a good driveability and then the car will be faster. Who want to wait 1 second (or 2) for boost when shifting?