toddk911

A search should bring yo uup a lot.

Also, there are several videos of a 951 on youtube/streetfire with a GT30 or 35 doing runs and a boost vs. rpm. I think he got full boost about 4K

Porschefile

On stock displacement:

300-350rwhp - Gt3071R .63 or .82
350-400rwhp - Gt3071R .82
350-450rwhp - Gt3076R .63 or .82
400-500rwhp - Gt3076R .82 exhaust minimum for ~500+rwhp
500-600rwhp - Gt3582R .82 minimum
600-650rwhp - Gt3582R .82 min or 1.06, T3/T67 .82+ minimum (aka Super 75)

After countless hours of charting out compressor maps, examining other people's results, etc I've come to the conclusion that a Gt3076R with a .63 or .82 exhaust is the perfect balance for most of our needs. The 3071R would be an excellent choice as well.

Up to around ~400rwhp a .63 hotside should be fine, though much above that and it will be too small and generate alot of backpressure so you will see minimal hp gains. A .63 can still support over 400rwhp, though not efficiently and you will have to run alot of boost to do it. Judging by what I've seen from the few using Gt3076r's on our stock 2.5l's (Edman951 for example), most seem to have 1bar @ ~3k with a .63. With a .82 it couldn't possibly be worse than 3.5k for 1bar, and IMO that isn't laggy at all considering the power level. It all depends on what kind of powerband you want. I'd personally rather sacrifice 300-500rpm spool with a .82 and be able to easily push 400-450rwhp without running so much boost because a powerband of 3.5-6.5 or 3.5-7k is perfectly useable for my tastes.

Any of the bigger turbos like the Gt35r, Super 65, Super 75, etc really shouldn't be running anything less than a .82. Anyone can argue all they want, but at the point that you have a 61-67mm turbo then you better damn well be looking for at least 500+rwhp or it's all just a waste. Why use such a large turbo and create unnecessary lag, when a much smaller turbo with a slightly larger hotside can still make some big numbers while being more responsive.

toddk911

"600-650rwhp - Gt3582R .82 min or 1.06, T3/T67 .82+ minimum (aka Super 75)"

YOU KNOW IT!!!!

But great info Porschfile!!!

Some tuners you might be getting nervous though

And 18psi by 4,100 and with my newly purchased 951MAX chips, might be able to drop that some and run to 7K. But I will play it safe at first and keep an eye on the EGT's.

AL951

Well don't get me wrong, But a 16V head is in it self a superior design. And sure our stock head is not perfect. It has issues, but like you said, good tuning and the right hardwere goes a long ways in the quest for power and reliability. IMO our engines are well suited for turbocharging. With its oversquare design, they can produce alot of torque. The limiting fator has always been the valve train and oiling system. but that is a cooky for another day.

Regards,
AL

SchnellerUmsetzer

Tell him it is "Rice o Roni" and to buy a 951!

toddk911

"Why use such a large turbo and create unnecessary lag, when a much smaller turbo with a slightly larger hotside can still make some big numbers while being more responsive."

Cuz I got talked into it!!!

GO BIG OR GO HOME!!!! LOL

Rogue_Ant

Tuning is a major factor, but head design has a HUGE effect on things... timing advance needed, dynamic CR, acceptable Air Fuel Ratio, ect.....



Rogue

Porschefile

There's nothing wrong with that. Heck, I just got a Precision T71 for my 911 (T4 71mm compressor, rated at 880fwhp) as I've been bit by the dyno queen bug! Todd, I will gladly pay the dyno fee if you will agree to run about 30psi and push that big turbo a bit!

I believe the stock Greddy T78, at least in the Supra's application, comes with a 14cm2 housing which is apparently about equal to a 1.02ar housing!

Fishey

Yes, Fishey FTW!

Garrett T25-45

Garrett T25-55

Garrett T25-60

Garrett T25-60



Garrett T3-40

Garrett T3-45

Garrett T3-50

Garrett T3-60

Garrett T3-Super 60

Fishey

Garrett T-61

Garrett T-64

Garrett T-66

Garrett T-68-1

Garrett T-70

Garrett T-72

Garrett T-76

Fishey

Fishey

Fishey

IHI Maps

IHI Specs

IHI BRL3911

IHI BRL4016



KKK K03

KKK K04

KKK K14

KKK K16

KKK K24

KKK K26

KKK K26

KKK RS2

Fishey

Now the common mitsu turbos
Mitsubishi TD04 09B

Mitsubishi TD04 13G

Mitsubishi TD04 15G

Mitsubishi TD04H 18T

Mitsubishi TD05 14B

Mitsubishi TD05 14G

Mitsubishi TD05 16G large

Mitsubishi TD05 16G small

Mitsubishi TD06 17C

Mitsubishi TD06 20G

Mitsubishi TD06 20g

Mitsubishi TS04

Fishey

Eaton Superchargers














Vortech Superchargers