What power/torque to expect?

[turbotim1980]

Hi everyone, just seeing if anyone has similar mods and what figures they have, my car has not been mapped yet with these mods though as it was previous to this about 415bhp 1.05bar 370ftlbs torque on standard turbos.

I have a R33 GTR, it has fitted to it:-

Power FC
600cc injectors
Nismo AFM's (still to be fitted)
Tomei fuel pump
Nismo fuel pressure regulator
Garrett 707160-5 turbos
Tomei poncam type B (still to be fitted)
Tomei adjustable cam pullies (still to be fitted)
Exedy uprated clutch (40% stiffer)

No other mods have been done engine internals are standard so is the head gasket.

Just wondering what peoples views might be on this sort of tune/upgrade.

[turbotim1980]

Oh yeah one more thing, does anyone have these cams with adjustable pullies, if so what do you have them set to?

thanks much appreciated.

[GT-R Glenn]

Wow no ones ever asked that question before.
600hp

"search"

[pupsi]

You should see close to 475bhp, 400 torque, what exhaust do you have??

[kismetcapitan]

your fuel system is going to limit you and how much boost you can run. 1.3 bar sound good to you? You'll make about 440 at the wheels, so 500 and change at the crank.

[turbotim1980]

I got a hks silent hi power exhaust and hks front pipe

boost wise i was thinking of 1.4 bar maybe?

[turbotim1980]

Why is my fuelling system going to limit me what needs to be done? i thought that with 600cc injectors were fine.

[kismetcapitan]

nope, you'll find 600cc to be a limit. The rule of thumb of 1cc = 1bhp holds less true, the more power you run and the more boost you push. I have the same turbos, and on a single Tomei (Nippondenso) pump, at 1.3 bar, you start getting lean misfire, which is a great way to put holes into your pistons.

A single Tomei will easily support -7 (GT-SS) turbos at 1.4 bar with 600cc injectors, but the total airflow is less. In order to fuel -5 turbos at any boost I want, I have had to run 800cc injectors, twin Bosch 044 pumps, and Tomei fuel rail along with a host of numerous other fuel modifications.

With Poncams and -5 turbos, I had to run a couple weeks on a single fuel pump, and I assure you, it DOES NOT support 1.4 bar boost. 1.33 bar was the absolute dead limit for safe air-fuel ratios. If you want more boost, start thinking of an entirely new fuel system, or at least change your injectors, and use the Tomei to feed a Bosch 044 in series.

[Sub Boy]

I run -5's with a Nismo in tank pump, Nismo fuel pressure reg and 550cc injectors....And have no problem with over 500hp @4w.

....Tuned right, there shouldn't be an issue

[GT-R Glenn]

What rail pressure though ...
I would say they would have 0 headroom with 500whp
700's would be much safer

[Sub Boy]

A bit more than factory....

Are you running multiple pumps? 750cc's?

[GT-R Glenn]

Look at your hand controller next time you stand hard on the noisey pedal see what % they get up to.

[kismetcapitan]

A Nippondenso pump (Tomei/Apexi/Nismo) can support 600 crank hp at the absolute maximum with no headroom on a stock fuel rail. They will not flow over 5 bars rail pressure for very long (this lesson cost me $1500 in failed Apexi pumps to learn )

I pulled 500whp (496whp@6500rpm and 1.5 bar boost, we didn't go more than that on that dyno run) on a single Apexi pump...but rail pressure was boosted to get more flow out of the 720cc injectors I run, and we could not get richer than 12.5:1 AFR. Much power, very high risk at that air/fuel ratio.

[roadie]

I was running over 2 bar with 720cc injectors on a gt40 turbo. 2 in tank pumps, stock fuel lines, stock regulator, upgraded rail. Maxed the injectors at about 6800 rpm. Have since upgraded to 1000cc's. Leaving everything else alone 'cause it works for me...

[turbotim1980]

Thanks guys i think i will stick to a safe boost level for now 1.3 should do me fine, lets see what it does next time i get it mapped.