Figure I would post this in here since the thread is already going. Right now I am making a switch from twin T04E 57trim/stage 3 .48A/R and was wondering if twin GT3076R's would spool. I am running a 3.5L EFI that spins to 7000rpm. Optimal max boost would be between 28-30#'s. Keeping in mind I have extremely long gearing in the form of a 76 4 speed. The car is a drag car, and I am looking to make between 800whp-900whp, the old turbos made 710whp. Any insight as to what I should run would be greatly appreciated. I know this seems like a pretty newb question, but I am pretty new to the Porsche game. I was also figuring since they are a ball bearing turbo, it would have pretty similar spool characteristics compared to the 57trims. I was also going to go with .63 A/R Turbine housings.

I know when I made the switch from my standard 60-1 T3/T4 to a ball bearing T66 it only spooled 500rpm's later. This was on a 2L I4 However, and I don't know how H6 3.5L's respond to upsizing or if roughly 1.75L will spool a GT3076R in time (per bank).

 

Sorry for the late reply. here are the pics of the heat exchanger for the water circuit i am building for the GT35RBB turbo. By the way im in Brisbane Australia. i have also attached a pic of the porting done to my cyl heads to accept the 3.2 manifold.
Alex...

 

Guys for thoes of you who want to run the GT35RBB on the Schnell extractors, be aware that the flange on the sump is for the KKK turbo and will not match up with the GT35RBB. i can email any of you who are interested with a DXF file that you can take down to your local laser cutting shop and get the correct flange cut out out of 10mm 316 SS then just have to old one cut off and the new one welded on. just send me an email and ill send you the file.
Alex
amartin@trane.com

 

I'm using a Garrett GT35R on my 930 with SC cams, Fabspeed intercooler and exhaust, 7.5 to CR and a BL WUR, we adjusted the fuel pressure warm under .8 bar boost but it doesn't go any less than 32PSI and the engine runs lean at WOT, looks like the turbo is too big.
Any one knows how low can we adjust the fuel pressure on the WUR
We set it at 50PSI warm and then apply boost to it and starts lowering pressure at .4 bar and the pressure goes as low as 32psi.
Any ideas??
The engine runs nice
Idle 14.5 to 1
Cruise 14 to 1
Under load up to 5000 at 12 to 1 but after 5200 RPM and up goes lean at 14 to 1 or even leaner.
HELP!!!!

 

Just to let you all know, Fabspeed can build and send out our headers for use with any turbo flange.

 

What have you done with the fuel delivery system, namely, the fuel pumps? Are you running the stock Bosch's? Have you checked what your system pressure drops to when under boost?

__________________
Dave
'85 930 Factory Special Wishes Slant - B&B Headers/Muffler, Werke I Cams, Kokeln IC, Electromotive Crankfire Twin-Plugged,
Tial Wastegate(1.0Bar), K27-7006 turbocharger(Werke I), Euro fuel distrib, 8:41 R&P

 

Have you had your fuel head modified for additional flow?

 

Wow that's a lot of power

 

I have run a gt35r for a few years on my 3.6. It's been very reliable, zero issues. I just had my car on the dyno to check the tune and it made 526 wrhp at .90BAR. I have a 1BAR map but have never run it since I can't get anything better than 93 octane gas in Atlanta very easily. I am not sure if it really spools up any better than The turbo Kevin made for me several years ago, it still hits like a freight train at about 3000 rpm. It was the perfect fit post EFI conversion. For a non EFI car, I loved the HF from Kevin.

 

....but, what is the gt35r between 5- 6K RPM's compared to the HF?

__________________
Dave
'85 930 Factory Special Wishes Slant - B&B Headers/Muffler, Werke I Cams, Kokeln IC, Electromotive Crankfire Twin-Plugged,
Tial Wastegate(1.0Bar), K27-7006 turbocharger(Werke I), Euro fuel distrib, 8:41 R&P

 

I did not run the GT35r prior to my EFI conversion, which netted 150 to the wheels, so it's no comparison. My car peaks right at 6,000 now, and I agree the HF was falling off at 5,400-5,500 and I still had plenty of fuel. So from that perspective, the GT is a better fit for the current build.