Give up a 991 GT3 for a Superformance GT40?

[SFSDFGT]

Originally Posted by Cobra #3170

Thank you, I made up a spray bar for the intercooler and designed a solid state timer that would turn it on for 5 to 20 seconds every minute depending on outside temp. I used a motor home washer bottle mounted in the front compartment filled with distilled water. That gives me 15 TO 20 minutes of track time. Running 26.5 psi with 105 unleaded. Factory air box with intake support,
The big problem is the blower heating intake air.
Just as I chicken lift going into 1 it is 194 mph and a little over 150 under the bridge, really stout acceleration for a non turbo car. I also have AP rotors, Carbotech pads and spring rates roughly 2 times higher than stock.

I am surprised that your factory airbox is sufficient to flow enough air to support that kind of boost & power. I just put a 4.0L Whipple on my GT, and have been figuring out how to have my local fabricator make a better intake setup, similar to the GT Guys, only better. So many people have said that the factory airbox is a major power limiter once you go Whipple. People have told me that they picked up anywhere from 2-4 psi of boost just by either drilling holes in the bottom of their airbox, or going with a dual-conical filter/dual snorkel type setup.

[Cobra #3170]

Originally Posted by SFSDFGT

I am surprised that your factory airbox is sufficient to flow enough air to support that kind of boost & power. I just put a 4.0L Whipple on my GT, and have been figuring out how to have my local fabricator make a better intake setup, similar to the GT Guys, only better. So many people have said that the factory airbox is a major power limiter once you go Whipple. People have told me that they picked up anywhere from 2-4 psi of boost just by either drilling holes in the bottom of their airbox, or going with a dual-conical filter/dual snorkel type setup.

I am sure you are correct, Whipple kept telling me they were going to develop a carbon fiber air box that would solve all problems and I waited and waited. They never made one. Car made 862 rwhp which was more than enough for most road courses but a better air box would have been nice. Did you install fuel pump boosters?

[SFSDFGT]

Originally Posted by Cobra #3170

I am sure you are correct, Whipple kept telling me they were going to develop a carbon fiber air box that would solve all problems and I waited and waited. They never made one. Car made 862 rwhp which was more than enough for most road courses but a better air box would have been nice. Did you install fuel pump boosters?

Yes, JMS brand. I had the GT Guys do the install last year just before Rally X, when I needed some service done anyway. Along the Whipple, did injectors, Accufab throttle body, Cooltech exhaust, new SPEC clutch, lowered 1 inch, SpeedHut gauges (originals working, safely packed away), all fluids flushed and changed, new belts, etc. Did 754 rwhp on 100 octane and 19 psi boost. But I am not impressed with their tune- very safe/rich. Once I get the intake improved, I expect 780-800 rwhp on pump gas. My GT500 with a 3.4 Whipple makes 751 rwhp on same fuel, same boost, so the GT should do at least as well with the 4.0 Whipple, considering it has more cam, more fuel and injector capacity, less driveline loss, etc. But now I am doing a total rebuild on my GT500 engine, including cams, so it is a constant horsepower war between these two in my garage. But my cross-ram 572 hemi trumps them both.