MustangWorks.com : Ford Forums - View Single Post - GT-40 irons

89 Cobra LX · 06-07-2001, 01:03 PM

This topic is perfect timing. About 2 months ago I purchased a 302 GT-40p long-block from Excessive Motorsport and I will never do business with them again. The Ford production block came with "stage 2" ported GT-40ps, a Wolverine Cam (5110), and stock rail rockers. This combo is supposedly good for 325 horsepower. I added 1.6 roller rockers, a Cobra intake, fuel pressure regulator and 24lb injectors thinking I would have an honest 325 horsepower.

Last week I went to the dyno and produced a peak of 200 rear-wheel horsepower @4500 RPM (my initial pull resulted in 190 peak HP, by tweaking with the fuel pressure we gained 10 HP). This was not a Dynojet, but a Mustang Dynomometer. The dyno-guy advised me this is probably the most accurate dyno currently on the market and instead of the usual 15-20 percent loss in power he has to adjust by 30-31 percent. This means my motor peaked at about 260-265 horsepower. This is 70 horsepower less than the motor was advertised to make, talk about being sick to my stomach. The 24lb injectors are way too much for the motor. Even with the regulator turned down as low as it would go, my air-to-fuel ratio was down in the 12.2 range.

Excessive Motorsport is telling me something's wrong with my set-up (70 HP in the set-up on a naturally-aspirated fuel-injected 302?... my *** ) I'll tell you what I think is wrong with the set-up, it's the heads. There is no way I should be getting peak power at 4500 RPM with the intake and cam I've got.

I'm tempted to slap a set of aluminum heads on the motor and see how much difference it will make, but I've already invested so much this won't happen. What I am going to do is switch back to the 19lb injectors and add an MSD ignition. I'm hoping to gain another 20 HP at the rear wheels (this would put the motor in the 290 HP range). This isn't great, but I've got to do something to gain some more power. I'm running with all of the standard bolt-ons (headers, off-road pipe, flowmasters, 65mm T-body, 73mm MAF, pulleys and 14 degrees timing)

Can someone help me? How can I gain 70 HP in the set-up? Is there some magic dial I need to turn?

Thanks - Eric

06-07-2001, 01:03 PM	#7
89 Cobra LX Don Corlione Join Date: Jun 2001 Location: Omaha NE USA Posts: 491	This topic is perfect timing. About 2 months ago I purchased a 302 GT-40p long-block from Excessive Motorsport and I will never do business with them again. The Ford production block came with "stage 2" ported GT-40ps, a Wolverine Cam (5110), and stock rail rockers. This combo is supposedly good for 325 horsepower. I added 1.6 roller rockers, a Cobra intake, fuel pressure regulator and 24lb injectors thinking I would have an honest 325 horsepower. Last week I went to the dyno and produced a peak of 200 rear-wheel horsepower @4500 RPM (my initial pull resulted in 190 peak HP, by tweaking with the fuel pressure we gained 10 HP). This was not a Dynojet, but a Mustang Dynomometer. The dyno-guy advised me this is probably the most accurate dyno currently on the market and instead of the usual 15-20 percent loss in power he has to adjust by 30-31 percent. This means my motor peaked at about 260-265 horsepower. This is 70 horsepower less than the motor was advertised to make, talk about being sick to my stomach. The 24lb injectors are way too much for the motor. Even with the regulator turned down as low as it would go, my air-to-fuel ratio was down in the 12.2 range. Excessive Motorsport is telling me something's wrong with my set-up (70 HP in the set-up on a naturally-aspirated fuel-injected 302?... my *** ) I'll tell you what I think is wrong with the set-up, it's the heads. There is no way I should be getting peak power at 4500 RPM with the intake and cam I've got. I'm tempted to slap a set of aluminum heads on the motor and see how much difference it will make, but I've already invested so much this won't happen. What I am going to do is switch back to the 19lb injectors and add an MSD ignition. I'm hoping to gain another 20 HP at the rear wheels (this would put the motor in the 290 HP range). This isn't great, but I've got to do something to gain some more power. I'm running with all of the standard bolt-ons (headers, off-road pipe, flowmasters, 65mm T-body, 73mm MAF, pulleys and 14 degrees timing) Can someone help me? How can I gain 70 HP in the set-up? Is there some magic dial I need to turn? Thanks - Eric