94 gt zex question

[blksunshine88]

i have a 94 gt with GT40P heads E cam 1.6 rockers tfs track intake 70mm tbody shorty headers bassani xpipe, mac mufflers, 3.73's msd ignition coil wires ect, 19lb inj and an a9l computer , took the car to the dyno and made 330hp 380 ft lbs with a 100 shot, put the 125 in and made the exact numbers anyone know why ?? full bottle for both pulls any help would be much appreciated,

[Rodeheaver's]

did the tires spin on the dyno? did the clutch slip? what was the bottle pressure? That size of a shot should not do this, but i have seen cars that simply would not take more spray... We had a camaro that had a 250 shot on it and it did same exact ET with a 300 shot.

[gmkillr]

First thing I would do is upgrade your fuel system. Get some 30 lb. injectors, and Walbro 255 gss 340 high pressure-high volume intank pump, and adjustable fuel pressure regulator. You car should make 270-280 rwhp with no juice.

[blksunshine88]

no tire spin no clutch slip bottle press 950 i do have a 255 pump and an adj regulator fuel press is 43 lbs last NA dyno pull was 277hp 305ft/lbs

[blksunshine88]

lastnight we pulled the heads off (p heads) to give them a good hogging, checked the valve springs at 1.80 installed height and found that there was only 80 lbs of seat pressure and less than 230 @.500 lift valve float???

[Rodeheaver's]

you would need at least 110lbs@1.875 installed height for a stock cam.. stock springs are ok for a e-cam, but they would need to be newstock springs... I have a set here if you need em Greco...

[stieny]

no tire spin no clutch slip bottle press 950 i do have a 255 pump and an adj regulator fuel press is 43 lbs last NA dyno pull was 277hp 305ft/lbs

First, your bottle pressure is too low. I always tried to have mine at 1050-1100 at the very least. Bottle pressure makes a huge difference for N20 applications. Zex bottle heaters blow so if you're using one I would swap it out with a better one.

N20 is just too inconsistent to make exact numbers every time. There are a ton of variables that can happen. IE: spark plug gap, spark blow out, lean or rich conditions that can often result.

I never had bigger injectors. I had the stock 19's with a bigger pump and I had a ton of fuel left in my tune but then again that was on a wet system in a '00 GT.

I'd up the pressure in your bottle, check your plug gap and look at your tune.

[blksunshine88]

thanks for the offer TIM but ben (torqueboxer) had a set he was willing to let me use for this combo, anyone have any DIY piston cutting tips i'm going with the trick flow stage 2 camshaft while its torn down this far