ahittz24

I have a 190lph fuel pump and I also am running 24lb injectors, 70mm tb, bbk adj FPR, Cobra intake, GT40 heads. I THINK my supporting mods are sufficient for a 75-125 shot.

Portmaster

With the ZEX kit the best place for mounting the nozzle is 8 inches back from the throttle blade on the throttle body. The Zex kit has a fuel managment unit that works really well. Start off with the smallest jet just to make sure evrything works good and then move up.

ahittz24

I am starting with a 75 shot and going up from there, I do have the jets for a 55 and 65 shot, should I try those first?

ahittz24

Also, I have a question for you guys. I had the engine machined by a shop and had them order all of the parts for me and I reassembled it myself (I trust my own work above everyone else and if something goes wrong I can only blame myself) I assembled it and everything was in great running order. When I was doing the HCI last month I utilized some skills learned at my current job (engineering) of writing down part numbers for everything and taking pictures along the way. When I was looking at the pistons, I found the part number stamped on the top of the piston and it was 517CP. So I got on summit and looked them up to gain more insight to the specs on it so I could figure out my compression ratio and it turn out they are .020 over cast aluminum pistons that and it specifies 87-89 ford 5.0 truck.

Is this bad? I am kinda weary on running nitrous on a cast setup but the nitrous shop (compucar) that I talked to and my machine shop both say there wont be any problems running a 125 shot on this. This is a 91 block, so whats the difference in the 87-89 truck pistons. Thanks again.

302army187

start with 75, see how it like's it and move up.

dont run over a 100shot till you figure out what's going on with those piston's, that's pretty odd.

a 100shot will gain REAL good power, a 150shot is the max I run, and it gained 27hp and 40ftlb's to the wheel over the 100shot, and that is through my old automatic that was falling apart and holding back alot of power.

so your missing out on some good power between the 100-150shot, but nothing to crazy, you will almost never get the hole "50hp" extra unless the car is setup for nitrous.

100shot will put you in the low 12's im guessing if you can drive and the clutch and tire's hold.

302army187

and yes, your mod's are good for 100+ shot, just dont spray under 3000-3500rpm.


what plug's are you running?

i recommend 1 step colder then OEM, gapped to .40-.30 (i run .35 i think) and run highest octane you can get. 93 pump, and throw in a lil race fuel at the track, back off timing, ETC

Portmaster

The 517CP are about the cheapest piston you can get for a 5.0. They are made by Federal Mogel and are a good stock low compression replacement for a stock rebuild. I wouldn't hit it with more than a 75hp shot to be fairly safe.