[2003_GT]

Forgot to add the tune to the list

[Zinc01]

Scratch on the injectors. You're using a wet kit, so you don't need bigger injectors. The fuel solenoid provides all the extra fuel necessary.

Your stock pump is more than capable of providing fuel for 100 shot. The problem with the returnless fuel system, is going momentarily lean upon activation. When the fuel solenoid opens, it drains the fuel rails and it takes a split second for the computer to realize this and ramp up the speed/voltage on the fuel pump. That's how a returnless fuel system works. It varys the voltage and speed of the pump, for more or less fuel as needed.

I tried a Focus pump and that never fixed the lean spike I was seeing when the kit activated. It is definitely better than the stock pump, but it will not fix the lean spike issue. I put in a 20 amp Kenne Bell boost-a-pump and it got rid of my lean spike issues.

[2003_GT]

So scratch the injectors and the pump and just go with the KB BAP?

[Zinc01]

You could honestly stick with the stock pump, no focus pump or BAP. For 100-125 shot, you're going to be fine.

Also, one last thing. I would suggest a 125 shot with your Zex kit. Zex and NOS both rate their kits at the flywheel, not rear wheel. A 125 shot with your kit will put out about 100rwhp. A 100hp Zex shot will only produce 75-80rwhp. It's just my opinion, but that's a waste of time.

With 100hp NX shot, which is rated at the rear wheels, I was able to run a best of 11.88. The other mods were bolt-ons, gears, minor weight reduction and slicks and skinnies (15" welds). In street trim I ran pretty consistently at 12.20's, on 17" stock rims with ET streets.

[2003_GT]

I thought the most you can run on these stock engines was 100 shot? not sure but thats what iv been reading

Also can i still use my predator with nitrous(and the dyno tune of course) or would it be better to switch to a chip like the sct instead of a hand held tuner?

[Zinc01]

The "safe" limit of the stock rods and pistons is around 400-450rwhp. I sprayed an NX 150 shot for awhile, before going forged. That should put a stock PI 2v around 400rwhp. As I said, NX kits are rated at the rear wheels, so NX's 150 shot, is more like a 175 shot.

Zex, NOS and others rate theirs at the flywheel. A 125 shot, should net you around 100rwhp. This is definitely in the safe range. That should put a stock/bolt-on car in the 350-370 range, depending on the number of other mods and tune.

Your dyno tune most likely has added more timing than stock, and probably tuned your A/F ratio to 12.5-13:1. This is to provide optimum numbers N/A. You cannot use that same tune with nitrous. With nitrous you want to subtract a degree or two of timing and the A/F ratio should be between 11.5-12:1. You can still use your handheld, just get a new tune for the nitrous.

[cravens02]

hay zinc01 I dont agree with you on the zex not providing the horsepower that they say because I have a zex kit with the 125 shot with LT,UDP,70mm bbk with a c@l intake bbk cai and when I had my car on the dyno at brenspeed that is were I got the kit at also, the run conditions were 77.83,29.75 in-hg,humidity was 28% I put down 378.07 hp to the ground and on just motor I put down 252.31 that was a increase of 125.76 hp but every car is different also
2003GT just call brenspeed they can give you everything you need. but if your gona spray get the windo switch,plugs,tune,heater,presser gage and the zex kit comes with the wot all ready if I would change some of the things bought the zex it is the zex windo switch you have to have a tach adapter and that sucks cuz you got to buy 1 of them, and the heater takes a wile to brake in but other than that have fun with it and NEVER spray under 3000rpm

[mell0]

if you have a few grand as a limit it certainly wouldnt hurt to get the svt focus pump. i got mine for $150 shipped on ebay. its cheap and safe insurance. very easy install and feel free to pm me with any questions you have.

also with the extra money i would look into workign the suspension a bit to help at the track (maybe some upper and lower control arms).

[Zinc01]

I didn't say that Zex, NOS, etc. don't make the horsepower they claim. I said that they rate their kits at the flywheel, rather than rear wheel. Therefore, a 125 shot will generally produce 100rwhp.

Nitrous jetting is very close, regardless of the brand. The only difference, being what number they put next to it on their jetting chart. IE. NX would list the same jets for 100 shot, as Zex or NOS would list as a 125 shot.

[Evil_GT]

If anyone needs an Aviator Fuel pump I have one, I also have a 90mm MAF.

Let me know And if you dont know, a Aviator pump flows just as much as a Focus pump.

[cravens02]

yeah any brand of zex,NOS ect makes power, I wasn't trying to say that you were wrong on the power you get from the spray and they do rate the increase at the flywheel I was just saying that I got the 125hp increase, Seth from brenspeed said that its uncommon to see the ect 125,100 shot actually be the amount it says its going to make when spraying

[MustDangRider]

Your wasting your money on all this stuff in "preperation". Tha A/F ratio gauge, fuel pump, thermostat. You may not have read the manual to the ZEX kit but it has built in safety features that control the flow of nitous. For example, the ZEX kit will cease spraying if it senses the A/F ratio is off, long before your gauge even processes the info. You will need colder plugs and if you plan to run it alot a custom tune but thats about it.

[Zinc01]

The Zex kit can't tell what the A/F ratio is doing. If they tell you that in the manual, they're full of it. The only way that would work, is if it tied into a wideband o2 sensor, which it doesn't.