Danielsmustang

So im going for the gt40 set up. I got a quick question. Im putting gt40 heads, gt40 upper and lower with roller rockers. Could i keep my injectors and just bump up the fuel pressure since i have to get a bigger fuelnpump and i have to get a fuel pressure regulator? Or would 24 be the way to go? And this is is list of what i will need

Gt40 heads
Gt40 upper/lower
Roller rockers
Pushrods
Fuel pump
Fuel pressure regulator
New gaskets
65mm tb
Anything else?

BaltRavens

If you increase your injector size you should also buy a better fuel pump.

Danielsmustang

Im getting my gt40 upper and lower from a 97 explorer. The injectors on that car were 19lb. Couldnt i just keep mine? get a better fuel bump and bump up the pressure on my stock injectors

BaltRavens

It depends if you're going pass 300HP, that's key 19# injectors aren't made to sustain per say 350HP. My recommendation? Yes you will need to step up from the 19lbs injectors. And the mods you listed it seems you're passed the limit for 19# and their cycle is gonna be harsh with what you got coming. You will also need a tune and that will also increase your HP rating. You're looking at 300HP easy when you're finished with those mods.

Someone else can correct me if I am wrong, but eh I feel what I am saying is pretty spot on. My car has upgraded injectors the factory ones weren't enough.

Danielsmustang

Oh I didnt Expect that much. I appreciate the help. Another concern is, Someone is selling me ford motorsport roller rockers but 1.6 ratio for the exhaust and 1.7 for the intake. They are used. I heard about the 1.6,1.7 variation but im not sure how efficient it really is. And if i where to get those roller rockers, i was thinking about some comp cam valve springs (dual Springs) with ford racing lifters and some comp cam pushrods. STOCK CAM though. I dont wish to change my cam. Would you rather go with the used ford motorsport roller rockers? or some new harland sharp roller rockers at a 1.6 ratio?

mjr46

no you can't just bump fuel pressure, the eec iv has adaptive strategy and once you bump pressure o2's will pick up a rich condition and trim the pulse back, do it right or don't do it at all.

majohns

how is it that, that set up will bring 300HP and cobra's come with almost the same set up and only at 240HP? just wondering.

mjr46

the cobra was underated, even though the 93 said it only had 235 and the 94/95 had 240, they were closer in all reality to 255/260 fwhp, there was an article back in the day I had on it

majohns

ok so just a wild guess what would your estimate be on my current hp? 3.73 gears under drive pullies, shorty headers with off road h and flows?

jthorn9

With the mods you have listed no you do not need to change the fuel injectors to 24lb. Your 19s will be about maxed out but they will hold. If you swap to 24s it would be a good idea to get a Cobra ecu as it is perfectly calibrated for that setup.