fuel injectors

[LETZRIDE]

Going through my logs today I was reminded that I am maxing out my 36# injectors...I seem to be sitting at roughly 90% injector duty at WOT when I had it on the dyno...how do I know which injectors I should upgrade to? 42.5 or 60#'s? The UIM/LIM are 100% stock still, so those will eventually be swapped/modded so I'm thinking the 42.5 *might* be ok for now? but what about with additional intake manifold work done?

[ssms5411]

Re: fuel injectors

I P/P my own and they came out great even the TB. Aren't you running bigger valves on your heads? I'm running the Manely valves which are bigger than stock and with 65lb injectors I'm not even close to maxing and their priced about the same so might as well do 65lbers.

[LETZRIDE]

Re: fuel injectors

I P/P my own and they came out great even the TB. Aren't you running bigger valves on your heads? I'm running the Manely valves which are bigger than stock and with 65lb injectors I'm not even close to maxing and their priced about the same so might as well do 65lbers.

yes, Im running the manleys as well, 1.9 and 1.57's

the ARH cam only had me at like 65-70% duty...I'm pretty steady at 90% in the upper rpm's now with the new cam it looks like...same kinda tune as the ARH just more fuel added obviously to compensate for the AFR leaning out.

[Meemperor]

Re: fuel injectors

What is the total HP goal? With a 36# injector you should be able to get approx 265whp out it at 80% duty cycle, assuming 25% drive train loss.

[LETZRIDE]

Re: fuel injectors

What is the total HP goal? With a 36# injector you should be able to get approx 265whp out it at 80% duty cycle, assuming 25% drive train loss.

I dunno what the hp goal will be, she was at 239 on the mustang dyno at 6000rpm.

I lied to you though when I was talking to you about this...I said she was at 12.4 afr across the board...when she hits 90% she's leaning out to 12.9afr...I didn't realize that until I looked at the scan again last night.

Seems to be at 5300rpm I am at 78-80%, by 5600rpm I am at 88%, and 90% by 6000rpm. At the start of the run at 4900rpm I am as low as 69% duty.

I guess from here I still want to stay N/A for now so its just a matter of how much hp I can gain from swapping to a custom Holden intake manifold...since no one really has hp numbers, I dont know how much I can increase my hp by, by doing a swap and p&ping it along with a custom top (whatever that ends up being)

[ssms5411]

Re: fuel injectors

I would go with the 65lbers(60 on ours) incase you do a dry shot of nitrous you'll have plenty to go 12's or even 11's with a 100 shot. The price for 42.5 lb injectors is pretty close to 65lbers so might as well get the bigger injectors.

[ssms5411]

Re: fuel injectors

Also the 36lb injectors are more like 33lbs on our fuel system.

[Meemperor]

Re: fuel injectors

I would go with the 65lbers(60 on ours) incase you do a dry shot of nitrous you'll have plenty to go 12's or even 11's with a 100 shot. The price for 42.5 lb injectors is pretty close to 65lbers so might as well get the bigger injectors.

Way too big, especially on a S/D tune. 42#'s would be more than enough for an N/A build, even with a hit. But really something still seems weird that you're running out of injector.

You're running a Walbro and hotwire kit right?

[LETZRIDE]

Re: fuel injectors

Yup, walboro and hotwire...only thing I haven't installed yet from that kit was the 8 gauge ground that came as a bonus for the battery....I gotta find time to do that... Ya I'm kind of suprised I'm running out of injector to to be honest...