21 Lb. Fuel Injectors

Bob F · Mar 8, 2016

I know most people say convert to mass air and I will eventually but my budget is maxed out on the Vortech, Cobra intake with tmoss ported gt40, aeromotive 340 pump, drag radials, torque box plates and a few other things. Some speed density owners get away with 24 lb injectors and some don't. I am a little worried about 28 yr. old 19lb. Injectors with the Vortech. It seems to me 21lb. Size would be a perfect fit for now. What do you guys think?

stykthyn · Mar 8, 2016

What the what??
Too much for a stock engine and not enough for a modded one. I wouldn't even run 24s with a power adder. Save for 32s.

hsean · Mar 8, 2016

good luck i have 21 pounders on my car and plan on switching to 19 pounders soon because when at idle it runs great as soon as i start to drive it it bogs down badly.the motor is relatively stock as for as internals hopefully it fixes my problem.

Bob F · Mar 8, 2016

I talked to Vortec and this kit is 5-6 pounds of boost and is designed for a stock engine with 19lb injectors so I thought 21lb would give may a little safety margin. It does have a fmu that will increase fuel pressure with boost.

madspeed · Mar 8, 2016

fmu hahaha

bentley429isBAC · Mar 8, 2016

Convert to mass air and get the car tuned properly. 42 lb injectors.

mikestang63 · Mar 8, 2016

I hope you installed a one way check valve in the vacuum line before the MAP sensor, so the MAP sensor does not see any boost , I would also put a pinhole in the line to help bleed off boost. I've run A trims on SD mustangs but had a tune.

No sense in 21# injectors.. I would swap to Mass Air for better driveability and manners, then get a set of 42# injectors and the largest MAF you can fit- then get a tune and throw away the FMU.

Bob F · Mar 9, 2016

Ok I concede, it makes the most sense long term, for future mods which I will always do till the day I can't drive anymore, and for the safety of my engine. I am gonna go mass air with big injectors and a dyno tune. I'm having Mike Post do the work

A5literMan · Mar 9, 2016

Good choice IMO. Money well spent

Bob F · Mar 9, 2016

A5literMan said:
Good choice IMO. Money well spent

It puts me over budget but thats life. To help pay for it I'm gonna sell the nitrous kit, my new 16 inch e fan, and maybe the new Canton valve covers i got from you.

A5literMan · Mar 9, 2016

Bob F said:
It puts me over budget but thats life. To help pay for it I'm gonna sell the nitrous kit, my new 16 inch e fan, and maybe the new Canton valve covers i got from you.

You'll like the blower more than the nitrous anyway...so win win. You'll have to give me a ride when it's done!!

Noobz347 · Mar 9, 2016

mikestang63 said:
I hope you installed a one way check valve in the vacuum line before the MAP sensor, so the MAP sensor does not see any boost , I would also put a pinhole in the line to help bleed off boost. I've run A trims on SD mustangs but had a tune.

No sense in 21# injectors.. I would swap to Mass Air for better driveability and manners, then get a set of 42# injectors and the largest MAF you can fit- then get a tune and throw away the FMU.

The check valve is part of the kit I'm pretty sure.

Now about those injectors. There are not many out there that I would trust to still be able to spray fuel at 90 psi. The OEM injectors are one of the few. Do yourself a HUGE favor and send them out to be flow tested, balanced, and refurbished.

You can replace any weak injectors one at a time and get some assurance of the health of ALL of your injectors whether new or old.

You can tell by the reactions of some of my compadres here, that FMUs are not the prefered method of supplying fuel for well... anything that you care about. It is what it is and I'm going to try to change your mind. What I will do though, is make an attempt to have you send those injectors out to be cleaned and balanced.

I ran 19s and FMU for a couple of years with no issues. I also had an wideband in the car with a lean AFR warning. They eventually gave way to a larger motor, blower, and injectors.

Bob F · Mar 10, 2016

Thanks for the advice guys. I know I keep changing my mind but I really cant afford to do it right with MAF and injectors. I dont want to do it half assed with stock injectors and I am now scared of the FMU. So I have decided (no really) that I'm gonna do a budget but high quality build. GT-40 heads, roller rockers, big fuel pump, adj. fuel pressure reg, new 19 lb injectors, quality gaskets, hardware etc. This will leave me extra money to do an aluminum driveshaft, Stifflers spider brace, a SWAR or similar rear end support and a few other small things. Plus I already have a 130 amp alternator, Canton valve covers with Ford racing gaskets, Cobra intake (going to tmoss for his porting magic), e fan with shroud, Moroso overflow tank, Hurst line lock and Cobra grill insert. I can do all of it for less than the Vortech done right. I will be selling the nitrous kit with purge kit. Then next year's budget will be the Vortech done right.

mikestang63 · Mar 10, 2016

if it were ME, I'd just add the nitrous kit, larger fuel pump, E fan and other non engine related upgrades, and wait until you can afford to go to a good set of TFS or AFR heads, cam, etc that will work with the Vortech. Do it once.

You can keep everything on the motor stock except for colder plugs, back off the timng and get a Crane CD box if you want. That way, you get the added 100 hp when you want it and a stock driveability otherwise. Then you can sell the Nitrous kit when you swap to a Vortech.

A5literMan · Mar 10, 2016

I would to. Save money for better heads and/or blower. 40's are ok I guess if you just want that slight power increase and have no future plans of exceeding that limit. With your future plans...id just wait and bypass the GT40 option. By the time you have those heads on the car you're 1/2 way to the price of a good aluminum version. Used heads are usually around 750-1250(depending on brand,state of use,etc). 40's usually cost around 500$ by the time they are machined,proper springs,etc. Heck I know a certain member on here who is selling some nice heads package for around 1k(not sure on exact price) cough cough @hoopty5.0

21 Lb. Fuel Injectors

Bob F

Active Member

stykthyn

I want to measure mine. It doesn't look that tall.

hsean

Bob F

Active Member

madspeed

Colonel Mustard

bentley429isBAC

mikestang63

Bob F

Active Member

A5literMan

At least it is lumpy...

Bob F

Active Member

A5literMan

At least it is lumpy...

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

Bob F

Active Member

mikestang63

A5literMan

At least it is lumpy...

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21 Lb. Fuel Injectors

Active Member

I want to measure mine. It doesn't look that tall.

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At least it is lumpy...

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At least it is lumpy...

Stangnet Facilities Maint Tech... Er... Janitor

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At least it is lumpy...

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