Are 24 pound Injectors OK with Speed Density??

Kdubslugga

Active Member
Jun 7, 2003
1,515
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38
Akron, OH
Would upgrading to 24 pound injectors work with a speed density car, my stock 19s have 130k plus on them and i wanna change them, get a little more power. I dont wanna get 19s again because im going to eventually convert to mass air, and new heads and stuff, So i guess the only question is will it work?
 
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NO, not without some dyno time, a Tweecer, and a custom chip using the dyno/Tweecer numbers.

The stock 19# injectors are good to 300-320 Flywheel HP. Adding bigger injectors to your present setup would not make more power.

If the car can sit for a while, have your current injectors pressure cleaned & flow tested. See http://www.cleaninjectors.com/process.html
 
Yeah I was going to upgrade to larger injectors when my old ones went to hell. But I haven't converted over to MAF, nor have enough mods on,so I knew it wouldn't work. 24# will make the car backfire like hell I think.
But if you are going to mess around with the injectors (stock), make sure you look for little black cracks in the plastic up by the metal inlet. Took me a whole week to figure out why they were leaking lol.
 
BlackFox5.0 said:
You need to hit the dyno to change this in TwEECer....all you have to do is imput the high and low slopes for the injectors, easy enough....

You can do almost anythingI you have the $$$ and the time to do it... :spot:

No custom chip, and the first time the computer loses power and forgets its settings you are in for much trouble. Mass air conversion would be cheaper and more reliable for most engines.
 
i just dropped in 30lb injectors,gt40 upper and lower and 155lbh in tank pump in my 88 GT w/ speed density. it made a big difference.. about half a second.. but runs like hell at idle and low rpms. getting way too much fuel.
 
sn9550 said:
Well I run 24# injectors on my setup and I don't have any problems.

From the looks of your setup you probably needed 24's anyway. I was thinking of going with 24's and an adjustable regulator, but after reading this thread I think I'll just get some new 19's.
 
You could always install an adjustable FMB (Fuel Management Booster) and do your tuning that way. You'll need a wideband 02 sensor and reader to ensure your air/fuel ratio is correct across the RPM range. The FMB will allow your 19 lb injectors to act and run as much fuel as 24 lb injectors. If after tuning the injectors, you idle on the lean side you can relocate the ACT sensor to the air box to get more fuel at idle and part throttle.