will stock injector's be enough??
 

I just ordered some new parts and i'm wondering if my stock 98 injector's will be ok. Parts that are to be added are a LSX 78mm intake along with absolute speed's 5.3 stage 2.5 heads. this will go with my tsp 231/237 cam,3 inch oryp & ported Mac's with the ball flanges removed. rest of mods are in sig if needed. Thanks Shawn

do yourself a favor and at least upgrade to the 28.8lb injectors. i think our years came with the 26's. you can get the 28lbs for like $60 from TSP...

1998 cars came with 28.8 injectors. The 99-00 cars came with the 26's and then 2001 went back to the bigger ones again :)

the 28.8's should be enough

I think you should just go to the SVO 30s. There is a variety of opinion on this, but if you make it w/ the stock ones, you will be JUST making it... then you're running the injector practically wide open-- which heats it up. The bigger injector will run at a more reasonable pulsewidth-- plus think of the wasted tuning time/$ if you try and it doesn't work.

Dean

Ok, say i go with a bigger injector then at what point do i have to go to a larger fuel pump? Or will my stock pump have enough to power the SVO 30 lb?

ok can somebody set this straight, sshould i get larger injector's or not? :judge:

OK i'm ordering SVO 30LB injectors today will this be enough and will my stock pump supply enough pressure? TTT for my new mods that are coming :drive:

Thats what I'm going to use, 30lb injectors and stock fuel pump. Should be fine, IMO.

I just had my car done, of course mine was a 99, but the stock injectors were all done at 6200 rpm's on the dyno. I had a set of 30lb SVO's installed with the stock fuel pump & put down the numbers in the sig with a 228/228 cam. It runs good now!

What other mods are done to your car? also did you check the 30lbs injector's to see how close they were to maxing out? Thanks

My car has the following for HP mods; LS6 intake, P/P LS1 heads with stock valves that flow 300 @.550, 228/228 112lsa 571/571 cam, Kooks 1 3/4 stepped to 1 7/8 headers, y-pipe, no cats, free mods, LS1 edit, ported stock TB, ASP pulley, cutout & flow master cat back and that's about it.

As far as to how close the 30lb svo's were to maxing out you'd have to ask slowhawk from the eastern section. he built & tuned it.

I picked the car up today & doesn't it ever haul azz :D :gruffy:

Thanks for the info. I'll try to get in touch with slowhawk. BTW good luck and have fun :cool:

Fred99LS1,
Do you know how much hp and tq you picked up when you went with the bigger injectors? I am in the middle of putting a Moser 12 bolt with 4.10 gears, and SVO 30 lbs. injectors in. I know I will lose a little bit with the Moser but was wondering how much I might get back with the injectors.

At the point the stock injectors were maxed out I believe my tuner told me I was at 405 RWHP. With the 30 lb injectors I was able to put down 426 RWHP. That is tuned for daily driving & not some dyno queen number, Fred

destroyerSS,
I'm not trying to take over your thread here dude.

Fred99LS1,
You think that you picked up close to 21 hp when you went to the larger injectors? I hope that I have am increase like that. TEA did my tuning and they said that my stock injectors were maxed out as well. Thanks.

For a rough estimate of what's needed, try this.

If your Brake Specific Fuel Consumption (BSFC) is around .50 to .60 PPHp (where most engines run), then the most that 26 PPHr injectors can handle is ~26*8/.6 = 350 hp; ~26*8/.5 = 418 hp. The 30 PPHr jobs with .6 BSFC ~30*8/.6 = 400 hp. A typical .55 BSFC with 30 pounders would be ~30*8/.55 = 435 hp. Remember the injectors are spec'ed at about 48 psi pressure (IIRC - could be 43 psi) and the FPR usually delivers some more which would give you a little more flow. Also remember that most injectors want to be run at 80% duty cycle for best operation. So assume high BSFC at .6 and you want to feed 450 hp: .6*450 = 270 PPH total needed/8 injectors = 33.75/.8 (or 80%) = ~42 PPH. For an efficient engine with .5 BSFC: .5*450 = 225/8 = 28 PPH/.8 = ~35 PPH, so 30's on a 55 psi fuel pressure would do the job with about 80-85% duty cycle.

There's no doubt that this leads to a little larger injector than is absolutely needed, but gets you in the ballpark. HTH :)

WS6#4541 were :cool: I just want to make sure that the SVO 30lb inj is good for me as i hope to be putting down around 450+ hp :chug: