New head cam kit on it's way need help

[g.t.o.boy]

I just pought a new head and cam kit for my 99 vette, but I will need some new injectors as the 26# units are under sized. I cannot run my car with injectors at 90-95 static. I have heard that the 38# units are hard to tune with, I was wanting to know if the 42# units are better? I would like to use gm delphi/msd units but I'm having a hard time finding the part # for these. I'm not sure about the bosch units as they use a pintle tip and the spray is said to be a little poor for good idle. Anyone with any good luck with any type/brand and have a part # to offer?

Thanks

[BlackNight]

I just pought a new head and cam kit for my 99 vette, but I will need some new injectors as the 26# units are under sized. I cannot run my car with injectors at 90-95 static. I have heard that the 38# units are hard to tune with, I was wanting to know if the 42# units are better? I would like to use gm delphi/msd units but I'm having a hard time finding the part # for these. I'm not sure about the bosch units as they use a pintle tip and the spray is said to be a little poor for good idle. Anyone with any good luck with any type/brand and have a part # to offer?

Thanks

What other mods are you running?If you are just going with the heads and cam your 26 pounders should be fine, and fairly easy to tune.You should not be close at all to maximizing the injectors if you are upgrading heads and cam only with the rest of the motor stock.I rebuilt a stock Ls1,dropped in a 600 lift cam,stage 2 ported heads,hooker headers,weiand aluminum intake,.05 over forged diamond pistons.Just modified the pcm thanks to Clints tuning Pushed out over 400 to the wheels, dont remember exactly what the horsepower was but I know it was over 400.That was all on the stock Camaro Ls1 injectors, aspirated motor of course. If you are running NOS or a supercharger thats a whole other situation.

[Mr. Luos]

Agreed.
I would be a touch more worried about the fuel pump. Unless the Vette got a better one.

[Ed Blown Vert]

If you do get injectors. Ford SVO 42# are easy to tune.

[Z06-Goose]

I agree you won't need bigger injectors. H/C package on a Vette usually yields over 400hp at the wheels, at least on the Z06 it does, so you should be in that neighborhood.

[g.t.o.boy]

Here is the problem with not upgrading to a larger injector
1 All injectors are rated at three bar or 43.5psi, the ls1 is a 4 bar or 58psi.
2 The stock injectors are 22# units or 26 four bar
3 You never want to excede 80% duty cycle on an injector
4 at BSFC .5 for a streeet engine at 80% duty cycle my injectors are rated for 343 hp at the flywheel
5 The 97-98 and the 20-06 units are 28.5# at 4bar and rated at 80% duty cycle are only good for 366 hp
6 You can run them both at 100% duty cycle full open at all time at wot but that is only good for 458, and 429 hp and if you run them at wot often the injectors will burn up. These are flywheel hp figures.
7 If I want to run a 402-427 cid next year and get around 600 hp them I need to size for that combo now.
8 With the combo that I'm running now I'm at or near the peak 100% duty cycle at 360 rwhp, or 410 flywheel, and after the heads cam looking at 410-430 rwhp, and 480 flywheel then the smallest injectors that should be used is a 36# 3 bar unitor 42# at 4 bar.

NOW lets re-ask the question does anyone know of a good injector (thanks for the advise on the ford 42# units) and have a part # on them so I can do a little research on them?

[Ed Blown Vert]

NewEra has them.

And the next logical step would be 60# Mototrons

[Blown 98 Z]

Google....Precision Turbo Fuel injectors

[BlackNight]

Here is the problem with not upgrading to a larger injector
1 All injectors are rated at three bar or 43.5psi, the ls1 is a 4 bar or 58psi.
2 The stock injectors are 22# units or 26 four bar
3 You never want to excede 80% duty cycle on an injector
4 at BSFC .5 for a streeet engine at 80% duty cycle my injectors are rated for 343 hp at the flywheel
5 The 97-98 and the 20-06 units are 28.5# at 4bar and rated at 80% duty cycle are only good for 366 hp
6 You can run them both at 100% duty cycle full open at all time at wot but that is only good for 458, and 429 hp and if you run them at wot often the injectors will burn up. These are flywheel hp figures.
7 If I want to run a 402-427 cid next year and get around 600 hp them I need to size for that combo now.
8 With the combo that I'm running now I'm at or near the peak 100% duty cycle at 360 rwhp, or 410 flywheel, and after the heads cam looking at 410-430 rwhp, and 480 flywheel then the smallest injectors that should be used is a 36# 3 bar unitor 42# at 4 bar.

NOW lets re-ask the question does anyone know of a good injector (thanks for the advise on the ford 42# units) and have a part # on them so I can do a little research on them?

So what combo are you running besides your heads and cam?
And what are your cam specs and flow numbers on the heads and chamber size?
Then I can recommend injectors.
With the build up I listed before with over 400 hp to the wheels naturally aspirated the duty cycle at WOT was at 90% with stock injectors here at this altitude.Regular street driving the duty cycle never exceeded 82% unless you stand on it for a stretch then she punched back up to 90% on stock injectors.
It all depends on your upgrades for the future as well.All I know is injectors are pretty pricy so if you dont need them for a naturally aspirated motor,then just wait until you step to a supercharger,stroker,or NOS.
At this altitude you can get away with smaller injectors and save some money and still generate excellent horsepower.


But ultimately its your choice, just trying to help you save a few bucks.

[HUGGER ORANGE SS]

G.T.O. Boy..

Good info.. Yes you can obtain 400 to 440RWHP with the stock injectors at 58psi of fuel rail pressure..

Correction..

1997 - 1998 LS1 Injectors Vette/F-body are 28 lb injectors at 58psi
1999 - 2000 LS1 Injectors are 26lb at 58psi when GM went with a different cam they changed the injectors.
2001 - 2002 LS1 F-body and Vette Back to 28lb Injectors at 58psi.

The car mentioned above by Trent was a 2000SS Camaro.. 347ci Stage 1 Heads, 233/237 .598 .598 112LSA Cam, 4.10 gears 10 to 1 compression, after some miles on the motor the car got 433RWHP at 6800 RPMS with my tune.. and the 26lb injectors.

Now are the injectors close to maxing out, YES.. Is he pushing his luck, no I don't think so.. How often will he be at 6800 rpms and 430RWHP?? Hardly ever, so we kept the stock injectors in there to save money and keep the car easier to tune and best Gas mileage possible.. But we made it clear that if he upgraded to NOS or a blower, he would need a pump and injectors.. Injector Failure is minimual..

SO.. I'll ask you a question.. What Cam / Heads?? If your looking to Upgrade to a Supercharger or NOS or turbo and want to buy the injectors now, up to 550RWHP I'd run the SVO 42 lb injectors.. If your going to run NA for a while and want that extra insurance, I would say go with 30lb SVO injectors MAX.. They will flow about 36lb at the GM fuel rail pressure of 58psi. These injectors will be goo up to 500RWHP and will provide you with the cushon you'll need..

Remember the bigger the injector the harder to tune it will become and the more gas consumption..

If you were a customer of mine and wanted that insurance I would say 30lb SVO's, then upgrade later as you gain HP...

Clint

[BlackNight]

The car mentioned above by Trent was a 2000SS Camaro.. 347ci Stage 1 Heads, 233/237 .598 .598 112LSA Cam, 4.10 gears 10 to 1 compression, after some miles on the motor the car got 433RWHP at 6800 RPMS with my tune.. and the 26lb injectors.


Clint ,
Have you spoke with Chad lately?

[HUGGER ORANGE SS]

Nope.... He took our Tune and the Motor we built and our 433RWHP we gave him, and the 4.10 gears you installed. He took all of this, paid minimal money and never looked back...

Too bad....

[g.t.o.boy]

G.T.O. Boy..

Good info.. Yes you can obtain 400 to 440RWHP with the stock injectors at 58psi of fuel rail pressure..

Correction..

1997 - 1998 LS1 Injectors Vette/F-body are 28 lb injectors at 58psi
1999 - 2000 LS1 Injectors are 26lb at 58psi when GM went with a different cam they changed the injectors.
2001 - 2002 LS1 F-body and Vette Back to 28lb Injectors at 58psi.

The car mentioned above by Trent was a 2000SS Camaro.. 347ci Stage 1 Heads, 233/237 .598 .598 112LSA Cam, 4.10 gears 10 to 1 compression, after some miles on the motor the car got 433RWHP at 6800 RPMS with my tune.. and the 26lb injectors.

Now are the injectors close to maxing out, YES.. Is he pushing his luck, no I don't think so.. How often will he be at 6800 rpms and 430RWHP?? Hardly ever, so we kept the stock injectors in there to save money and keep the car easier to tune and best Gas mileage possible.. But we made it clear that if he upgraded to NOS or a blower, he would need a pump and injectors.. Injector Failure is minimual..

SO.. I'll ask you a question.. What Cam / Heads?? If your looking to Upgrade to a Supercharger or NOS or turbo and want to buy the injectors now, up to 550RWHP I'd run the SVO 42 lb injectors.. If your going to run NA for a while and want that extra insurance, I would say go with 30lb SVO injectors MAX.. They will flow about 36lb at the GM fuel rail pressure of 58psi. These injectors will be goo up to 500RWHP and will provide you with the cushon you'll need..

Remember the bigger the injector the harder to tune it will become and the more gas consumption..

If you were a customer of mine and wanted that insurance I would say 30lb SVO's, then upgrade later as you gain HP...

Clint

The current combo is a 346 cid, stock bottom end, with Dynamaxx headers and cats, blackwing filter, descreened maf, high flow bellows, 2001 and newer intake, coolant bypass on TB.

Adding stage two heads with 64cc 2.055 and 1.57 valves, and 1.7 harland rollers, and a 232/230 and .580 at 110lsa.

Future mods will be a 402 or 427 stroker, and little side note is that I do a lot more roadcourse than I do 1/4 mile this car has never even been to a dragstrip.

[HUGGER ORANGE SS]

Okay... Your your current setup to your 346ci, run with the SVO 30lb injectors.. They are a great injector and will handle lots of power.. Your stock pump is fine. Fuel rails fine.. You will need some tuning to max the power.. Also realize GM on their ZL1 Camaro's with the 427ci high compression motors, they chose to run the 30lb SVO injectors.. Sounds like you'll keep this new setup for a while, so going bigger to say a 42 or 50 lb injector will net you less power, and harder to tune.

Clint

[HUGGER ORANGE SS]

On another note.. Good choice in Cam.. In this higher altitude having the intake durration slightly longer than the exhaust will provide you with more power!!

Clint

[BlackNight]

On another note.. Good choice in Cam.. In this higher altitude having the intake durration slightly longer than the exhaust will provide you with more power!!

Clint

Yes excellent cam choice for power,however you will sacrifice some vacuum with those durations, so watch those brakes on the road course.
I love the road course as well, autocross is good, dragstrip is good, but there is nothing like taking a long progressive turn at a 110 plus feeling the G,s pull you out of your seat........

[Capster78]

Id go with 42# injectors myself. Just dont like running high duty cycles.. dont want to risk cloging the injectors. That would be BAD!!! Id upgrade the fuel and oiling systems as well just as a precaution. Can never be to carefull. I don't know about you but id rather be safe than sorry.

[HUGGER ORANGE SS]

42 lb injectors for a Heads and Cam car... In also high altitude as well.. umm ok.. GTO do whatever you would like..