We will be doing some testing on injectors shortly, but I just wanted to share this information for people to use when purchasing parts. Math always seems to work. Let me know how else I can help.

Below are common injector applications for this vehicle:

42lb SD Injectors that come with the GM Stage Kits
Number of Injectors: 4
Rated Flow of Injectors: 42
Pressure at Rated Flow: 43.5
Actual Fuel Pressure: 58
BSFC (Brake Specific Fuel Consumption): .6

Maximum HP that this system can support: 325BHP - aprx - 275whp
Actual Flow rate of injectors: 73

60lb SD Injectors
Number of Injectors: 4
Rated Flow of Injectors: 60
Pressure at Rated Flow: 43.5
Actual Fuel Pressure: 58
BSFC (Brake Specific Fuel Consumption): .6

Maximum HP that this system can support: aprx 460BHP - aprx - 395whp
Actual Flow rate of injectors: 73

 

Just got my 60lbers yesterday!

 

60lbers FTW

 

With our tuned vehicle making 240+whp, adding 3-4psi with a 2.85" pulley (smallest for pump gas IMO), the increase of 3-4psi should equal aprx 30whp and approach the limits of the 42lb injectors

We are currently working on our 60lb file, which will allow stock like drivability and reliability

No one else really makes a good, quality injector between 60-42......

 

60lber do have a hurtin on idle quality... I've been messing with them for a while and still can't get it perfect... but drivabilty has been outstanding....

 

have yet to see any testing on a 2.85(which i have), i know the 2.8's are pretty much maxed, just curious if i may have a bit more leg room, i had the weird idle surges when i was stock, and it really pissed me off, dont want that again.

 

So according to those calculations, 60lb's are not going to be enough for 750hp. I don't know of larger ones for our cars. Do you have suggestions?

 

rc engineering man.... I'm sure they got something we can fit in these cars... if not... custom fuel rail

 

You are going to need a complete fuel system for this

Pump, or twin pumps, lines, rails, injectors, ignition, etc

I need to look through the software and see what kinda Fuel Pressure we can play with. They make 90+lb/hr injectors

 

https://www.cobaltss.net/forums/2-0l-lsj-performance-tech-47/2-85-pulley-gm-stage-2-hub-35145/

according to this a 2.85 will be good for tune with the 42 pounds....thoughts?

 

We will find out.........i think it will be very close

 

paul, read this thread if you havnt already.
https://www.cobaltss.net/forums//showthread.php?t=35148

 

What up Mike, while the 2.85 will basically put the 42's close to their limit. I would rather have my 60's @ 40 % IDC than my 42's @ 80%. I say if ya got the 60's and ur getting tuned use them. Cant see how easy fuel delievery could be a bad thing. As well with 42's there isnt much room for any type of safe guard. IMO.

 

I dunno on the 2.7 with 42's I saw well over 100% on the gm stg II inj at 700 rpm... kinda scary....

 

this is true, i just wanna see the exact number on my car and take it from there, if the 60's are needed then its not an issue cuz i have them and the harness.
the one thing im worried about is the idle issues everyone is having with them....

 

I have been worried about those as well but i trust once paul sorts out the 60lob file that issue will be non-existant.

 

ya, as do i, he plans to make this car run better than stock, and as of now mine runs pretty damn good(2 GM flashes later) lol

 

There will be 0 idle issues with our tune and 60lb injectors.....working on a file as we speak

 

Noice!

 

BTW Mike, on the day of the c7 cruise, Sean and I went at it on the 401 from a roll at about 90 km/h in 3rd. He put less than half a car on me - he was running the 2.7 and I the 2.85. I don't think the extra boost is worth the potential damage to the injectors. I too would like to get 60lb'ers with a 2.6 pulley. Do you think Paul has a tune for that??

 

paul will tell you that around 17 psi is the max hed go on pump gas, there are otherways around tuning for a 2.6 pulley, ex. watermeth, but talk to him on satuday bro, he can explain everything you wanna know about ruuning SAFE high boost applications in our cars.

 

I will not tune any car beyond 15-16psi for pump gas....this is way to much boost/heat and you will cook a piston....some cars will last longer than others, and there may be that freak car that stays together....i pride myself on safe, reliable vehicles that make power

Now, if you wish to sign a waiver stating it was your choice I have no problem tuning it for you...or you can run race gas all the time, which we sell here at the shop...109 un leaded

If we do not haave a tune pre built, we offer custom dyno tuning for only $300 more

 

thats actually a pretty damn good deal... I do run 20+ psi on the street been doin it for a while with 0 problems... minus broken axles... but I also have a front mount h/e dual pass intercooler, and meth injection... so I guess thats why mine is fine... I also run about 25 deg timing too... (I know bit much for the street, but I get no KR and no weird problems as of yet)... but the motor is coming out soon for pistons and rods and a little head porting... should be interesting

 

this may not be true, but came from a pretty reliable source, the GM stage 3 kit includes a smaller pulley, i belive it to be a 2.9, hence with that youll get about 17 psi give or take, they also reflash your comp to accomadate new settings.
ive read so many horror stories on here with pullies smaller the 2.7.
the safest bet is the 2.8-2.9 pullies imo.

 

For the daily driver... non mech skilled person... I'd agree with you... I'm not a big fan of noobs just slapping on a 2.5 pulley getting a generic tune and calling it a day... for all those guys I always reccomend gm stg kits as the best alternative... also running high boost on a stock intercooler setup is not the best idea either as the heat generated will start causing some seriuos issues down the rd (I've seen this already in person)... I have the supporting mods for what I"m running so for now I don't have any problems... knock on wood..