A while back when the lean problem first started, someone mentiond that injectors would not solve the problem for some reason. But now that GM has listed their Stage 2 as including injectors, has anyone else thought about picking up some injectors and trying them out again, without GM?

What size are the stock injectors? Used GM injectors go pretty cheap. I believe that my GT uses 24# injectors where as GTPs use 36#. And I know that both sell for pretty cheap on ClubGP.com

If someone would pick up a set a little larger than the stock ones, and use the AFC 2.2 (theres a thread on it) to tune it via wideband on a dyno, you would have a nicely setup car. I know thats a very reliable way to tune in larger injectors. Yes a whole new PCM would work also, but that AFC is very proven for dialing in new injectors.

I really feel that would totally eliminate the lean condition.

Some sort of fuel-booster may work just as well with the stock injectors if theres any room left in them. Also assuming you can keep the boost solenoid from releasing boost at high RPMs or whatever it seems to be doing.

But my point being that injectors arn't that big of a deal. And obviously GM thinks that will fix some of the problems.

 

Drewfu$ you're right. Some users (like me) already think of that. I've made some calculation yesterday to find out what injectors would be the best for my personnals mods, along with a Mini AFC 2.2 to tune it. I think it will be very interesting to try.

 

i dont no if there the same as a 2.2 eco motor or the flow rate ?

but if you upgraded them with some modds what type of gain would you get and how

would control the fuel and air mixtrure ?

piggy back ?

would it work?

 

- 2.2 injectors aren't the same one.
- The gains directly depends of the mods for sure.
- It would take a reflash of a air fuel controller to fine tune them.
- Yes it will work.

 

you dont gain anything from injectors! Stop playing NFSU! Injectors only allow you to add more fuel into your engine. The only feasible way you would gain horsepower is if you maxed them out and were running really lean.

 

Injectors are a supporting mod. Nothing more. Once you get to 90% duty cycle, its been time to upgrade for awhile.

Since increasing airflow to and from the engine is the end goal for modification, injectors merely follow suit. Tuning -is- required for proper operation.

 

Hey stuffy236 and Malaclypse guys: The injectors on Cobalts SS / SC have been voluntarily detuned by GM and the Maximum Injector Duty Cycle seems to be around 0,88 (or 0,9) when the car is totally stock ! Several users and myself have withnessed that stock injectors are totally maxed with a very few mods (for example a 10% smaller supercharger pully only). That's why GM come with stages with bigger injectors. The purpose of this thread is to customize our own stage; bigger injectors and a air/fuel controller (maybe a pump booster also).

 

I didn't know what the duty cycle of stock SS injectors was... since its that close to maxed anyways then yes.. I can understand going with bigger injectors on a stock motor.

 

me too, i was just pointing out that you wont gain any HP from injectors

 

So I finally took an injector out today. Stockers are Siemens Deka (GM part #12790827). The connector is a Delphi Multec 2 type connector (like the third picture on the following web site).

http://www.injector.com/electricalcomponents.php

 

Nice. Glad to see some progress is being made. I think you may regret selling that intake once you get it dialed in, and the gains from an intake can really shine.

 

Firts I want to fine tune the car with the stock intake, then maybe try again a K&N filter in the stock airbox to see if I can tune it with better gain with the Mini AFC. And nothing prevents me later (after the winter) to buy again a better intake, but I don't recommend those with without any mods.

 

hey Jcm just sounds like a ECU reflash like which come with teh GM system of perhaps the Psi Fi kit would be what you need.

 

The reflash will be probably good and the PSI-FI kit is also a little bit lean for the few high RPM's ...

 

I want to see what the Stage 1 reflash and injectors will do with a 2.8" pulley!?

 

It will give very good numbers !

 

Ok, bigger injectors work, but don't you have to program the ECU to flow more fuel? Isn't that the problem people are having cuz GM did an awesome job (from business perspective) in locking the program until they come out with upgrades?

 

the stock green top injectors are 35 or 36 lb injectors

 

wait wait wait. Are you sure on the flow of the injectors? #36 with a Delphi Multec 2 type connector? If so, that could mean some good things for 01+ grand prix GTs. I really need hard facts on the flow rates.

Just an FYI, 01+ GTs also have a Delphi Multec 2 type connector for our stock injectors. However, if we want to upgrade our injectors to stock GTP ones (36#) we have to solder in the older connectors. If you are indeed #36s, then that would mean we wouldnt have to do any wiring. They could be a direct bolt on for us.