I have a question as to how much horsepower 24lb bosch injectors can support. The motor im having built is a 355 at 9:1 compression.I plan on running 10 to 12 lbs of boost on a p600b ati procharger.any help is appreciated thanks





Steve

 

I'm going to say 36# to start out with. I don't know if you would need to go to a 42# or not, depends on how much power its going to make. If you run a FMU is also going to be a factor in injector size as well, personaly I don't like them but thats up to you.

 

1LE ..i havent thought much about the fuel end of things..i just had the standard stuff the p600b came with im not positive what exactly it entails or how it works......so if i went to a 36lb injector do ya think id be ok? im assuming id get 500 hp at the motor...

 

You will find the 24# injectors insufficient.

I am running 30# SVO injectors with an FMU, see 65psi fuel pressure on the big end.

I also upgraded to a 255lph intank fuel pump.

I dynoed 437 at the wheels with 11psi of boost.

If you are not going to use the FMU, then I'd say 42# injectors.


Hope this helps

LWM

 

I'm not running a FMU with my car and trying to squeese by on 50# injectors, base fp at 48psi (1:1 reference) and a RaceTronix high pressure setup. Guess I'll find out Saturday morning if I got enough gas to support it.


Defenatly think about your fuel system, thats going to be the major saving grace of any high hp motor. Going lean is a bad thing and even worse when your forcing air into it.

 

the stock injectors with be fine witht hat set-up, sence it is a kit right? then it will be able to run with the 24lb injectors.
I am getting the D1SC blower which is more boost then that one and it says that it will run fine with 24lb but you can get bigger ones but dont have too.

 

I don't think the stock injectors will support 10 - 12psi of boost. I tried 10 psi of boost with 24# SVO injectors and was seeing over 90 psi of fuel pressure and lots of knock and detonation.

Went with a set of 30# SVO injectors and a larger intank fuel pump and the problem was resolved. I now only need to run 65 psi at 10 - 11 psi of boost. The MAF is in there trying to supply the fuel when under boost, if I went to 42# SVO injectors, I'm pretty sure I could eliminate the FMU and just touch up the PE curve for extra fuel.

Be careful on the fuel end of things, and I always recommend a wide band dyno tune session.


Hope this helps

LWM

 

LWM it helps alot ..and i appreciate it....is there a downside to going to too large an injector?.. i dont think i'll see 550 hp at the motor..with the engine im putting together.....will the car be more of a pig at the pump... if i go too large an injector or..does the injector just require less fuel pressure...to produce the given amt of flow needed? thanks for your time



Steve

 

with the kit it should come with a new fuel pumo and a booster that way you can use the 24lb, but the 42 will work nicely, it is better to have more fuel then to have less fuel, the reason why when you had the 24lb and had over 90psi could be because you didnt have the right fuel pump to send fuel fast enough, but thats just what i think, and from talkin to procharger all the time.

 

You will need to have your PCM reprogrammed in order to use the larger injectors, Ed Wright and some others do this by mail order.

You could also use LT1 editor or Tuner cat to reprogram. It amounts to a 5 minute operation, nothing to it. I use the LT1 editor myself, but you need to figure the costs of getting the program, a lap top and the necessary cables ... will it be worth it?? Dunno, kinda depends on how far you intend on going.

As long as you get the PCM reprogrammed to accept the larger injectors, there is no down side to using larger injectors.

LWM

 

Granted mine's a little different but see my post about my intial dyno numbers in the Forced Induction section If you want to know roughly whats going to start maxing stuff out.

And thats with 50s

 

Isn't a supercharger/turbo kit built specific to each vehicle with a lot of R&D and testing. So, why bother with fuel demand and start changing things.

The supercharger kits are built for the specific vehicle, stock vehicle, and will take care of all fuel requirements. It will conatin all parts necessary to make the supercharger "kit" run efficiently with the car's existing setup. This is why it is called a "kit". Besides, you can check with the vendor about the needed changes cause every supercharger kit maker has his own fuel delivery system. Unless you are making a do-it-yourself supercharger installation.

This is what I understand. Correct me if I am wrong.

 

HAHAHAHAHAHA

Thats funny. I thought ATI made kits for LT1 cars too, I think the only ATI pieces left on my car is the head unit, a couple brackets and the intercoolers, everything else was changed just to get it to work right.

I'm sure I'll get some big flame about it, but so far I have yet to see a ATI 'kit' out there. I hear the LS1 kits are really great but the ones for the LT1 cars are almost a DIY thing and you figure out what you need for your car.

 

Yup, yer correct, a "kit" should not require any upgrades, Vortech kits are usually pretty good, I can't speak to the other manufacturers.

However the original post specified 10 - 12 psi of boost and that is definitely outside the range of any "kits" out there.



LWM

 

U R right about the 10-12 psi boost. I missed that in the original post. Thanks for reminding.

I think the kit's manufacturer will tell you what it takes if you want to go higher boost. I believe they test it to higher boost pressures than the working boost pressure and will be able to tell what it needs at higher boost.