After Lloyd Elliot heads a dynotune and a an XE224/230/112 I'm hoping for around 375hp at the wheels give or take some. What kind of fuel system upgrades are in order for this type of power? I won't be spinning past 6200 if that's an issue....

Thanx, Brad

 

I Believe your stock injectors are good up to 400 horse power,your stock fuel pump is more then capable of handling antthing under 400 horsepower.

 

Diffenent years have different injectors. But I would think you are gonna need some #28s or an adjustable Fuel pressure regulator.
I think 97 had #28s stock. Or you can pick up SOme SVO #30s fairly cheap. on e-bay all the time go for 120- 150 a set That is what I run. But that may be a bit too much fuel for you. I think it is a bit much for me and mine is a 383 W lt-4 heads (mild port) and a CC306

 

So the stock injectors/fuel pump can handle like 450HP at the crank then if their is like a 15% loss in the drivetrain?

Brad

 

Here's a formula you can use to calculate (approximately) which injector size is right for your application.

 

All 94-97 LT1's are "24#". The PCM is programmed with the flow constant of 24.9# stock.

A 24# injector is only good for roughly 400flywheelHP at an 85% duty cycle (exact number varies depending on the exact BSFC you get with your tune). There are people running 450flywheel on stock injectors, but they must be running at 100% DC.... not a good idea.

You can increase the flow capability of the stock injectors, within reason, by raising the fuel pressure.... running 53psi (vs. 43.5psi stock with no vacuum) will increase the flow capacity by 10% .

My personal opinion would be to go up to 30# injectors when you go over 400flywheelHP. If you are getting a custom tune, and you program for the correct flow constant, there is no problem with going "large" on the injectors. At least not when looking at a 30# vs. 24#.

 

Thank you Mr. Fred for your expertise as well as everyone else. I will be purchasing some SVO 30lb'ers.

Brad

 

Did the corvette LT-1s havew the #28s then or was it just the LT4s??

 

Corvette and F-Body LT4's.

 

Ahh anf the F body LT-4s were made in 97, Thats why my buddy told me some 97s came with #28s. makes sense now. Glad I didn't post that as fact.

 

I am still running the 24lb injectors in my 95 TA with the 224/230 cam as well. I was told it would ok to stay with these. I do have a horrible bog at rpm under 3500...would this be because the injectors are too small? Should I change them out to #30's? Hummmmm....now I'm wondering!!!

See mods below....

 

My guess would be that your bog is due to your heads, Are they pretty hogged out? if so your car will have great top end power but bog at low RPMs because your air velocity is too low. Sounds like you need a 3500 stall.

 

No, the heads aren't hogged out...I don't recall the flow numbers off hand but the are lower than a lot of the other guys heads on the board...but nothing to laugh at either!

 

did you get bigger valves with those heads?
Do you happen to know at what degree your intake valve closes? it would be on your cam card.

 

I had a three way valve grind job done on the heads (stock) but I don't know know at what degree the intake valve closes. I don't have access to the card at the moment!!