Is anyone here happy with 38#'s

Captain Mark

New Member
Oct 28, 2002
I haev heard pro and con, but mostly con. Is anyone here successfully running 38# injectors. Any tuning problems with them? I may be using 38's with a stock turbo and alky.

Need opinions please.

Thanks in advance.:)
I ran 38# injectors with stock turbo down to 12.3 with no problems. Jay Carter made a high timing chip for me and had no fuel issues. My stock injectors with stock turbo became marginal at 12.6s so that is why I upgraded.

Had my 38# injectors cleanded and flowed and the reported flow was 36 to 36.5#, I can not remember the pressure at which they were flowed by Chuck Leaper.

If I was going to use standard available chips, 36# injectors would be easier setup.


With the stock turbo you are boost limited because once the mass air flow exceeds a set amount the compressor efficieny drops off. Because of this you will have to run higher timing than you would with a more efficient turbo (at high boost levels).

At boost level of more than 20 psig, I was running over 29* of timing with race fuel. I was using the Variable Timing chip so at boost below 10 psig my timing was almost 40*.:eek:

I am running the same motor with bigger injectors and a different turbo now.

Delphi 37.5's here (some call em 38's) caspers thumbwheel, stock turbo, no problems w/tip stumble, hesitation, idle, etc.
They should be fine. I was told years ago that MSD 50's were way to big for my stock turbo intercooler combination and thats the reason my car was running like crap at the time. Luckily before yanking them I talked to a chip vendor that told me it didn't make a difference as long as the chip was burned correctly. Try the chips you got with the injectors and if it doesn't run right call a reputable chip burner. Also verify that the injectors actually work before you spend a bunch of money on chips. Steve Monroe made a pretty cool little tool to verify that injectors are working and spraying good. Check his website.