Ok, I've found out that i have bad injectors and they are the old 17# injectors from the 85-88 305 tpi. Now i need new ones to accomodate my mods when i get my car dyno-tuned. I'm not sure if i should go for 19# injectors of bump it up to 21# injectors. Here's a list of what i have:

-91 305, stock bottom end
-Edelbrock TPI intake, mildly ported
-World Products torquer heads 58 cc
-LT4 Hot Cam w/ 1.6 rr's
-SLP siamesed runners
-Ported Plenum
-SLP 1 3/4" Headers, 3" catco cat, Borla exhaust
-3.73 Gears
-MSD 6al
-Holley afpr

Do you think 19# injectors would be good or should i get 21#.
I'm thinking if i get the 21# injectors, they would work better for my application. It will be tuned, so 21# should work. Any suggestions? I know the cam is a little big for a 305, but i'm experimenting a little, and it should be good for a blower later on (distant future)

 

With the mods you have I think the 21#s should be fine

 

19# injectors are stock for a 305 TPI and 22# are for a 350 TPI.

 

i realize that the 19# were for stock 305 and the 22# were for 350s, but when i talked to mr Myron of TPIS, i had him run the injector id #s and he came up with 17# injectors. I just need to know if the 21# injectors would be better for my application.

 

If your going to Be Getting it Tuned So you can accomodate the extra fuel - I would go for some 26's.

Lower Dutycycle Will be easier on the injectors - Plus plenty big engouh for Future Modification.

And Small enough not to have BPW problems at Idle.

 

Some of the 305s had 17lb injectors.

If you are going to upgrade to a 350 reasonably soon, go ahead with 22s or 24s from an LT1 and burn a prom & change the injector constant and tune from there.

If you're going to be running the 305 for a good # of miles, put some 19s in.

Matthew

 

if you're interested in buying a set of 19#'s, i recently went through an engine replacement, and bought a set that used but bluprinted & balanced by TPIS. unfortunately, one of the plastic shields on the tip got cracked in shipping, and it's only about $15 to fix, but i couldn't afford to wait for it to get done to put them in, so i reused my old ones.

the blueprint & balance was $225 alone, and i've got receipts for that. I'd sell the set for about $300 if you're interested. email me at:

m c g i n l e y 0 0 (at) h o t m a i l . c o m
(sorry, i put the spaces in because i hate getting spam from putting addresses on boards)
but put "TPI fuel injectors" in the subject so i know it's not junk mail.

 

A new set of 19's if you are sticking with the 305 and up the fuel pressure a bit. A new set will flow better and more consistenly, giving an advantage over the old ones, and they are already rated at 2 lbs higher than the stock ones. Plus you should see if the ECM will take 19's with no problems. If not, then you know it wont do 21's either. Myron Cottrel from TPIS also said that you can take a motor up to 400hp on 19 lb injectors.

 

FYI thi LS1 injectors are rated at 58psi vs 43.5 (I think) for the L98 ones

 

I'm looking for another set of injectors for my IROC. My original plan was to score a set of 22lb pre '89 injectors USED, and just send them out to have them cleaned and flowed. I can't afford the downtime on my car, so I'd need another set. I didn't realize how pricey the used ones can be...it seems for the price of the used injectors, plus getting the flowed / cleaned, it would almost benefit me to go ahead and upgrade, and compensate when I start burning chips shortly.


Engine is a L98, heads have been ported, plenum ported, headers, free flowing exhaust.

Mods will probably be limited to a ZZ4 cam, some intake porting and maybe some runners. I'm going to be starting my '870 to '165 conversion shortly.


Any advise here? I looked at the used LT1 injector route, but I see that some people had trouble because the injectors are shorter than the L98 injectors? Anybody want to field this one as well?


Thanks