Got my motor apart to replace the base with a accel base and it occurs to me this would be a good time to upgrade the injectors as well. Currently I drag race about once per month, and only drive the car on weekends. Its a 350 with Nittos, fastchip, 52mm tp, CAI, Borla exaust, very soon headers and catco cats. I eventually would like to finish up with superram plenum and runners, LPE219 cam and AFR 190 heads. AT this stage I see my injector options as follows

1. send them to Cruzin to be cleaned and flow matched
2. Get new 22 lb stock ones
3. Get new 24 lb ones

What do you think would be best, I can moneywise do any of these options, although it might be stupid to get 22lb ones now and 24 lb ones in a few months. Also at some point I know I will need a custom chip. I assume that would only be necessary when going to the 24 lb injectors.
Please help, my car is apart and I need to decide now.

 

With that new setup, I'd go with the 24# injectors at the minimum. 30# injectors would probably do you good, but may be too much. Also, if you upgrade the injectors, you'll need to increase the fuel pressure by buying an AFPR or making one out of your stock FPR. I can't recite it off the top of my head, but I know there's some sort of formula you can use to get a general idea of how much fuel flow you need for a particular setup. And you are correct in saying that you need a custom PROM if you go 24# and above. But for $250 in equipment and software, you can do that yourself, and have the stuff to be able to burn a chip for all those induction and exhaust mods.

EDIT: And check this post out regarding your stock injectors. You'd be better off replacing them anyway.
https://www.thirdgen.org/techbb2/sho...hreadid=160981

 

I would like to go with the 24# injectors so I don't have to upgrade later but I don't know when I can afford the chip burning equipment after buying all this other stuff. But in the meantime I don't want to be running rich and have my performance suffer at the track. I guess Im going with some new 21 lbs Accel injectors, then try to sell them used and swap for 24lb ones when I can get the chip burning stuff. At least in the meantime I can race and should see some improvement from the Accel base and new injectors.

 

Just get the 24#ers now. No sense in downgrading to 21#ers. Get an AFPR if you don't have one already. There isn't that much a difference to require a chip change immediately anyways.

 

Ive already got the AFPR and am installing it now. but what do you mean downgrade to 21#, Are those not the stock injectors? So I would be getting new injectors with the same rating as the stock right? Well shoot, now I am confused again. The question is will my performance suffer with 24# and the chip I have (which is Ed Wright Fastchip for a 350). If so I would go with new stock 21 # ones.

 

Stock is 22#. You won't lose performance at the current time. But if you get 24# injectors you will be running a little rich. The computer will think that it is dumping 22# and the injectors will be putting in 2# more. The chip just needs to be told what the injector constant is. Within time, running rich will make carbon build-up, rough idle, and hot spots are common with two much fuel.

One thing to remember is if you get SVO injectors, they are rated at a lower psi than stock/GM injectors. Let's take for example the chip says stock 22# injectors, you are running the same fuel pressure 43.5psi. If you were to just replace the injectors with 24# SVO, your injector constant would be 25.18#. That would be a little more fuel that stock.

Also the stock 22# are good enough for 400hp, I think. Someone will need to confirm. Anyway, you could have the stock ones flowed, but I recently heard that they are the worst on the block. Read This: https://www.thirdgen.org/techbb2/sho...hreadid=160981

 

I spoke with Rich he recommended accel #23 he said #24 would be to rich for my app, but 23s would be perfect for nitrous use.

He also said accel #21 would work great if you test and tuned your fuel pressure to work with your combo.

Larry what are your 60 foot times?

 

Just get some goddamn 30#'s and call it a day

Seriously tho, If you plan on going larger in the future, don't waste money On Smaller ones now.

Get your 22#'s cleaned and put them back in, or Just put them back in.

When you have the money to Buy the PROM burning Equipment, Buy some 30#'s and Be done with it.

 

last time out, averag 60' time for four runs = 1.98
average 1/8mile time for same 4 runs = 8.71.
Thanks for the info. I am going to put the stock ones back in for now. don't have the money for anything else now.