So I’m doing a mild upgrade rebuild to my 97lt1 motor. With what I am doing, I calculate out to a 30lb injector. I found these at Summit ( I have a gift certificate &#129305, I believe these will work on this motor? Any feedback? Anyone have personal experience with TFS? Thanks

 

What are you doing? Stock injectors are good for about ~420hp (flywheel) before going 100%. Use stock if you can and get them cleaned and flowed. I'd trust stockers at this point than any newer aftermarket crap.

 

.010 forged pistons, cc503 cam, 52mm ported stockTB, LE1 head job, 1.6 RR, 125 NOS, tune

 

I'd suggest doing all that, then getting it dyoned on the stock injectors to see where the a/f ratio is before considering buying a larger injector. If yours are good then at the very most send them off to get flow tested and cleaned if need be.
If you want to go to 30#, hit up the SuperCoupe websites. The 3.8 supercharged engines run 30# stock injectors at the same flow rate. Plug and play. Probably get them for cheap, but would still send them off to be checked.

 

Red top Ford Motorsport or as stated 89-93 Super Coupe (94-95 were different) 30lb injectors.

 

Need to add it’s not “plug and play” per se. Still have to get PCM tuned for a different pressure or risk fuel washing down the cylinders.

 

What are people using to tune OBDII LT1s these days? Wondering what the injector offset and offset adder tables look like compared to OBDI in TunerPro RT, etc. I can run the numbers for conversion between 39.15 and 43.5psi on pretty much any Ford injector with their published calibration sheets. Also, I don't think stock injectors are going to cut it with a 125 shot without a bump in pressure, and DC will still be above 90%, I think.

 

I don’t know, everything I’ve been reading and compute, shows I should at least be a 30# injector, not stock.....

 

I highly doubt the 30's are gonna cut it. If you want a little more headroom, you can get a flowmatched set of 36# Bosch 3's for under $150, p/n 0280155811 or 0280155737. They're reconditioned takeoffs from L67 Buicks and you'll have to figure out a system to retain them (either add e-clips to the bottom, or cut grooves in the tops with a coping saw to use stock retainer clips).

 

A few things being variable like (deck height + compressed head gasket thickness and resulting quench), ring type and end gap (moly rings, I'd hope) will affect static and dynamic compression ratio and resistance to or tendency toward detonation and pre-ignition. If the block isn't decked with .010" over pistons you're maybe 10.6-ish:1 with a .040" gasket, which is a pretty loose quench, better off with the .026" gasket. LE1 heads- very slight increase in chamber volume from unshrouding the valves. Still a very efficient chamber and conducive to plenty of timing off the spray, and with some means of controlling the timing and adding fuel during the 125 shot, probably safe. Off the spray you're in the 420-430 flywheel range (no front accessories, electric water pump sort of engine dyno method). BSFC .45-.47 or so. All that said, for an 85% duty cycle NA about 328cc/min (31pph). On the spray, another 5% DC with longer pulsewidths to add fuel should be adequate on that 31pph injector without pushing the injector static. I'm NA with the same cam, heads equivalent to LE2 from a local porter and running Ford M-9593-BB302 30s which are 31.6-ish pph at 43.5psi. Those aren't made anymore but can sometimes be found refurb. Never go for an injector that has been drilled out, garbage. Accel (Holley owned product now) makes a few high-impedance EV1 injectors that are spec'd at 43.5psi. You can also use high-impedance EV6 with the wiring adapters. I personally like the Ford injectors for the spray pattern/ atomization, but to use them properly you have to do the math to get the voltage offset and low pulsewidth adders right. MAF tables for any additional fuel and airflow have to be adjusted accordingly and if you're runnign an auto trans the shift points need to be tuned, and that cam will want a 2200 stall minimum and probably 25-2600 would be better, and 3.73:1 rear gears. Some say just throw a 3600 stall at it but I think that's really too much for that cam. M6, 3.42s are fine, I'm still running them though I have a set of Motive (red box) 4.10s going in soon just to see how they feel.

A lot more than you were asking but there's a lot to be considered aside from selecting the right injector.

 

^^ what he said. 36-38 would be better for the 125 shot.

 

Ford Racing dark blue top 36lb injectors from a 94-95 Thunderbird Super Coupe
Ford Racing medium green top 42lb injectors from a Lightning
Its pretty easy actually.

 

c'mon, maaaaaaaaaaaaaaaaaaan. c'moooooooooooon.
30's will be just fine as long as it's a wet shot and the right jetting is used. I'm at 440rwhp and 36's would cover that just fine.

 

TFX injectors are rebranded Accel's. I have a set on the shelf in the garage. When I asked Trick Flow for flow data, the sheet they sent had Accel branding.