Thread: pushing the limits on the 42.5# inj?

Right now im running a 3.1” pulley and commanding ~23-24* of timing with a set of 42.5# injectors. I did a rolling WOT run from ~13mph and my IPWs range ~18-18mS while the injector duty cycle(IDC)% starts out at 75-80% and right at the top of each shift it’l hit at 96-99% then jump back down to 75-80% and IPWs would be at ~19mS. I do have a PLX WB but with the use of alky its pegged at “RCH” and my narrowband’s also useless which would be ranging from 980-1000. also my MAF only hits 105xxx hrtz. Do I have a bit more room to increase fuel or am I pushing the 42.5# over the limit? also the most KR i see at the s hiftds is ~2* but i also get random blips of them ranging from 1-2* which brings the overall timing sometimes down to 20* FWIW.

bare in mind i dont think alot of guys on here running 3.2" pulleys down to a 3.0" are running any timing over 20*.

thanks in advance

18ms IPWs are not maxed yet. when you get to 20s, then start looking. i was hitting 22.xx on stock injectors with a 3.4 last winter, which is pretty much static at that point.

i dont think youre running out yet.

Originally Posted by Reptile

2.8 on mine, and the most I've seen with this setup was 16ms on 25* timing.

then im obviously doing something wrong in my tune to run it that way. do any of you guys also tune your VE table? reptile is there a chance i may take a look at your bin file, specifically the injector flow rate table, and the maff table if possible please

reptile, what size nozzle ar eu using to spray the meth? im currently using a M3 nozzle but plan on upgrading to a M7. also for the controller i have mine set to turn on at 5psi(even though the knob says 6psi its off by 1psi) and a max psi setting at ~12.5# fwiw

thanks reptile, i still have the 2 bins u gave me and im just glancing them over. the IFR are the same since the formulas what i used from dhp. now the MAFF table i noticed yours is way higher than what mine is at lol. im also using an AFC2.2 and i have it scaled +1% over 100% default. im gonna increase my MAF in the PE areas a bit and just adjust the afc back to 100% default and go from there. my PE/AFR's commanded at 11.55.

what do you mean by "FULLY" when the meth/alky initiates at 7#, as in the knob turned all the way to 15psi? are u using devils own progressive controller?

Originally Posted by Reptile

You know, I don't know why I didn't think of this sooner. I run an adjustable FPR on my car, and it has actually helped me keep my duty cycle down. Completely slipped my mind. Ever since I put that thing on earlier last year, I haven't had any fuel delivery shortage. I bet that has a LOT to do with my duty cycle being so low.

hmmm interesting....

thats the main reason i still have the afc, for quick changes on the fly so i can go back and make adjustments where i can. i also have a happy knob which helps in retarding and adding timing XD.
thanks reptile. i hope i get this squared away or at least where i want it to be T_T

I just noticed that a few of those who posted your info are either running an intercooler or have an adjustable fuel pressure regulator. Im using no I/C nor an AFPR. I just did a few runs and noticed with a 3.1” pulley with 24-26* of timing im hitting 20-21mS and my IDC is going from 75% to 88% from the bottom of the powerband to the top of the gear its in. im also getting blips of 1-2* of kr so its bumping the timing between 22-26* of timing.

i have no intercooler or adjustable fpr. i also dont have my bigger injectors on or my meth. i am also still running the 3.4 for the winter.

hmm, what i was getting at was if the IDC and IPWs look in line with each other? im hitting somewhat static at 20-21mS but my IDCs no higher than 86%(96% at top of 1st gear).

isnt the IDC a function of IPW? have you tried tuning without the alky to see if your fueling is spot on?

i tried a few instances. heres my findings:
if i dial in 11.2-11.5 KR-free with whatever pulley, either 3.2 or 3.1 and w/o alky i can only run 14* of timing and if i recall my IPWs would be like 14mS. if i try to add timing i'd get knock. however since i have an AFC i can adjust the fueling on the fly and if i increase the fueling up top i can run KR-free but my AFR would get richer.

i can try running my setup wit the afc adjustment and alky since i retuned/adjusted my MAF table via PT. im gonna be out on th road ina bit and will report my findings lol.

also isnt IDC the area where it shows how much flow the injectors are flowing and the IPWs show how much (wide) open the spraying is or is it backwards?

injector pulse width is how long it is spraying gas at a time. im not sure exactly what duty cycle is.