650hp

[Chevy1925]

Assuming he goes to 100 overs, how low can he be tuned for a tow tune with that weak trans? Mine was 390hp on tune 1 with 40 over LBS tips on my LMM with 68mmstg2r (685 on tune 5).

ive gone down to i think 800 or 900uS in the Limo and that was around 450hp when i was fighting overheating issues while towing. i could stay foot to the floor at that level and keep temps cool. i cant remember what i dailied on but i think it was 1200.

The injector power per uS increase is like a bell curve. too low, aint gunna run right. as you increase it, power dramatically comes up and the truck runs proper. This is usually the 800-1500uS range, peak point being in the 1100-1200uS area. now after 1500uS, power still increase but each jump in uS is not giving the same amount of power jump as it did before and it gets worse as that uS increases.

 

[N2BRK]

I was at 1300 in that tune 1 and 2400 in tune 5. I was thinking that to do a low tune 1 with such a large injector would put it in an inefficient area... especially guys with even larger than 100-over. I feel like this has been discussed here before

 

[Bdsankey]

I was at 1300 in that tune 1 and 2400 in tune 5. I was thinking that to do a low tune 1 with such a large injector would put it in an inefficient area... especially guys with even larger than 100-over. I feel like this has been discussed here before

It was just answered in the post above yours

 

[Dozerboy]

I was at 1300 in that tune 1 and 2400 in tune 5. I was thinking that to do a low tune 1 with such a large injector would put it in an inefficient area... especially guys with even larger than 100-over. I feel like this has been discussed here before

I think like James I went down to 800/900us. No idea on the power level since that was just my starting point to build on since I had never tuned big injectors before. I daily/tow at 550hp-ish and 1500us. I haven't had a need to use the small tune.

 

[Chevy1925]

I was at 1300 in that tune 1 and 2400 in tune 5. I was thinking that to do a low tune 1 with such a large injector would put it in an inefficient area... especially guys with even larger than 100-over. I feel like this has been discussed here before

Mark put some good info up about too low of a uS years ago but i dont remember the cut off point. i know that 900 is a non issue though from my personal experience. its also gutless when you are use to 600hp

@MarkBroviak, do you mind sharing where that fine line is on lowest drivable uS?