i just finished my 7730 $8D tpi swap, i have accel base, accel runners, full exhaust and a crane 2032 cam, FMS 30lb/hr injectors, i'm using the stock bin file AXXD, it runs really rich at low rps, blm's at 108, i have to take fuel out of that area in the ve table to bring the blm's up, my question is, why being a stock bin do i have to take fuel out seeing the car is modified which seems that it would need more fuel? is it due to the bigger injectors at idle rps...700-800 it seems fine with blm's 122 and up in all other areas of the VE table

 

VE= volumetric effiency.

Is the answer to your question.

It "may" want more fuel it prolly will "want" more fuel on the other end of the VE table :-)

U moved the map at which the car idles at.

Where it would be at 128 or maybe a tad lean before, u shoved it over enough to make it rich. Overlap, duration all the fun stuff figures into it.

From my time with the 30#'s they seem to be fairly linear, so its more than likely a case of u needing to rework the fuel and spark tables back to optimum moreso than anything else.

So go ahead and rework the idle VE and see how it goes.

later
Jeremy

 

thanks! lots to learn but this stuff is cool! , i just ordered an ostrich too!

 

Probably moving the 30-40kPa VE values at the old idle rpm to the new idle RPM load areas would be a start, then fine tune from there. The overlap will definitely look rich to the O2, though, as unburned charge throws lots of O2 into the exhaust. The only fix is to either change the rich/lean crossover points or simply run open loop at idle.