WS6Formula305

Finally had the car dynoed, which showed us that the WOT A/F ratio is around 14.6:1-- I'm sending the chip back tomorrow (with the graph) to get it reprogrammed so I'm not running so lean. Is there anything specific I should request of them in the burning of the new chip?

What WOT A/F should I request? I'm running 24lb SVO injectors with 1.6 rockers, LT4 hot cam, Vortec heads (64cc), SLP runners, Vortec TPI intake, stock plenum and a 52mm throttle body. It's been suggested to me from LS1 gearheads from the dyno pull to get it reprogrammed for somewhere in the ballpark of 12.75:1 to 13.0:1.

Another person on the board (gta383 I think) recommended to ask them about Acceleration Enrichment Tables. Can anybody give me any more info on that?

Thanks guys.

TheGreatJ

I agree with the 13.0 vicinity for WOT A/F. As for the AE tables, does the car try to bog or hesitate when you punch the throttle? If not I'd leave the AE pretty much alone. It basically serves the same function as the accelerator pump on a carb....it adds extra fuel when you nail the throttle to account for the suddenly increased amount of air available to the engine. The MAF (or MAP if you run SD) will have a slight lag in reading the extra air (or load,) and the AE accounts for this lag (as well as slightly richening the mix to help the engine rev faster.)

WS6Formula305

There isn't really any bog or hesitation at all... there's just 30 or 40hp missing, probably due part in temperature on the dyno day (99 degrees) and the tune.

I'm having idle problems, which has been suggested to me is a bad CTS which is going to get replaced early next week. The car pretty much won't idle without me giving it some extra gas until it warms up to operating temp (I've been told before it reaches operating temp and begins reading from the O2 sensor, the ECM reads from the CTS to calculate A/F?). My mechanic checked it with the scan tool, it has been running lean at idle... we installed an AFPR and cranked it up to 50psi to try and compensate, not thinking to check the sensor.

Is 50psi too much for my setup? And should I specify the fuel pressure when I talk to Fast Chip tomorrow? Car blew a nice big black cloud of smoke on the dyno pull... it's running rich at part throttle because of the AFPR probably. And then the ECM leans it out at WOT, hence my current problem.

89gta383

iTrader: (5)

Tell your mechanic to record some scanner data and send it in an excel file to Ed, that will help more than anything. Take a scan at idle so he can fix the idle blms. Mine was running lean at idle. Tell Ed to bump up the acc enrichment also, it looked like it went lean when you went wot. He never touched my acc enrichment tables. Tell him you want a 'safe' wot afr. I don't know why he makes the chips so lean.

The idle problem sounds mechanical? Check the tps voltage, pull out and clean the iac motor, and tighten intake bolts/check for vacuum leaks.

Steve89GTA

WS6, did you every sort out your tuning issues with that motor?

WS6Formula305

Seems to be running like a champ now-- I haven't had any time or money to get it dynoed again, though. Hopefully I'll be able to over the holiday break (I'm busy and poor because of school).

A/F and BLM were spot on via the Scantool when we swapped the ECM out.