Tuning 85 TPI - Need spark tuning advice

**Fast355** · 01-23-2017

Just in case you are curious I had a 1985 Camaro TPI setup I tuned using the 1985 305 TPI Computer a few years ago for someone I knew. It was on a 290 HP GM 350 performance parts engine in a Monte Carlo SS. I just copied the spark table into a 1985 700r4 Corvette's calibration, along with my PE Fuel multiplier and Command closed loop at 14.2:1. WOT air/fuel ratio is programmed for 12.5:1. Total timing is 36* from 2,800-4,000 rpm, 37* at 4,400 rpm, 38* at 4,800 rpm. I would only try this timing map if your distributor is set at the stock 6* BTDC. I would put your stock MAF table values in place for now. You should lean out the air/fuel ratio using the PE Multiplier rather than the MAF tables and once you command the air/fuel ratio leaner, fine trim the WOT with the MAF Tables.

**BlueCorvette** · 01-25-2017

I don't see a stoichiometric scalar. Is that what I am looking for? Yes I heard that around 36 was good for TPI so your map makes sense. Thanks, I'll take a look at that bin. I think some of the names are different depending on the tool. Is PE multiplier a tunerpro RT name?

**BlueCorvette** · 01-26-2017

I see %Change To Fuel/Air Ratio At WOT Vs. RPM and %Change to Fuel/Air Ratio At WOT Vs. Coolant Temp. tables. I like your idea about not changing the MAF tables for WOT AFR. I think I will restore the last two MAF tables to stock, and try to tune these to get the AFR to 12-13.

**Fast355** · 01-26-2017

Originally Posted by BlueCorvette

I see %Change To Fuel/Air Ratio At WOT Vs. RPM and %Change to Fuel/Air Ratio At WOT Vs. Coolant Temp. tables. I like your idea about not changing the MAF tables for WOT AFR. I think I will restore the last two MAF tables to stock, and try to tune these to get the AFR to 12-13.

The stoichiometric value is a constant, not a table.