2005 Impala SS 129,000 miles in June 2021. 86 Olds 442 with a '68 Olds 350
I just did the very typical 3" DP , front powerlog, FWI , 180 stat, 605 plugs, manually controlled engine fan and a 3.5" pulley . Tune is stock. Before I did this, years back I got a cheezy hypertech used just to raise the shift points and firmness by 25% and eliminate top speed cut out, use it was a DTC reader. That's all it's good for. I have an aerotech gauge and below 4800rpms (shifts at 5800) the KR stays at 0, it climbs up to around 4 between 4800-5800. Same with punching it at 75 mph. Tach flies up to 5000 and I get that stubborn 4-5 degrees. A couple regulars on this sight pointed out that Im no doubt leaning out with a stock tune. This isnt an ongoing project, it took 11 years to get to where I wanted to put the exhaust , pulley, aeroforce gauge on it, so Im not interested in getting into an HP tuner , getting famiiar with it all for a one time use. Once this is straightened out, that's it. I really dont want to go mail order tune because I dont want the shift points cranked up, firmed up to chirp the tires, torque management altered......just that (most likely) fuel mixture issue at WOT beyond 4500 rpms. You'd think in the motor city area there would be a place that tuned L67/L32s (dont care about the cost) but no luck with looking around on Google. If Milan dragway wasnt SHUT DOWN, Id go out there, find an L67 guy and pick his brain as where to go!.