Shift points after headers
Thread Starter
TECH Fanatic
Joined: Jun 2007
Posts: 1,062
Likes: 2
From: Westminster, MD
Shift points after headers Hey guys, I recently installed ARH 1-7/8" LT's and 3" ORY and swapped in some new TR55 plugs and poly motor mounts and did an oil change. During the install we removed the battery. The car has not been tuned yet. I've noticed that the car seems to shift a little earlier than it used to, maybe 200-500rpm sooner in some cases. Is this normal as the car is running on stock calibration for transmission shift points and the battery removal for the headers going in, and a tune is all I need to fix it?
"....drive it a bit and see if it works itself out.."
PCM may take a bit to relearn ( after disconnecting power) the OE tune according to your driving, just get a tune when possible
Johnny
PCM may take a bit to relearn
The PCM learns fuel trims and how to adjust fueling part throttle, but most other parameters are hard set in the tune and don't just change out of the blue...and certainly not after certain driving scenarios.
Never have I seen my WOT shiftpoints change from the set 6500 just because I have been driving like a grandma for a few days unless the transmission is hot in which point it moves over to a different table with lower shiftpoints. Never have I seen my timing table change either unless I am running bad gas and the tune reverts down to a low octane table.
My guess is that your tranny fluid temps were rather high and the tune was using a different table for 'hot' conditions which has lower shift points to preserve itself.
