Hitting rev limiter?
07-02-2015, 10:02 PM
#1
Hitting rev limiter? Okay, so I have a 98 z28. 4l60e that supposedly has a shift kit. I'm currently having a problem at wot, more specifically 2-3 shift. As far as I know the car never had the issue before I swapped to 3.73s, but now it bangs the limiter at the top of second. I'm not sure how long it actually does it because as soon as it hits limiter I lift and let it shift.
My question is, is it because I didn't tune for the gears? I've read that the shift tables are based off of mph and rpm, which should be the same without correcting the mph for the 3.73s right?
Also, the car has since I bought it hit second gear pretty stiffly. I was told this is from the shift kit, and its been doing it for roughly 8-10k miles. Trans doesn't slip, or act up at all other than the 2-3 shift at wot as far as I know.
Any help would be greatly appreciated, thanks in advance!
My question is, is it because I didn't tune for the gears? I've read that the shift tables are based off of mph and rpm, which should be the same without correcting the mph for the 3.73s right?
Also, the car has since I bought it hit second gear pretty stiffly. I was told this is from the shift kit, and its been doing it for roughly 8-10k miles. Trans doesn't slip, or act up at all other than the 2-3 shift at wot as far as I know.
Any help would be greatly appreciated, thanks in advance!
07-02-2015, 10:27 PM
#2
Moderator
WOT shifts require reaching both the programmed Speed -and- RPM.
If you did not tune the PCM to correct the speedometer, then the change in rear ratio should make no difference. (I run 26" tires on the street and 28" on the track and don't need to change my tune; only my speedo is off.)
Before assuming a real trans problem, I would suggest tuning to correct for the rear ratio and then reducing the "WOT Shift Speed" table by 5%. This 5% reduction is often done when installing a high stall converter too.
If you did not tune the PCM to correct the speedometer, then the change in rear ratio should make no difference. (I run 26" tires on the street and 28" on the track and don't need to change my tune; only my speedo is off.)
Before assuming a real trans problem, I would suggest tuning to correct for the rear ratio and then reducing the "WOT Shift Speed" table by 5%. This 5% reduction is often done when installing a high stall converter too.
Last edited by mrvedit; 07-02-2015 at 10:40 PM.
07-02-2015, 10:39 PM
#3
WOT shifts require reaching both the programmed Speed -and- RPM.
If you did not tune the PCM to correct the speedometer, then the change in rear ratio should make no difference. (I run 26" tires on the street and 28" on the track and don't need to change my tune; only my speedo is off.)
Before assuming a real trans problem, I would suggest tuning to correct for the rear ratio and then reducing the "WOT Shift Speed" table by 5%. This 5% reduction is often done when installing a high stall converter too.
If you did not tune the PCM to correct the speedometer, then the change in rear ratio should make no difference. (I run 26" tires on the street and 28" on the track and don't need to change my tune; only my speedo is off.)
Before assuming a real trans problem, I would suggest tuning to correct for the rear ratio and then reducing the "WOT Shift Speed" table by 5%. This 5% reduction is often done when installing a high stall converter too.
1-2 shift hits the limiter sometimes, but its only one hit then a shift. Its always dome this though.
Thanks for the suggestions, and hopefully soon I'll be able to follow through with them!