problem with WOT shifting from 2nd to 3rd

[rcsfastgto]

Ok guys, the car is an 05 gto A4. It has a custom twin turbo setup with twin 57 trim turbo's external gates yada yada, has a Rossler stage 3 transmission with a percision 3 clutch lockup converter. I have the rev limiter set at 6200 rpms just to keep it safe, in first gear if I command 5000 rpm shifts, it shifts at 5000, if I command 6000 it shifts at 6000, in second gear I have the shift points set at 5000 rpm and it hits the rev limiter EVERYTIME its at wot, and will NOT shift until you let out of it and get back into it again. The car seemed to be alright with a set of 17 inch wheels and dr's but we switched to a 15 with a 28 inch tire, and now it won't shift, I lowered the shift mph by 5 then 10 mph and its way over the mph that it needs to shift, but it still won't, I'm wodering if the trans is on its way out because it did this once before and the trans went shortly after it started doing it but were hoping for the best. Also tried disabling the p0121 dtc for the TP sensor just trying different things, but it still didn't work , also have the line pressure set for max pressure at wot, I have a log of it doing it, and the bin thats in the car. Any help would be appreciated

[Russ K]

Post your stock tune. What brand & size rear tires are on the car? Do you have the Corvette servo installed?

Russ Kemp

[rcsfastgto]

Yes it has the corvette servo installed in the trans, there 275/60/15 mickey thompson drag radials, I attached a stock gto tune, The one in the previous thread is the tune that is currently in the car.. we tried lowering the shift points to 4000 and still no go, hits the limiter from 2nd to 3rd, also tried turning torque management back on.. thanks guys

[Russ K]

Make the changes as shown. A 28" tire is entered as 27.53". Same as for a stock tire dia of 25.7, it uses 25.27 in the stock tune. Also return the torque management table to stock as shown, your settings will prevent the trans upshift torque reduction from working, and your traction control won't work either. Zero the AC torque reduction table, this stops the timing from retarding when the AC is turned on & off.

Russ Kemp

[RamAir02TA77]

Had a similar problem with my 4l60e when I upped the shot alittle bit and then upraded to a 4l80e and it shifted the 2-3. The 3-4 clutch pack on the 4l60e sucks it seems even when built thats why the 2-3 shift hits on the rev limiter.

[rcsfastgto]

Make the changes as shown. A 28" tire is entered as 27.53". Same as for a stock tire dia of 25.7, it uses 25.27 in the stock tune. Also return the torque management table to stock as shown, your settings will prevent the trans upshift torque reduction from working, and your traction control won't work either. Zero the AC torque reduction table, this stops the timing from retarding when the AC is turned on & off.

Russ Kemp

hi we made the changes still bangs off the rev limiter in 2-3 change,the trans has a vacume modulator so is what makes it shift,there was a blow off valve that rossler sold me it was in the line vaccume went to the trans but under boost it blew this off ,ive even tryed to take that out and took a vaccume line and ran it too the air cleaner on the inlet side of one of the turbos thus it has a constant vaccume signal,im running out of things to try here drive the car normal it shifts fine,nail her to the floor and every time you get wot it bangs twice before it shifts!also this is a speed density tune no maf i have a IAT sensor and the car is drive by wire..

[TRENT]

It could be the 2-3 shift solenoid even if it is not coding out / the input sprag can cause a flair shift on the 2-3 and cause it to hit the rev limit. The shift soleniod can work good under lower pressure and not under high.

[rcsfastgto]

It could be the 2-3 shift solenoid even if it is not coding out / the input sprag can cause a flair shift on the 2-3 and cause it to hit the rev limit. The shift soleniod can work good under lower pressure and not under high.

I have some extras which one is it in the trans ill change it,i have the original ones out of trans where they replaced them,thanks RC

[TRENT]

When did you change the shift soleniods and did it have this problem before the change. If you have to replace one just replace both soleniods are cheap.

[TRENT]

You can call me at the shop from 8-6 843-549-2205 Trent

[rcsfastgto]

You can call me at the shop from 8-6 843-549-2205 Trent

there was no problem before the rossler build trans shifted fine,they did replace them with new ones,maybe this is the problem,frequency diffrence? bad noids?