I have a 2010 ctsv that I just purchased that has a 3-4 shift issue. In regular drive mode it will act like the throttle body is closing and feels like its getting a fuel cut out, etc. In sport its a definate noticable flair. It does this at 30-35% part throttle just on that shift. Driving around town otherwise, shifts are fast and crisp. Driving regular in sport mode shifts are very firm. Apparently this issue came up when the car was re tuned and the inidivudal never brought it back to the tuner to have it addressed. The 4-5 shift also hit the limiter, but I believe i just need to back that down... Not trying to do a bunch of WOT testing on the street in town...
Looking for the best possible way to attack this issue. Car has 46k miles on it and is modified (will post mod list below).
Mods: (car makes 780rwhp on e85)
2.5/9.1 combo with LPE soild isolator.
weapon x track attack hx
New Era Performance HX expansion tank
weapon X heat exchanger pump
ZL1 Lid
ported LSA heads (Fasterproms)
ported blower, snout to 102mm, and stg-1 runners (Jokerz)
BTR stg-1 camshaft
ARP head studs
GM LS9 MLS head gaskets
GM performance lifters
7.4" pushrods
LS2 timing chain damper and c5r timing chain
installed a brand new factory oil pump while cam was being swapped.
BTR Trunion upgrade
BTR dual valve springs with titanium retainers good for .660"
Fasterproms thermal reduction plates
NW 102mm TB
weapon X 5'' intake
FIC-1000 injectors
DSX aux fuel system
weapon X E85 flex fuel kit
Jinks fuel pump access hatch (upgraded the stock pump within the last year due to crack on the fitting leaving the assembly)
ARP header studs and 12pt nuts
Kooks 1-7/8" ceramic coated headers with catless x-pipe
MSD plug wires with NGK TR7Xi plugs
MBRP resonators back to factory mufflers
weapon x aux tranny cooler installed under spare tire well
Lokar transmission dipstick
Eibach sedan lowering springs (still have factory one available)