30 Ounce

I have completed the install of my LS1/T56 and have a few questions. I purchased my engine and trans from a shop that buys wrecked F bodies and GTO's and dismantles them to sell the parts so the history of my engine is not known. What I do know is it has a FAST 92 throttle body and intake, Mahle forged pistons, Scat rods, ARP bolts, Summit 85mm MAF and a "midrange" cam. I put Hawks American Racing 1 7/8" headers to a 3" single exhaust. I had it dyno tuned and it runs awesome at full throttle but cruising speed seem to stumble and buck a little. I did extend my intake track to in front of the radiator to get colder air and put the MAF in a straight section of tube and that seems to help a little bit. It no longer stumble on throttle tip in but it still feels like a lean stumble at cruise. Is it possible to tune this with hptune (I don't have it yet but am considering purchasing) so it doesn't stumble? Also the trans doesn't like to downshift from 3-2. Doesn't grind it simply won't go. Sometimes it will but most of the time not.

Project GatTagO

iTrader: (7)

Tuning for WOT power is relatively easy. Tuning for good drivability takes time and knowledge. Yes, your issues can be tuned out.

The car sounds good and the number look about right.

Not being able to downshift could be clutch release (or the lack of) problem. If it is an aftermarket clutch it might need a shim...or it could need a good bleed.

Andrew