so last Sunday morning i headed down to KAZ MotorSports in Colorado Springs for some much needed dyno tuning for my Turbo Cutlass Supreme. i know the guy that owns KAZ MotorSports from tgpforums.com. he owns two Turbo Grand Prixs and one of them has a 5-speed swap like mine. i couldn't have asked for a better shop to tune my car
anyways, last year i dyno'd the car at DynoPros in Denver and i got 227whp & 325wtq pushing ~12psi with a MBC. not bad, but A/F was off-the-scale sub 10:1 as soon as it spooled up (yikes!) so there was definately room for improvement via tuning alone. this time around i wasn't really going for more power; i just wanted to get it tuned safely and work out some driveability problems i had. the car used to buck really bad in 1st & 2nd gear under very light decel/accel conditions and even while trying to maintain a steady cruise in 3rd gear at 30mph. it was driving me nuts. the speedo was also wayyyy off and it is now spot on
however, the #s i achieved this time aren't directly comparable since DynoPros uses a Dynojet whereas KAZ MotorSports uses a DynoDynamics machine. numerous members of the Rocky Mountain Club Grand Prix guys wanted to "test" the differences between the two dyno shops and they found that all of their cars dyno'd between 38-40% difference (uncorrected) between the two shops.....and that was with NO changes to their cars between dyno sessions and they dyno'd at both shops on the same day!
sooo....my Cutlass dyno'd 205whp after the KAZ MotorSports tune. that is with a 15% correction factor the DynoDynamics software called for for altitude etc. (the KAZ MotorSports shop is at ~6200ft varified with GPS). to compare my numbers to the DynoJet i ran on last year, i added another 24% to that (39% correction factor total). the result - 254whp & 360 ft/lbs at the wheels! this time around i was pushing ~14psi but was now using the stock wastegate solenoid (which may have hurt my #s - see below). the only changes to the car since i dyno'd last year:
- added Magnecor KV85 spark plug wires
- added fake dual outlet exhaust from my old Grand Prix Turbo STE, BUT i think this actually hurt my #s. the dual outlet exhaust i put on has two RUSTY stock mufflers that are probably clogged up pretty good (the car is wayyyy quieter after i put this on). when i dyno'd last year i was using the stock single outlet exhaust but with a straight through glasspack that i think probably flowed alot better.
- i deleted EGR completely but i don't think that mattered at all.
- i used the factory Turbo Grand Prix wastegate solenoid boost controller instead of my M&M Racing grainger valve style manual boost controller.
the car is now much faster AND sooo much nicer to drive without that bucking problem and a speedometer that is finally accurate. A/F is now around 12:1. gas mileage increased dramatically. the most noticeable difference in power is that the car will now HAUL @$$ up to 100mph in 4th gear and 5th gear power dramatically increased as well. previously, after i shifted to 4th & ecspecially 5th gear the car would turn into a total dog. the way it is now, downshifting to 4th gear at 75mph on the Interstate to pass someone the car just gets up and GOES! i did this with a Cobalt SS on the way back home and he tried to keep up. he was probably wondering WTF!? i had under the hood seeing an older grandpa looking Cutlass Supreme four door sedan fly by him so fast. i also played around with a modded (ie louder than stock) LS1 Z28 but suffice to say i'm definately not at that level....yet. i didn't actually race the Z28 but i did see him race the Cobalt SS (we were all kind of messing around on I-25 at the same time). the Z28 walked the Cobalt SS and let off pretty quick since it was obvious the Z28 was out of his league. after i realized they were racing (i was behind them on a 3 lane stretch of I-25) i floored it just to see what would happen. i was about 1.5 car lengths behind when i started and probably went WOT 1-2 second after they did. like i said, the Z28 had stopped racing the Cobalt SS pretty quickly (about 5 seconds after i floored it) but meanwhile the Cobalt SS noticed i was "trying" to keep up and he stayed on it! i ended up walking by him haha...even with his head start.
i'm happy
i took a few pics last week while getting the car prepared for the dyno session..
my new Turbos Unleashed manifold distribution block is only being used for the boost/vacuum gauge right now but as soon as i have time to remove the plenum and get rid of the stock lines the capped fittings you see will be the sources for MAP & FPR.
http://www.turbosedan.com/cutlass/engine/DSC03003.jpg
http://www.turbosedan.com/cutlass/engine/DSC03004.jpg
http://www.turbosedan.com/cutlass/engine/DSC03005.jpg
more pics & vids coming shortly....
------------------------------------------
Joshua Mitchell
'89 Lebaron GTS Turbo - T2/A555 - 1 of 268
'91 Cutlass Supreme sedan - 3.1 Intercooled Turbo/Getrag HM-282 5-speed - 254whp/360wtq
Reply With Quote
That'd be kool to see that motor in an older Cutlass.
12.57@104 :O) 
Originally Posted by LynX853
i think the problem was actually the rubber vacuum 'L' fitting line on the wastegate solenoid leaking. it appeared to be stretched out and just worn out from heat over the years. i was worried my wastegate actuator might have a torn diaphram or the wastegate solenoid itself was bad, but that doesn't appear to be the case. i might put the TGP wastegate solenoid back in later....but i just like the grainger valve so much 
the RFL is MUCH louder even at part throttle lower boost shifts (which i like), it's easily adjustable, and of course less lag (as if a little T25 on a 3.1L V6 would have lag anyway lol). that's kind of good and bad though. in 1st & 2nd gear it's bad becuase i have NO traction at all. in 3rd gear on up less lag is great since traction isn't an issue there. basically, the car sucks to race from a dig, but from a roll it's GREAT! at the track i'd probably get some pretty horrible 60ft times 
right now the gauge is spiking to 13-14psi then settling right on about 12.5psi to redline. so does that mean i'm really pushing an actual 10.5psi?? as it is right now, i have the grainger valve almost all the way tightened up. there is no threading showing at all.
