Just got back from my dyno tuning session at Slowhawk Performance in Bridgewater, Massachusetts. Don Kinder has an excellent reputation amongst the Corvette community and turned out to be a badass CTS-V tuner.
Despite the miserable weather (87°F and 97% humidity), my 90 mile cruise back from his shop was one of my best drives, ever. One of Don's specialities, beyond coaxing power from LSx motors, is getting them to idle nicely. Believe it or not, my car idles more smoothly than it did before the cam installation. He also corrected several significant mistakes that Ted Jannetty (of Jannetty Racing in Waterbury, CT) made when tuning my engine.
Another thing that Don did differently was that he gave me an honest-to-goodness 30 minute real-world test drive, both with A/C on and off. Janetty just threw the car on the dyno and called it a day. On top of that, Don charged me $450, whereas Janetty charged me nearly $800.
Although it's almost futile to try to compare Janetty's non-SAE corrected Dynojet numbers with Slowhawk's SAE corrected Mustang numbers, here it is: 2011 @ Jannetty Racing (intake, OBX headers, clutch, exhaust) 370 RWHP / 361 RWTQ
(dyno sheet not available) 2012 @ Slowhawk Performance (+cam, +ported LS2 intake, +IAT relocate) 422 RWHP / 383 RWTQ
(the above video is available on Youtube in 1080p @ 60fps)
The IAT relocate that I did
worked pretty damn well. Average temperature rise over ambient in the Lingenfelter airbox in casual driving conditions was +6 degrees (e.g. if ambient was 87°F, IAT pulled from the ECU was 93°F). During extended stops, I saw +18°F. So heatsoak is still an issue, but not as bad as it was before.
Don gave me a couple of homework assignments to carry out in the next couple of weeks. First up, I'm installing a 160 degree thermostat. Second, he thinks the Volant intake tube that I've got is very restrictive. I'm to replace it with 4" pipe. Third, he believes that based on my driving style (more of an autocross application) that a Procharger D-1SC would be far more appropriate than a TVS2300, due to it's less abrupt power/torque characteristics. If that's the case, I guess I'll also have to spring for a FAST 102 and sell my newly-ported LS2 intake manifold. Curses!
Anyway, I'm very pleased. This fall, I'm going to be concentrating on getting my aesthetic mods installed (Forgestar F14s, Extreme Composites hood, refinished front bumper, projector fogs, dual halo headlamps, etc). Poor engine needs a rest, anyway.
If you have any questions, let me know! I'm still getting 13-15 MPG in aggressive mixed urban driving and 23-27 MPG on the highway. Idle is set to 850 RPM. To recap: this CTS-V has a stock 364 CID LS2 motor with unported 243 cathedral heads, blower cam, and a bunch of bolt-ons (see below):
1. Lingenfelter airbox / Volant intake tube / S&B filter
2. Relocated IAT sensor to filter (6-10 degree temperature rise over ambient)
3. Ported/polished LS2 throttle body by Affordable Speed in Woodstock, IL
4. Ported LS2 intake manifold by LS2 Port Works in Poulsbo, WA
5. Thunder Racing TRuTorq L3 cam 223/236 .612/.610 115 LSA
6. 7.425" Comp hardened pushrods, Comp 26926 470 in-lb valvesprings
7. Comp LS-series rocker trunnion upgrade kit
8. ATI Serpentine Series SuperDamper
9. GM LS7 clutch and aluminum 13 lb Fidanza flywheel
10. OBX 1-7/8" stainless steel headers (DEI wrapped)
11. Kooks 6760-FC high flow cats
12. Magnaflow 16637 2.5" catback exhaust with X-pipe
13. NGK Iridium TR55IX plugs, MSD 8.5mm wires
- 7 quarts of Redline 15W-40 diesel oil in the engine
- 3 quarts of Redline D4 ATF and 1 quart 70W80 GL-4 in the transmission
- 2 quarts of Redline 75W140 in the differential