95 Z28 M6 - CC306 w/ported factory heads

**Blackbird96WS6** · 10-21-2013, 10:52 AM

^ That's what I thought, factory gauge shows redline about 5700 RPMs.

***SSlowBoat*** · 10-21-2013, 11:32 AM

5749 was factory set in my tune as rev limit but i haz autocraptic.

**Mr. Brett** · 10-21-2013, 05:25 PM

Sorry, meant to say the limiter. It was revved to 6500, don't want to spin a bearing. Bottom end is stock.

**bowtiedad_z28** · 10-26-2013, 07:52 PM

My wife's car is a bolt-on (LT's, 1.6 rockers, EWP, 36lb injectors) with a 306. Other than the rockers the heads are completely untouched put down 351/351 only taking it to 6000. A good tune is where a lot of it is at.

**sweet-94z28** · 10-28-2013, 10:24 AM

Seems like the LTX cars like to be a little richer than the newer stuff. I have seen 2-4 tenths of track time gain from 13.0 WOT to 12.2 in a couple of the heads/cam cars I've done. I would definitely go a fuzz richer and stuff some more timing in it if you can. Mail order tunes are usually 35-36* of timing, so you can sometimes get another 1-2* in and make more power. Just depends on the car. While a mail order tune gets the car running OK, they leave a LOT on the table.

I would also go to a NGK TR6 plug with your setup too. Especially if you run a 160* thermostat. Going to a colder heat range seems to be a good move with most heads/cam cars, even without nitrous.