bcbosley

iTrader: (2)

I got finally got my car dynoed today at Backstreet Performance in Medina, Ohio. I made 482HP/462TQ off 6psi spring. AFR was steady at 11.2-11.3. My car has stock bottem end, T-70 turbo and SI5 cam(231/237 112). I can't get my scanner to work to show you the dyno graph, when I get it working I'll post it. The tuner was concerned about the cam and the exhaust duration. My concern was that my max timing was 22 degrees. Is that way to much timing, does it need more timing because of the cam. I just don't want to be too close to the edge blowing **** up.

bcbosley

iTrader: (2)

Also the first pull with the 5psi spring, my car only made 355hp. Between 1800-4500rpm it was seeing 4 degree KR, timing when down to 9 degrees. He couldn't figure out why and just tried adding a little timing and then tried adjusting fuel and KR stayed the same. Knock was not getting worse. We found the throttle body was not opening all the way. We adjusted the throttle cable and I think he adjusted fuel and made about about 400hp and no KR. He kept adding timing and got 440hp. I the put in a 6psi wastegate spring and made 482hp/462tq, with 22 degrees max timing. My dyno graph looks funny between 3000-4000rpm. Torque dips down and hp levels out a little, then starts picking back up. I think he said he brought in the timing and had to back out a little at about 3000rpm and the ramp it back up. Would that be why my graph looks like that?

viper9403

iTrader: (14)

Post graph

98Camarod

iTrader: (43)

I run 15*. IMO that is way too much. It depends on how the timing is implemented though and where its at. Can you get a screen shot of the timing table or post the tune?

Drewstein

I can't imagine that cam doing you any favors. The LSA seems awfully low for a boosted car. I bet you change that to a boost friendly stick and you pick up a ton of power.

Yes your timing is very aggressive at 22*. I would think 18* would be more suitable to your setup with safety in mind.

Schantin

iTrader: (6)

Timing is a little aggressive, but not too crazy. When I had my STS at 5PSI, we did the 1st dyno pull at 16*....got #'s around 400RWHP and a fat 10.7 to 1 AFR. Bumped the timing to 20*, power jumped to 450+RWHP and AFR leaned to a 11.1 to 0. I logged the car on the street for anoth 3 weeks after the dyno....no knock from those #'s. I then put 8K miles on the car driving all over the country. Logged it occasionally, nothing bad noted.

So, the AFR being set (you have a nice conservative value), if there's no knock....I'd assume you're probably OK with 22* timing at 6PSI boost level. If you're worried about it, ask the shop to dumb it down to 19 or 20* for piece of mind. Trading a little HP for an engine safety margin is never a bad thing.

BTW, I think a lot of people forget that the timing numbers in the low RPM/ high g/cyl cells are really critical ones for a boosted engine. Depending on the setup, you can see boost (high g/cyl values) as low as 2000RPM. This requires very low timing numbers (under 10*...even negative values in some cases) to prevent knock or detonation.

spaz1

iTrader: (9)

is that 22 deg logged or is it what is in the value on the timing table. There are a couple things that pull timing. The Iat table pulls timing see what that is set to. Mine pulls 5 -7 degrees.

ModularTurbo

iTrader: (14)

LSA 114 is the minimum that I like to see on my stuff. I think that it is a factor.

DarkFormula

iTrader: (80)

I run 14* of timing with my blower. Your cam is not turbo friendly, you'll want a bigger exhaust duration and a higher lsa.

I'd also recommend you take the car an hour south to Delaware and have the tune redone.