Final tune opinions traction control and stoich

[Phill]

So I'm finishing up my fist tune on a cammed 08 c6 m6 corvette (thanks for the great help dsteck!) and I was wondering what the gneral consensus was on what to do with traction control and alchohol stoich for a final daily tune.

What I'm wondering about stoich is; should I change the values back to stock for the different alchohol values? ie, set 6% alch. back to 14.3:1 or whatever stock was, just incase i fill up somewhere with ethonal blends?

Now as to the traction control, are you guys putting it back to stock values for the torque allowed in each gear or just maxing it out? I know this is something I can play with but I thought I would ask what people like to do on here, and what works well.

Thanks again.
Phill

[DSteck]

I leave the stoich table alone unless I have an explicit reason to change it (like running E85). Your car doesn't have an alcohol sensor, so that table is worthless past the 0% cell. As far as traction control, I typically max out all the tables on the left side. That's torque management, and not really traction control.

[Phill]

Right on, I had just assumed the car could tell of there was alcohol in the fuel since it had the table. I'll just leave her at 14.67 then.

Thanks again! Looks like the cars running good, 12.5 afr at wot, and ~14.67 when cruising/light throttle. It feels good.

[TARANTULA]

I leave the stoich table alone unless I have an explicit reason to change it (like running E85). Your car doesn't have an alcohol sensor, so that table is worthless past the 0% cell. As far as traction control, I typically max out all the tables on the left side. That's torque management, and not really traction control.

So you dont think is necesary to correct for E10?

[DSteck]

So you dont think is necesary to correct for E10?

GM doesn't. So no.

[pontisteve]

My theory is that GM can't (so far) globally command for Ethanol since not every state has it. But at this point, they nearly all do. I put in a stoich for E10 of 14.13 before I start doing any tuning. You have to remember this when you're setting up your wideband, or looking at A/F ratios. Tune in lambda and this change in all the math just goes away. Lambda is always lambda. But A/F is lambda x stoich.

If the vehicle isn't for sure running the same gas all the time, you could split the difference and run a 14.35 like some new Fords do. Then the trims are only off a little bit one way or the other.

Also, GM knows that the O2 sensors can fix a 20% problem either direction, yet the E10 problem is only worth 3 or 4% error, so well within the range of the O2s. But who wants any error!

[DSteck]

If your wideband and your PCM use the same stoich number, it's fine. I use lambda usually so it really doesn't matter... But I still don't change stoich.

[pontisteve]

It really doesn't matter if you're only going to tune the car once, and stick with the same fuel. But if you tune it correctly, you can make future changes to fuel stoich to compensate for different new fuels. I'm hedging my bet that Uncle Sam will stick us with even more ethanol in the future. I figure if I'm tuning from scratch anyway, might as well start with the right stoich.