ls2 learning to tune.

Im about to get my long tubes put on and start tuning.
First question. Do I copy the high octane spark table to the low octane spark table before I do anything?

Second question. Does anyone run on the e10 afr, believe it's 14.08 at perfect stoich.

Third question. What's better to tune, maf or sd. Or can I dial in the ve table and re enble the maf and dial it in as well?

Fourth and final question. Do I zero out the iat spark Advance table to the temp I want after the tune is done?
Thanks in advance.

High Octane only needs to be copied to Lo octane when tuning in Speed density and then only if pre-E38. You will copy High Octane into Lo when complete and reduce by say 15% for knock retard.

E10 is about all you can get these days. Unless you have otherwise than set AFR to 14.2 as a compromise when the E10 is really E8 or less.

As a bolt-on only setup, the blended MAF/VE factory mode is your choice. Tune MAF-only first, then VE up to say 4000 rpm and put back in blended mode when complete. The VE will then be used to "validate" the MAF readings and compensate for transients in fueling needs. Make sure you read up on the procedures for MAF and Speed Density Tuning procedures.

I wouldn't zero the IAT (or ECT) Advance tables, merely give them a bit more room. IAT say 110F start pulling timing and ECT say 220'sh.

Ed M

So, I shouldn't copy the high octane to the low?

The car is on a stock map now, so perfect stoich is 14.6 I believe. I will be changing that.

I tuned my cobalt maf only and had the ve turned off.
So I can do the same thing in the gto ?

That's what I meant, I was gonna have it start pull timing at 122.
Thanks for the reply.

Or are you saying copy the tables after im done but reduce the table by 15 percent.

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I will be changing that.

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You can change all you want, it's not going to do anything. The stoich is hard-coded in the computer and you can't just change it to your liking.

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Originally Posted by slobalt342

So, I shouldn't copy the high octane to the low?

The car is on a stock map now, so perfect stoich is 14.6 I believe. I will be changing that.

I tuned my cobalt maf only and had the ve turned off.
So I can do the same thing in the gto ?

That's what I meant, I was gonna have it start pull timing at 122.
Thanks for the reply.

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Assume you are running an E40 PCM so you wont be using the low octane table to tune s in the LS1 days, only for the knock retard scalar. So use High Octane table as you would and make the Low Octane 15% of the High.

Yes, by setting the High RPM enable/disable to 400/390 rpm, you force the PCM into fueling from the MAF only. From the factory it is set to 4000/3900, giving you a blended MAF/VE strategy until 4000 at which it uses MAF only. That is why you lower the High RPM enable/disable to 400/390 to force MAF only.

Your 122 strategy is fine.

Changing the stoich will tell the PCM what fuel blending is being used and make adjustments accordingly. I am not sure EFI why you refer to the Stoich being hardcoded in the PCM. There is actually a scaling approach which doubles the AFR and half's the IFR. Even today the flex fuel setups create a blending value based on % of ethanol. I do agree that Lambda is lambda and it will always be 1 at any fuel blends Stoichiometric value.

Thanks

Ed M