Basic SD no MAF questions

[FastEddy]

Was over at a friends shop yesterday checking out a couple tunes they were having difficulties with. We were discussing gen 4 SD tuning as they had a GTO they couldn't get to fire up correctly after custom fabbing a cold air intake and deleting the MAF. I told them to install an LS3 MAF and tune with that because without a MAF the ECM doesn't know what TPS to target to achieve base running airflow.

Having said that, no MAF in SD tunes with 6L80/90 vehicles throw off shift parameters with the computer unable to calculate torque outputs.

I don't do a lot of SD tunes so I don't have the answer to the question, but is there a way to get rid of the MAF and not have idle and transmission complications? Or is the best method to keep the MAF and set dynamic airflow to max rpm?

[redhardsupra]

If your SD is good, project the SD-derived airflow figures onto the MAF table and you're done.

[DSteck]

I've never had a problem deleting a MAF.

MAF/VE has nothing to do with TPS or base running airflow.

[FastEddy]

I've never had a problem deleting a MAF.

MAF/VE has nothing to do with TPS or base running airflow.

You can't say that with complete certainty. You are making an assumption. Go tune a cammed gen 4 car w/ a maf and then with no maf. After that try telling me the MAF has nothing to do with base running airflow.

Also explain how the ECM/TCM calculates torque without a MAF to command the correct shift pressure on 6L80/90 vehicles? Or are the only cars you tune manuals?

BTW keep in mind that my original post said "complications". I never said it was impossible to make it halfway decent. Just saying the MAF clearly plays a key role in idle and shift pressures so I'm curious what others are doing to compensate for these issues that doesn't involve spending hours upon hours working on one tune.

[DSteck]

The MAF helps the trans for sure, but it isn't impossible to make it shift properly. I do lots of auto cars, but definitely run into scenarios where a MAF won't play ball.

The MAF and VE has nothing to do with idle TPS. The base airflow number is run through an equation using the ETC scalar to convert it to a throttle position. That can be said with complete certainty. Scale a tune and see for yourself. Idle airflow values have nothing to do with MAF/VE.

I tend to use a MAF whenever possible, but sometimes it just isn't feasible. I had a 2005 GTO with one of the garbage Vararams that would not spit out a clean MAF signal at all. We deleted the MAF and ran it in pure SD, and it has never idled smoother.