MAF Swap Re-Tune?

**bhunter0830** · 02-28-2013, 05:48 PM

I am finding conflicting answers to this question. Some say yes, some say no, and site says plug and play... If I replace my stock MAF with the SLP MAF do I need a retune? I had the PCM tuned last year when I removed the EGR and AIR, deleted the rear O2's, added LTH's and SLP CAI.

**0rion** · 02-28-2013, 05:51 PM

have you already bought the MAF? If not don't waste the money on it.....the stock MAF flows fine. If you've already bought it I would strongly suggest getting a tune for it.

**bhunter0830** · 02-28-2013, 05:55 PM

Bought it last year as part of an SLP package but never installed it and came across it this week when started digging into projects for the spring. Figured if I needed a retune now's the time to do it before its nice enough to get it out. Any downfall to not retuning?

**GTP231** · 03-03-2013, 03:54 AM

The car will be lean without it. Sometimes they'll be out enough to ping sometimes not. Just the results I've come across in the past. Like 0rion said I wouldn't bother with it for now but if you want to do go for it and I'd consider a retune. I'd switch it out when you do more upgeades and need a tune myself

**pajeff02** · 03-03-2013, 04:50 AM

+2 on everything already posted. Is there anything wrong with your stock MAF -- has it been ported, de-screened or de-bladed?

**35th-ANV-SS** · 03-03-2013, 07:22 AM

I had one for several years installed on my stock 2002 SS. Didn't have any issues. The majority ruling though is to leave the stock MAF in place as long as there is nothing wrong with it, like Jeff points out. The stock MAF is very capable of handling 500+ HP.

**bhunter0830** · 03-03-2013, 08:19 AM

Nothing wrong with the stocker. Was cleaning up the garage and came across the MAF that came with the SLP Flowpack I had ordered last year before I had the PCM Tuned. From what it sounds like it's more of a hassle not to get any gains other than a headache. So, I have deleted the EGR and AIR, added LTH's ORY, SLP LM2, Lid, Smooth Bellows, WB02, Founders LCA's, Relation Brackets & PHB, BMR Lowering Springs (on order) and a tune by Frost. I have SFC's that will get welded on when the snow melts and I can get to a weld shop. Outside of starting to pull components of the engine apart and messing with a rear end that doesn't seem to have any problems, does anyone have any suggestions on what to do next?

**pajeff02** · 03-03-2013, 01:04 PM

ProCharger would be a good next step.

**bhunter0830** · 03-03-2013, 01:09 PM

I agree, got an extra laying around?

**35th-ANV-SS** · 03-04-2013, 01:37 AM

Originally Posted by pajeff02

ProCharger would be a good next step.

I like how this guy thinks

**Firebirdjones** · 03-04-2013, 06:10 AM

I've read a couple times now that you mention you've already had your car tuned by Frost. He has already leaned the car out to a safe AFR to make a little more power, and I'm sure he sent you a revamped MAF table as a result.

My concern is since installing the aftermartket MAF leans the car even more it would likely put you in a danger zone as far as AFR's are concerned, so a retune with the aftermarket MAF would be a definate MUST DO.

Guys that are getting away with aftermarket MAF's are cars that haven't been tuned at all and run pig rich from the factory where the computer commands an 11.7 AFR while in PE mode.

Personally I'd just leave it alone, and when the time comes for bigger power, go SD and get rid of the MAF all together.

**98TransAmWs-6** · 03-04-2013, 07:53 AM

Originally Posted by Firebirdjones

I've read a couple times now that you mention you've already had your car tuned by Frost. He has already leaned the car out to a safe AFR to make a little more power, and I'm sure he sent you a revamped MAF table as a result.

My concern is since installing the aftermartket MAF leans the car even more it would likely put you in a danger zone as far as AFR's are concerned, so a retune with the aftermarket MAF would be a definate MUST DO.

Guys that are getting away with aftermarket MAF's are cars that haven't been tuned at all and run pig rich from the factory where the computer commands an 11.7 AFR while in PE mode.

Personally I'd just leave it alone, and when the time comes for bigger power, go SD and get rid of the MAF all together.

This. That is exactly what I did. Funny thing is it is cheaper than a bigger MAF, plus there is no electronics to go bad and all you need is a tube to connect your lid to your TB. Besides performance it looks a lot cleaner. I received a SD tune along the side with a tune for my other mods from Frost with his mail order tune for $150. A new MAF costs around $300ish. Personally I would sell that MAF to give you some more money to either get a SD tune with or do other mods with.

**Firebirdjones** · 03-04-2013, 08:00 AM

Originally Posted by 98TransAmWs-6

This. That is exactly what I did. Funny thing is it is cheaper than a bigger MAF, plus there is no electronics to go bad and all you need is a tube to connect your lid to your TB. Besides performance it looks a lot cleaner. I received a SD tune along the side with a tune for my other mods from Frost with his mail order tune for $150. A new MAF costs around $300ish. Personally I would sell that MAF to give you some more money to either get a SD tune with or do other mods with.

Yep, just makes more sense to me. Not to mention I really like the added throttle response you get running an SD tune. You also generally pick up a few HP because you are eliminating what can be a slight restriction in the air track. That's what most tuners report anyway.
My LS stuff doesn't make big power, but the fact that I removed another (sometimes) troublesome electronic device is what really appealed to me

Probably not for everyone I guess though.

**bhunter0830** · 03-04-2013, 12:13 PM

So the consensus is to sell the MAF and thank you all for the input. Gaining experience as I learn. It's always better to learn from others mistakes as I have found out in the past. So it's greatly appreciated. My AFR is about 13 with the throttle wide open and runs about 14.5-15.0 at idle. If I remember correctly that should be right, please correct me if I am wrong.

What is an SD tune?

**35th-ANV-SS** · 03-04-2013, 12:26 PM

FBJ - Correct me if I am wrong, but while removing the MAF for a Speed Density set-up is a good way to go, doesn't that also make the PCM rely a lot more on the O2 sensors for your A/F and any adjustments? What I mean is, if either one of your O2's get lazy, what is there to try to correct the A/F reading without the MAF? Nothing is my understanding. Which means you need to pay a lot more close attention to your upstream O2's. At least with a MAF, it's kind of having a fail-safe. No?

**bhunter0830** · 03-04-2013, 12:27 PM

So I take it SD is Speed Density.

**35th-ANV-SS** · 03-04-2013, 12:29 PM

Correct

**bhunter0830** · 03-04-2013, 12:46 PM

So I am clear. Do a SD Tune and rely on my AFR gauge for my for my upstream O2's since my downstream O2's are deleted and I have no MAF to rely on as a failsafe? Or just leave it alone, sell the MAF and have some extra cash to throw at something else like a pro charger. If I do add a pro charger, do I need to upgrade the fuel pump and injectors? Anything else need upgraded? Would you do with a motor with 115k on it?

**35th-ANV-SS** · 03-04-2013, 12:50 PM

Originally Posted by bhunter0830

So I am clear. Do a SD Tune and rely on my AFR gauge for my for my upstream O2's since my downstream O2's are deleted and I have no MAF to rely on as a failsafe? Or just leave it alone, sell the MAF and have some extra cash to throw at something else like a pro charger. If I do add a pro charger, do I need to upgrade the fuel pump and injectors? Anything else need upgraded? Would you do with a motor with 115k on it?

If you are seriously contemplating a Procharger set-up, there are numerous things you need to upgrade prior to just installing one. Numerous things you need to consider too.

Here is my Procharger thread with some good info: http://www.ls1.com/forums/f11/my-pro...-kinda-153052/

**Firebirdjones** · 03-04-2013, 01:06 PM

Originally Posted by 35th-ANV-SS

FBJ - Correct me if I am wrong, but while removing the MAF for a Speed Density set-up is a good way to go, doesn't that also make the PCM rely a lot more on the O2 sensors for your A/F and any adjustments? What I mean is, if either one of your O2's get lazy, what is there to try to correct the A/F reading without the MAF? Nothing is my understanding. Which means you need to pay a lot more close attention to your upstream O2's. At least with a MAF, it's kind of having a fail-safe. No?

Orion is a more savy tuner than I am when it comes to computers, but to try and answer that question, your MAF also relies on your 02's for fuel trimming, so either way, your 02's are important. When the MAF fails, it relies on your VE tables (which is what an SD tune does/is), so either way you need those VE tables spot on, and you need properly functioning 02's (if you run SD in closed loop). All the SD tune does is get rid of the middle man (the MAF).

What an MAF does do however is have the ability to make slight adjustments to incoming airflow, which helps in situations like changes in altitude, or mild bolt ons, etc...but that only goes so far.