3-bar MAP sensor change on Whipple Supercharged LS3 -any change besides linear/offset

[Mach Schnell!]

Question to those who changed the factory 1-bar MAP sensor on forced induction LS3: I am changing factory MAP sensor to 3-bar GM P/N 12592525, strictly for the purpose of displaying gauge & logging boost in hptuners. Other than changing scaling ("linear" = 312.5 kPa and "offset" = -11.25 kPa) parameters on Engine> Airflow> General > MAP is there anything else that I need to change? Note that I verified (I believe) that I have MAF-only tune by observing Engine> Airflow> Dynamic> Dynamic Airflow "High RPM Disable" =150 rpm and "High rpm Re-enable" =100 rpm. (This per Hptuners Thetuningschool instructions.) thanks.

[Unreal]

Nope, you will be good to go.

I would look into getting rid of the maf only tune IMO.

[JANNETTYRACING]

MAF only is never really MAF only, it still blends Virtual VE during throttle transitions.

Tuning both is best but only really affects operation below 3000 rpm.

[Mach Schnell!]

Thanks Nick and Ted

[scv_guy]

Originally Posted by Unreal

Nope, you will be good to go.

I would look into getting rid of the maf only tune IMO.

Can you elaborate on that, im currently running MAF only and the car seems to run great.

[Unreal]

Maf doesn't deal with low RPM well, doesn't deal with transitions well. I said the same thing for years, until I did my SD tune and didn't realize how much I was giving up. Throttle response, low throttle, all that is VASTLY improved. I went around for years saying MAF only is fine, then I tried SD and Hybrid and felt like an idiot.

Lots of tuners do MAF only because it is easy and quick, but it is never ideal.

[scv_guy]

Originally Posted by Unreal

Maf doesn't deal with low RPM well, doesn't deal with transitions well. I said the same thing for years, until I did my SD tune and didn't realize how much I was giving up. Throttle response, low throttle, all that is VASTLY improved. I went around for years saying MAF only is fine, then I tried SD and Hybrid and felt like an idiot.

Lots of tuners do MAF only because it is easy and quick, but it is never ideal.

Thank you for the input, I'll look into SD and or a hybrid tune

[JANNETTYRACING]

Originally Posted by scv_guy

Thank you for the input, I'll look into SD and or a hybrid tune

On a 100% stock engine it won't help because all your Dyn air tables are already correct.

It is when you change cams, heads compression, intakes, headers etc that the Dyn air tables get out of whack and need to be calibrated for optimum low speed operation.

The Older computers were much slower and really need the dyn air tables to be perfect, these newer computers are much faster responding MAF and are not as sensitive.

Hope this sheds a little more light on the subject.

[scv_guy]

Originally Posted by JANNETTYRACING

On a 100% stock engine it won't help because all your Dyn air tables are already correct.

It is when you change cams, heads compression, intakes, headers etc that the Dyn air tables get out of whack and need to be calibrated for optimum low speed operation.

The Older computers were much slower and really need the dyn air tables to be perfect, these newer computers are much faster responding MAF and are not as sensitive.

Hope this sheds a little more light on the subject.

Yes thank you..One of these days I'll do a cam swap, not sure if I'm going to keep the VVT or do an LS3 conversion.

[Unreal]

Even with the newer computers being faster, a tuner should be adjusting both IMO, and not just doing a quick/easy maf tune and sending someone on their way which is VERY common.

[Nighthawk89]

Now I'm considering buying this 3 bar.. hmmm

[scv_guy]

Originally Posted by Nighthawk89

Now I'm considering buying this 3 bar.. hmmm

They are cheap, allow you to log boost and 5 min install. You will need to rescale your map settings

[JANNETTYRACING]

Originally Posted by Nighthawk89

Now I'm considering buying this 3 bar.. hmmm

Every boosted car should have one.

It is way more than just logging it.

The computer uses manifold pressure VS Fuel pressure to come up with a Pressure Delta which leads to final pulse width calculation.

Right now without the 3 bar, the computer is not seeing your manifold pressure so your injector pulse width calculations are way off, which also means your MAF calculation is way off, and your PE table is more than likely raped.

Ted.