Exceeding MAF - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

eLeSthree · 01-13-2022, 10:45 AM

I just installed a new Pro Flo intake manifold, increased my lower pulley size, and decreased my SC pulley size. While doing some testing, I can see that I've already hit 14,700Hz. The MAF maxes out at 15,000 and I have heard awful things happen when you exceed the maf's limits. Like fueling is cut in half

If cylinder airmass is an indicator of power potential, I am seeing a good increase. Max grams on previous setup was 2.21. Now I'm seeing 2.56 grams at 18#s of boost with some RPM left to turn.

What are my options?

dreksnot · 01-13-2022, 12:43 PM

I've been told I'd have to go SD with my CID and twins, so I did (fully). It's requires much more tuning - instead of one row for MAF now there's rows and columns for RPMs and manifold pressures in the VE tables. If you're seeing 2.56g/cyl I presume you've already scaled your injectors in the tune so your spark table is already max'd to 2.56g/cyl. Did you adjust your manifold volume for the Pro Flo intake in the tune?

eLeSthree · 01-13-2022, 03:24 PM

I did not change the intake manifold volume, because I dont know how much it has.
The spark table is still stock maxing at 1.2X i think.

EDIT: 1.36

cc-rider · 01-13-2022, 05:09 PM

As dreksnot said…you need to go speed density and forget the maf. You should work on your VE tables in the tune regardless of exceeding the maf or not. Helps with transient throttle, even when your in maf range. You may want to go over to HP Tuners forum and do some searching on what happens inside the ECU when MAF is exceeded. I have to admit…I don’t know. It may just peg and fuel at that point off the MAF. Which would be dangerous. Or it may flip to VE table. Which would be dangerous if you haven’t tuned it…or perhaps fine if you have it tuned in at the higher end.

dreksnot · 01-13-2022, 09:07 PM

Quote:

Originally Posted by cc-rider

…I don’t know. It may just peg and fuel at that point off the MAF.

Kinda, sorta concerning. You'll be in your PE (power enrichment) table and/or boost enrichment when running WOT and have high MAF conditions. So, the fueling will be "pegged" at your max MAF when you go over. If not much over, then you'll be fine. If a lot over, then could run lean (using the MAF and not going SD). Still think you should shift over to SD.

eLeSthree · 01-14-2022, 06:18 AM

My concern is at those MAF values, my boost is increasing rapidly. So a constant fueling value isn't going to work. I've also read that increasing the MAF pipe diameter will shift the scale downward. Of course I'd need to retune. But I agree, tuning the vve table is ideal.

Curious what the negative side effects of a larger diameter pipe are. I imagine it would have less velocity and maybe some low speed issues. IDK.

cc-rider · 01-14-2022, 08:08 AM

With a larger intake pipe, you’ll have less velocity of air running over the maf for the same total volume of air running through the total pipe. So its true that it will shift the curve down for the maf and you’ll be able to move more air before pegging the maf. You could try that. But the entire maf/fueling curve in the tune will be shifted so you need retune the entire range.

But still take the time to get your VE dialed in too. If the maf ever fails, the tune will default to the VE tables. And if they are left stock, you’ll go way lean instantly and blow your engine almost immediately unless your knock sensors bail you out.

eLeSthree · 01-14-2022, 10:51 AM

I'm glad to say, that was a false alarm. I had Jannetty take a look at the log file. I blew a charge pipe off during this log, and bad data was collected. I had my cell hits set to 1. My normal hz peak is around 13,500ish. So I have plenty of MAF headroom.

Still not a bad idea to do the SD tune, its just a huge pain in the ass.

dreksnot · 01-14-2022, 11:08 AM

Good to hear. MAF is so much easier than SD tuning (not having to go there).

FasNuf · 01-14-2022, 11:14 AM

Quote:

Originally Posted by cc-rider

With a larger intake pipe, you’ll have less velocity of air running over the maf for the same total volume of air running through the total pipe. So its true that it will shift the curve down for the maf and you’ll be able to move more air before pegging the maf. You could try that. But the entire maf/fueling curve in the tune will be shifted so you need retune the entire range.

But still take the time to get your VE dialed in too. If the maf ever fails, the tune will default to the VE tables. And if they are left stock, you’ll go way lean instantly and blow your engine almost immediately unless your knock sensors bail you out.

This ^^^^

cc-rider · 01-14-2022, 06:37 PM

There is a mathematical formula that does exist that allows you to build a VE table from MAF…and vice versa. Go search over at HP Tuners forum and its there somewhere (at least it used to be). In a thread I started in the 2016 or 2017 timeframe back when I was tuning. May allow someone the “easy” way of creating a VE table that’s at least somewhat close by just tuning the MAF. But I still think both should be tuned in individually to be as accurate as possible.

cc-rider · 01-14-2022, 06:57 PM

Here it is. See post 21 on this thread: https://forum.hptuners.com/showthrea...nd-Dynamic-air

Slowhawk · 01-15-2022, 01:15 PM

You can change pipe size,maf locations till it works for you.

In truth,I haven't tuned a boosted 5th gen with a maf in a very long time. Only SD on all of them.

cc-rider · 01-15-2022, 02:32 PM

Quote:

Originally Posted by Slowhawk

You can change pipe size,maf locations till it works for you.

In truth,I haven't tuned a boosted 5th gen with a maf in a very long time. Only SD on all of them.

That's interesting. Curious as to what makes you take that route on all builds? You find it to be more accurate?

01-13-2022, 10:45 AM	#1
eLeSthree Drives: 2011 Camaro SS 6sp Join Date: Nov 2016 Location: Drivers Seat Posts: 1,904	Exceeding MAF I just installed a new Pro Flo intake manifold, increased my lower pulley size, and decreased my SC pulley size. While doing some testing, I can see that I've already hit 14,700Hz. The MAF maxes out at 15,000 and I have heard awful things happen when you exceed the maf's limits. Like fueling is cut in half If cylinder airmass is an indicator of power potential, I am seeing a good increase. Max grams on previous setup was 2.21. Now I'm seeing 2.56 grams at 18#s of boost with some RPM left to turn. What are my options? __________________ 2011 Camaro SS---SOLD TMS Dart 427 FED M311s, ESS Tuning G4 Blower, DSX Triple FP Assembly, DSX FF, FIC1300, Mcleod RXT 1200HD, Edlebrock Pro Flo XT 1158whp 1017wtq. 2010 CTS-V A6 - "Stock" SOLD 630whp 658wtq 2024 F-150 RCSB 5.0 4x4 waiting for tunes...

01-13-2022, 12:43 PM	#2
dreksnot Served USN - Atomic Chimp Drives: 13 Camaro LSX434 TT M6, 21 ZLE A10 Join Date: Jul 2012 Location: Fort Collins, CO Posts: 1,605 View My Garage	I've been told I'd have to go SD with my CID and twins, so I did (fully). It's requires much more tuning - instead of one row for MAF now there's rows and columns for RPMs and manifold pressures in the VE tables. If you're seeing 2.56g/cyl I presume you've already scaled your injectors in the tune so your spark table is already max'd to 2.56g/cyl. Did you adjust your manifold volume for the Pro Flo intake in the tune? __________________ In excess of 1,000WHP LSX434 \| AGP 65/65 TT \| BTR Equalizer Intake \| Trickflow 245cc cathedral \| BTR custom cam \| Cortex EBC \| n2mb WOT \| ID-1700x \| Brisk GR12S \| RPM Lv 7 TR6060 \| AGP's Triple 525LPH Fore Fuel \| Monster LT1-S Triple \| 4.11 DSS Proform 9", CF driveshaft, 1400hp axles \| Hurst Line Lock \| MGW Retro Short Throw w/old skool Hurst T-handle \| ADM solid subframe mounts \| Prothane Motor Mounts \| Revshift Poly Trans insert \| Moreno camber/caster plates

01-13-2022, 03:24 PM	#3
eLeSthree Drives: 2011 Camaro SS 6sp Join Date: Nov 2016 Location: Drivers Seat Posts: 1,904	I did not change the intake manifold volume, because I dont know how much it has. The spark table is still stock maxing at 1.2X i think. EDIT: 1.36 __________________ 2011 Camaro SS---SOLD TMS Dart 427 FED M311s, ESS Tuning G4 Blower, DSX Triple FP Assembly, DSX FF, FIC1300, Mcleod RXT 1200HD, Edlebrock Pro Flo XT 1158whp 1017wtq. 2010 CTS-V A6 - "Stock" SOLD 630whp 658wtq 2024 F-150 RCSB 5.0 4x4 waiting for tunes... Last edited by eLeSthree; 01-14-2022 at 05:08 AM.

01-14-2022, 06:18 AM	#6
eLeSthree Drives: 2011 Camaro SS 6sp Join Date: Nov 2016 Location: Drivers Seat Posts: 1,904	My concern is at those MAF values, my boost is increasing rapidly. So a constant fueling value isn't going to work. I've also read that increasing the MAF pipe diameter will shift the scale downward. Of course I'd need to retune. But I agree, tuning the vve table is ideal. Curious what the negative side effects of a larger diameter pipe are. I imagine it would have less velocity and maybe some low speed issues. IDK. __________________ 2011 Camaro SS---SOLD TMS Dart 427 FED M311s, ESS Tuning G4 Blower, DSX Triple FP Assembly, DSX FF, FIC1300, Mcleod RXT 1200HD, Edlebrock Pro Flo XT 1158whp 1017wtq. 2010 CTS-V A6 - "Stock" SOLD 630whp 658wtq 2024 F-150 RCSB 5.0 4x4 waiting for tunes...

01-14-2022, 10:51 AM	#8
eLeSthree Drives: 2011 Camaro SS 6sp Join Date: Nov 2016 Location: Drivers Seat Posts: 1,904	I'm glad to say, that was a false alarm. I had Jannetty take a look at the log file. I blew a charge pipe off during this log, and bad data was collected. I had my cell hits set to 1. My normal hz peak is around 13,500ish. So I have plenty of MAF headroom. Still not a bad idea to do the SD tune, its just a huge pain in the ass. __________________ 2011 Camaro SS---SOLD TMS Dart 427 FED M311s, ESS Tuning G4 Blower, DSX Triple FP Assembly, DSX FF, FIC1300, Mcleod RXT 1200HD, Edlebrock Pro Flo XT 1158whp 1017wtq. 2010 CTS-V A6 - "Stock" SOLD 630whp 658wtq 2024 F-150 RCSB 5.0 4x4 waiting for tunes...

01-13-2022, 05:09 PM	#4
cc-rider Drives: 2010 Camaro SS Join Date: Dec 2006 Location: MN Posts: 1,172	As dreksnot said…you need to go speed density and forget the maf. You should work on your VE tables in the tune regardless of exceeding the maf or not. Helps with transient throttle, even when your in maf range. You may want to go over to HP Tuners forum and do some searching on what happens inside the ECU when MAF is exceeded. I have to admit…I don’t know. It may just peg and fuel at that point off the MAF. Which would be dangerous. Or it may flip to VE table. Which would be dangerous if you haven’t tuned it…or perhaps fine if you have it tuned in at the higher end.

01-14-2022, 08:08 AM	#7
cc-rider Drives: 2010 Camaro SS Join Date: Dec 2006 Location: MN Posts: 1,172	With a larger intake pipe, you’ll have less velocity of air running over the maf for the same total volume of air running through the total pipe. So its true that it will shift the curve down for the maf and you’ll be able to move more air before pegging the maf. You could try that. But the entire maf/fueling curve in the tune will be shifted so you need retune the entire range. But still take the time to get your VE dialed in too. If the maf ever fails, the tune will default to the VE tables. And if they are left stock, you’ll go way lean instantly and blow your engine almost immediately unless your knock sensors bail you out.

01-14-2022, 11:08 AM	#9
dreksnot Served USN - Atomic Chimp Drives: 13 Camaro LSX434 TT M6, 21 ZLE A10 Join Date: Jul 2012 Location: Fort Collins, CO Posts: 1,605 View My Garage	Good to hear. MAF is so much easier than SD tuning (not having to go there). __________________ In excess of 1,000WHP LSX434 \| AGP 65/65 TT \| BTR Equalizer Intake \| Trickflow 245cc cathedral \| BTR custom cam \| Cortex EBC \| n2mb WOT \| ID-1700x \| Brisk GR12S \| RPM Lv 7 TR6060 \| AGP's Triple 525LPH Fore Fuel \| Monster LT1-S Triple \| 4.11 DSS Proform 9", CF driveshaft, 1400hp axles \| Hurst Line Lock \| MGW Retro Short Throw w/old skool Hurst T-handle \| ADM solid subframe mounts \| Prothane Motor Mounts \| Revshift Poly Trans insert \| Moreno camber/caster plates

01-14-2022, 06:37 PM	#11
cc-rider Drives: 2010 Camaro SS Join Date: Dec 2006 Location: MN Posts: 1,172	There is a mathematical formula that does exist that allows you to build a VE table from MAF…and vice versa. Go search over at HP Tuners forum and its there somewhere (at least it used to be). In a thread I started in the 2016 or 2017 timeframe back when I was tuning. May allow someone the “easy” way of creating a VE table that’s at least somewhat close by just tuning the MAF. But I still think both should be tuned in individually to be as accurate as possible.

01-14-2022, 06:57 PM	#12
cc-rider Drives: 2010 Camaro SS Join Date: Dec 2006 Location: MN Posts: 1,172	Here it is. See post 21 on this thread: https://forum.hptuners.com/showthrea...nd-Dynamic-air

01-15-2022, 01:15 PM	#13
Slowhawk Drives: 1999 Trans Am Join Date: Jul 2009 Location: Bridgewater,Ma Posts: 2,017	You can change pipe size,maf locations till it works for you. In truth,I haven't tuned a boosted 5th gen with a maf in a very long time. Only SD on all of them.