MAF calibrations for bigger intakes

[Tomas]

It will buck about the same and it will be more prone to litlle backfires. At least in my experience.

[Boosted Beluga]

Ok thank you.

[Voltwings]

So i installed an HTP 4" intake on a 3071 car this weekend and got his base map dialed in last night, and all i can say is the car drives beautifully, it doesnt seem to buck or hesitate during shifts at all.

Changes to the tune include:
Scalaing the MAF (i will do a full MAF cal tomorrow once the car has had a chance to learn some trims)
Upping idle to 1000 rpms

Hardware:
Garrett GT3071r (no surge porting)
HTP 4" intake
Custom intercooler with BPV like 3-4" away from throttle body. Maybe it blows the air off so close to the throttle body / IM it doesnt have time to get turbulent when the throttle closes?
Stock downpipe ... he bought the big turbo on kind of a whim haha

I can try to get some logs for you guys to see but just wanted to check and see what you would like in them / under what conditions.

[Boosted Beluga]

@Lex; I know this isn't the right thread but im too lazy to search lol

This was my findings between the AEM filter HTP supplies with their intakes and Spectre filter.

The Spectre Flows 9g/s more then the AEM filter there was 2* difference in intake temps. No changes to the tune.

Datalog 12 is with the Spectre filter
Datalog 14 is with the AEM filter

Both 3rd gear logs on the same stretch of road going the same direction.

[Lex]

Originally Posted by Boosten Ya(josh) @Lex; I know this isn't the right thread but im too lazy to search lol This was my findings between the AEM filter HTP supplies with their intakes and Spectre filter. The Spectre Flows 9g/s more then the AEM filter there was 2* difference in intake temps. No changes to the tune. Datalog 12 is with the Spectre filter Datalog 14 is with the AEM filter Both 3rd gear logs on the same stretch of road going the same direction.

Even after correcting for the slight AFR difference there seems to be about 7g/s between the 2. Interestingly your throttle also seems to be more open with the AEM filter. Do you have a link to the Spectre filter?

[Boosted Beluga]

I think I was hitting the load limit with the spectre.

Spectre Performance :: The 400 MPH Company

You can get them at pepboys, autozone, ect.

[Lex]

Originally Posted by Boosten Ya(josh) I think I was hitting the load limit with the spectre. Spectre Performance :: The 400 MPH Company You can get them at pepboys, autozone, ect.

Do they publish filtering ability? Flow and filtering ability are often inversely proportional.

[Boosted Beluga]

I have no idea. I'll ask my friend that works at O'Reillys. Maybe he can find out?

[Lex]

JBR WP 3" MAF calibration added to the OP @jbarone;

[2.0t03speed]

Originally Posted by Lex JBR WP 3" MAF calibration added to the OP @jbarone;

lex you might want to note the jbr intake as the full aluminum version. I don't know if it will make a difference, but his new 3" wp silicone intakes use a different maf housing with a non honeycomb straightener.

[Lex]

Originally Posted by 2.0t03speed lex you might want to note the jbr intake as the full aluminum version. I don't know if it will make a difference, but his new 3" wp silicone intakes use a different maf housing with a non honeycomb straightener.

JBR never had a 3" full aluminum. This calibration is for the new 3" WP which uses that MAF housing and a silicone inlet tube.

I have also added instructions on how to apply the MAF cal and what to look for afterwards to the OP.

[2.0t03speed]

Originally Posted by Lex JBR never had a 3" full aluminum. This calibration is for the new 3" WP which uses that MAF housing and a silicone inlet tube. I have also added instructions on how to apply the MAF cal and what to look for afterwards to the OP.

doh you are right i was thinking of htp lol. i forgot that jbr only made the 3.5" in full aluminum.

[Boosted Beluga]

@Lex; my friend couldn't find anything out about the spectre filter ether.

[Voltwings]

Slightly off Topic @Lex; so feel free to move this elsewhere if it seems fit, but I was playing around and my 4" intake stutters when lifting off the throttle have been smoothed a bit increasing my low load WGDC.

I'm sure some people tried this a long time ago but the other day driving in slow moving traffic I would feel my car basically fall on its face every time I lifted and it got VERY annoying. Looking through my map a bit later I figured the abrupt change from some WGDC to no WGDC may have had something to do with that, adjusted values to the following and its much smoother.

@Tomas; not sure if you ever got your 4" settled, but here you will see the difference between a regular map and mine, hope it helps.

[Boosted Beluga]

I'm going to have to try that. Thank you.

[ry1g2uy3]

Lex, I noticed that about two weeks ago when I copied the values for the htp 3.5 You mentioned it was a beta . Now the (beta) has been removed. Did you make new revisions that I should re flash or were those values adequate? Thanks

[Lex]

Originally Posted by ry1g2uy3 Lex, I noticed that about two weeks ago when I copied the values for the htp 3.5 You mentioned it was a beta . Now the (beta) has been removed. Did you make new revisions that I should re flash or were those values adequate? Thanks

Nope, just saw it on enough cars to feel comfortable with it. Remember that with these big intakes it's always good to do a MAF cal log on your particular car.

[djuosnteisn]

Originally Posted by Voltwings Slightly off Topic @Lex; so feel free to move this elsewhere if it seems fit, but I was playing around and my 4" intake stutters when lifting off the throttle have been smoothed a bit increasing my low load WGDC. I'm sure some people tried this a long time ago but the other day driving in slow moving traffic I would feel my car basically fall on its face every time I lifted and it got VERY annoying. Looking through my map a bit later I figured the abrupt change from some WGDC to no WGDC may have had something to do with that, adjusted values to the following and its much smoother.

Interesting observation. My only $.02 on it is be careful with 100's down there. Having 100's throughout the entire light load and idle range could result in a very hot solenoid, and may lead to premature failure.

It's robust... and can handle 100's for short stints while wot... but i wouldn't want to leave 100's on it for a 20 minute period while you cruise down the highway at light load:

FEAR NOT........... the 100% WGDC

[Boosted Beluga]

What about say 50%?

[Voltwings]

Originally Posted by djuosnteisn Interesting observation. My only $.02 on it is be careful with 100's down there. Having 100's throughout the entire light load and idle range could result in a very hot solenoid, and may lead to premature failure. It's robust... and can handle 100's for short stints while wot... but i wouldn't want to leave 100's on it for a 20 minute period while you cruise down the highway at light load: FEAR NOT........... the 100% WGDC

Noted! I am on a grimmspeed but still in no hurry to piss away $100, ill gradually start lowering it and see where the happy median is, thanks for the heads up.

Originally Posted by Boosten Ya(josh) What about say 50%?

See above ^^ ill either pm you or start a new thread to keep from crapping this thread up. The 4" intake stutter seems to have been moved here so I guess if its "relevant" enough we'll leave it here.

[Boosted Beluga]

Sounds good. I've learned to live with it so I'm not in a hurry.

[Voltwings]

Originally Posted by Boosten Ya(josh) Sounds good. I've learned to live with it so I'm not in a hurry.

New WGDC table, may bump them up to 60% just to see but 50% still seems very effective. Basically to test this what I would do is leave it in first and get to about 2700-3000 rpms, cruise for a second then lift off the throttle to simulate stop and go traffic. Basically doing this there was a slight hesitation as soon as I lifted, but then a smooth gradual deceleration, Seems to have smoothed things out quite a bit.

[Boosted Beluga]

Thank you. I sit in stop and go traffic almost every day. Lol

[mrdouble99]

My Full3 Aeros ID300 Intake is installed.

MAF cal is done using @Lex Cal.

Long ride tomorow, so i'll update how it goes

[bstover17]

I got my maf cal down to -2.34 so I think I am done with my cal thanks to this thread. I used Lex's figures for the HTP 3" intake and tweaked them somewhat. Now to learn how to tune until I can get a stratified tune!

[Redline143]

Has anyone else noticed that if your MAF is dialed-in with a 93 tune and you switch to an ethanol tune that your ECU is consistenly needing to add ~5-8% more fuel, everything else being equal? I know it's not a hardware issue. The only variable is the fuel (FSG and injector scalar changed for the proper ratio too, of course).

Any tuners care to speak to this? @rfinkle2? @atvfreek? @Lex? @Bucker? @phate? Any of the numerous other highly competent folks I didn't mention?

I don't know the technical terms, but doesn't ethanol create sort of a vacuum effect in the combustion chamber and therefore mean that at a given MAF voltage, you actually should be seeing more grams/second when properly calibrated? I was thinking of multiplying all of my open-loop ranges (150 grams+) by a conservative 1.02 and seeing what my WOT logs show. The open loop fuel trims which we know exist on Genpus (but don't have access to) means there's a lot of guess work. Ideally, I'd want to be in the center of the ECU's range of O/L fuel trim adjustability, but since I'm tuning blind up there (not seeing those O/L trims) I'm trying to get a good idea where to start.

TLDR version: when running ethanol, should we scale the O/L MAF table ranges (~150 grams+) by a certain amount to account for the additional grams/second we see when running ethanol, everything else being equal?

[Lex]

Ethanol is an oxygenated fuel. That means it carries more oxygen in the fuel itself and this is why you will run "leaner" if you add E85 without scaling anything to add extra fuel volume.

[phate]

I've always chalked it up to 1 of 2 things: the scalars aren't perfect, or the mix isn't perfect. If I'm close on trims when I switch and I'm hitting OL fueling targets, I don't worry about it. I do MAF cals on my own car when LTFT's are >|10%|.

[bhamitgeek]

Originally Posted by 802MS3 just fyi with the JBR intake, you should probably just zero out anything below 0.9v. @Ziggo figured out that this will trip the Crank Position Sensor circut malfunction CEL because the KOEO voltage is around .9 when its scaled so much. The ECU sees no airflow and thinks there should be at that voltage, or something like that ha. I used to get the CEL occasionally, and since I've zero'd out everything below 0.9v, the CEL has not returned.

Would this be the case for the regular St2 PowerPath too? @Lex

[Lex]

Originally Posted by bhamitgeek Would this be the case for the regular St2 PowerPath too? @Lex

No the powerpath is a stock sized maf intake. This applies to the much larger intakes.

[elroes]

Installed the HTP 3.5" last week and used the MAF cal here (also bumped the idle to 850 rpm for good measure). First start had a slight stumble, after that all is good. LTFTs are within +/- 5% after 5 days of driving with one longish trip thrown in (about 1 tank of gas). Sadly the one log I took showed almost no change in g/s at redline However, car was holding slightly more boost on the Cobb Stage 2 map (a little over 18 psi) and Vdyno showed about a 10 hp gain. None of that means a whole lot though, just know that the cal works! Now I need an e-tune...

[Lex]

Added the JBR 3.5" WP silicone intake MAF calibration.

Also added MAF cal for 4" HTP Beta.

[Mistersix]

Installed and calibrated a JBR 3.5" and everything is fine except for some issues during cold start up. When the car is full cold it struggles to find idle and either stalls a few times and needs re started or nearly stalls. Which throws a code, p0300 i think which is random misfire due to the stumbling i assume.

Any advice? Was wondering if an air straightener would help.

[Boosted Beluga]

You don't have a honeycomb air straightener? Could be your problem.

[Mistersix]

Originally Posted by Boosten Ya(josh) You don't have a honeycomb air straightener? Could be your problem.

No. The all aluminum JBR intakes didn't come with one. And i don't think he's stocking them any more so i'll have to look else where. Car runs great other wise. Just stumbles when i start it after sitting all nite.

[JBR]

You don't need a straightener and I doubt it will help with a momentary cold start stumble.

[TiGraySpeed6]

Do a cold start log & see what's what-
key on, start log, start car

[Mistersix]

Originally Posted by TiGraySpeed6 Do a cold start log & see what's what- key on, start log, start car

I'll get one tomorrow morning. I've been monitoring things when it happens but all the figures go wonky because of the stumbling.

The maf cal is zero'd at .9v and down. But the voltage is higher than that during warm up so i don't think thats it. I'm puzzled atm.

[EmPeEs6]

Originally Posted by Lex Added the JBR 3.5" WP silicone intake MAF calibration. Also added MAF cal for 4" HTP Beta.

@Lex:
Could you please explain why you're using the same maf curve for MS3 and MS6 models, which have totally different oem curves (or are the factory differences just because of the different airbox constructions)?
After upgrading from a CS sri to a 3.5" JBR wp I get extremely low maf voltage values (max around 4V) and thus very low load and maf g/s values.
I'm still using a rough maf calibration resulting from a constant, commonly recommended multiplication factor of 1.65 (which is d^2/d_oem^2), but in your suggested maf curve for the JBR 3.5" you are using a varying correction factor up to ~1.75.
Why do you use such a large factor - and doesn't the size of the tip connection (2.25"/4") matter at all?

[Lex]

Originally Posted by EmPeEs6 @Lex: Could you please explain why you're using the same maf curve for MS3 and MS6 models, which have totally different oem curves (or are the factory differences just because of the different airbox constructions)? After upgrading from a CS sri to a 3.5" JBR wp I get extremely low maf voltage values (max around 4V) and thus very low load and maf g/s values. I'm still using a rough maf calibration resulting from a constant, commonly recommended multiplication factor of 1.65 (which is d^2/d_oem^2), but in your suggested maf curve for the JBR 3.5" you are using a varying correction factor up to ~1.75. Why do you use such a large factor - and doesn't the size of the tip connection (2.25"/4") matter at all?

Generally speaking only the inner diameter of the MAF housing (where the sensor sits) matters for the MAF calibration. The MAF calibration is simply dependent on that piece of pipe and the sensor itself which is the same for the MS3 and MS6. What is in front and behind the MAF housing (TIP, filter, etc.) can skew the MAF curve slightly but generally should not have a large effect. Air straighteners also affect the curve and you will see this in intake that have them (HTP) versus ones that don't.