VZ LS1 MAF vs MAFLESS?? After clarification.

[vz57ssz]

hey guys, I know this has been covered heaps.

I am fitting a full exhaust to my VZ SS (LS1) Pacemakers, 200 Cell High flow cats and a twin 2.5 cat back (apparently same brand used in the V8 Ute series, which I forget the name of).

Once it is done I want to get a tune and Intake, I have heard that in the VZ due to the MAF size, there is no restriction in compassion to pre VZ LS1 Commodores, I am not sure if this is true or not and was told there would be nothing to gain going mafless over MAF in a VZ. Is this true?, if not what are the differences? (power,consumption,torque etc?). I have been quoted for a MAF tune, $1300 with a VCM OTR CAI and $1500 for the Mafless with a ramjet OTR CAI.

I am sorry for another MAF vs MAFLESS thread, though I am just confused as what one to go with on the VZ.

Thanks

[pvk308]

The VZ maff is bigger than the pre-VZ maff........ as for having a benefit over the OTRCAI the only way top tell will be to get it on the dyno and see what happens when they tune it. The only differences i can see is the intake wont be as long ie airbox, into pipe into throttle body less direct path for air flow as compared to the OTRCAI which has i direct path for the air....... Surface area of both woul need to be calculated to see which gathers more air

[swingtan]

The VZ LS1 MAF is the same size as the PRE-VZ LS1 MAF.

The VZ 6Lt (Gen IV, LS2, L76) MAF is bigger than the LS1 MAF.

Airflow difference is better with an OTR compared to a stock intake (LS1 especially), but to be honest, there wouldn't be much difference to notice on the street. If you like the look of an OTR, then that's a good enough reason to get one.

Tune wise, for a daily driver, there's not a lot between MAF and MAFless when it comes to checking results. Both return good power / economy / torque.




Talk to a few shops and ask their opinion, as one of them will be doing the work. Go with whoever you feel the most comfortable with.

Simon.

[Phillshz]

The VZ V8`s all run a 90mm intake and MAF.

http://www.google.com.au/imgres?q=vz+ls1+maf&start=138&hl=en&sa=X&biw=1366&bih=673&tbm=isch&prmd=imvnsfd&tbnid=EmFYI6lbFbr3oM:&imgrefurl=http://www.chevythunder.com/ls1_page_1.htm&docid=ScmAc5jYPE9sLM&imgurl=http://www.chevythunder.com/LS1_MAF_sensors.jpg&w=603&h=264&ei=ogOoUJyJDImeiAeZgoH4Cw&zoom=1&iact=hc&vpx=179&vpy=181&dur=437&hovh=148&hovw=340&tx=180&ty=67&sig=103433896330212510664&page=6&tbnh=131&tbnw=262&ndsp=30&ved=1t:429,r:61,s:100,i:187

L76/98 VZ use the 90mm VE style MAF. A 2 hole MCAI VZ is approx 12-15kw down on power compared to a OTR.

Cheers Phill

[pvk308]

So which one of you is right one is saying all vz have a 90 mm maff and the other is only saying ls2 not looking to cause a fight just want clarification

[whitels1ss]

Yeah I thought all the VZ's had the bigger maf as well?:confused:

[pvk308]

Good read Phillshz so for the guys who are running a vy eg series 1 and 2 they will have the smaller 3 pin maff and the guys runnning the vz (may have either or) maff it will be a 5 pin maff....... Ok so question is is there a connector that enables guys with a vy to run the larger maff and go from 3 pin to 5 pin......... im curious as the early 3 pin unit does not have the provision for the IAT sensor as it appears to be a seperate harness where as im gussing the 5 pin maff takes care of that issue so thee in lies the question can they be swapped

[IJ.]

So which one of you is right one is saying all vz have a 90 mm maff and the other is only saying ls2 not looking to cause a fight just want clarification

85mm Maf ;)

Was working on a Mates car that has a 75mm Maf, it almost fit inside the 100mm LPE Maf!
(just missed out by half a mounting lug)

[pvk308]

85mm thanks IJ mate so how many have converted there early ls1's over to the larger MAFF sounds like easy air flow potential as the larger MAFF doesnt have the restrictions and minor hp gains to me

[zorro]

I suppose wouldn't be hard, difference is the iat is in the vz maf while earlier ones are separate. Cut and shut the vz one in, may need calibration though. Jez/Macca/swingy what are your thoughts?

[pvk308]

That what i was thinking as well and agree with you Zorro mate as for calibration should be ok shouldnt it if you leave the IAT alone

[pvk308]

Well KPM do a conversion for early ls1 to 85mm MAFF

i wonder what happens with the early IAT sensor with this fitted heres the link

http://www.kpmauto.com/tabid/158/Default.aspx

Sorry if the link is against forum rules

[IJ.]

Just to be 100% accurate the VZ 6.0L 5 wire MAF is 86.5mm :)
(was curious)

You'd still have the TB restriction running the bigger MAF on an LS1..
(MAF ID is fairly close to the TB bore on each combination)

So no real gains unless you change both, then I'm not sure what the manifold inlet size is.. and so on.

[pvk308]

I was just thinking the same so you would have to have an ls2 throttle body and an ls2 MAFF........ there are benefits to going to the bigger throttle body any way evenm if you go MAFFless or OTRCAI

[macca_779]

I suppose wouldn't be hard, difference is the iat is in the vz maf while earlier ones are separate. Cut and shut the vz one in, may need calibration though. Jez/Macca/swingy what are your thoughts?

Just looking at it now. For the same frequency the VZ MAF actually calculates less airflow.

I can't say with 100% certainty that it would work as something must be different there because one would think with the same air speed but more area it would be calculating a higher air mass in the VZ not lower.

It probably is still compatible and would just require using the VZ settings, but just find it odd with the difference in cal's

FWIW

VY MAF maxes out at 12000hz with 511.99g/sec
VZ MAF maxes out at 12000hz with 467.04g/sec

If you were going to do it you would just pick up a VZ pigtail and splce in the earlier harness. Using the IAT in the later MAF or retaining the external one would be entirely up to the individual. But I would probably go with the internal one in the MAF and tweak it as per swingy's guide from years ago to reduce the heatsoak

[JezzaB]

Just looking at it now. For the same frequency the VZ MAF actually calculates less airflow.

I can't say with 100% certainty that it would work as something must be different there because one would think with the same air speed but more area it would be calculating a higher air mass in the VZ not lower.

It probably is still compatible and would just require using the VZ settings, but just find it odd with the difference in cal's

FWIW

VY MAF maxes out at 12000hz with 511.99g/sec
VZ MAF maxes out at 12000hz with 467.04g/sec

If you were going to do it you would just pick up a VZ pigtail and splce in the earlier harness. Using the IAT in the later MAF or retaining the external one would be entirely up to the individual. But I would probably go with the internal one in the MAF and tweak it as per swingy's guide from years ago to reduce the heatsoak

Bigger oriface but the engine consuming the same amount of air as the smaller one. The air speed should be slower going through the sensor area and the g/cyl reading lower so you wouldn't max it out as quick.

[white lie]

Well KPM do a conversion for early ls1 to 85mm MAFF

i wonder what happens with the early IAT sensor with this fitted heres the link

http://www.kpmauto.com/tabid/158/Default.aspx

Sorry if the link is against forum rules

You can also get an 85mm MAF from Speed Inc a lot cheaper than that!
The C4B's were MAFless from the factory, so I can't really see how its a requirement to keep it. The $200-550 that you spend on a bigger MAF could be spent in much better ways.

But back to the OP, if the tune is cheaper and you can keep the MAF, then i'd go that way. Provided you use a competent tuner, there's no major benefit either way.

[pvk308]

Excuse the newbie question but explain c4b and sorry i was thinkingform the perspective of guys keeping the maff for ADR and emssions etc and getting the most out of it

[zorro]

Bigger oriface but the engine consuming the same amount of air as the smaller one. The air speed should be slower going through the sensor area and the g/cyl reading lower so you wouldn't max it out as quick.

That makes sense as the larger dia opening the air would be passing slower. How would you go on the frequency table, just copy and paste the high/low values from VZ calibration and match it to the LS1 single table?

[zorro]

Excuse the newbie question but explain c4b and sorry i was thinkingform the perspective of guys keeping the maff for ADR and emssions etc and getting the most out of it

C4b is the engine code for the Calloway ls1 300kw GTS motor, is mafless from factory and has c4b heads/cam/throttle body.

[pvk308]

Thanks Zorro mate appreciated

[JezzaB]

That makes sense as the larger dia opening the air would be passing slower. How would you go on the frequency table, just copy and paste the high/low values from VZ calibration and match it to the LS1 single table?

Just calibrate it. BEN map or histogram, what ever you want to do. Pick a few points of flow and command an AFR and dial it in until its right. The interpolate the missing data and re run over it to make sure it's correct.

[IJ.]

That makes sense as the larger dia opening the air would be passing slower. How would you go on the frequency table, just copy and paste the high/low values from VZ calibration and match it to the LS1 single table?
You'd "tune" the MAF Transfer as it needs to be an accurate measurement of the actual airflow going through the MAF, for this to work you need the correct injector data in the PCM, this also takes into account the airbox and it's entry including all of the pipe work between the box and TB, I got Cal files with the LPE 100mm and in the real world the end numbers will be quite a bit different as their CAL file is just for the MAF on it's own.

Benefit of using a Blended Airflow model MAF/MAP is you're measuring what goes in as opposed to MAP only where it's a best guess calculation based on the MAP CAL file, Big enough MAF sensor is no longer a restriction so I figure I'll take the best of both worlds, as Macca pointed out Air Speed slows and this can help keep you under the 512G/sec hard limit in the PCM, if you need more you can switch to a custom OS, i.e. 2bar OS allows for 1024G/sec.

[JezzaB]

Was a nice walk down memory lane lol. I think back in the day Harrop were selling the sensors and patch harnesses for the conversion. Then HPTuners and EFILive came out with custom OS's that allowed everyone to use two timing tables instead of one mafless and it wasn't the in thing to do anymore.

[macca_779]

Bigger oriface but the engine consuming the same amount of air as the smaller one. The air speed should be slower going through the sensor area and the g/cyl reading lower so you wouldn't max it out as quick.

Correct the air speed would be slower for the same mass of air as would the frequency, but the grams would be the same going by that example. Slower air speed, lower frequency. But the numbers don't represent that.

Take the max frequency available to both which also represents the max air speed to the LS1 PCM. With a bigger orifice but keeping the airspeed the same you will get more air mass. But thats not what the tunes tell us.

The fact that the earlier MAF is capable of measuring more airmass is the simplest way of looking at it and seeing somethings up as the VZ MAF maxes out a fair bit earlier.

My theory is that they scaled the later one down so its more sensitive to slower airspeed.

[macca_779]

That makes sense as the larger dia opening the air would be passing slower. How would you go on the frequency table, just copy and paste the high/low values from VZ calibration and match it to the LS1 single table?

I have a couple of VZ tunes here with a single MAF table. I think it was only the later E40 and E38 that went to dual tables. Here is a VY and a VZ to compare



http://i68.photobucket.com/albums/i39/macca_779/VZVYMAFs.jpg

[zorro]

I have a couple of VZ tunes here with a single MAF table. I think it was only the later E40 and E38 that went to dual tables. Here is a VY and a VZ to compare

http://i68.photobucket.com/albums/i39/macca_779/BA697A3D-9D3F-4C1D-B5A3-9FCFE1B06E9C-259-0000001A355696CE.jpg

Ahh that would make sense then, so did VZ ls1 share the same AFM as l76/l98/ls2 and obviously the difference being ls1b>e38/e40?

[macca_779]

Ahh that would make sense then, so did VZ ls1 share the same AFM as l76/l98/ls2 and obviously the difference being ls1b>e38/e40?

Not sure on that one.

[vz57ssz]

I think I will stick to a MAF tune, even though most people say the MAFLESS get better results, though I don't like to rely on an air density look up table.

[swingtan]

The VZ LS1 MAF is the same size as the PRE-VZ LS1 MAF.

Simon.

Sorry guys, It's been a few years since I worked on a VZ LS1 MAF. I remembered it was smaller than the Gan IV one, but couldn't remember the specifics.

[whitels1ss]

From what I have read on U.S. forums many people over there are upgrading to the bigger MAF on the LS1 engine cars
mafless does not seem to be as popular over there.

[Swisscheeze]

Think this will clear a few things up taken from a LS1 upgrade kit. Also achieves vz57ssz figures: Link to website http://www.bobromano.com.au/LS1-power-up-kit-review.html

"In VTII – VY LS1s, the standard airflow meter is upgraded with the unit used in the current VZ series. So what’s the advantage of the VZ ‘meter? Well, with an internal diameter of 94mm, it offers a massive 21 percent greater cross-sectional area over previous airflow meters.

The VZ airflow meter is installed in earlier LS1s using a small adapter loom, which is made by Bob Romano Performance. The adapter loom is necessary to accommodate the VZ airflow meter’s different plug and integrated intake air temperature sensor. (In early LS1s, the intake air temperature sensor can be found in the airbox or the pipe between the airflow meter and throttle.)

Fitment of the VZ airflow meter to early LS1s also requires a larger diameter pipe between the ‘meter and throttle body. The BRPM upgrade uses an off-the-shelf VZ throttle body pipe which, as seen in the top of this photo, maintains a far greater cross-sectional area along its length. The VZ airflow meter also offers less intrusive pipe fittings to achieve a further gain in airflow."

Cheers.

[macca_779]

From what I have read on U.S. forums many people over there are upgrading to the bigger MAF on the LS1 engine cars
mafless does not seem to be as popular over there.

Yeah they're not very confident going MAFLESS over there unless they have to. With us I believe it was the GTS that made it mainstream. So much so guys still use it in marketing tunes for the later vehicles which really see no benefit in ditching the MAF

[chocco]

Yeah they're not very confident going MAFLESS over there unless they have to. With us I believe it was the GTS that made it mainstream. So much so guys still use it in marketing tunes for the later vehicles which really see no benefit in ditching the MAF

Please correct me if I am wrong, one of the reasons they keep the MAF over in the US is the cause of the snow/cold. Thats why I am keeping my MAF, we head up the snow every year.

I have looked at and spoken to a tuner in the US that installs LS3 MAF cards into a DUS for the Pontiac GTO, decided to keep my 2 hole mod, couldnt be bothered moving all my coolers to allow for the DUS front pickup.

Cheers

[macca_779]

Please correct me if I am wrong, one of the reasons they keep the MAF over in the US is the cause of the snow/cold. Thats why I am keeping my MAF, we head up the snow every year.

I have looked at and spoken to a tuner in the US that installs LS3 MAF cards into a DUS for the Pontiac GTO, decided to keep my 2 hole mod, couldnt be bothered moving all my coolers to allow for the DUS front pickup.

Cheers

It's a myth mate. Part of the speed density calculation is temp which we all know the controller sees. The yanks also play the altitude card. The controllers also measure barometric pressure so that too is calculated. Then of course for any other error that could creep in you have fuel trims.

Think about it this way. Plenty of engines to this day get along fine without a MAF in all conditions. My Subaru Outback (A car built to play in the snow). No MAF. All current Falcon engines. No MAF.

[swingtan]

Correct Macca, the real reason the MAF is used is because it auto compensates for all conditions, temp, pressure etc.

The design of the MAF means that you don't actually need any of the correction factors, so it's a lot simpler to get the fueling right. It's not the only way, but it dies make it easy.

[chocco]

It's a myth mate. Part of the speed density calculation is temp which we all know the controller sees. The yanks also play the altitude card. The controllers also measure barometric pressure so that too is calculated. Then of course for any other error that could creep in you have fuel trims.

Think about it this way. Plenty of engines to this day get along fine without a MAF in all conditions. My Subaru Outback (A car built to play in the snow). No MAF. All current Falcon engines. No MAF.

That makes sense

But when they tune a car mafless dont they tune for the temp of the day because the tables are static, so if you have a temp of -10deg the car has a hissy fit because there is no info for that set point ???

[swingtan]

Depends on the tuner.....

There is a table to correct fueling based on Intake Air Temp. Basically, it adds fuel when IAT is low and removes fuel when IAT is hot. This corrects the fueling for the change in air density with temperature. Same goes for barometric pressure, as the injector pressure delta changes as the barometric pressure changes. When these two tables are correct, the fueling stays constant with changes in IAT and Altitude. As Macca says, add in the fuel trims and you have a a very stable fueling model once set up.

[chocco]

Depends on the tuner.....

There is a table to correct fueling based on Intake Air Temp. Basically, it adds fuel when IAT is low and removes fuel when IAT is hot. This corrects the fueling for the change in air density with temperature. Same goes for barometric pressure, as the injector pressure delta changes as the barometric pressure changes. When these two tables are correct, the fueling stays constant with changes in IAT and Altitude. As Macca says, add in the fuel trims and you have a a very stable fueling model once set up.

So everyone says you get a fair increase in power going mafless on a LS1compared to MAF, considering what the Cross 8 is used for towing and snow duties, it would be safe then ?

[IJ.]

So everyone says you get a fair increase in power going mafless on a LS1compared to MAF, considering what the Cross 8 is used for towing and snow duties, it would be safe then ?

Personally I'd go an L98 MAF Choc.
(along with a bigger TB to match)

[swingtan]

To be honest, I doubt going MAFless will make that big a difference for towing. You'd be more concerned with torque off the line rather than peak power.

[Phillshz]

Personally I'd go an L98 MAF Choc.
(along with a bigger TB to match)

All VZ V8`s run a 90mm MAF. Gen IV VZ`s (L76/98) Use a different style but it`s still 90mm.

Cheers Phill

[CalaisBoy]

Depends on the tuner.....

There is a table to correct fueling based on Intake Air Temp. Basically, it adds fuel when IAT is low and removes fuel when IAT is hot. This corrects the fueling for the change in air density with temperature. Same goes for barometric pressure, as the injector pressure delta changes as the barometric pressure changes. When these two tables are correct, the fueling stays constant with changes in IAT and Altitude. As Macca says, add in the fuel trims and you have a a very stable fueling model once set up.

Swingtan,
I think you are saying for 2 identical OTR's, but where one has a MAF and the other doesn't ( say like the DUS options for a VE), that the MAFLess is better if tuned using the fuel trims etc? Or is the MAF OTR better? Or is there hardly any difference?

Note I am not referring to legality here - just best set- up.

[macca_779]

Swingtan,
I think you are saying for 2 identical OTR's, but where one has a MAF and the other doesn't ( say like the DUS options for a VE), that the MAFLess is better if tuned using the fuel trims etc? Or is the MAF OTR better? Or is there hardly any difference?

Note I am not referring to legality here - just best set- up.

The biggest issue with OTRCAI's and MAF's is reversion off the throttle body. Thats why Holden installed reversion chambers in the OEM tract.

[dgp]

The biggest issue with OTRCAI's and MAF's is reversion off the throttle body. Thats why Holden installed reversion chambers in the OEM tract.

What do you mean when you say reversions of the TB?

[macca_779]

What do you mean when you say reversions of the TB?

Air bounces off the throttle and gives false airflow readings its subtle and not a major concern. But it's an issue non the less

[IJ.]

One good reason for the Hemholtz resonator on the stock intake pipe :)