What do you think of the 85mm Z06 MAF conversion? Way better priced than the Granetelli MAF. Worth buying? Would I have any problems with it?

Here about 1/2 down the page it is.

 

I have that exact one. No problems with it so far. I know the mail-order tuners don't like them though because of the difficulties they create.

 

not worth the $$$ IMO.

money better spent on tuning or something else. just my .02

MAF is just going to lean u out. havent seen too many people gain from it.

 

I have that one aswell. Can't say I felt a difference but my track times improved. If your stock MAF is working properly and not modded I wouldn't switch. That Z06 maf is actually made by Granatelli too.

 

I've heard of some people running it fine, and others having MAJOR programming issues with that 85mm MAF.

1st. I don't recommend replacing the MAF unless the stocker fails, or you're making HP levels where it becomes a restriction (typically >500rwhp), or you just feel light making your wallet lighter by $150+

2nd. I also recommend the GM part instead of the Grantenelli one. But this requires an adapter cable, and re-programming of your PCM for the new MAF.

But if the GM one ever fails, I just go to ANY GM DEALER and I have a new one for ~$100.

And to get technical why there are programing issues with the Grant one is because they will NOT release the Freq Vs Flow Curve that's needed in the PCM. The GM one is known, thus making it able to enter it into your PCM to make sure everythign is running correctly. The Grant one you can't not do this, you can only plug-n-play it an hope for the best.

 

My problem with the ZO6 MAF is that it maxes out at a lower flow than the LT1's.

The max MAF frequency the LT1 computer reads is 11216 Hz. At 11216 Hz, the ZO6 MAF is only flowing ~360 gm/sec, versus the 471 gm/sec of the stock LT1. Therefore, not only do you have to rescale your MAF tables, but the max airflow reading will be lower. This will be a problem if you're making over ~400 rwhp.

The max frequency output of the ZO6 MAF is around 12000, but it doesn't matter if the computer ignores any signal higher than 11216.

Mike

 

Unless the MAF is a restriction, I wouldn't expect to see any gains. In fact, I believe that if your car is properly tuned, changing to a different style of MAF sensor may cause problems.

Just my .02

 

My Z06 MAF works great, its cheaper than the Granetelli and its reprogrammable. I felt the difference as soon as the MAF went thru its 4-5 stages. around 45-75 miles after the MAF was installed.

 

I've got a question for you...

I'm dealing with a 1997 Chevy Pickup with the 5.7 Vortech and a WhippleCharger.

It had a granatelli MAF on it and at about 5000 it would consistantly set the CEL and throw a code that translated to "MAF High Frequency"

After putting on a stock MAF the problem improved but didn't go away.


Everything I have been able to discover so far, especially when combined with finding out just now what the high frequency code means, leads me to believe that the stock MAF is still too small for higher RPMs with the supercharger.

I was thinking about trying an F-Body MAF on it, and I gather that I'd be looking for a 1997 MAF, because that's an OBDII year.

Do you think that this would be a good solution to the problem we're dealing with, and also, do you know anyone who does aftermarket programs that can be uploaded to the PCM and would work with the 97 5.7 Vortech?

 

Sounds to me like you have the classic OBD2 problem with the MAF maxing out. I thought those supercharger kits came with a MAF translator that's supposed to fix that problem???

On an OBD1 car, when the MAF maxes out, nothing happens. On OBD2, the computer sets a code and the injector pulse width is cut.

Changing the MAF may fix the symptom, but not the problem. If you replace the MAF with one that reads lower, then your computer will not set a code, but your engine will run leaner since the computer is not calibrated to the different reading.

Mike

 

So what do we do?

 

Do you have a MAF translator? If no, then I'd contact Whipple and make them supply some sort of fix.

Mike

 

I got the MAF numbers for the Stock GM Z06 MAF that have been interpolated to the LT1 tables. PM me if u want them. Stock Z06 MAF and these numbers seem to work the best. I believe the translator is just a global change (resistor?). We all know that the MAF tables are not linear so if the translator uses a resistor then it's just a "pretty close" type of fix.

Jeff D.

 

I installed a Gen-III MAF on a built LT1 my buddy put in his Porsche 944 (yes it's stupid fast). Don't bother paying extra for the Z06 or aftermarket MAF's. All the GM Gen-III MAFS are the same, with the exception of the flow straighteners.
All that needs to be realized a that running a Gen-III MAF with an LT1 MAF cal will make the PCM fuel for ~30% more air than really is coming into the motor.

I compared an LM7, LM4 and a Z06 MAF table, and they are basically the same until you get to the higher frequencies, so the flow restrictions in the induction system are all that makes a difference in the cal. Mass Flow rate is a function of inlet pressure depression, and CFM. At WOT, the PCM looks more at MAP and RPM to determine fueling, going to the larger MAF just helps in the inlet restriction department.

BTW, you only need about 305-310 g/sec to make 400 HP..

 

My bone stock LT1 (tb-bypass only) pulled 267grms/sec just a few days ago. I know I am not making near 320hp Are you sure 305 - 310 g/sec is all thats needed for 400hp?

That sounds awefully closed to my readings and I am bone stock.

267grms = 35.32 lbs/min
310grms = 41.01 lbs/min

thats only 6lbs/min more.


How did I pull 267grms fron a bone stock LT1? I removed the OEM plastic duct. Thats it. with the duct connected to the MAF it only pulls 227 grms... Removing that duct is good for 40grms/sec. I am thinking of building my own Cold Air.

Anyway correct me if I am wrong but are you sure you dont need any more grms/sec to produce 400 hp? sounds like I am awefully close to that number..

Marvin