well most of the users who blown Maf seems are with Evo filter.
one of them was me.
I just went back to factory box and i hope everything will be ok.
if that evo filter is that good as most of you said,
then someone can tell why the Mafs blown?

 

Maybe it's a coincidence, and maybe it isn't. If 25% of 996TT's have MAF issues, then 25% of 996TT's with V-Flows will have MAF issues regardless of whether there is a causal connection. You can't assume causation in the absence of reliable data, and I'm not aware of any.

 

no issues with my v-flow. i bought it because i was bored and wanted to see if it would blow my maf. it hasn't. i did notice better response lower in the rev band when i first installed it, not so much now... probably because i'm used to it already.

 

We have been exploring many different options and theories. We are aware that there are MAF issues both with and without the V-Flow. There is no real consistent reason why some fail and some do not. Why do some like BuddgG who has a GT700 upgrade and probably 10K hard miles and over a year time on his car and no problems and then you take a stage 1 customer who has an MAF issue in a few months. To add further debate to this, I have a race team that is running our stage 4 upgrade with the stock airbox and paper filter who sporadically will blow 2-3 MAF's in a race weekend?

I have spent many months deciphering different data on a flow bench at different flow levels / voltage levels to try and replicate some sort of consistent data. Up until this point we have very little to go on but we are field testing a few ideas that we came up with that may help the lifespan of the MAF. Additionally we have a few other plans for direct replacement Hitachi MAF sensors that are programmed to output the same 0-5 volt signal for the given airflow, which could be a direct replacement meter without a software change.

The benefits to the Hitachi style meter are it is a "hot wire" meter vs. a "hot film" meter like the Bosch. The hot wire meters are proven to have much more robust circuitry and can take voltage spikes in the meter at higher levels than the bosch meters. It is almost impossible to break these style meters and their resolution is equivalent to the Bosch meter. This study and development process has been in the works for over 9 months and we have made some great advances in the past few weeks. I was planning on releasing more information on a separate thread when it becomes available,

In conclusion, there really isn’t any right now. Blown MAF's are prevalent in all vehicles and we are aware of them in the German vehicles because that is all we do. Porsche, Audi, VW all use the same style meter and they are always being replaced. The problem is the VW meters are rebuilt at $60 while the Porsche meters are $270. I will post more details in the future regarding the progress.

Email me directly at info@evoms.com if you want to be placed on a mailer for more information on the MAF development process and as soon as it is compiled, we will email the information to you directly. In the subject line pleas put "MAF". Thanks

 

Thanks Todd. One issue is we have a hard time measuring these things...it seems they either work or not. I know this complicates development or an "improved" MAF. We all look forward to the Hitachi replacement should it work.

 

I've got the EVO intake on my car for about a year now and haven't blown the MAF yet.....afraid to say anything that might jinx this!

 

have evo, just installed new paper filter.... have cleaned my maf 4or 5 times ran great for 3k or so.. now cleaning will not fix.... can't wait for todds. have to buy a new one mon. will post results... will try todds new maf as soon as it is on the market.

 

Thanks Todd. Again, the intent was not to be negative but to gain more education.

I appreciate and respect your posting here and look forward to the upgrade when it becomes available.

 

IM not against the V flow... I just know that as much as it really helps... it also may be apart, and only apart of casueing the issue. I never had the vflow and never blew a MAF. I dunoed 575 rwhp on my stage 5... hope they find the answer soon casue I know guys that replaced 3 mafs in 1 year.
Just take it out and see how she runs... wait for the fix...
Here is a technical answer to why MAfs blow:
The stock MAF makes it's peak voltage at 1400 kgs/hr, or 51.33
lbs/min, and at 10hp/lb/min, that's 513hp max. But those engine's don't
make that efficiency, so maybe 490 or so hp, they're pegged.
Now, the input voltage is 12v, so the thing keeps making more output
voltage, but the ecu has a diode clamp on it to keep it from exceeding that
voltage, so the thing just keeps drawing more and more current till it pops.
markski

 

Sounds feasible. Maybe that's why GT2s never went over 470 or so from the factory?

 

Todd,

Hitachi filters seem to be very good, Jim Wolf uses them on many highly modded (high HP) Nissans with greay success (I have never heard of any failures from people I know that run them).

Also if part of the problem is that you are maxing out the MAF how about designing a system that either uses 2 MAF's or uses a 2nd dummy MAF (in parallel) and remap the computer to double the fuel (since the real MAF will only see half the airflow) for the ouput the MAF is giving? This is also a Jim Wolf trick that works wonders..... I understand some piping would be required but it could probably solve most of these issues and it would be less restrictive and allow for more HP.

I have a question though, why don't you guys switch to speed density? This is what Supra guys usually do (not because of blown MAF's as they are very robust but for greater airflow). I understand tunning with a MAF is a bit easier but the Supra crowd has proven that you can tune a high HP car very well with a speed density system rather than the MAF route.

 

I have had the Evo intake with no problems on my 996TT, but my stock Boxster needed a MAF at around 35,000 miles. On the Boxster I did notice a stumble when cold when taking off for the first time in the morning. After the MAF replacement it was smooth as glass.

Roger