mass airflow sensors for the 3.2

[Rutherford]

A Quick little question has any out there had enough cash and tried a mass airflow up grade on the DME Carrera and if so, did you get a good results?

[RSupdate]

I read in a recent issue of xcellence in BA's column that the stock airflow meter will actually flow more air than the stock engine can use and that unless you are increasing the displacement along with other modifications, i.e. hot chip, headers etc the stock unit is just fine. He did say that it couldn't hurt to open the stock airbox up or change to a cone style air filter to ensure maximum air flow. He went on to say that the MAF is a very sensitive piece and that changes in temp and humidity will affect it's performance negitively.

This is just from memory...pretty close to what BA said anyway...

fyi...I have a complete MAF sitting in my garage..... But I don't know if I want to risk all the possible hassles...

cheers!!

John R

Are you saying that MAF kits are instable in general?

[Rutherford]

The one in question is the Huntley it is suppose to take in efect density altitude changes. My experience on making this change on the Ford Merkur was tremendous gain in H.P.

[RSupdate]

Mikkel, I don't know if they are all unstable or not..... again, I was only attempting to paraphrase what I remember BA putting in print in Excellence recently. fwiw....as I mentioned, I have a complete unit sitting in my garage, ready to install. But, All I have heard over the years is either they work REALLY well or they are terrible.
Case in point, I got mine from my wife's shop, the owner of the MAF had it installed and was so unhappy with it, he had it taken off and his factory set up re-installed.

So anyway.... I don't know which way to go with this issue, I got mine but I am not real hot to put it on just to end up with marginal HP increase and alot of tempermental issues to deal with every time I try to drive my car.

[1fastredsc]

I believe that maf's on NA cars aren't really all that helpfull in the HP departement. It's on turbo cars that want to run larger turbos that maf's are great since they can realize the potential of the turbo with there free flowing design and large size. And as far as the air flow meter on an na motronic car, the cone filters can sometimes have negative affects because if you notice that the air box (on a 944 anyway) has a horn shaped plastic outlet. This is designed to stabalize the airflow for accurate air flow readings. Personally, i ran a cone on my 44 at one time, all it did was make the exhaust note sound better and give a slight better top end. The low end kind of sucked.

[jtratza]

I've been very happy with mine (Autoathority). Installed by previous owner at about 40,000 I now have an additional 90,000 miles on it. Its never exhibited tempermental issues even with Houston's wild swings in temperature and humidity. There was a potentiometer failing about 10,000 miles ago which was a pain to track down but finally fixed that for $90 bucks. The car does run a lot cleaner as judged yearly when passing inspection. Throttle response is great. As to performance its impossible for me to judge since I've never had the chance to dyno it with original system in place. I did have the original intake installed about 8 years ago when tracking down another problem which turned ou to not be related to the MF system. Seat of the pants felt I was getting either more power or the hp/torque curve changed with the engine coming alive around 4,000 rpm. My repair shop owner has been on me to install headers. I did put a cat bypass on as a concession. One thing I do notice is the louder intake noise than stock which I like especially the turbo like whistle it makes.

[1fastredsc]

My reply was mainly geared towared price to performance. In your case it came with the car, but new those setups are like over 1k i think which is rediculous. You can get more power and better response from a hot chip that's mapped for a decent grind set of cams. Then your making some power.

[Mike Feinstein]

I have an Autothority MAF and chip in my 89 Carrera. I also had one in my 94 964. I've never had the slightest reliability or driveability problems with either one. I also know of a few others that have the system and have never heard a complaint. It won't work properly with your stock chip...perhaps this is part of the problem mentioned by RSUpdate.

Regarding performance, I'd have to say that it's not dramatic. If I had port-matched heads, enlarged throttle body, cams, SSI's or headers, I'd probably gain more benefit. Unfortunately, I need to pass emissions each year so I run stock heat exchangers with a Europremuffler (swap in cat for emissions test), and a plain old Bursch muffler. Car runs great and I'm confident that the MAF is part of the reason. A breeze to install also. Just make sure that you adjust your idle mixture, with the engine cold via the pot on the MAF wire harness. From the box it was way too rich...really idled poorly. 3 or 4 clockwise rotations of the pot and it idles smooth as glass.

Cost was $1500 (ouch). Next step for me will be cams....but that'll have to wait until I recover from my recent Centerforce clutch / KEP PP and Quaife installation. Will probably do the cams when the car becomes due for a valve job. Unfortunately, that's lots of $$$ also. I love the Porsche. I hate the Porsche tax!

[Purrybonker]

I'm with Feinstein & jtratza - proud owner of an autothority maf/chip combo. These were installed by a PPO so I cannot speak to performance vs. stock.

The car runs great - but my sense is that power is comparable to other non-modified G50 cars that I have been exposed to. The added bit of intake "rush" with the K & N cone is a nice plus.

Originally posted by RSupdate
But, All I have heard over the years is either they work REALLY well or they are terrible.

EXACTLY my experience!

Recently I asked around here and on Elfertreff.de about MAF kits. Either people loved their MAF Kit or else they absolutely hated it...!??

From my seat of the pants experience in a 911 CS with SSI's and a MAF kit I'd say; YES you gain extra power! That car felt very fast. Beacause of the ride I got in the CS I really want a MAF kit (already bought the SSI/Dansk exhaust).

But how come the MAF Carrera 3,2s are so sensitive if the 993s run perfectly with MAF from the factory? Isn't it the same basic concept?

[dad911]

How far are you from NJ? I have an autothority MAF I want to sell (search the want ads), If you want to drive to my place, we can put it in, and if you like it buy it. It ran fine for me, but I never compared it to stock, it was in the car when I bought it.

[1fastredsc]

If your speaking of a 964 with your comment of a cs, then it's the exhaust. I've heard many times that a good exhaust setup pulls a lot of pony out of a 964 motor. Why i can't explain, I'd assume the stock exhaust isn't all that great and needs aftermarket improvement but i could be wrong. The maf is only responsible for like 2-3% of the gain and throttle response improvement, that's it.

[Rutherford]

Huntley maf, has any one tried it out it has a fully controllalbe mixture set up from inside the car and goes for 1100 bucks. The one Performance Products offers is 1700 and doesn't have this feature. The Huntley also comes with a stoich guage, food for thought.

[ZCAT3]

Rutherford - if you do a search on this forum you will come up with all sorts of info on MAFs for the 3.2 911s. Here is a thread I started:

MAF Kit for 84-89 Carreras - 25 real HP - any interest?

As you can see by reading the post (and looking at the Dyno chart I posted) I saw a 25 HP increase with a MAF kit (the same MAF used by Autothority). The MAF also smoothed out the overall power band and greatly increased low end torque. Contrary to the info posted above, Brue Anderson in his 911 Performance Handbook got very good results from a MAF for the 3.2. At $2000 for the Autothority kit I do find these pricey (which is why I started the thread reference above).

[Rutherford]

Im not suprised I read what you had to say and it nice to see dyno numbers to prove maf works better then the barn door set up thats in there.