Quote:
Originally Posted by Quicksilver
People have maligned the barn door AFM for years but it isn't a source of inefficiency on the 3.2l engine. Talk to the people who have worked on hundreds of these cars and they agree. (Bruce Anderson coined the term, "It is a cash flow device. Jerry Woods reported a 5hp loss with the AutoAuthority MAF. I recently spent a week with the owner of a major LA shop and when MAFs came up he volunteered that no one had one that was better than a barndoor.)
There have been a number of MAF conversion products and no one has had one that performs better than the original. The closest you can come to an improvement is when it comes with a chip to retune the engine but retuning would make comparable improvements in an AFM equipped engine (by narrowing the safety margins that Porsche built into their chip).
There are some conditions where I would expect an MAF to out perform the AFM. When you are dealing with major altitude changes such as climbing Pikes Peak an MAF should perform better. When the basic parameters of the engine have changed such as displacement, RPM range, compressed induction, etc and you would have to completely retune the engine anyway and that would put the MAF on equal footing and if you had a truly increased air flow requirement the MAF could be a clear winner.
Just don't go spending major money on an MAF expecting to find a magical source of horsepower that Porsche missed out on. They didn't screw up the intake.
(If you want "more" look at the exhaust. There is about 20 HP to be found there by ditching the stock exhaust.)
|
I am very leery of taking advice from someone who has cobbled together a bunch of quotes
from other people and has had no first person experience with the situation themselves.
That said, I have had an excellent experience with the MAF update on my 964 3.6. The motor starts better, idles better, and part throttle acceleration is transformed. I can't speak about the 3.2 Carrera performance, but I assume it would be similar.
I never expected a "magical source of horsepower that Porsche missed out on" but wanted to eliminate problems with tracking wear of the AFM contacts on the resistive strip in the unit (a problem we all know happens on these 30+ year old units). The performance improvements I experienced were a bonus. As far as the AFM being just as good as a MAF, PAG sure thought it was an improvement when they when they UPGRADED the 993 to a MAF instead of the 964 AFM!
I will agree, there were some less then steller attempts early on in replacing the AFM with a MAF (AutoAuthority and others), but that was years ago and over the years some folks have improved and upgraded with a new approach.
Do a little searching on Scarcellers excellent MAF upgrade solution and the glowing reports from the folks who have used it.
In my world, first person experience trumps Googleing and posting a lot of quotes from other people from who knows how long ago.
Kinda like "the proof of the pudding is in the eating"
Just my $.02