Thought I'd share my dyno results with the New Gekkatec MAF installed. If you haven't heard, it's a "plug and go" MAF system for the 3.2 Carrera that does not require a chip. I have no affilation with the vendor, just admiration for the product since it opens up alot of tuning options. (www.gekkatec.com)

After the MAF install, I thought it would be wise to check the AFR's to be on the safe side. Also, the fact I am running a SW chip that wasn't programmed for such a change made me curious what, if anything, could be left on the table for tuning.

I have to so say, I was pretty impressed at how well it performed on the dyno. Although not "earth shattering" by today's HP standards, the 25YO P-car still managed 208.8 RWHP. If my math is correct, then that works out to about 245 HP at the crank!!!!

For those interested in my setup, I have a Dansk Euro Pre-Muff, Steve Wong Chip, and M&K Exhaust 1in1out 3" diameter.

Here's the Youtube of the dyno. Enjoy!
http://www.youtube.com/watch?v=bIwFM19tSEY

 

"I have to so say, I was pretty impressed at how well it performed on the dyno."

So where's the before and after?

It has yet to be shown where a MAF makes any significant difference on the
911 forum nor on the 964 forum. Usually that mod includes a 'performance
chip' which tweaks the timing to achieve basically a 3-4 times sale of a standard
'performance chip', i.e. good marketing strategy if you can 'pull-it-off'.

 

How about picking up the latest "911 and Porsche World" Mag (issue 188) if you want results of the Gekkatec MAF before and after. Or if you'd like, I'll supply the time if you provide the dime and I'll show you more dyno results.

Say what you want about MAF marketing. My stock AFM was in need of a rebuild and there was no way I was going to spend $1300 to refurbish/replace antiquated technology when newer, better exists.

Of course, why should I explain this to you? I'm just one of many satisfied chip and MAF customers out there to which you would disagree. Seems that some things never change.

 

...theres an app for that.......
come on SOMEONE had to say it

 

Here you go, Lover:

911&Porsche World, November '09, p94-p98, before and after dyno test.

Before:229.5hp
After: 241.4hp

Not that EVIDENCE would make any difference to you.

 

Dyno day yesterday with new RarlyL8 Headers and M&K 2in 2out exhaust.
A bit of a dissapointment, it looks like the car pulled almost the same HP as last time, however, the AFR's are completely off, running extremely rich.

What is odd is the last dyno session the AFR's were very consistent across the range until about 5500 RPM where is leaned out slightly. The only thing I've done since then is bolt-on the headers and exhaust. I find it hard to believe the fueling would be this bad. Some have suggested reduced exhaust reversion, or possibly the FPR or damper is bad. Any thoughts on a rich condition associated with headers and exhaust changes?

http://forums.pelicanparts.com/porsc...ml#post5574966

Stock Headers, MAF, Euro Pre-Muffler, 1in1out M&K


RarlyL8 Headers, MAF, 2in2out M&K


Interestingly, we did a 20% throttle run to check cruise AFR's, they were between 12 & 13; not as bad as the full throttle map.

 

This is just with a MAF, headers, and muffler?

Do you have a custom chip? I wouldn't want to run an off the shelf with those mods, just my $.02.

 

A custom chip has not been mapped... yet. This was to get a baseline of the changes from the before stock headers and 1in1out muffler. As you can see, the AFR's went very rich, but my question is why? I spoke with Steve Wong and he thinks it could be related to the MAF signal. However, after speaking with Chris of Gekkatec, he doesn't feel it's the issue.

Looking for any input from others that may have experienced similar issues running headers.

 

It has to be the MAF signal. I mean, your universe of variables is populated with exactly what, three variables?

When I install a stock '86 barn door air flow sensor in place of my '84, it tightens up the lambda wave from 1.4~.96 to 1.2~.98. And this is an immediate, verifiable cause and effect with the same physical part. You are sending new data to the dme, with the same physical motor and getting rich AFRs. It just sounds like you need a custom chip to correct this, unless you have other signal problems like a bad O2 sensor, or your MAF is sending bad intake temperature data.

You could buy or borrow an LM-1 and maybe re-install the stock AFM to get baseline data.

 

Compared to the before and after AFR's, and given that only 2 variables were changed (headers & exhaust), I don't suspect the MAF at this point. The SW chip installed is tailored for stock headers. I never assumed I would see perfect results with the changes, nor did I expect to see the AFR's so rich either!? (I would have guessed lean). Some have suggested reduced exhaust reversion as a possibility for the rich condition.

Maybe I will re-Dyno the car with the Stock AFM and see how it responds.

 

If you are going to re-dyno, then ask Steve to send you his dyno results first. That gives you baaeline for his chip.

 

Puzzled by the rich condition all day, I decided to look elsewhere and check a few things. Compression shows 170 on each cylinder. Idle switch and WOT switch are both good. However, Cylinder Head Temp Sensor (Cold) = 1780 Ohms - (Hot) = 1100 Ohms!?! Car was fully warm with 30 mins of hard driving. It is my understanding the readings should be below 300 Ohms when Hot? If the DME sees 1100, wouldn't it make mixture be overly rich?

 

Watching a car dynoed always makes me nervous.

 

I pulled 207HP at the wheels back in the stock 3.2 days with headers and a chip. I think that figure is pretty consistent for bolt-on power in a 3.2.

 

Nothing to add, but had to say, good response.