I have been reading up on this and am looking for opinions on chipping a 3.2 Carrera. Autothority's chip sounds like what I'm looking for, which is more low-end torque. Weltmeister seems a little cheaper, but I hear theirs offers more on the high-end of the tachometer. Who has had good results and with which chips? And who thinks I'm just looking for a way to burn money? Thanks.

 

No, I don't think you're looking for a way to burn money. According to many people who know more than I, a good chip and breathing improvements are the best and cheapest ways to increase hp and tq of the 3.2 without going inside the engine. Just don't expect substantial gains.

In his Porsche 911 Performance Handbook, Bruce Anderson describes the tests he and Jerry Woods did on 5 popular performance chips (p. 148 of the 2nd edition). An Autothority chip was among them. The best chip (he didn't say which one that was) produced a 9 hp gain at peak hp (217 DIN to 226 DIN). That's about 4%. The average improvement (across the rpm band) of the best was a 3.4% gain. In contrast, they found exhaust improvements (switching to SSI heat exchangers and a sport muffler with twin pipes) yielded a 13 hp gain, even with the OE chip. The tests were conducted years ago when commercial chip mapping/burning was still in its infancy, so the best chip for the 3.2 might even be a little better now. Maybe even enough to imagine you feel the difference.

If you also want to improve breathing, you should get a chip mapped for whatever breathing changes you make. The two changes will not yield additive gains, however, so you won't get 9 hp + 13 hp = 22 hp, for example. Some people advise to get before and after dyno measures to ensure there's a gain, but that can be expensive.

My personal opinion is that the 3.2 is a good candidate for both kinds of improvements. They don't cost a lot and they give fair return; maybe not as much as the vendors claim, but good enough for the money. 996 owners have to spend a lot more to get that kind of percentage increase. Of course, they have enough hp to start with (but enough hp = 30% more than you have).

 

Cool. I just ordered a chip and cone filter from Vertex. I wavered on the cat by-pass pipe, but may go back to it. I'm sure all three would complement each other nicely. But I'm not sure I want to R&R the cat for each emission inspection. I'll ask around at our PCA's next tech session and then go from there. I'll post my experience after I've installed and tested it well.

 

This spring I insstalled a Weltmeister chip, dual SS exhaust and the mass air kit w/ K&N filter. There is a considerable difference. The car feels like a different car, plenty more hp, and much more fun to drive.

 

Rick,
I purchased an 87 with an undetermined aftermarket
chip that i was skeptical about so I traded it off for the stock one. Boy was I disappointed,
I then purchased an authority chip and could really notice the improvement back the right way.
the car had cat bypass and a k and n in the stock
box so i replaced that with the same cone filter
you are concidering. made no differance except for engine noise was louder and easier to work around. ship the air cleaner us the stock one, add chip and cat bypass!
good luck keith

 

I just recently mapped out the fuel and ignition curves between the original, Weltmeister, and Autothority chips for the Carreras. I'll post out the differences and results in this forum later. In the meantime, you can preview the results here:

<a href="http://www.pelicanparts.com/cgi-bin/vb/showthread.php?s=&threadid=58173" target="_blank">Genome maps of OEM, Weltmeister, and Autothority chip here!</a>

 

Steve, your post was really interesting! I have a related question on chips: I have read that chips should be "matched" to specific engine mods such as intake/exhaust. If so, how does one get a "matched" chip? I contacted Fabspeed who offer "custom matched chips" from a owner data base, as it was explained to me. As you mentioned, if we have sport mufflers/cat-bypass pipes etc, a new chip that doesn't account for those mods may not be as beneficial. I'm not sure how to find the right chip? Also, do we have any owners with the Fabspeed chips out there?

 

I finally had a chance to post my chip dumps in this forum. Check it out here:

<a href="http://forums.rennlist.com/scripts/rennforums/ultimatebb.cgi?ubb=get_topic&f=1&t=001945" target="_blank">http://forums.rennlist.com/scripts/rennforums/ultimatebb.cgi?ubb=get_topic&f=1&t=001945 </a>

Rick: I don't know much about Fabspeed, or even if they do their own programming. Some chip manufacturers or tuners have chips mapped out for cars with similar modifications such as yours, and programming a custom chip is not necessary. I believe places such as Autothority, and Promotive Engineering have such a selection. Beyond that, there are ways to tweak your Motronic system to increase fuel delivery for modifications, even if you already have a 'stock' performance chip.

 

The published hp of Carreras went from 207 to 217 with the ’87 model year. This was explained by the fact that they started taking advantage of higher octane gas which became more readily available around that time. If the change to the chip gave the extra 10 hp, wouldn’t aftermarket chips take advantage of the better gas? This would be a quick hp boost for owners of ’86 and earlier Carreras.


Does anyone know the facts regarding this?