Computer chip?
 

Does it really increase the performance? How? Is it worth it? How much? Which brand? Possible damage to DME?

Caliber

I like the Weltmeister one I have in my '85. I noticed the top end has really picked up. I believe you, like me, will have to run 91 octane.

I hear THE PROgram or a piggy back or something like that is better, but it is also $$$.

Then there are others who say there is no difference when changing the chip.

What other mods have you done?

The HP difference between pre '87 and '87 on 3.2 U.S. Carrera's is 207 vs 217 respectively. Isn't this difference mainly from factory chip programming? If so, can a chip be made for a '86 car that mimics HP of '87on car?

SteveW--is this what your chip does?

thanks
Mike
'86 coupe

According to Bruce Anderson, the "207" and the "217" hp motors make the same horsepower on the dyno. I don't know if this refers to an engine or drive on dyno.
-Chris

The difference in hp between the different years of 3.2 was due to the way Porsche programmed the chips. As the years progressed, Porsche became more aggressive with their programming until the 89s, with the 1267355358 chip, which was the most agressive and produced the most power of them all. 84-86s were all programmed the same, and the 87 1/2 to 89s used the 28 pin chip. Porsche also had another chip for those years and it was the 1267355357 chip which was a little more conservative than the 358 chip. Most U.S. 88-89s came with the 357 chip. For example, at 6000 rpm, the 357 chip runs 17.2 degrees total advance, with a lambda ratio of 1.01. The 358 chip runs with 21.3 degrees total advance with about 1-2% more fuel. Since full throttle is a region most drivers are infrequently in, the full throttle maps are optimized for power and are exempt from emissions requirements.

I have programmed a chip for the 84-86 cars that is mapped identical to that of the late 358 chip at the request of a previous customer - so it can be done. However, it's performance is still not the same as that of a full performance chip. The factory U.S. cars still need to comply with U.S. emissions and are leaned out to stoichometric in the part throttle regions, and ignition timing also controlled to a limit. Reworking the part throttle regions to provide additional enrichment on sudden throttle acceleration, and increasing ignition timing helps to increase part throttle torque and response in the low to midrange driving region, where most people do 95% of their driving. The current iteration of chip I developed takes the best parts of the part throttle ignition and fuel maps of the factory 358 chip, the clean low and mid part throttle emissions power of the Autothority chip, and nice low end torque of the Weltmeister chips, and combines the full throttle fuel maps from the factory European chip to produce a chip which I believe is pretty much as optimized as you can get. If you're interested in any of them, feel free to shoot me an email - steve@911chips.com