U.S. Carrera ClubSport demystified - DME chip analysis

[Steve W]

For years now, I'm sure some of us have wondered about what makes a Carrera Clubsport 3.2 motor any different than a typical Carrera. We all know it's a stripped down lighter model that cost more and has hollow valves (option M637) with a higher rev limit of 6840 programmed in the chip. And it's supposed to be quite a bit quicker than a stock 3.2 But I've read speculations from different folks who think the engine is balanced and blueprinted by the Factory, specially handpicked after being dynoed off the assembly line, and it has a special DME with a special performance programmed chip with the motor producing something like 250 hp over the factory 207-217.

Wil Ferch, one of our Pelican members here was kind enough to send me the chip from his friend's '85 Clubsport for a chip dump and analysis. The first thing that was peculiar was that it contained a 28 pin chip in a Bosch DME box that came on the later 88-89 3.2s. The only differences between an 84-86 24 pin box and the later 28 pin boxes are a different chip socket, and the placement of some jumpers in different locations to address the larger memory of the 28 pin chips.

The chip number of this chip is 1267355330. This number alone is a bit unique in that all 28 pin chips on U.S. cars are either the more common 1267355357, or the more aggressive 1267355358. I had some time tonight to review this 330 chip and found indeed it is factory programmed with a 6840 rev limit, as opposed to the standard 6540 limit. But the real surprise came when I did a byte by byte comparison with the standard 358 chip. Other than the rev limit hex value being different, there were NO other differences between the binaries. In other words, the Clubsport chip is basically identical in every way to the U.S. factory 358 chip that came on some 88-89 3.2s. So does the Clubsport motor produce any more power? Maybe a little if it was blueprinted, but I kind of doubt it. I think the stripping of weight was the key factor responsible for the increase in acceleration. Bear in mind though, the factory 358 chip only came on some U.S. 88-89s and was quite a bit more agressive than the 357 chip, and the chips that were programmed for the 84-86s. So if you raced for example, a stock 86 against the stripped Clubsport, of course the Clubsport will outrun it. Also note, that a European Clubsport is different with a higher CR like all the 3.2s are there, so they of course are a bit different. European's don't have to contend with U.S. EPA regulations, and a chip analysis of a European chip shows a much more aggressive fuel map throughout - read more power and torque.

So can the Clubsport/358 chip be improved upon? Sure it can. Though it is Porsche's most agressive chip, it is no where as aggressive as some of the performance chips out there. Even a modified factory European chip will outperform here. The part throttle ignition and fuel maps have room for improvement, and some folks who replaced the 358 chip in their 88s with a chip I supplied them noticed a nice increase in power and response. Here are the screenshots of the chip dump:


ClubSport Fuel mapping


ClubSport Ignition mapping

[avi8torny]

It never ceases to amaze me what people can do with a little free time. My mind is spinning just figuring out how to set up a secondary email account on Road Runner. Good Work!!

[Thomas Owen]

Once again Steve, very nice work!
Regards,

[Early_S_Man]

SteveW,

Any ideas on a source for PC software to communicate with a Data I/O 29B Eprom Programmer?

[Joeaksa]

Steve,

Thanks and still love the chip you programmed for me! Glad you have the time to map things like this out and share it with the group!

Joe

[ljonespwc]

That's an interesting analysis Steve. I used to own a 1988 Club Sport, and there was never a 1985 CS. The car was produced only in 1988 and 1989--that would explain the connector issue you mentioned.

My paperwork indicated the the motor was in fact assembled at the Werks division of Porsche--so there was likely a balancing/blueprinting (or something to that effect) that took place.

I raced my friend's 1989 911 Coupe many, many times. We swapped car many times as well. My CS always came out on top, no matter who the driver.

Thanks for those readouts.

[Steve W]

Thanks guys for the kind words. Warren, unfortunately I don't have a source of software for the Data 29b programmer. If it's for programming eproms for Bosch DMEs, Marc Skarshinski is working on a realtime emulator which interfaces with the factory Bosch box and allows one to change fuel and ignition values on the fly. Should be interesting.

Good to know that the CS was built by the Werks division. Tim Polzin in a previous thread did mention the DME was from an 89.

[TomTurtle]

Steve W:

Thanks for the info! I'm going to have to check which chip I have on my CS; since its a US car, I would guess its the 57 or 58. My car always seemed faster than my '89 Targa, but that could have been, as you surmised, totally due to the weight difference.

I was surprised to hear of a '85 CS as I understood from all my research that the 3.2CS was only built from '87 to '89 and the '87 model was Euro only. Its also good to have confirmation that the CS was built at the Werks division!

If I wanted to upgrade to a more agressive chip, what chip/brand would you recommend? Also, what would be the possible impact on the engine of upgrading the chip (other than increased hp)?

Thanks!

[Randy Webb]

You should send the info to Pano and Excellence. It deserves to be published in a permanent format.

[MIK911]

Strong work, Steve!
This raises a couple Q's in regards to my '86.

1)can a 358 28 pin chip be modified to fit my 24 pin socket?
2)how does 'your' modified 24 pin performance chip differ from the 358 aggressive chip? in regards to hp increase, torque,etc.

Thanks
Mike

[Steve W]

Tom, could you check and let me know which chip you have in your CS? The last digits are 330 then it can give me official confirmation on the chip I just dumped. We've found that most chips cause excessive predetonation with much too aggressive ignition timing, or are too rich on the bottom end and too lean on the top - also causing predetonation. And all chips are not the same - they are all so drastically different.

Mike, yes, the 28 pin mapping can be implemented into a 24 pin chip - actually I've done it already, and your 24 pin box can be modified to accept the 28 pin chip. It's not that difficult and requires the change of the chip socket to a 28 pin, and the removal and replacement of a couple of jumpers on the board to address the increased memory of the eprom.

[TomTurtle]

Steve, thanks for the info. I'll check out which chip I have; as luck would have it, my car is at the garage for some handling updates. Will get back to you asap.

If I do go with a more aggressive chip, will I have to reinstall the old one every 2 years to pass CA smog? What kind of hp increase are we talking about? I had an Autothority chip on my '89 Targa and the difference was most noticeable in mid-range. My CS has a noticeable ability to pull harder in the upper ranges, much more so than my Targa! Is your hp increase noticeable throughout the whole torque range or more on the lower and upper as opposed to mid-range? I will mostly be interested in autocrossing as opposed to racing so low-mid is more important.

Thanks!

[Wil Ferch]

Guys:
Just to clarify...
Yes..I'm working with Steve on a a new chip for my car as well as for my friend who owns a stock 1985 widebody...BUT..that was apparantly modified somewhere along the line, probably by Stahl Motorsports in Florida. This car should have a 24 pin box (like my stock 85)..but we find a 28 pin box, instead. His box is labelled:
-Bosch 0 261 200 085 ( 911.618.111.16) .."Typ 911-MWS-02", and this label is red instead of the commonly-seen black. Factory manual reference is that the .16 box is for option code M637...which we deduce to be Clubsport.
Just trying to be clear why an 85 has a 28-pin/clubsport box.
---Wil Ferch

[RickM]

Steve,
Great work! Why do you suppose Porsche went to the larger memory chip? Is there that much more info to store? Faster access time on the 28 pin Proms? Also, do you programm on EEProms?

I recall seeing a in-cabin dual chip console. You could switch from using one chip to another at the flick of a switch.

Rick