[Harvey]

Today I installed a new Racer-X performance chip and for the first few minutes the car put out a smokescreen like a car with broken oil rings. I freaked out...even at idle it put out a LOT of smoke.



However, having disconnected my battery, and knowing that the brains need a minute or so to "reprogram" I took the car for a 10 mile spin. Boy did it perform well! I'm ever a skeptic but I'm sure it was running noticeable more responsive than before. When I parked, no smoke.



However, after an hour I cranked it up again and there was "some smoke" in the exhaust but not anything remotely close to what was there when I first installed the chip.



Frankly, I love the apparent enhancement in performance this chip gave..pretty steady across the curve. However, the question remains....does the chip cause some smoking exhaust? If so, why? Does this mean I will need to change plugs more often? More carboning? Or will it eventually go away as the pipes clean out? Or is this just a characteristic of the chip?



When I chipped my 928 (Autoauthority) I didn't notice smoke but I did notice a slight increase in the smell of unburned gasoline at idle. But...on the track..the car performs like a champion. And there was no decrease in gas mileage.



What's your experience with Racer-X?



Thanks,



Harvey

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[Cloud9...68]

Mine had the Racer-X chip when I bought it, and it has never smoked. During the troubleshooting of a stumbling problem I had awhile back, I put the stock chip in, and then put back the Racer-X, and didn't see any smoke. I have no idea why the chip would cause the car to smoke. Were you by chance doing any other work to the engine that could be responsible?

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[orphanowner]

There is a collective misconception that the DME in the pre OBD1 or 2 ECU's (as fitted to all 944 series Porsches) can actually "learn" based on dynamic or changing engine parameters , but this is not accurate information.



The engine management in the 968 or any 944 series car cannot "learn" or "reprogram" itself. The EPROM has ONE static program that does not "adapt" to any condition. There IS a series of maps or tables that the ECU can reference for application data based on various sensor input, but there is no "learning" or to use the correct nomenclature, "adapting" like you would find on a current OBD Porsche. The engine is turned off, the DME resets itself and once again looks for new information to make moderate adjustments in the timing and fuel tables based on current operating conditions.



The simple digital brain in the 968 does it's best to find a (preexisting) compromise fuel and igintion map based on engine RPM, load, coolant temp, ambiant air temp. RPM, throttle position etc...moon and star alignment... but does not have the capacity to make adjustments beyond the fuel and timing maps programed into the chip.



The discovery of smoke upon startup, or a 10 fold increase in power, or evidence of new hair growth and stronger, longer lasting e...you get the idea. None of this can be attributed to simply pluging in a new EPROM chip into the DME.

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[ds968]

no smoke at all with mine - on the very first run it backfired once ( I think around 7200 rpm ) .. and that was the first and the last time anything was less than perfect with this chip..

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[Harvey]

Followup Note: As you know, I bought the RacerX chip, disconnected the battery, and installed it in my '94 968, grounded, careful install, etc. Then when I started the engine it sputtered for several seconds, a couple of small backfires, and then it smoked like a banshee for nearly a minute. Then the smoke cleared out...and smoked less and less for the first 10 miles. I've driven it about 300 miles now. For a while there was some brownish smoke on startup in the mornings but no smoke once warm.



Today, I had a thorough leak-down test done and all's tight as a drum....3-5% deviation. Also, no smoke on startup now. And the car seems to run stronger with the chip.



I have a stock chip and a proven Weltmeister chip that I was going to substitute in and compare with the RacerX but it's running great right now and no smoke so I'm leaving it as is.



What happened? I don't think it was coincidental. I think that the Motronic must have gotten sideways somehow with the new chip and it took a minute to adjust itself. Probably confused the injectors or something. Don't know why it took 300 miles to clear it all out though. I'm crossing my fingers that it will keep running fine. Sure ran well today. When it hits about 4400 rpm it really comes alive.



Harvey

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[flash]

not sure what was going on there, but i am sure there is nothng wrong with the chips in general - yours is the first i had heard of any such issue - keep an eye on it, but i'm sure the chip is fine



did you make sure that your dme cable was securely in place? that lever can be tricky

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[Harvey]

[quote name='flash' date='Feb 3 2006, 07:17 PM']not sure what was going on there, but i am sure there is nothng wrong with the chips in general - yours is the first i had heard of any such issue - keep an eye on it, but i'm sure the chip is fine



did you make sure that your dme cable was securely in place?  that lever can be tricky

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You're right about the DME cable being tricky...mostly because of the tight quarters and angles but that went smooth. As long as it runs like it is right now, I'm delighted.



Harvey

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