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996 Cup Car - Fitting an alternative switchable ECU for a less aggressive map?

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Old 03-09-2018, 06:05 PM
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More Cowbell
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Default 996 Cup Car - Fitting an alternative switchable ECU for a less aggressive map?

Hey everyone.

I have an ex-carrera cup 996, late spec (2004) and it's great.

The only thing is I would like to be able to enjoy it for longer than a hundred or so hours without the engine going bang. I've thought about a remap down to maybe GT3 mk 2 road car spec, or maybe a 996 GT3 RS profile so that it's still pretty hardcore, but then someone suggested getting a new ECU but keeping the Cup Car one in place with a switch so I can go between the two. So if I'm doing a high speed test or demo (Spa Classic etc) I can keep it hardcore, but preserve engine life on trackdays with the less hardcore option.

The question is, has anyone done this? Is it even possible to source a road car's ECU without spending huge money? And is it as easy as it sounds to be running two chips?

The GT3RS ECU sounds like a great idea, but it's not like they're advertising them on ebay.

All advice gratefully received! Please assume I have the mechanical understanding of a small child or albeit rather intelligent dog in tailoring your answers.

Joseph AKA More Cowbell.
Old 03-09-2018, 06:40 PM
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Laurence Gibbs
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If your car is an 04 does it not have switchable maps anyway? Warm up and race ? You could could probably have the original ecu flashed with a de-tuned map . The MS 3.1 ecu is quite old now and there must be tuners out there that would be capable of this? Alternatively buy an MS 3 Sport which is configurable out the box, but not cheap. To be honest though I am not sure how much this will really help engine longevity. I would imagine you would only be softening of fuel and ignition timing. keeping to a self imposed lower max RPM would have much the same effect .
Old 03-09-2018, 07:57 PM
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bgiere
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Just keep the revs down...shift at 7K instead of 8K. Should be able to get 150 hours out of a well built/fresh engine by shifting conservatively. The Map switch in mine gives me "Race" "Rain/Fuel Saving" and "Qualify" modes....I have dyno'd it extensively and can't see a difference in the settings.
Old 03-10-2018, 01:32 AM
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spiller
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As above driving style would be the major difference. Shifting before redline and going easy on the downshifts is the key.

What average mph is generally used to determine how many miles equate to the hours on a given cup car engine?
Old 03-10-2018, 02:42 AM
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More Cowbell
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Originally Posted by Laurence Gibbs
If your car is an 04 does it not have switchable maps anyway? Warm up and race ? You could could probably have the original ecu flashed with a de-tuned map . The MS 3.1 ecu is quite old now and there must be tuners out there that would be capable of this? Alternatively buy an MS 3 Sport which is configurable out the box, but not cheap. To be honest though I am not sure how much this will really help engine longevity. I would imagine you would only be softening of fuel and ignition timing. keeping to a self imposed lower max RPM would have much the same effect .
If my cup can handle dual switchable maps that would be awesome. How can I tell? The dash buttons are the usual battery, fire, Bosch fuel injection and air blower. The alternative would be another stock ECU and flashing it I guess. Would want to be able to go back for the big events. As has been suggested below I could of course shift earlier. That’s a bit too much margin for error for m to be comfortable with. They rev so fast it always seems time to change up anyway!

Last edited by More Cowbell; 03-10-2018 at 03:10 AM. Reason: Typo
Old 03-10-2018, 11:33 AM
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Viperbob1
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On one car we did 185 hours with 8k shift points and when we took it out, the leakdown and compression were all still fine. Took motor apart and no evidence of wear hardly on anything. I have seen guys with 300+ hours on these motors.

A shop that tells you 100 hours is trying to FUD you (fear, uncertainty, doubt) with horror of the "what ifs??"". These motors WITH PRO DRIVERS ON THE EDGE EVERY SECOND lasted longer than that.
Old 03-10-2018, 01:53 PM
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That’s a welcome bit of reassurance Mr Bob. Pro pilot I certainly am not, and what seems like late shifting for me is probably closer to 7200 revs anyway...

Thanks all for comments and feedback. I guess psychologically there could be an element of ‘it’s all working well with motor and gearbox and I want to feel I’m looking after the car so what should I be doing?’ - even when the answer could well be nothing.
Old 03-10-2018, 02:36 PM
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Juha G
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I agree with everyone else here, don't mess with the factory mapping, just make sure you run and maintain the car correct (Warm-up, cool down, change oil often etc.).
Old 03-11-2018, 08:36 PM
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spiller
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Originally Posted by Viperbob1
On one car we did 185 hours with 8k shift points and when we took it out, the leakdown and compression were all still fine. Took motor apart and no evidence of wear hardly on anything. I have seen guys with 300+ hours on these motors.

A shop that tells you 100 hours is trying to FUD you (fear, uncertainty, doubt) with horror of the "what ifs??"". These motors WITH PRO DRIVERS ON THE EDGE EVERY SECOND lasted longer than that.
300 hours is amazing. Are these numbers referring to total engine hours or hours between refresh? Would it be fair to say an engine that has already been refreshed previously does not have as many hours in its ceiling compared to an unopened engine?

Last edited by spiller; 03-11-2018 at 10:18 PM.



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