Just some info that may or may not be usable for you guys, here are my plugs changed at 21,000m with about 15000 of those miles with the EVOMSit flash.

The car is never tracked and a weekend mostly car, its not babied but also not abused.

It often comes up what time the plugs should be changed on a flashed Turbo, maybe the pros can chime in and let us know if these should have been pulled earlier or if they had some life left in them yet.






worst looking plug up close

 

You should replace them more frequently...

 

Novice question, but is the longevity of a spark plug proportional to the power you're pushing? ...(such as tracking at higher rpms so averaging a high output per mile, or tuned so every rpm gives higher output)

 

Yes, some tuners mentioned you should change more often if flashed. I think the GT2 also has recommended change intervals much shorter than the Turbo. I posted the pics to get feedback on the condition on the plugs, maybe get some insight on a good interval change for flashed cars.

 

Interesting thread and looking forward to hearing the replies.

 

Those plugs have an awful lot of carbon for 21k mikes. The tips are even a tad rounded. You should change them more often. Carbon build up that much can / will cause a lot of detonation, especially on boost. You may wish to investigate proper heat range for the plugs, oil consumption, crappy gas, as well as the tune being too rich. You been running leaded racing fuel ?

If the tune has increased boost you will always need to change plugs sooner. 20k or 30k miles is the recommended interval on the stock 997.2tt's I think. I think that's maybe a little extreme. We will see.

--CC

 

Those were oem plugs, never ran anything other than the crap 91 we get in CA, typically 76 is what I use.

The new plugs installed are same type but gapped to the recommended 'flashed' spec.

 

Based upon your pictures replace them every 10kmiles...

 

+1 for sure.

 

I replace mine every 10k kms

 

You are doing the best Antonis...

 

those plugs look pretty bad. The amount of carbon is unacceptable. I would consider changing fuels also - maybe go to a Techron or use fuel system cleaner regularly.

 

considering the type of fuel that you are using they look as they should after the mileage you put on your car
I would recommend for you to try one of those engine treatment , especially for your throttle body.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&_trksid=p4340.m748&item=310 331979176&viewitem=&_trkparms=clkid%3D134522056672 9017450

 

I have copied the folowing link covering spark plugs. The information on this site is very comprehensive and, if you trawl over the site the information provided should answer all of your questions.

http://www.ngksparkplugs.com/tech_su...3.asp?mode=nml

Looking at your photo it would appear your plug fits within the range where it is unable to clean the accumulation of combustion deposits, additionally is also being subject to higher than normal combustion temperatures..

 

Thank you very much for everyones input, this is great info.