Hey fellas, during what we were expecting to be a routine project today we actually discovered something new... There are indeed some folks that actually drive these cars In all seriousness though we had a customer drive down from Calgary (Canada) with a "higher" mileage 07 Turbo and some 24K miles on the odometer. Usually the cars we've seen here have anywhere from 3 miles (from our local dealer) to 10K. On tap was a full EVT580 Stage II with the EVOMSit software, Cargraphic exhaust and EVO BRVs. A run-of-the mill type of deal for us you would think... But we were right to be suspicious

So far the only time we've ever changed the spark plugs on 997TT's was on EVT700 kits because once the turbos are off access easy. Thanks to Porsche and the layout of the VTGs, controllers and turbo ducts access hasn't looked very friendly unless the turbos are off. From our 996TT experience we know that the most stock beru plugs last in a flashed/modded car is about 13K. Anything over that and we absolutely insist on changing plugs (01s with FR5s have to be changed no matter what) before doing any sort of modification. Porsche calls for a spark plug change at 30k intervals (much more realistic than with the 996TT which was every 60K) so this car was getting close to needing new plugs even in stock form. Sure enough with an extra 100hp or so these plugs were not happy. The plugs for the 997TT are a more "delicate" design and this time use a Bosch double platinum style set up.

Hence, those of you with higher mileage cars that are thinking of modifying make sure you consider changing your plugs around the 20K plus mark. At least plan for it. For those of you already with modded cars just know that going over 20K might mean a trip to the dealer/shop for a spark plug change. Symptoms will be a flashing CEL under hard acceleration between 3-4K and bucking/stuttering (misfiring) and a P03xx missfire code. It's subtle at first and gets worse quickly to the point of a flashing CEL. I don't yet know what a dealership would charge or what book time is but James did do it without taking the turbos off and he has wee hands (albeit bloodied). My guess is that it won't be cheap because apparently the turbos have to come off Oh and the plugs aren't cheap either

Here's James measuring the gap of the ones that came out vs the ones going in. Should be around .7mm and this one was a "bit" out of spec at 1.14mm:

New (top) vs Buggered (bottom)

Left (new) vs (Buggered (right)

Look closely at the Electrode of the "crap" one...

 

Cargraphic Exhaust (they've always nailed the sound even from the 996TT days):


With some techart tips, which are easy to install and line up thanks to the adjustable outlet pipe on the Cargraphic (please everyone do this):


In go the BRV's (in black this time):


Just about ready now with the new plugs back in to go for a final drive tonight before she's ready to go home...

 

Great write up sharky as always. Good info!

 

Great write up.