Respected engine builder Jake Raby posted a video the other day about a 996 and has claimed there and elsewhere that using anything besides the stock engine mounts results in, without exception, retarded timing and decreased power output.

Thought I would gather input here since I know we have a lot of experienced tuners and builders on this forum. Do your experiences match his claims? I sure never noticed any power drop after I had some semi-solids installed but I didn't dyno or run diagnostics either.

 

Interesting. Tough to argue with the displayed results and the reasoning makes sense (more vibrations passed to the sensors). I went with the Function First urethane filled stock mounts and have not noticed anything negative, however I have never had the car on a dyno.

I was more worried abut NVH than anything else when I made my decision.

I am guessing I can log timing using the Durametric to see if anything shows.

Ed

 

Apparently aftermarket motor mounts create a vibration/sound that messes with the knock sensor iirc and messes up timing. Usually only notice in high hp application.

I believe markski on that forum posted about it.

the preferred updated mount is a Porsche motor sports part.

 

Yeah, I had always heard rumors of the knock sensor thing but I've also seen people report that they've datalogged their cars and not seen the engine pulling timing, even when using totally solid mounts. In typical Raby fashion, his posts on Rennlist imply that he's the only guy on earth to have attained this secret wisdom and that everyone with rigid mounts is a dumb keyboard warrior so it made me think surely some of the tuners and builders here would have noticed such drastic problems and it would be widely known. Or maybe most of the cars here are running stock mounts? Or could the Mezgers/Turbos be less susceptible? Would be a real shame since they really improve the chassis characteristics of the car in my opinion.