dan_189

Hey cds - how's the fit of these? Does it bulge the rubber or fit quite well?

Waiting on mine to arrive but thought I'd ask

cds72911

dan_189

Love that - any power differences? Not expecting gains - few people have reported losses??

cds72911

dan_189

Good enough for me - thanks!

porschedog

More good noise is all the inducement I need

dan_189

Received mine, very well made - what you'd hope for the price that it cost...

dan_189

Update: installed this and noticed I lost the nice burble I used to have when I let off the gas... @Porschetech3 we need your help!
Why did that happen? Do I need to give the ECU longer to adapt.

Ive taken it out already...
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808Bill

dan_189

It's contentious - I know there is no power to gain but perhaps the turbulence the box creates helps with the pulses etc.

Anyone into thermodynamics? I need answers! Haha

Esfoad

Porschetech3

The burbles, crackles, pops, on deceleration are caused by fuel that is not burned completely in the cylinder and is burnt in the exhaust. Our cars have a program in the DME that shuts down injectors during decell at certain times/temps/rpm, then turn back on near idle. On 991 and newer cars the DME is programed to "waist" some fuel during decell to deliberately cause more burble,cracks, and pops..It does sound cool. I had a friend who was complaining that his 996 didn't have any sounds on decell, I advised him to crack the throttle slightly during decell to keep the injectors ON during decell to induce the burble,cracks, and pops, he was pleasantly satisfied.

I would suspect that you may have unconsciously changed your driving style, or that the parameters for " injector shutdown on decell" were met during your road test. The elimination of the Helmholtz Resonator would have no effect on the decell sounds on closed throttle.

dan_189

Thanks Porschetech3! Might give it another shot

Actually @Porschetech3 one last question - sorry! Would a tune make a difference? I.e. there is a certain air/fuel parameter manually set and the cap/block off might change the air/fuel parameters?

Porschetech3

Certainly any/all parameters can be changed with a tune. It would all in the hands of the programmer/tuner.

But, I can't see the elimination of the Helmholtz Resonator having any effect on the Mass Air Flow unless it had a "leak"?? Have you checked it for a leak/seam split?? Maybe you could swap it back and forth a few times along with road tests to get a definative answer if anything other than noise at above 5k RPM is happening.

dan_189

Thanks! Yep checked - no leaks. Might but it back in but I could have sworn it felt slightly less punchy down low - my imagination? Perhaps...

I can't really hear anything but the exhaust at over 5k so I don't think this mod is for me.