Porsche Enthusiasts Club Forum

I'm mid way through a big overhaul of my Turbo (top end rebuild, head work, new water pump etc.) and whilst I'm at it I decided to chop out the centre exhaust resonator box and replace it with a straight section of stainless pipe I bought from a local exhaust shop. I cut through the box itself towards the back to provide more of a sleeve for the join and I happened upon an interesting venturi feature in the box, presumably as part of the resonator but also a big restriction!!







Glad I tackled this one now, although I've not started or driven the car yet but the new pipe has gone on nicely a few more photos of the job:

Just a bit of feedback on this: I'm very pleased with the result and the car now sounds like a Porsche should! The exhaust tone isn't too loud, but it now emits a lovely orchestra of burbles and crackles on the over run and it really roars when on boost. There's no unwanted boomyness or resonance and when driving gently you can't hear much difference inside the car.

It doesn't sound too dissimilar to an r54 Mini Cooper S now, only a bit deeper. My only criticism is the idle tone could be a little more refined, but it's not particularly loud or unpleasant. I can't really tell if the car makes any more power as I've carried out a few other tweaks at the same time, but I'd like to get the car back on the rollers soon any ways so I may report back on that one. Although in theory it should help.

For the sake of an afternoons work and the tenner I spent on the stainless pipe I'm a happy chappy

Rich

Good work.. maybe you should offer this service to 944t owners!

I wish I had the time to, but there aren't enough hours in the day to keep my own cars in check!.. My mates have to go on a waiting list if they need me to help with their cars/projects

Any decent custom exhaust shop should be able to do this though, just bear in mind to do a proper job the whole mid section needs to be removed from the car and there's always a risk that a stud could shear on the turbo exit pipe... I asked for quotes a while ago and it was between £50-100, but I would say its on the higher side of that to do it properly. But I have all the kit to do it myself so it was an easy job in the end.

If anyone does plan on doing this you'll need some stainless weld wire and argon shield gas (I.e. Proper weld gas not just co2 pub gas).

I did mine on the car, it was a PITA to weld the top of the tube. At some point I'll fit the big turbo I have and add a 3" downpipe to it. I'll weld it off the car though.

Interesting stuff.

There are no doubt some power gains to be made by performing this modification. What exactly those benefits are is intriguing.

I've said before when I ran the exhaust practically straight through it was more laggy but seemed to come on stronger at the top end, maybe the car wasn't optimised for that setup, but not everyone thinks some back pressure in the exhaust is a bad thing.