Switchable PSE

I bought a 996 a couple weeks ago and have since then spent a considerable amount of time trying to come up with a suitable alternative to the switchable PSE. The non-switchable looks to be the Oettle or H&S preferred method choice seems to be to weld in a 1" pipe between the muffler pipes. But I'm really keen to have the option to switch between the two. Oettle now appear to be offering the switchable mod but it's running in at around £1k more than the simple welded pipe solution that they offer: http://www.oettle-tuning.de/epages/...ctPath=/Shops/61293769/Products/96.330SKLAPPE I'm from an engineering background and I'm fairly certain I can find a welder (in fact I possibly already know one) that could do the 1" pipe mod for the promise of a couple pints down the local. So the extra £1k for a switch, unfitted, really is a stumbling block! I toyed with the idea of fitting some sort of manual valve in between the two 1" pipes but couldn't find any suitable valves as the exhaust temperatures are far higher than the PTFE seals could handle. I also thought about stripping the PTFE seals out the 1" manual valves which would shut off the bypass somewhat but it's all or nothing for me and don't want to go about this half-arsed. I guess the next step will be to see if I can source some original Porsche components like the switch (which I've found) but more importantly the valves themselves. Does anyone know if these are stock items or if they are only supplied as part of the PSE unit? Does anyone know where I'd even start looking for these other than calling Porsche themselves? Anyone want to take a stab at how big a job routing the switch back to the dash would be? Is anyone even reading this? :lol: :thumb:

opcorn:

On the subject of routing the wiring to the dash, I discovered this was not too hard in so far as I had to run some wiring from my wideband O2 sensor up to the OBD2 port in the passenger footwell. It was easier than I expected to get that wiring from the engine bay to the footwell. However I didn't run the wiring under the front carpet (I went under the seat and under the floor mat since the wiring was only going to the OBD2 port. In reality though, running the wiring under the front carpet wasnt the part that I was concerned about either. There are pics on my web page (as always ) in the WBO2 section showing where my wiring penetrated the aft bulkhead.

ABZ911 this is how the PSE mufflers are - valves, bracket & vacuum actuators, by-pass tube and a bit of neat TIG welding. Copy this and you're half way there :thumb:

I see the PSE version is running a far larger diameter pipe between the inlet and outlet than the Oettle version, which I believe is 1" in diameter. Comparing the previous two photos above, it seems like the PSE version is also run from another part of the box, which bypasses even more of the muffler: I take it this means that PSE is far louder than Oettle or H&S mods?

You have PSE1 and PSE2 there. They are basically the same SPL, but the PSE2 is slightly lower overtones (marginally more bass). Note: the 1" is a full stage (1,2,3) bypass, the 2.25" is only a 2/3 stage bypass. The smaller 1" bridge bypass varient is 996.1 identical, the second 2.25" nipple bypass is 996.2 and 997.x compliant. Technically the PSE2/nipple mod is called a FisterD (as opposed to Markus Oettle for the PSE1 mod), as Darren Fister was the first to promote that mod. See here: http://911uk.com/viewtopic.php?t=56966 http://911uk.com/viewtopic.php?t=54591 http://911uk.com/viewtopic.php?t=53215 Video/sound files: http://911uk.com/viewtopic.php?t=51776 Here is PSE1 for comparison:

In the US I have seen motorised butterfly valves for exhausts, so it might be worth doing a bit of Googling. It would be easier to rig up than the vacuum actuators and solenoid valves of the PSE. Edit: This sort of thing: http://www.jegs.com/p/Race-Ready/Race-Ready-Performance-Electric-Exhaust-Cutout-Kits/757985/10002/-1

That's cleared up a lot of questions for me GT4 :thumb: I have a 2004 C4S, so am I right in thinking that I can go for either the 1" bypass (inlet to outlet) or the 2.5" (from 'additional' blanked port to outlet pipe)?

Correct. The blanking plate is the cormer "nipple". There are crazy variations where you do 2.25" bridge (PSE1 style) or even both (!) bridge and nipple bypass. These are far too noisy.

I got the Cargraphic back boxes recently installed. Good God, the sound is awesome. Granted it's a little bit more expensive than the above mod(fractionally more hp). It's allegedly the same sound as the PSE without the switch. I'll post up a video next week when I get home. :lol: :lol: . That Oettle mod sounds very sweet too.

I had originally planned to introduce a valve somewhere along the 1" pipe between the inlet and outlet and figured I'd have to introduce a bend or loop to fit it in. But I'm struggling to find anything smaller than 2.5" and I'm not sure if stepping up and down from the 1" size might introduce back pressure into the system as the gasses expand then are forced back into a smaller bore? Too much guess work on my behalf there. :dont know: So I'm pleased to hear that I can go from the nipple with 2.25" pipe and fit the valve before feeding back into the outlet pipe. As Richard H said earlier, there are the electronic Jegs valves which might suit: Likewise there are these manual ones: And I also tracked down which I suspect to be the actual PSE pneumatic valves themselves: But the prices for valves alone are neck-and-neck with the cost of the Oettle mod itself, so I find myself asking the same question I did to begin with; is it all worth it to have a switchable exhaust? :?:

You can't if your mufflers are 996.1 The internals are different. That is why H&S, Sport and Classic, Oettle etc do the bridge mod, it is compatible with any muffler (996.1, 996.2, 997.x). The problem is 996.1 and 996.2 mufflers look identical from the outside, and only after doing a nipple bypass on a 996.1 would you find out you just wasted the last hour of your life (or £300 etc). PS - don't bother with a switch, just drive below 2,000 rpm for stealth mode.

Now why would I want to drive around at 2000rpm? uh: Sorry, I took it that 996.1 were the older 3.4l models and 996.2 were 3.6l models. Is this not the case?

Yes. 996.1 = 3.4 996.2 = 3.6 Sorry, I missed you mentioned you had a 2004 C4S (3.6) on the first page. The advice is still true for anyone else looking to do the mod. It is possible that someone has a 3.4 and has fitted 996.2 replacement mufflers, which is viable, or even someone has a 3.6 and (incorrectly) fitted replacement 996.1 mufflers - which will physically fit, but isn't really viable. This possible confusion is also why the modifiers tend to prefer the bridge mod, which is valid for both (and a lot cheaper in time and materials than the nipple mod).

Yeah, ok. I'd mentioned earlier that I had a 2004 C4S but maybe you missed it? So the nipple or bypass mod is suitable..... isn't it? (spot the newbie!) :lol: