Homemade PSE version 1.0 done, behold the "Evan Sport Exhaust"! pics/vid/writeup =>
 

Yes, I know I'm crazy. At least my wife thinks so. If you've seen my posts the last couple months, you'll know I've been trying to figure out how to make my own PSE with valves and a switch, which I have (mostly) successfully done:

http://www.evan.com/boxster/ESE/ESE_installed-1.jpg

http://www.evan.com/boxster/ESE/dash_switches.jpg



I started with a donor muffler from a 2000 S, purchased from a forum member. First it needed some polishing of course. I sourced the vacuum valves from Capristo in Germany.

http://www.evan.com/boxster/ESE/polishing.jpg

http://www.evan.com/boxster/ESE/polished.jpg

http://www.evan.com/boxster/ESE/capristo_valves.jpg



The plan was to do a partial muffler bypass (think Pedro or Fister) but pipe the bypass into the outer chambers of the muffler like the PSE, and with valved control. While this ended up being very tidy, in hindsight I should have run the bypass to the tips for more sound. Version 2.0 will do this, also internally so it will retain the tidy look (and hopefully pass EU inspections.) Since I can weld, I could build it any way I wanted to, but my box lives at my second house… so I had to configure the piping without access to the car, fly down there, and hope it would fit!


http://www.evan.com/boxster/ESE/mockup.jpg

http://www.evan.com/boxster/ESE/mockup2.jpg

http://www.evan.com/boxster/ESE/holes.jpg



The finished work:

http://www.evan.com/boxster/ESE/done_side_top.jpg

http://www.evan.com/boxster/ESE/ESE.jpg



More in the next post!

On to the wiring. Unlike the stock PSE from the factory, I am not interested in letting the ECU decide when to close or open my exhaust valves. I wanted a dash switch, where I get to pick when the beast is on or off. Since OEM dash switches are momentary, there needs to be a way for the circuit to stay activated or be deactivated with just a pulse from the switch. Solution: a latching relay. This great invention will allow a circuit to remain energized or be disconnected when triggered by a 12 volt pulse. Push the dash switch, the relay gets a quick pulse of 12V, and turns the circuit on (or off). In my case, I have the relay switching ground, since I needed a switched ground to turn on the LED on the switch when the circuit is active.

When active, the circuit switches a vacuum solenoid valve in the engine compartment to start or stop the pull of vacuum to the exhaust valves. These valves default to open (i.e. sport mode) so I set up my vacuum connections such that the solenoid valve is off when the exhaust is in quiet mode. My thinking here was that I didn't see the point in having a solenoid switched on, getting hot and using energy on long highway drives in quiet mode. This meant getting a solenoid valve that has both normally open and normally closed connections, which was a bit of a pain. Carnewal sells a complete kit including a valve that is normally closed, and this would have worked too. I just wanted to do it my own way, as usual, so I bought the kit and sourced my own valve:

http://www.evan.com/boxster/ESE/solenoid.jpg


Here is the wiring diagram as I set it up:

http://www.evan.com/boxster/ESE/ESE_..._schematic.gif


Here is the relay connected up. Blue wire is +12V from a fuse tap, and from a switched supply. Brown is from constant ground. Red and orange in the harness are 12V that supply the PSE switch and solenoid valve respectively. Yellow is the 12V pulse from the PSE switch. Black and purple are the switched ground that activate the LED on the switch and the solenoid valve itself. It was important to me that this circuit shut off with the key to avoid battery drain, though it "remembers" the last setting. If you shut off the car in sport mode, it is still in sport mode when you start it next time, since the relay is mechanical and not electronic:

http://www.evan.com/boxster/ESE/durite_relay_wiring.jpg


Backside of the switches, I took this opportunity to add the Targa sun shadeswitch too, for my garage door opener.

http://www.evan.com/boxster/ESE/dash_switch.jpg


I ran the wiring under the center console and up into the engine bay along with the shift linkage:

http://www.evan.com/boxster/ESE/wiring1.jpg


Then there were the vacuum connections. I don't have so many pictures of this part, but here you have the overview of what needed to be connected:

http://www.evan.com/boxster/ESE/engine_vacuum_ese.jpg


Here are some closeups of the exhaust on the car:

http://www.evan.com/boxster/ESE/ESE_installed-2.jpg

http://www.evan.com/boxster/ESE/ESE_installed-3.jpg


Lucky me, I have the world's coolest indi shop, TallerBox in Cartagena, Spain. I rented a bay for the day with a lift and tools, and had a blast doing all the work myself!

http://www.evan.com/boxster/ESE/tallerbox.jpg


A rough list of parts:

-used OEM muffler
-exhaust valves from Capristo
-PSE connection kit and dash switches from Carnewal in Belgium
-Durite latching relay from the UK
-Pierburg vacuum solenoid valve from eBay UK
-random wiring, fuse tap, etc
-a ton of work and fun (priceless)

All told, I think I spent over $1000 on everything, not including my time and welding consumables.


And of course… I had to record some sound clips. The verdict: not enough cowbell. Everything functions perfectly, the valves open and shut as they should, the electronics function just as designed. However, I was really hoping for a more dramatic difference in sound, so in version 2.0 I'll ensure more flow on the bypass side, plus pipe the bypass directly to the outlets. Back to the welding bench I go!

I hope this is helpful to anyone else thinking about such a mod… I'll be happy to answer questions. Just don't ask me if it drones, its an OEM muffler so, no. :-)

Video:

<iframe width="560" height="315" src="//www.youtube.com/embed/whhbpRwjMuU" frameborder="0" allowfullscreen></iframe>

Overall cost and how much for you to start producing them?

Never mind. I didn't read your entire post. Great job. I wish I had the know how to do that.

Let me be the first to say Well Done! Nicely conceived and skillfully executed, my hat's off to you.

Thanks! I don't actually know anything, and I don't know that I don't know anything, so I'm not afraid to try stuff like this since I don't know that I don't know how to do it, and do it anyway. :D

Still has rear cats??

:(

Great job!!

He is in Europe, which like many states here still require a visual inspection of the cats, regardless of what an OBDII scan or tail pipe sniffer say. No cats, no pass emissions, period..................

Jeff is correct, plus one other factor: ROW cars like mine don't actually have front cats on the headers, only the rear set. So no rears = no cats at all on a ROW car...

This looks great I've been thinking of doing something very similar but now that you say not enough cow bell I'm thinking I may skip the valves and just drill a hole where I show it in this picture to go through the inner pipe and then just cover the hole in the muffler casing to keep the OEM look.

http://986forum.com/forums/uploads01...1391788191.jpg

That will give you about the same effect I get with valves open. If I were to go that route knowing what I know now, I would probably drill that hole all the way through both sides of the inner pipe to double the flow into the outside chamber. While my mods sound good, if you heard this in person you would not be impressed. My wife even commented that she could hardly hear the difference, as did my indi shop. Thats a buzzkill for sure.

If you cut a big square out of the top of the outer chambers, you could work inside more easily. Then I'd just cut a big section out of the inner pipe, and finally weld your squares back in place. That might provide a good level of cowbell, but still not extreme since your bypass isn't going straight to the tips.

FYI all my piping is 1.5", so don't be shy with drilling big holes or opening up the bypass to allow good flow. Good luck!

Fantastic info and pics- :cheers:

this is very impressive.
i wanted to do that mode since the first day i bought my car.
i collected parts and information for over 2 years.
unfortunately i sold my car before getting to it. still have all the parts.
now that i have the 99, not sure if i will do it.
just one question. it took me a long time to find a vacuum operated valve.
i finally scored some from a BMW 740 and another set from 335i.
where did you get yours?

Amazing job. I realize you didn't get quite what you hoped for, but the fact that it all works is to your credit. When I listened to the video, I thought I heard a distinct difference.

The effort and workmanship that went into it was very dedicated. Do post about the garage door opener.

Brilliant undertaking! But, it still sounds like a food processor. :(

There are lots of places to get the valves, actually. I got mine from Capristo in Germany as these are very high quality and the price was surprisingly less then some others I looked at.

Pierburg makes the valves for the factory PSE. Helical in the UK make inexpensive valves but they and their sales rep also don't return emails. Carnewal in Belgium can source nice valves as well (I can't remember who they get them from.) There is also an ebay seller that has them cheap, but to be honest I was put off by the way he answered any of his customers who complained. Capristo and Carnewal were both a joy to deal with.

Thanks everyone!! I am of course happy that it fit perfectly and that all my wiring, vacuum system and valves work properly. As far as getting the sound I wanted, this was a crap shoot since I'd never modded an exhaust before. Thats ok though, it just means I'll have to get it right in version 2.0, then I'll sell the first one. No food processor sounds next round. :D

Why not bypass the muffler completely? I want to hear what that sounds like. :dance:

You don't need me for that: Boxster with Straight Pipes - YouTube :cheers: