Top Speed Bypass pipes initial impression

[Steve Tinker]

Yes - running without cats at the moment - I was taking the car to a Porsche hill climb event in a couple of weeks ago but my wife broke her hand so new I can't go so I will probably put the cats back to be legal.
Shame really as the sound over 4,000 rpm is intoxicating........

[2000boxster986]

For anyone interested that's been following this thread. I plugged the Pedro mod exhaust tubes with super results. Now the TS bypass pipes are doing their job. Sound is nice and crisp without that straight pipe blow. Running the car up to about 4k makes a very sweet purr that a sports car should. Thanks Andy and Shadrach, you guys were right on.

[shadrach74]

Originally Posted by 2000boxster986

For anyone interested that's been following this thread. I plugged the Pedro mod exhaust tubes with super results. Now the TS bypass pipes are doing their job. Sound is nice and crisp without that straight pipe blow. Running the car up to about 4k makes a very sweet purr that a sports car should. Thanks Andy and Shadrach, you guys were right on.

Glad it worked out! Incidently, what method did you employ for blocking tubes?

[Homeboy981]

If you put on headers….are you still going to use those cats?

Don't most all aftermarket headers employ an O2 sensor fix that takes the sensor "out of the exhaust stream" in other words, doesn't it require an O2 sensor extension adapter?

And do these adapters throw a CEL? I was told they would not but I want the headers, not the CEL. I don't care about passing inspection - since they do not check it in my county. Will it work? Has someone done it here? Also, will it affect the computer by dumping more gas or leaning it out because of the reading the O2 sensors are now getting? Someone who has headers, can you ring in?

[2000boxster986]

Shadrach, I wanted to be able to undo the mod if needed. I built two plugs out of copper pipe and caps. Spun them down on the lathe to fit the holes and then used pop rivets to hold them in place (although they did fit pretty tight). I haven't as yet but will shoot them with a little black header paint and they won't been seen. Pic attached isn't great but shows the caps.

Homeboy, I'm running stock exhaust manifold. Headers may come later. I have a 2000 so the post cats do not have O2 bungs. With the TS pipes added the car does breathe much better. Throttle response is really nice. So far there have been no codes.

[shadrach74]

Originally Posted by 2000boxster986

Shadrach, I wanted to be able to undo the mod if needed. I built two plugs out of copper pipe and caps. Spun them down on the lathe to fit the holes and then used pop rivets to hold them in place (although they did fit pretty tight). I haven't as yet but will shoot them with a little black header paint and they won't been seen. Pic attached isn't great but shows the caps.

Homeboy, I'm running stock exhaust manifold. Headers may come later. I have a 2000 so the post cats do not have O2 bungs. With the TS pipes added the car does breathe much better. Throttle response is really nice. So far there have been no codes.

The workmanship looks nice!

However, I would be concerned about galvanic corrosion. I'm not sure what Pedro's pipes are made of, but it's likely to be on the anodic side of copper. Steam on those early morning start ups will make a nice if not slightly acidic electrolyte...

[2000boxster986]

I agree, copper doesn't play well with some metals. The straight pipe tubes appear to be stainless. They were difficult to drill into. The actual plan here is to get an exhaust I'm happy with. Using the bypass pipe plugs and stock muffler is more of an exercise toward this goal. I just had so much blow by with the straight pipe mod and the bypass pipes it wasn't funny. This copper plug mods appears to be working so I'll likely fab some steel plugs in the near future. Copper was easy to work with so I figured I'd paint em black and run with them awhile. I've also been playing with a Stebro sport exhaust but since my car is a daily driver I didn't like the drone. So I removed the Stebro. I did put on dead pipes to try and overcome the drone but I don't think they're long or wide enough. So I'll either mod it again or sell it. Still on the fence on that one. Thanks for your input. I do agree.