Top Speed Bypass pipes initial impression - Page 3 - 986 Forum - The Community for Porsche Boxster & Cayman Owners

black_box · 10-03-2012, 08:51 AM

Still waiting on my replacement test pipes to come in (they did ship ASAP when I called to let them know there was a mixup on the packaged order).

I did want to say that John (Che) was super cool about it and let me keep the gaskets from the old set free of charge so I could swap the pipes around in the future without getting an exhaust leak from reused gaskets.

Still planning to do 3.8 swap, which is sitting in the garage, but will be taking a 700 mile RT with the 3.2 this weekend, so I'd like to swap in the headers and midpipes just to try them out since I have the extra gaskets. Hopefully the exhaust manifolds will come off easily -- I know they were removed 25k miles ago, so they should.

Looking forward to doing the job tomorrow.

Steve Tinker · 10-03-2012, 03:03 PM

black box...
If you are planning to fit John's (Che) headers, here's a tip which I learnt when I fitted mine last year. Before installing the headers, slightly enlarge the bolt holes as the originals line up with the head OK but I found that it left no room for slight adjustment to fit the bolts. One header was good, but the other required the slight movement to fit.
Installing the Top Speed headers & cat delete pipes coupled to the original Porsche S muffler certainly sounds good without the dreaded 3000 rpm drone. But here in Australia we don't have the primary cats in the headers (ROW specs) so it may be a different story your side of the ditch....

sparker · 10-03-2012, 05:02 PM

Steve - are you running without cats at all? I have been for the last couple of weeks whilst I was waiting for some 200cell cats to arrive to install in my bypass pipes.

Seems when I ordered my bypass pipes, I didn't get those slip in reducer parts so had to make my own. As a result, there are some small leaks adding to the already loud noise. Looking forward to this weekend when the cats will be installed and the leaks fixed!

Sam

Steve Tinker · 10-04-2012, 03:10 PM

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 · 10-06-2012, 02:44 PM

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 · 10-06-2012, 06:44 PM

Quote:

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 · 10-07-2012, 05:42 AM

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 · 10-07-2012, 07:26 AM

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.

jovie · 12-05-2012, 09:32 PM

Are these test pipes will pass EMISION TEST (smog test)? does it create CEL? Does it sound better or it needs the whole catback exhaust? I just want to make sure I don't encounter minor erritating issues when I purchase and install it.

shadrach74 · 12-07-2012, 05:03 AM

Quote:

Originally Posted by jovie

Are these test pipes will pass EMISION TEST (smog test)? does it create CEL? Does it sound better or it needs the whole catback exhaust? I just want to make sure I don't encounter minor erritating issues when I purchase and install it.

The emissions issue will depend on how it is tested. If it's a simple OBD plug in test, than passing should be no sweat. If the emissions testing is done with a sniffer, then passing will depend upon state standards. I don't know how much work the secondary catalyst is actually doing, but I would expect to see some increase of unburned hydrocarbons (I doubt it's a significant increase) as a result of removing the secondary cat.

Mid pipes should not cause a CEL as the secondary cats they replace are unmetered.

WRT fitment issues, I would not expect any aftermarket part to fit perfectly without some degree of fettling. Sometimes things fit perfectly, sometimes not so much...

jovie · 12-09-2012, 09:41 PM

chad,

thanks.

Homeboy981 · 12-10-2012, 04:29 AM

No CELs here and I have been running with the TS Bypass pipes for a few months and several thousand miles now. The secondary cats just seemed to be necessary in CA. I have not noticed any difference….except in PERFORMANCE from NOT HAVING them STRANGLE MY EXHAUST! The Cat Backs make the system IMHO.

The fitment was a little struggle, long since forgotten. "Fettling" would be a good word to describe it. However, if you have seen muffler shops install pipes they move 'em around quite a bit!

shadrach74 · 12-10-2012, 01:07 PM

I installed my bypass pipes yesterday. The good news is that I was able to get them installed, but it required loosening all of the exhaust joints between the muffler and the bypass pipes. The bad news is that the bends are not the exact proper angles for my stock exhaust. I do not like the amount of stress on the system to "make" it fit. I really had to manhandle the muffler pipes to get the slip joints in place and that was with the flange bolts completely loose. The gaps at the flange befor tightening were big! Further more, I have a slight leak that is very perceptible at idle. This gives it a bit of a "fart can" civic sound which I dislike. In terms of power, it's hard to tell. It's been pouring here so I can't really get my foot in it without breaking the ass end loose. I will report more on it this week as I decide whether to keep them or take them off...

BTEMY · 12-19-2012, 07:20 PM

I have a m2 headers and exhaust, planning to install them this weekend. Looking to buy the midpipes for the whole exhaust installation.

Where should I purchase them? How much should I expect to pay?

Any points on my upcoming installation?

thanks

shadrach74 · 12-20-2012, 06:06 AM

BTEMY,

If you have existing aftermarket exhaust pieces, I think you should purchase all additional parts form the same vendor if possible. It's hard enough to ensure a good fit without throwing multiple manufacturers into the mix.

First, spray penetrating lubricant on all fasteners the night before. PB Blaster will work, but it's at the bottom of the quality spectrum of penetrating oils though a bit better than WD40. I use Mouse Milk or Kroil, which are both very high quality aviation grade products that out perform the other stuff on the market by a large margin. A 1 to 1 mix of ATF and Acetone is about as good a penetrant as anything.

As far as disassembly, I would suggest separating all "slip joints" (between midpipe and muffler) and thoroughly cleaning them with a brass brush (a brass wire wheel on a drill is the way to go). Make sure you have some high temp anti-seize on hand and coat the mating surfaces of the slip joints generously.

If you do the above, it will make articulating the slip joints much easier and help to ensure that everything can move as you position the exhaust.

Fit everything loosely and the start tightening at the parting flange where the header meets the mid-pipe and move aft doing your best to make sure that the pipes are not binding (some of the connections may be slightly stressed, but try to keep it to a minimum).

Good luck!