Cat Bypass Fitment Issue
Thread Starter
Three Wheelin'
Joined: Oct 2002
Posts: 1,879
Likes: 3
From: Pasadena, MD - Land of Taxes
Cat Bypass Fitment Issue
Hello all. I just received the Vertex Cat Bypass from FedEx today. I decided I really want to get it installed tonight. I ran into a problem removing the inboard shield bolts but after a quick search found this is a common issue and that most run with the shields off after installing the cat bypass. So... Easy enough there. My problem is that the cat by pass is coming up about 3/4" - 1" short! I don't think I have enough play in the muffler to accommodate the difference. I searched all over the site and only came up with one (almost) similar issue. It sounded like DaveK noticed an orange/brown, rubbery type connection between the end of the cat bypass and the muffler flange. Is this the way to go? I hate to take an easy way out but if this is an acceptable solution I'll head down to the auto parts store tomorrow morning. I thought I read somewhere that someone had done away with the stock clamp in favor of two screw type connectors and something to fill the gap.
So.... Any words of wisdom from the pros? I'm just dying to crank it up and take it out for a ride!
So.... Any words of wisdom from the pros? I'm just dying to crank it up and take it out for a ride!
RIP
Joined: Mar 2006
Posts: 2,433
Likes: 2
From: Austin, TX
When I installed mine, I already had a primary bypass installed. No gap, they mated right up. Maybe you need to loosen the straps that hold the primary in place a bit and get them mated up, then re-tighten? Good luck. 
RL Community Team
Rennlist Member
Rennlist Member
Joined: Oct 2003
Posts: 7,883
Likes: 878
Steve is right. It will fit, you just need to get the primary closer. Loosen it up on the secondary side, loosen the straps, and give it a shove.
Enjoy... Your car will now smell like an old 911!
Enjoy... Your car will now smell like an old 911!
Thread Starter
Three Wheelin'
Joined: Oct 2002
Posts: 1,879
Likes: 3
From: Pasadena, MD - Land of Taxes
Well... I have everything apart and loose. No joy! The B&B muffler is shoehorned in there and it is a TIGHT fit. (I know some don't like the B&Bs)
Any other ideas?
Any other ideas?
Rennlist Member
Joined: Jul 2006
Posts: 1,253
Likes: 0
From: 12 Miles North of Ilko
I ran into similar problem when i changed mine. What it turned out to be was a coupling ring (about 1.5" thick) that fits btw the cat and the primary muffler (out the back end of the cat) . When I took the cat off, the coupling ring went with it. After much fussing, somehow I was able to see that that coupling ring comes off (needed a screwdriver and a hammer to tap it out of far end of cat)... If you can't locate, I will help you with parts diagram...
Hope that helps...
Hope that helps...
RL Community Team
Rennlist Member
Rennlist Member
Joined: Oct 2003
Posts: 7,883
Likes: 878
Since you've got it all apart, can you measure your cat bypass? I am curious how it compares to my GHL bypass since just last night I removed the bypass to reinstall the catalytic converter after my last race.
Measure it from the flange to a wall: put the cat bypass on the floor, and you place the flange away from the wall and the part that connects to the muffler against a wall, measure the distance to the wall. Just curious to see how much difference we're talking.
Measure it from the flange to a wall: put the cat bypass on the floor, and you place the flange away from the wall and the part that connects to the muffler against a wall, measure the distance to the wall. Just curious to see how much difference we're talking.
RIP
Joined: Mar 2006
Posts: 2,433
Likes: 2
From: Austin, TX
Ahhh, sorry, I thought we were dealing with an OEM primary muffler. Still, if your original cat mated up with it, you'd think a bypass would. You tried having the input side of the cat bypass loose too? Got any pics?
Trending Topics
RIP
Joined: Mar 2006
Posts: 2,433
Likes: 2
From: Austin, TX
Since you've got it all apart, can you measure your cat bypass? I am curious how it compares to my GHL bypass since just last night I removed the bypass to reinstall the catalytic converter after my last race.
Measure it from the flange to a wall: put the cat bypass on the floor, and you place the flange away from the wall and the part that connects to the muffler against a wall, measure the distance to the wall. Just curious to see how much difference we're talking.
Measure it from the flange to a wall: put the cat bypass on the floor, and you place the flange away from the wall and the part that connects to the muffler against a wall, measure the distance to the wall. Just curious to see how much difference we're talking.
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
9 Features and Characteristics That Only Porsche People Understand
Verdad Gallardo
I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way
Joe Kucinski
10 Most Unnecessary Porsches Ever Built (And Why We Love Them)
Verdad Gallardo
Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner
Joe Kucinski
This Builder Is Turning Heads With Its Slantnose 911 Creation
Verdad Gallardo
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture
Verdad Gallardo
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look
Verdad Gallardo
10 Porsche Colors That Have More Personality Than Most People
Verdad Gallardo
Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod
Verdad Gallardo
Thread Starter
Three Wheelin'
Joined: Oct 2002
Posts: 1,879
Likes: 3
From: Pasadena, MD - Land of Taxes
Well.... Here is the cat bypass....
And here is the gap that I need to close....
You would think that I could just push these together. I can get them a little bit closer... But not totally together.
It is difficult to measure exactly since there is a slight curve to it.... But the closest that I could measure was 19" for the cat bypass and 19 3/4" for the stock cat.
Good idea about loosening up the front of the cat... I just worry that if I could get it to fit by doing that one of two things would happen. The first would be that the fitting might not hold well... The second is that when I tightened up that it would put too much strain on the rest of the system.
Any thoughts?
And here is the gap that I need to close....
You would think that I could just push these together. I can get them a little bit closer... But not totally together.
It is difficult to measure exactly since there is a slight curve to it.... But the closest that I could measure was 19" for the cat bypass and 19 3/4" for the stock cat.
Good idea about loosening up the front of the cat... I just worry that if I could get it to fit by doing that one of two things would happen. The first would be that the fitting might not hold well... The second is that when I tightened up that it would put too much strain on the rest of the system.
Any thoughts?
Pro
Joined: May 2006
Posts: 693
Likes: 6
From: Pittsburgh, PA
I wouldn't try to pull it together...something will eventually break.
If you are interested. I could fab up a spacer to fit between the 4 bolt flange. I may have some scrap aluminum... will have to check. Let me know.
Bill
If you are interested. I could fab up a spacer to fit between the 4 bolt flange. I may have some scrap aluminum... will have to check. Let me know.
Bill
Thread Starter
Three Wheelin'
Joined: Oct 2002
Posts: 1,879
Likes: 3
From: Pasadena, MD - Land of Taxes
Bill... That's what I was thinking... That would be perfect... I think the spacer would need to be about an inch thick. Please let me know what you'd need.
Thanks!
Thanks!
Instructor
Joined: May 2008
Posts: 208
Likes: 0
From: San Jose, CA.
how big is the gap when you insert the doughnut that goes between the two ends?
also you have an aftermarket cat bypass being used with an aftermarket primary.....maybe too many variables from stock configuration and measurements.
also you have an aftermarket cat bypass being used with an aftermarket primary.....maybe too many variables from stock configuration and measurements.
Thread Starter
Three Wheelin'
Joined: Oct 2002
Posts: 1,879
Likes: 3
From: Pasadena, MD - Land of Taxes
Wow... Talk about your "DUH" moments... The donut was still stuck in the end of the cat.... I just popped it out... I think it may work now. It was so covered over with crap I didn't even notice that it wasn't supposed to be part of the cat!
I'm going to try it again now and see...
I'm going to try it again now and see...