VW Vortex - Volkswagen Forum banner
1 - 20 of 39 Posts

·
Premium Member
Joined
·
36,790 Posts
Discussion Starter · #1 ·
This is something that I've wanted to do for a while, and when I saw that Evan and the guys at 42DD started making high flow cats, I asked them to make one for my Corrado. Considering they had never even seen a Corrado cat, the fact that it fit perfectly is rather amazing. Link to their site: http://www.42draftdesigns.com/categories/products/vr6cats.html

It's an aluminumized steel pipe with a 200 cell magnaflow stainless steel cat, and compared to the factory 600 cell cat, it looks ridiculously small and is about 20 lbs lighter:



Regarding the O2 sensor, it is imperative that you get Bosch 13267 and not one for a Passat VR6. The difference is that the Passat O2 sensor is 2.4" longer, but it doesn't have the heat shielding over the wires, which is necessary. The O2 sensor wires are touching the heat shield above the cat, and if you don't have the heat shield over the wires, it'll get messy. Make sure you double check the part that you recieve to make sure it is 13267.

One thing that I didn't account for was that I'd need all new hangers and clamps. Considering the Corrado has a 59.5mm OD clamp at the end of the cat, and a 64.5mm OD clamp at the end of the resonator (to rear section), you can't just go pick these up at the store. I did a half install where I installed the cat, then ordered the correct clamps and hangers from German Auto Parts: http://www.germanautoparts.com/Volkswagen/Corrado/Exhaust/349/1

None of these photos show the new clamps or hangers (you may as well replace the rear hangers as long as you're under there), but that's because I forgot my camera when I went back and redid the exhaust. I noticed that my hangers for the suitcase muffler were completely stretched and that my exhaust was crooked, and new hangers fixed this. It's as new now, even though it has 106,000 miles, yet no rust on the exhaust.

A photo of the welding:



A few photos installed:





As for the sound, it is a bit throatier, but there is no drone. This is exactly what I wanted. I am past the point in my life when I can have that ridiculous 12v VR6 drone below 2500 RPM. When you are under throttle you can hear the throatiness, it almost sounds semi-R32 ish, but not as raspy.

Performance increase was absolutely drastic. A lot of this had to do with the fact that my 18 year old oxygen sensor wasn't quite up to snuff anymore, but I think the removal of the factory cat really freed up the airflow. Coupled with the supercharger, when I pass 4k RPM in 1st gear, the wheels just start spinning. As I said, drastic increase in power.

For only $195 for the 42DD high flow cat, it's the lowest priced high flow cat on the market, and the quality is top notch.

Evan said he was going to start making and stocking some of the Corrado cats, so if you're looking for one, give him a call.

- Anthony
 

·
Premium Member
Joined
·
36,790 Posts
Discussion Starter · #2 ·
Oh, and for why you need new clamps, this is what happens when you try to loosen 18 year old clamps, even after soaking them in PB blast:

 

·
Premium Member
Joined
·
36,790 Posts
Discussion Starter · #3 ·
And the only other thing I was looking to do, but was unsuccessful, was replace the resonator with a straight through pipe:



I took it to midas and they wanted $140-$180 to cut out the resonator and weld in a pipe, so I told them "No Thanks".

It should be super easy to fabricate one, so I may take it to a fabrication shop and ask them to make one for me. I think that will give it a bit more exhaust noise, but still keep it from droning.

- Anthony
 

·
Registered
Joined
·
18,889 Posts
Nice write up. I think I just might look into this, if only because it is smaller and less prone to hitting stuff. the factory item hangs too low!
 

·
Registered
Joined
·
3,839 Posts
cool! the flow must really help w/ the s/c, i will def look into this as well. I agree about the material. almost looks galvanized or aluminized...
 

·
Premium Member
Joined
·
36,790 Posts
Discussion Starter · #7 ·
looks good

but the piping is not aluminum
Yes it is.

42DD said:
Construction

•Magnaflow 200 cell 409 stainless steel cat
•14 gauge aluminized steel tubing
•CNC machined flange mates exactly to the stock flange
•TIG welded construction
•2.5" piping reduces to stock 2.150" band clamp for a bolt-on fit
 

·
Registered
Joined
·
12,624 Posts
From my experience of doing several exhaust set ups on my car over the years. Replacing the center muffler, suitcase muffler, with a resonator will make it drone. I had a smaller resonator for years and it was too loud. At certain freeway speeds the sound was a bit annoying. Overall it was too loud for my taste. Recently I installed a new cat and replaced the old resonator with a much larger one. IIRC its 20" and its a little quieter and still has a bit of drone to it. I think the best way is to put a small middle muffler like TT does on their quieter systems. Jetex does this as well. Gets rid of the drone and also makes it sound more tuned IMO.
 

·
Registered
Joined
·
18,889 Posts
From my experience of doing several exhaust set ups on my car over the years. Replacing the center muffler, suitcase muffler, with a resonator will make it drone. I had a smaller resonator for years and it was too loud. At certain freeway speeds the sound was a bit annoying. Overall it was too loud for my taste. Recently I installed a new cat and replaced the old resonator with a much larger one. IIRC its 20" and its a little quieter and still has a bit of drone to it. I think the best way is to put a small middle muffler like TT does on their quieter systems. Jetex does this as well. Gets rid of the drone and also makes it sound more tuned IMO.
Techtonics replaces both factory items (resonator and suitcase muffler) with identical resonators. Combined with the Borla back-box on a VR, the system does not drone at all. In fact, some have commented on how quiet it is, barely being louder than stock. I have a hard time drawing a comparison, however, because I went from a Midas Special - only a small resonator in place of the stock resonator, straight pipe to replace suitcase - and that droned like crazy. I would get headaches on highway drives.

cool! the flow must really help w/ the s/c, i will def look into this as well. I agree about the material. almost looks galvanized or aluminized...
I am thinking with my Genie headers, and the TT exhaust, this would help. That, and I question the effectiveness of my cat 17yrs later, despite the fact that the car returned amazingly low numbers the last time I ran it on the emissions dyno.
 

·
Registered
Joined
·
1,793 Posts
I'm not quite sure what you guys are talking about... for whatever it counts for, i replaced my "bullet" muffler on my stock system (no-suitcase) with a straight pipe and couldn't be happier with the results. The sound increased by ~10% and there is no drone to speak of ever, i'm sure you will be very pleased with the results Anthony! As always great work on the car, go shoot some pics of it and post them up!
 

·
Premium Member
Joined
·
36,790 Posts
Discussion Starter · #14 ·
I'm pretty sure with the suitcase and the rear muffler in place, removing the resonator wouldn't add any drone. I'm going to see if I can get Evan to fabricate a resonator delete. ;)
 

·
Premium Member
Joined
·
36,790 Posts
Discussion Starter · #16 ·
Well I took the Corrado on a 200 mile trip yesterday, and it was flawless. I can't quite put it into words how much the new cat and O2 sensor brought the car to life.

I wish I had dyno'd the car before and afterwards, but I am going to go take it to a dyno in the next couple of weeks and I will post up my results.

- Anthony
 
1 - 20 of 39 Posts
Top