etom

I am about to pull the trigger on a cat bypass, but I want to do one more round of info gathering before doing so. (I already have a primary bypass.) Options:

I am tempted to go Dansk at about $550 (from EBS): apparently excellent quality, excellent fitment. Comments?

Fabspeed has, it seems, two cat bypasses: 964 European Pre-Muffler Catbypass Pipe ($375) and 964 Sport Race Catalytic Converter ($550). What are the major differences between these two? Compared to Dansk?

Then there is the Schnell Catalytic Bypass Exhaust Test Pipe - Catbypass T-304 Stainless Steel (15 lbs) that sells for $279. Anyone know much about it?

Other brands? Preferences? Opinions?
Any comments on performance/sound greatly appreciated.

MisterRisky

Is this the Schnell one you were looking at:

http://www.vertexauto.com/ShowItem/3...st%20Pipe.aspx

It looks like it has a bung for the O sensor. And the price is half of the Dansk. Anyone used the Schnell? I might be inclined to get one at that price.

joey bagadonuts

In general, anything called a bypass will be close to a straight pipe and not pass your State's emissions test. They're also a bit louder--think booming. Your neighbors will love you for it.

etom

Joey--thanks. You may be right (although the primary bypass sound I have at present is relatively tame). There isn't an emissions test to worry about.

I would be curious about the noise level, though--I have heard a one recording of the cat bypass with primary bypass (cup pipe), and while it sounded rough, it didn't seem obnoxious. Any others out there running this combo?

etom

And I should have added one more candidate to the cat bypass possibilities:

PORSCHE 964 C2 C4 RSA SPORT CATALYTIC CONVERTER 100 CELLS
PART#964SCC PRICE $399.99 from Maxspeed.
http://www.maxspeed-motorsports.com/964cat.html

TR6

You'll love the sound of the cat bypass. I have the cat bypass and the secondary bypass and mine is a little louder than deep_uv's with the cat bypass and the primary bypass. My cat bypass is a simple straight test pipe with the O2 bung in it. Not sure of the brand. I love the sound of mine. And the cat bypass is fairly easy to swap back and forth if it becomes a problem for some reason (long trip with the wife for example)....

zicoramone

joey: the interior of the Dansk race catbypass is ceramic coated and will pass emissions test.

Cupcar#12

zicoramone:
Well Maybe..... it all depends on your state and the emissions levels they are looking at - for Wa (for instance) i would say there is an 80% chance you will pass w/o and issue with no Cat. For Ca. it is closer to 0%. In IL i have no experiance to gauge by.

it does eliminate the Cat, ceramic coatings are used for heat shielding and have nothing to do with the levels of emissions passed.

A Sport Cat is not an eliminator pipe - but a Catalytic converter that is higher flow - it should pass emissions w/o and issue but you are not eliminating the Cat converter just replacing it.

hope that makes sense

964russ

Ive got a straight tube in place of my cat and it sounds great! And cost very little.

warmfuzzies

The Maxspeed bypass If that's the one I had looking like a cat, is excellent quality, with all fittings required i.e. heat shrouds and O2 sensor, If I wanted a Bypass I'd have kept mine. However I didn't; I wanted a 100cell, and they don't have any at the mo....apparently.

Kevin
Kevin.

zicoramone

Rob: that makes absolute sense. I was aware that the ceramic coatings work as a thermal protection and corrosion resistance as well affecting the sound of the engine. But that was the explanation they gave me when I've got the same level of emissions with both the stock cat and the 0 cells free flow ceramic bypass. If what you said is right (and I have no qualification to attest the contrary) what would it be the answer to this phenomenon?

TR6

For what its worth, my car passed Texas emissions with the cat bypass test pipe in place. But experience will no doubt vary from state to state....

Colin 90 C2

I have a Fuchs SS cat bypass with o2 bung hole for sale.
perfect fitment, great quality
$250 plus shipping

deep_uv

In Texas you are supposed to have a cat whether you pass the emission check or not. That's one reason I went with the Dansk bypass - it looks like a cat. Also, I heard nothing but goodness about fitment. Since I was doing it myself, that was pretty important.

Looking at my pictures of what's inside the stock cat vs. the Dansk bypass, there's got to be much more free flow through there. I used an inspection mirror to look at the insides of the outer chamber and it appears there's nothing in there except that the inside of the outer wall of the cat bypass seems to be lined with a very, very thin layer of something (there's some texture there is probably the best way to describe it). Probably the ceramic Zico mentions.

As TR6 said earlier, it looks purty too. I'll have to dirty it up at inspection time so as not to attract attention.

BTW, I have the numbers from my last inspection with the OEM cat. I'll post up the difference next time I get emission checked with the bypass. That won't be until May though.

etom

Didn't know Fuchs made one. Photo (or link to where they are sold)?