Hi flow cats???

[red98GTS]

Call JonB @ PartsRack. He can fill you in. pete the XGG

 

[GTS Bruce]

If they don't sniff your car then skip the cats.The Corsa has a very nice exotic sound.Louder outside but quieter inside.W/O cats it outrageous.If you delete the cats you will need apex rear syms which you can get from JOn B too. Bruce

 

[dancojax]

Check out www.roeracing.com
we put a set on Nancy's car and liked it so much put a set on mine.
good easy fit/installation and better sound and MUCH COOLER side sills.
check it out and call him (904) 733-5469.
I think he will be a VOI also, probably with his supercharger kit.

 

[ACR Joe]

I have a full Belanger header/exhaust system. I first went w/o cats, but the noise and odor were overwhelming. I then went to high flows which rob more power than most will suggest (IMO). I now about to go catless again. The O2 sims is a must (I have the Apex Snakebox) and I'm thinking the Roe Racing VEC1 (A/F manager) may minimize the assault on the olfactories.

VEC1 people RSVP ........

 

[Andrew2KRT10]

Sean Roe. Prewelded, very reasonable price! Be sure you have a tool to open up your muffler, if you have one, to insert the cat. I had to do quite a bit of banging, squeezing and still i had to shave down the end of the cat very slightly to get it into the muffler. Did it on my belt sander.

AC

 

[Snakester]

I also picked Sean Roe's 4" X 6" cats to go with my Corsa exhaust.
It easily passed smog, and doesn't smell gassy.
The combo sounds great and the sills are much cooler than stock.
We welded them in, but any competent muffler shop can handle the install, especially if you are doing the Corsa at the same time.

-Dean.

 

[garolittle]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by ACR Joe:
I have a full Belanger header/exhaust system. I first went w/o cats, but the noise and odor were overwhelming. I then went to high flows which rob more power than most will suggest (IMO).
<HR></BLOCKQUOTE>

Any idea how much HP you lose by using the high flow cats instead of "no cats"? Also, how much quieter was the car with the high flow cats as opposed to no cats?

 

[genXgts]

Good thread,

How about adding this to the fire?

Anyone fail the sniff test with no cats?

Thought I read that the V10 runs pretty clean and can pass the test sans cats? If that can be confirmed I'll go that route!!

 

[onerareviper]

If memory serves, Sean Roe did many dyno test with high flows vs. no cats. Only noticed 1-3 HP difference. The only advantage to no cats is extremely cool side sills. I do miss that. The sound with no cats is louder, but raspier. Almost an annoying sound at idle-3,000 RPM, IMO. Kinda rice sounding, god forbid. The high flow cats seemed to smooth the sound out, and deepen at idle-3,000 RPM. 4,000 RPM - redline, it almost sounds identical, awesome. This testing was performed via me, on a '98 GTS with 2.5 Corsa. I say for the money (around $250 for both - Sean Roe), go for the high-flow cats. Unless 1-3 HP and very cool side sills is of major importance.

P.S. - High Flow cats do drop the side sill temps, but those suckers still get extremely hot - during stop & go driving.

 

[ACR Joe]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by garolittle:
Any idea how much HP you lose by using the high flow cats instead of "no cats"? Also, how much quieter was the car with the high flow cats as opposed to no cats?


<HR></BLOCKQUOTE>

No dyno data, strictly SOTP and sound has a lot to do with perceived power. With that said, my PERCEPTION is that power is down by a few % (perhaps 3-4%) with the high flows, more than that with the OEM cats. Plenty of data out there to dispute this point - but SOTP and perception is what it is.

As far as odor is concerned, has anyone out there using the VEC1 with no cats noticed a reduction in exhaust odor?