100-cell or bypass cat?
05-02-2011, 04:56 AM
#1
Drifting
Thread Starter
100-cell or bypass cat?
Hi guys!
From what I've learned here our engines seems to respond well to a cat-bypass or a high-flow cat combined with a cup pipe. I'm more or less happy with my car now but now it's time to find some more power, So far I've concentrated on everything else except the engine. So my question is:
If I want the best possible "output" from the "cat area" is a bypass the best option or does a 100-cell deliver the same effect (and saves some trees)? I have a cup pipe and the second muffler. I still need the cat for the yearly MOT but I can easily swap the cat once a year.
So a bypass or a 100 cell?
Thomas
From what I've learned here our engines seems to respond well to a cat-bypass or a high-flow cat combined with a cup pipe. I'm more or less happy with my car now but now it's time to find some more power, So far I've concentrated on everything else except the engine. So my question is:
If I want the best possible "output" from the "cat area" is a bypass the best option or does a 100-cell deliver the same effect (and saves some trees)? I have a cup pipe and the second muffler. I still need the cat for the yearly MOT but I can easily swap the cat once a year.
So a bypass or a 100 cell?
Thomas
05-02-2011, 10:28 AM
#2
Drifting
Cat bypass is cheaper and provides better exhaust flow than 100 cell. 100 cell provides better flow than stock cat. I have cup pipe and cat bypass. Can't say I notice much of a difference besides the hydrocarbon smell. Sound is deeper, throatier. Keep in mind most HP gains are close to redline.
Last edited by Laker; 05-02-2011 at 11:17 AM.
05-02-2011, 11:27 AM
#3
Drifting
Thread Starter
"Keep in mind most HP gains are close to redline."
Yeah, but that's where I am on the track and going up through the gears so the difference should be useful.
Thomas
Yeah, but that's where I am on the track and going up through the gears so the difference should be useful.
Thomas
05-02-2011, 01:07 PM
#5
Thomas,
This is an FYI with comparison of oem cat vs bypass.
http://www.rsamerica.net/articles/me...yno_day_04.htm
This is an FYI with comparison of oem cat vs bypass.
http://www.rsamerica.net/articles/me...yno_day_04.htm
05-02-2011, 02:35 PM
#6
Drifting
Thread Starter
Yes, i have a euro RS chip.
Thanks for the article, i haven't seen that one before.
I saw this bypass from FVD today. It looks like nice piece of kit and FVD/brombacher doesn't usually sell any crap. Due to it's design it will also take off a lot of weight compared to a stock-cat which is good. And the price is also very nice with our ex-rate right now.
http://www.fvd.de/de/en/Porsche-0/96...964-89-94.html
Thomas
Thanks for the article, i haven't seen that one before.
I saw this bypass from FVD today. It looks like nice piece of kit and FVD/brombacher doesn't usually sell any crap. Due to it's design it will also take off a lot of weight compared to a stock-cat which is good. And the price is also very nice with our ex-rate right now.
http://www.fvd.de/de/en/Porsche-0/96...964-89-94.html
Thomas
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05-03-2011, 03:07 PM
#8
Hi Thomas,
One downside could be noise:
https://rennlist.com/forums/8419053-post4.html
Beauty is indeed in the eye (or ear) of the beholder, I for one like the mature growl of my cup pipe and cone filter but wouldn't like to draw any more attention to my car with an additional step in db's.
BTW the difference between 102db and 112db is immense since we're talking about a logarithmic scale in which a 10db change represents 10x sound intensity.
One downside could be noise:
https://rennlist.com/forums/8419053-post4.html
Beauty is indeed in the eye (or ear) of the beholder, I for one like the mature growl of my cup pipe and cone filter but wouldn't like to draw any more attention to my car with an additional step in db's.
BTW the difference between 102db and 112db is immense since we're talking about a logarithmic scale in which a 10db change represents 10x sound intensity.
05-03-2011, 05:29 PM
#9
Hi Thomas,
are you sure that your RS chip can manage changes? I installed 200 cel Cat instead original Cat. I lost about 40 kW of power, because flow throw new cat was much better, and fuel mixture war lean. I myself noticed nothing, but in dyno was graph terrible. Fortunately have I standalone ECU and was no big problem to change mixture.
Flow was surely better, engine sound increase by idle from 76 dB to 82 dB.
are you sure that your RS chip can manage changes? I installed 200 cel Cat instead original Cat. I lost about 40 kW of power, because flow throw new cat was much better, and fuel mixture war lean. I myself noticed nothing, but in dyno was graph terrible. Fortunately have I standalone ECU and was no big problem to change mixture.
Flow was surely better, engine sound increase by idle from 76 dB to 82 dB.
05-04-2011, 04:13 AM
#10
Drifting
Thread Starter
The noise shouldn't be a problem. there are other cars running with this set up at track and their noise level is well within the limits.
No I don't no about the chip. Is a re-mapp/modified chip a must if you use a bypass or a 100-kat? Can't the ECU adapt to this? If a new chip is a must, this whole cat-topic turns into something else.
Thomas
No I don't no about the chip. Is a re-mapp/modified chip a must if you use a bypass or a 100-kat? Can't the ECU adapt to this? If a new chip is a must, this whole cat-topic turns into something else.
Thomas
