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Old 08-22-2003, 03:11 AM   #1
Andrew Bacon
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Question Anybody using a Random Tech Gen2 cat pipe?

(The newer one with the small round can)

I just put on a used one and I'm liking the performance gain, but the sound SUCKS! I have a wrapped borla and an A'pexi muffler with the silencer. (not an axle-back, just a N1 muffler welded on the stock 1.75" pipe)

The sound is so raspy and buzzy. With the stock cats the sound was a deeper, throaty rumble that got "blappy" at high rpm/WOT. Nice. Now it's just a sick Honda kazoo buzz. It's embarrasing to drive, even though it moves better and winds up to redline with zero hesitation or flatspots.

Anyone else have this buzzy sound? Thanks -Andy

[edit] problem solved, it was the silencer in the N1.
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Last edited by Andrew Bacon; 08-23-2003 at 06:32 AM.
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Old 08-22-2003, 03:37 AM   #2
Keiho
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I'm sure the sound will improve if you changed to a bigger midpipe.
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Old 08-22-2003, 05:23 AM   #3
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I know the 1.75" is a bottleneck, but I doubt going 2.25" all the way through the way it should be will remove a mechanical buzz.
Thanks though!

Anyone else have this sound?
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Old 08-22-2003, 07:36 AM   #4
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Raspy is a good discription...sorry, can't recall the buzzy part.

After the RT install it got too loud for me so I had a longer resonator welded in. I already had a Borla, Injen, 2.5" Tanabe Hyper Medallion so with the cat pipe I was fully opened up. The throttle response on the highway was superb, instant excelleration, but I just couldn't stand the loud raspy sound.
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Old 08-22-2003, 07:06 PM   #5
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Yeah, the only way around it is a resonated midpipe. It will mellow out the exhaust tone and quiet the interior noise level.



Mick
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Old 08-23-2003, 06:30 AM   #6
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I found out tonight that the buzz was the silencer in the N1 muffler. With it removed the buzz is gone, and now it's just raspy and "hollow" sounding. I put a stock muffler in just for the hell of it, and it was worse. Just awful buzz.

I'm thinking I'll have a 2.25" dia. midpipe made with like a 24" resonator welded in.

Who makes good resonators?
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Old 08-23-2003, 09:36 AM   #7
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Quote:
Originally posted by Andrew Bacon

I'm thinking I'll have a 2.25" dia. midpipe made with like a 24" resonator welded in.

Who makes good resonators?

Well, if you would have bought the full N1 catback...it does have a secondary muffler/resonator. I've heard how it sounds at WOT and man does it scream.

The stock midpipe has a small resonator. I thought about trying this resonator with a custom midpipe, but I am still considering getting the N1 catback. If you do find any other types of resonator, please be sure to post about it.


Mick
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Old 08-23-2003, 11:06 AM   #8
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Quote:
Originally posted by Slack



Well, if you would have bought the full N1 catback...it does have a secondary muffler/resonator. I've heard how it sounds at WOT and man does it scream.

The stock midpipe has a small resonator. I thought about trying this resonator with a custom midpipe, but I am still considering getting the N1 catback. If you do find any other types of resonator, please be sure to post about it.


Mick
it looked like my stock midpipe had 2! resonators
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Old 08-23-2003, 05:38 PM   #9
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Quote:
Originally posted by Slack



Well, if you would have bought the full N1 catback...it does have a secondary muffler/resonator. I've heard how it sounds at WOT and man does it scream.

The stock midpipe has a small resonator. I thought about trying this resonator with a custom midpipe, but I am still considering getting the N1 catback. If you do find any other types of resonator, please be sure to post about it.


Mick
I wish I did get the full N1 catback. I got the muffler used for $100 so I couldn't pass it up. The magnaflow resonator you mentioned looks like a possible canidate, I'm looking for others. I don't see any from Dynomax...
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Old 08-23-2003, 08:32 PM   #10
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Quote:
Originally posted by Slack
I thought about trying this resonator with a custom midpipe, but I am still considering getting the N1 catback. If you do find any other types of resonator, please be sure to post about it.
Mick
That's pretty much the Magnaflow I had put in.
With my aftermaket catback, [and I suspect the oe also], the longest Magnaflow that would fit is the one with a 4"x22" can (even that one is a tight squeeze).
With a custom mid-pipe you might be able to offset the bends enough to squeeze in the 24 incher, but I wouldn't count on that since the angle required to get by the footwell protusion will hinder getting a good fit up.
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Old 08-23-2003, 08:35 PM   #11
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Quote:
Originally posted by Jejunum
it looked like my stock midpipe had 2! resonators
Never heard that about the 02's before, you sure you're not looking at the cats
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Old 08-24-2003, 01:12 AM   #12
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I put my Random Cat on with stock headers, a stromung mid, and Sti v6 muffler. - I thought it was an exhaust leak, or a bad gasket somwhere. Then I got borlas, and after painstakingly refitting the entire system, realized that the cat just sounds like that - that's probably why I got it for $100 on ebay from Cobb. I got used to it. The gains are worth it, but I might use its layout as a template for a custom hiflow setup later, and swap it out.
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Old 08-24-2003, 02:01 AM   #13
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Quote:
Originally posted by Albert

Never heard that about the 02's before, you sure you're not looking at the cats
yah i installed the stromung catback...the stock midpipe had two seperate "things" in it...
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Old 08-24-2003, 01:20 PM   #14
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oh...that's new, must be their fix to quiet down the catback due to complaints [from some] that the stromung muffler itself was too loud on a daily driver.
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Old 08-25-2003, 08:07 AM   #15
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Trust me. To solve the rasp problem get rid of the N1. They have virtually no fiberglass deadener in them to dampen and get rid of that tin-ny metally rasp like other mufflers do. A resonator may help a little but not much with a muffler that has no dampening. At that point the resonators will deadening the exhaust note more then the muffler.

This is a sound clip of the my MRT setup with an N1 clone muffler: Click Here

Here that nasty rasp that happens every time I step off the pedal? Thats why I got rid of the N1 muffler and the MRT setup and moved to the Borla/RandomTech/Stromung, which sounds like this: Click Here

There is much less metalic rasp in this system and the low frequency growl that the mic didn't pic up actually covers the little bit of rasp you hear in the recording. By the way neither exhaust has resonators.

Brad
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Old 08-25-2003, 09:53 AM   #16
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Quote:
Originally posted by Albert

Never heard that about the 02's before, you sure you're not looking at the cats
the cats on an 02rs all come before the midpipe. That "cat looking" thing on the midpipe is a pre res chamber
Pat
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Old 08-25-2003, 10:37 AM   #17
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Quote:
Originally posted by Pat L.I.


the cats on an 02rs all come before the midpipe. That "cat looking" thing on the midpipe is a pre res chamber
Pat
ahhh...whats a pre res chamber? and how should i get rid of the droning my stromung catback has introduced? I do plan on getting a high flow cat at some point.
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Old 08-25-2003, 12:28 PM   #18
Andrew Bacon
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Quote:
Originally posted by MY99 2.5GT
Trust me. To solve the rasp problem get rid of the N1. They have virtually no fiberglass deadener in them to dampen and get rid of that tin-ny metally rasp like other mufflers do. A resonator may help a little but not much with a muffler that has no dampening. At that point the resonators will deadening the exhaust note more then the muffler......There is much less metalic rasp in this system and the low frequency growl that the mic didn't pic up actually covers the little bit of rasp you hear in the recording. By the way neither exhaust has resonators.....

Brad
Thanks for taking the time to post those wav files Brad!
I don't understand why I still had the rasp on lift-throttle even with a stock muffler though. I put it on the car for 10 minutes, and took it right off after hearing a couple blips. It sounded sick.
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