CRD quiet exhaust

11 replies to this topic
  • Woodie

Posted March 06, 2003 - 01:06 PM


I hope you don't mind an "outsiders" post, I think that I may have some interesting info. The Michigan Cycle Conservation Club did some testing of the CRD quiet exhaust on the XR400. Yea, I know, the XR is not the most performance oriented bike BUT.....the 94db stock exhaust note was reduced to 83db!!!!!! Seat of the pants riders (a lot of them with a lot of experience) said that there was a slight performance gain. Here's a web site you can find more information on them

I've heard the "uncorked" WR's in my riding area :) and I know you guys need some help finding a good pipe that doesn't kill the power! :D

Sorry I tried not to give any digs :D!

  • cnacc

Posted March 06, 2003 - 01:10 PM


Thats what we CRD pipe owners have been saying for months! Just look at my sig. Way better low and mid than stock uncorked and only 96db's :)

  • dmp437

Posted March 06, 2003 - 02:28 PM


Have you had your CRD sound checked using SAE J-1287? (The 20" test at a 45 degree angle) We're hearing that the 96dB pipe will really test at 94dB for sound check purposes, but don;t want to buy the pipe and have it fail. The XR400 in the CCC test (December 2002 issue of Trailrider) was using the 91 dB pipe, which is um... HUGE. Looks like a torpedo under your fender.
I'm leaning strongly towards CRD since I have a dealer 10 miles from my house and they look high quality.

  • SFO

Posted March 06, 2003 - 05:29 PM


My CRD absolute power tested a borderline 96~97db at Stoneyford
over the thanksgiving weekend.
Ranger Matt said it could be a 50/50 pass fail pipe.
I would not call it a 94db pipe on the wr.

  • Desracer

Posted March 06, 2003 - 09:01 PM


You really have to put the pipe on the bike and test it. An Xr 400 is a real poor comparison to a Wr, low rpm power vs high rev power on Wr. Basic the more you rev it the louder it is, and rpm is a factor in sound checks. KTM has the best stock systems, so why cant Yamaha make a lightweight powerful but quiet system? CRD doesnt have any charts or tests for a 450 yet, I called. I want to see a dyno chart on the CRD and a sound check! Its to much money to may or may not pass for sound. I remember a post here on TT for a vortip in an XR that was 86db for like $79.00. The FMF Q in the Dirt Rider test was 100db and missing 5hp off the bottom when compared to the other loud pipes. Interesting thing is, it passes sound checks at 96db. The only good thing that will happen is more people will build exhausts, competition will improve the breed and they will be cheaper. The bad thing is we needed them yesterday.

  • cnacc

Posted March 07, 2003 - 08:26 AM


Yes I have had it tested, the local MX track is run by the park service and their ranger has tested it at 20" 4250 rpm's. When I initialy got the pipe it tested at 95-96, after a couple months of riding 96-97db. I think that with some new packing it will quiet it down again. They don't recomend the absolute preformance-91db pipe, for anything but enduros/dualsporting. The absolute power pipes work very well IMO, and it is not much longer,if any than the stock. The pipes are not only quieter, but it is a more mellow less iritating sound. Also there is currently no turn down tip on the pipe, one could help drop a couple more db. I have been really pleased with this pipe!!! :D :D :D :)

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  • techman

Posted March 13, 2003 - 04:54 PM


Have you had your CRD pipe apart? I'm curious if it's just an oversized version of a regular perforated center pipe, fiberglass packing plus outer can silencer like those used on pretty much every motocross bike ever made. Or, is there some internal baffles etc? If you've ever had a chance to look at the quiet version I'd also be interested in whatever you may have seen regarding it's internal design.

  • cnacc

Posted March 14, 2003 - 08:24 AM


no, I have not had it apart. I believe it is a reverse conical design, does that sound right? I don't believe it has any special baffels, just packing like most silencers. I will be repacking in the next couple of months, I will take Some photos when I do.

  • Fryboy

Posted March 15, 2003 - 04:25 AM


Hey Cnacc,

I noticed your quote "Way better low and mid than stock uncorked and only 96db's" Are you being honest for real deal holyfield? Cross your heart hope to die serious? Seriously though, I was looking at that pipe. Until I saw the 91db version on a YZF426 and didn't like how freakin long it was. Almost went to the end of the fender. Looked vulnerable to any slide outs or lay downs. Is the 96db version as long? Have any pictures of it mounted on your bike?


  • SFO

Posted March 15, 2003 - 11:14 AM


The 96db absolute power is about flush with the rear fender at its end cap.
The low end and mid range is not as bright as the arrow I was using or an uncorked stock pipe. The top end feels very similiar to those other pipes though. Will have to wait for the next dyno session to know for sure what is really happening.

  • Superbike

Posted March 15, 2003 - 05:57 PM


How loud was the Arrow? Who sells them in the states? Thanks, ---Mike

  • SFO

Posted March 15, 2003 - 06:31 PM


I would put the arrow silencer at 98db after testing similiar pipes but I didn't test this unit.
It didn't have a tinny note.


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