Quiet XR650R exhaust?

[phil_j]

Hey guys, nothing to contribute here other than to say thanks. As the owner of a brand new leftover '06 (no 07s in Canada), I really appreciate the testing you're all doing, as I'm in the market for something less restrictive than stock, but need/want to keep the noise down for street use.

I can't wait to hear the Mori results.

Right now I'm mostly considering a Q2 and a Leo Vince, leaning towards the Leo with quiet (94db claimed) tip.

Does anyone have a BD turndown tip to test?

Thanks again for all the work everyone!

[abby]

Thumpage, abby,

I did a very informal (no tach) db meter and got:

stock tip - 79db at about 1,000 rpm, and 87 db at about 3,000 rpm.

The HRC tip was 87db at 1,000 rpm and 103 db (I told you so!!!) at about 3,000. 3,000, 3,500, 2,900.....it's loud !

Metered in an open field with grass just mowed to 3.75", but I was not stradling the bike .. my wife doesn't do db meter tests

While the db metering was unscientific, the comparison between stock tip and HRC tip at the "approx 3,000 rpm" was informative cause I just took off the stock tip and installed the HRC tip with the carb set at the same rpm.

Next up the Mori, but it's going to take a while. Did you know that you need to remove the radiators to install new pipes? Did you know I need to replace my right radiator which is bent into a parallelogram? Two birds with one stone.

Laters,

Looks like our stock tip measurements are lining up at around 87 DB.

I am not really surprised by the HRC tip coming in around 103 DB.

I am definately sticking with my Q2.

[moto931]

thummpage can you put together the measurements on where and what you cut on the stock tip agian. What did you end up drilling the baffles inside the muffler to? I have a stock tip on mine and would like to make it run better.

Also, does anyone have any suggestions on head pipes? The stock ones are way small and have got to be choking the thing down. A buddy of mine has the fmf head pipes and mid pipe with a q2 tail section. It deffinately rips, in 3rd gear if we both roll on the throttle, his front end comes up and see-you-later. We both have the same gearing on and the same motor work exactly.

Any help or suggestions are appreciated.

Stu

[Chopp]

I run the HRC tip and don't find it to be too loud as long as you keep the RPMs reasonable. I drive real nice until I leave my neighborhood and get to the trails. But it is loud when you are WFO.

[Thumpage]

Did you know that you need to remove the radiators to install new pipes? Did you know I need to replace my right radiator which is bent into a parallelogram? Two birds with one stone.

Laters,

If it wasn't for needing to replace the bent right radiator, I would have hoped you hadn't completely removed the radiators to install the header. All anyone really needs to do is unbolt the radiators and move/hold them out of the way, not fully disconnecting them from the hoses and such, . You can get to the header bolts with a long extention on your ratchet.

[Thumpage]

thummpage can you put together the measurements on where and what you cut on the stock tip agian. What did you end up drilling the baffles inside the muffler to? I have a stock tip on mine and would like to make it run better.

Also, does anyone have any suggestions on head pipes? The stock ones are way small and have got to be choking the thing down. A buddy of mine has the fmf head pipes and mid pipe with a q2 tail section. It deffinately rips, in 3rd gear if we both roll on the throttle, his front end comes up and see-you-later. We both have the same gearing on and the same motor work exactly.

Any help or suggestions are appreciated.

Stu

Stu,

I didn't do anything to the muffler body's baffle plates. You don't need to touch them. It will make the muffler sound hollow. The modification is all on the tip itself. 1) you drill out the exit baffle with a deep 2" hole saw like you will see in many "uncorking" write-ups. 2) Cut off the baffle cap,(that is held on by the four 'legs') from the tip. You need to remove the tip from the muffler to do this. It will then expose the endcap of the spark arrestor section. The end of the spark arrestor section basicly does the same thing,(a second time) as the baffle cap that you just cut off. Both 'caps' line up with the internal baffle plates in the muffler body so that the exhaust gasses only pass through 2 ring gaps. 3) Then you drill/core out the backside of the spark arrestor section, (again, which is the 2nd 'baffle cap' to line up with one of the two baffle plates in the muffler body). I had used the same 2" hole saw used for drilling the exit baffle but I would recommend you use a 1.5" hole saw instead. This will allow you to leave a 1/4" rim so that you can drill holes and screw screen over the end rather than the way I had done. I had used JB weld epoxy to adhere screen over the end of the fully cored endcap. It worked well but if I had ever needed to replace the screen It would have been more work than simply screwing new screen back on.

For a more complete reference. Here is a link to a detailed write up I had done with pictures. Look at post #59. Any more questions, just let me know.

[Thumpage]

Stu,

For a more complete reference. Here is a link to a detailed write up I had done with pictures. Look at post #59. Any more questions, just let me know.

Ooops, heres the link: https://www.thumpertalk.com/forum/showthread.php?t=464838&page=6

[XRR-kat]

Thump,

I got a pair of near new rads off eBay and will install both in place of my near new (only 500 miles but bent to h***) rads. Maybe I can fab a fan cooler while I am there. Got a good suggestion for rad guards? BTW, I caved and ordered the Ebrock from Barnums - entirely your fault. That is, the rationale you presented about making the BRP more versatile (tight single track, etc) in addition to your Glamis-drills...... ... and, yes, I drop it alot (did I mention my bent rads?!)

[Thumpage]

Thump,

I got a pair of near new rads off eBay and will install both in place of my near new (only 500 miles but bent to h***) rads. Maybe I can fab a fan cooler while I am there. Got a good suggestion for rad guards? BTW, I caved and ordered the Ebrock from Barnums - entirely your fault. That is, the rationale you presented about making the BRP more versatile (tight single track, etc) in addition to your Glamis-drills...... ... and, yes, I drop it alot (did I mention my bent rads?!)

At least you got the radiators most likely fairly cheap compared to full retail price,

Fan? I am not really a fan, (pardon the pun) of adding one to the bike but I am sure they could possibly help for some riding conditions. My contention is, if your jetting is fine, you are getting at least some air flow through the radiators by rolling along to some degree and the thermostat is working properly, you should be fine in most cases. Some guys have reported problems nontheless, so who can really say, ? .

Radiator braces should help keep the side of the radiators from getting bent as easily. You may not be able to rig up a fan with the use of radiator braces though.

Some radiator gaurds,(grills) are said to make the bike run a bit hotter in slow riding situations, (so maybe a fan for you in this case). I believe part of the problem really stems from elliminating the stock plastic air louvers. The plastic louvers actually capture & direct the airflow inward into the radiators. Without them, their is less air being forced inward to flow through the radiators. There are so many designs and brands out there. Some, like the Devol brand protect the front and sides, (maybe good with use of your fan idea). Some brands supposedly have fitment issues, possibly including the devols. I would scour for info. before thinking of a particular brand if you really want frontal gaurds.

You will like the Edelbrock, . There will be a little learning curve to setting it up but it is easier than changing internal jets. Ha, just wait till you feel the new response. I know I will be seeing this, (?:excuseme:) from you after it is dialed in.

[jesusgatos]

Don't want to take this too much further off-topic, but I just installed a pair of Unabiker radiator guards that I purchased from the TT store and they're BURLY. I think it's hands-down the best rad guard design out there.

[XRR-kat]

Thumpage,

Correct, I figure the rad guard will restrict airflow some and therefore increase need for fan. The kind of rad guards I'm looking for would prevent the "parallelogram effect" when dropping bike - something to improve lateral stiffness, so would have structure across the cooling fins to resist "pe". Pretty sure I'll need a supplemental fan. Anyway, it would be insurance.

Also, I'm dual-sporting and stop lights here approach the boil-over limit for the pig. This is not constant wide open broad slides on fire-roads out here, or sand dunes (wish it was) and I can't always keep moving.

Jesus,

Thanks for the suggestion.

This is not thread hijacking - no db metering for the Mori until I get the rad guards, rads, fan sorted out

Looks like I'll be ordering the Unabiker Rad Guards - good design, stout and looks not to interfere with the Mori.

[jesusgatos]

Here's a picture that shows the cross-bracing between the two guards behind the radiator.

[XRR-kat]

Well it's been 2 months and I finally finished the Unabiker rad guards mounted over new rads; Moriwaki exhaust, Utah Sports skid plate and Edlebrock carb installs.

Did the DB check, same as before, even though I hadn't finished all my mods/upgrades/maint and the number is .................. actually a range - 96 to 98 db. Still no tachometer so I set the idle to about 3000 (low side) then I set it to about 3000 (high side) and got 96-98 decibels. I like to think I was right on my first estimate of "3,000 rpm" and the high side was more like 4,000 rpm but wanted to be sure I covered the bases. This is with the Mori spark arrestor and though I didn't measure it, I suspect the Mori without the spark arrestor would still be quieter than stock with HRC tip (103 db?).

Sound is vey nice and much mellower than stock though louder. It has fiber glass packing which accounts for this softer sound and was not objectionable when I first started it in the garage, without the spark arrestor.

Can't really comment on the Edie except once I got the BRP started, restarting was much easier than stock carb. Difficulty was in first starting as I changed so many parameters wasn't sure if I was starting it too lean. Also think I had some of that compression release hang-up as there was no compression for awhile. Bike would attempt to run even without setting up for TDC to kick.

I'm very pleased with the Moriwaki exhaust in terms of appearance, installtion, and loudness. Performance comments will come later though I can already say I don't have the off-idle stumble any more.

Laters,

[XRR-kat]

bump:thinking:

[Thumpage]

bump:thinking:

XRR-Kat,

I have been away from coming to look at the Thumpertalk posts since last time we were talking about this. I literally just checked in now to see what the current topics were and whala I see your post. I am sure it is great to have all the mods put on finally.

I suspect the reason why the bike was so hard to start with the new Edelbrock is that the idle adjustment cable was/is probably set too low. That is one fairly consistant flub with new Edelbrock owners after doing the initial install. Second, once the idle adjustment is in the proper range you still generally need to turn the idle up 1/2 -1 full turn up on a cold start. Along with a few twists of the throttle a few times to pump some fuel to prime the cold motor. As for the Moriwaki system, expect that you will lose some bottom end with the stock motor. That is what has been reported with the Moriwaki system since the headers are so large. Of course top end gain should be noticably enhanced. The Mori system is supposed to be really good with modded motors with larger cams and the like. With the Edelbrock you should at least gain back some feeling of low end power from the instant throttle response. Isn't it nice?

Once the Edelbrock is dialed in, what a difference...

[vkschatz]

Currently I am still corked (2005 xr650r). My main reason for uncorking it is not strictly for power gain, but for it to run cooler and start easier (but I'll take that power though if I can get a reasonable power/noise trade). When I am chasing my wife and my 7 and 8 year old kids around in the woods, my XR tends to overheat.

I am still on the fence about uncorking because of the noise. One place I ride has a 94 db limit. I do not want to be the loudest bike out there, even if that means I just make it under the 94 db limit.

So in my searching and talking, here is what I've gathered. If one of these facts seems wrong, someone please jump in and correct me - or even add in some more concrete data.

The HRC tip is supposedly somewhere around 100 db. I have no idea if that is a "real" value or not, but that's loud for where I am.

Baja designs makes a turn down insert for the HRC tip (but I can't find it on their website) which makes the HRC tip more quiet, but no consistent test data on noise level that I've been able to find. Some say under 96 db, some say not.

The drilled stock tip drilled out to 2 inches is supposedly quieter and more restricted in flow to the HRC tip, but no consistent test data on noise level that I've been able to find. XR650R.us FAQ says somewhere between 96 and 102 DB at test RPM (3250ish) at 8 feet back and 8 feet to the right.... but tests are normally done at 20 or 22 inches/45 degrees from the pipe. Too loud for me.

The drilled stock tip drilled to 1.5 inches is supposedly more quiet (and obviously more restricted) than when drilled to 2 inches, but no test data on how much. This was suggested to me to partially uncork more quietly, but I don't know how much. I'd bet though that is still over 94 db in a "real" test.

The other option I was looking into is the FMF Q2 Series, or the Q4 Series when it comes out for the XR (muffler only, not full exhaust). Q2 is available now, Q4 they told me to check back next month. FMF claims 96 db max for the Q2. And I don't know how they test, so I don't know what their claim of 96 db max means. They also say that "most models" test under 93 db - I don't know if the XRR is "most models". There is a site which tests the Q2 (not on an XR but on a crf450r) here: http://www.loudsucks.com/. Stock, the bike tested 97.3 db, with the Q2 it tested 95.4 db. I am GUESSING that an uncorked XR with the Q2 would test lower than the CRF with the Q2 does.

I have a tach and a sound meter, when it's not 10 degrees outside I am going to do a stock measurement (just curious what stock really is even on a cheapo meter), and hopefully uncork and get a drilled tip measurement. I wish I knew what the Q2 or Q4 would come in at before I drop $350.00 on one and I find that's too loud also and shelve it. I could care less how much the Q2 weighs or what it looks like -- if I knew that it would be the quietest of the above options, and hopefully come in the low 90's uncorked, then it is worth the money to me.

By the way, I personally am not bothered by the noise or the noise others make, but every person who does not ride around where I ride is. Every freakin' one.

Maybe a dumb question, but would adding muffler packing around screened part of HRC tip reduce the sound output?

thx, vk

[alfaris]

I have the possibility to rescue the FMFQ4 silencer from my former CRF450R 2006, and i would like to know if it would fit on the XR650R. Any info? thanks.

[motomanx]

i doubt it, but it might with some mods.

[alfaris]

sure crf frame is different than XR.....is not only the point where the two bolt fits to chassis, also the angle of the tube. And moreover, the Q4 collector is solidary with the muffler, not like leovince or others where you can just exchange collectors and even you just move the carbon piece back forward to fit the muffler in place.

any adaptations i see are expensive and gives headache.