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I'd just buy one if they made one but everything I see is for the MX racer WOT peak hp full rip bad mamba jamba.  Most are too loud and don't have a spark arrestor.

 

I recently gutted my OE muffler and installed a 2" diameter perforated core the length of the muffler body.  I stuffed the area around it with muffler packing.  The OE spark arrestor still bolts on and is centered in the core.  So essentially a glass pack that still uses the OE spark arrestor.  Currently the small removable baffle is still in place, this allows me to keep OE jetting.  Once I rejet, it will come out.  Will be a bit louder but still acceptable.

 

It was difficult to weld the OE muffler back together with my flux core Mig due to how thin the steel was, a Tig woulda done a lots nicer job.  My new plan is to build a new muffler or modify an existing one to be more easily serviceable and quieter.

 

Ok, so here is the criteria.

- Quiet but still sound good, like a large glass pack does.

- Spark Arrestor

- Flows better than OE muffler

 

I'd like to have an oval or tri-oval muffler body as large in diameter and long as will reasonably fit behind the number plate.  The end cap will accept the OE spark arrestor.  It has been my experience that an oval body glass pack is quieter than a round body, not sure why or the science behind it.  Most tri-ovals are quiet too.

 

How would y'all go about it?

What else would you want/need in the Ultimate Woods Muffler?

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All righty then.

 

After further review, it may be more cost effective to just mod a new aftermarket full exhaust to meet my needs.  If I were to make or mod an after market muffler, make a stepped collector between the OE headpipe, get it all ceramic coated, etc.....I might have close to what a Yoshimura, FMF, Pro Circuit or BBR system would cost and my home made job would not be stainless nor be as serviceable.

 

Has there been a review of all the available exhaust systems for a 230? 

Might anyone know the headpipe diameter(s) of the Yoshi, Pro Circuit or BBR?

 

I checked out the Yoshimura RS-2 system and I like how they step the headpipe diameter up in size as well as stepping up the collector diameter so it is the same as the muffler core, or at least it looks like it is.

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This has been said over and over by others here too, but Coeshow dynoed the major brands of exhaust and found the only one that actually made more hp than stock was the BBR, and we're talking like less than 1/2 hp gain! His review should be somewhere on this board. That's why on his big bore 250cc 27 hp super mod crf230f's he'd just run stock exhaust.

There IS some weight to be saved by going aftermarket, but it's expensive weight. Cool you're gonna try to make an exhaust yourself?

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That's just it, I'm not looking for more peak HP rather the best bottom end and mid range power/torque but with a little better exhaust note.  According to the exhaust design program I have, max torque will be with a slightly longer exhaust system, around 53" total length.  The OE 230 exhaust is around 48" total length.

 

I love the sound of a proper glass pack which typically has a bit of a tail pipe after the muffler.  This allows the exhaust pulse to expand into the damping material and most of the higher frequency noise gets muffled, leaves a nice mellow low boomy exhaust note. 

It's hard to listen to the various exhaust systems on YouTube because they usually pick up the higher frequency sounds and not the lower even if it has a nice boomy sound to it.

 

Did Mike Coe measure the various systems he tested?  The OE headpipe is a good size and steps up like it should but it isn't stainless and is hard to keep clean and painted.

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Today I have built a new 32 mm perforated pipe central, to my muffler. Before was smaller.

I am curious to see which is the different operation of my bike with a larger central pipe, since I recently bored my carburetor.

My internal pipe is not long as the muffler but it is about a third of it. In the muffler remaining part there is the expansion chamber and the final insert, even it with perforated tube rock wool coated (diameter pipe as stock insert.) Tomorrow I will finish my work.

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You're right MetricMuscle, a tuned note and great low-to-mid power are traits to strive for. Coeshow dyno tested for most hp, and his big bore motors were tuned for more race-like power, when in reality, play bike riders can put a low to mid powerband to better use. The tuned note you're describing, 'nice mellow low boomy', if you're describing something that doesn't have the annoying rasp, it sounds a lot like the stock pipe with the baffle removed? I wouldn't mind a note like that especially if it was a little quieter than that, which would work well with low to mid powerband enhancement (and my neighbors). The nice thing is, you really only need to compare, dyno or decibels, to improvement over the stock pipe. Now if u could do this, with stepped stainless tubing and a little black/red anodizing color or carbon bling, AND save a couple lbs over stock? Sign me up, I'll buy that!

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Designing it is one thing, building it well is another.

I have a MiG welder which will weld mild steel pretty well.  To weld Stainless Steel it is best to use a TiG welder and know what you are doing.

 

According to my exhaust design program, PipeMax, the length and diameter of the primary or head pipe is very important to maintain exhaust gas velocity.  After the primary, the collector can either be straight or tapered.  Tapered is better because the exhaust pulse ultimately wants to see open atmosphere once it clears the end of the primary/head pipe. It is also a good idea for the pipe entering the muffler to taper up to the inside diameter of the core. This will slow the pulse and allow it to expand into the damping material.  A small diameter pipe will keep the exhaust pulse moving faster and will not expand into the muffler core as well. 

I also like for the pipe exiting the muffler to taper back down to the size of the head pipe.  This puts a little squeeze on the pulse so it will expand into the muffler packing a little better and I've seen where it helps kill the raspy higher frequencies and make a more mellow boomy muffler.

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Maybe we have the same goals.

I'm pretty sure we do.

 

You have an Arrow Stainless Steel head pipe, correct?

Can you measure it's diameter? 

If it is stepped can you measure how long each section is and what the different diameter steps are?

 

How did it change the bikes performance?

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.....After the primary, the collector can either be straight or tapered. Tapered is better because the exhaust pulse ultimately wants to see open atmosphere once it clears the end of the primary/head pipe. It is also a good idea for the pipe entering the muffler to taper up to the inside diameter of the core. This will slow the pulse and allow it to expand into the damping material. A small diameter pipe will keep the exhaust pulse moving faster and will not expand into the muffler core as well.

I also like for the pipe exiting the muffler to taper back down to the size of the head pipe....

Sounds like the fmf 'powercore' expansion section, which I think is one of the coolest 'looking' head pipes, it would be real cool if it did something too! Wonder why fmf does not use the powercore on the crf-f's pipes?

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The first part (curve) arrow pipe is equal to the stock pipe (28mm? With rust and the curve situation section is not constant).

After the curve as seen from the image the tube is greater diameter.. mm 32.

Then in the muffler insertion is again as stock. (There is a conical part in the curve that comes to the first welding to be 32 mm.)

1406541609627.jpg

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Sounds like the fmf 'powercore' expansion section, which I think is one of the coolest 'looking' head pipes, it would be real cool if it did something too! Wonder why fmf does not use the powercore on the crf-f's pipes?

Not exactly. 

The primary/headpipe is supposed to keep exhaust velocity high/fast.  The PowerBomb allows for the pulse to expand and slow down, right in the middle of the headpipe.  PipeMax has a forum and I had intended to post a question as to why they would use this but I haven't yet. 

The PowerBomb should not improve exhaust flow in theory but, it either works to make power or it does not, regardless of theory.

 

The design I'm referring to is a megaphone style exhaust.  At the end of the primary, the exhaust pulse wants to see atmosphere or an expanding pipe area.

 

470404-1.JPG

 

The first part (curve) arrow pipe is equal to the stock pipe (28mm? With rust and the curve situation section is not constant).

After the curve as seen from the image the tube is greater diameter.. mm 32.

Then in the muffler insertion is again as stock. (There is a conical part in the curve that comes to the first welding to be 32 mm.)

Thanks for the info.

So essentially a SS version of the OE exhaust.

I'm gonna experiment with the OE muffler and see what I like and decide from there.

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Not exactly. 

The primary/headpipe is supposed to keep exhaust velocity high/fast.  The PowerBomb allows for the pulse to expand and slow down, right in the middle of the headpipe.  PipeMax has a forum and I had intended to post a question as to why they would use this but I haven't yet. 

The PowerBomb should not improve exhaust flow in theory but, it either works to make power or it does not, regardless of theory.

 

The design I'm referring to is a megaphone style exhaust.  At the end of the primary, the exhaust pulse wants to see atmosphere or an expanding pipe area.

 

470404-1.JPG

 

Thanks for the info.

So essentially a SS version of the OE exhaust.

I'm gonna experiment with the OE muffler and see what I like and decide from there.

 

I tried a power bomb actually it was a mega bomb on the WR450 it gained bottom and lost substantially on the top. Got rid of it.

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I like the way the Yoshimura RS-2 steps up the head pipe and collector and it has been my experience that oval or tri-oval mufflers are quieter than a round muffler.  The RS-2 is diamond shaped or square depending on how you look at it.

The RS-2 is tops on my list at the moment.

I kinda like that Mike Coe didn't see any peak hp gains with it or the PC or any other pipe except the BBR.  Suggests they didn't oversize anything to squeak out a tiny bit on the top end which usually means messing up the bottom and mid.

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MetricMuscle, that sounds a lot like the Outlaw megaphone made by Engines Only:

http://www.xr100.com/outlaw_series_exhaust_pipes.htm

Heard this is a good performing pipe but kinda loud when set up to make the most power. Add and remove Super Trap discs.

 

I have been trying to get my hands on one of these for months now.  Frank just told me they will not be available until he hooks up with a new fabricator.  I know a great shop here in Charlotte so I'm going to see if they can help him out.

Edited by VortecCPI

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What I don't understand is why are good four stroke pipes so expensive compared to two stroke pipes? Is this fat markup or is it really that much harder to make? MetricMuscle can u get titanium tubing or is it even worth experimenting with it?

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