Noise at Kaitoke

**jellywrestler** · 2nd July 2012, 22:31

Originally Posted by koba

Another point to consider is induction noise, it can actually add quite a lot to the overall noise.

yeah your Girlfriend is a classic example of that...

**bucketracer** · 2nd July 2012, 22:51

Originally Posted by speights_bud

Yea i will definitely be going back to the setup, it's worth playing around with. There was more noise from the motor mechanics than exhaust. I dunno about Dyno time though that doesn't sound like the good ol spirit of buckets... lol

Noise is a problem for us all .... and as the Bucket racings revival is pretty much due to the ever popular FXR.

In the interests of good silencing and power if someone who knows more than we do about the science of 4-stroke exhausts, tuned lengths and a suitable resonator size for a standard FXR150 and want to post their ideas about a quiet performance exhaust for someone to try.

Then TeeZee and Chambers would be happy to put up the dyno time to develop it on some local bike so long as the owner does/organises the construction work and the details are made available for everyone.

**TZ350** · 3rd July 2012, 07:46

Up close I don't think there is anything in it between 2 and 4 strokes noise wise but the 4-Stroke exhaust note seems to carry further.

So there it is, because we can't race without them, Team ESE is offering their dyno time to help with the development of a quiet performance exhaust system for 4-Strokes.

We are not looking for any old shitter, it has to be an exhaust system based on sound design principles and made from components that anyone can source so they can replicate it easily.

**richban** · 3rd July 2012, 07:53

Originally Posted by bucketracer

Noise is a problem for us all .... and as the Bucket racings revival is pretty much due to the ever popular FXR.

In the interests of good silencing and power if someone who knows more than we do about the science of 4-stroke exhausts, tuned lengths and a suitable resonator size for a standard FXR150 and want to post their ideas about a quiet performance exhaust for someone to try.

Then TeeZee and Chambers would be happy to put up the dyno time to develop it on some local bike so long as the owner does/organises the construction work and the details are made available for everyone.

A header pipe 450 to 500mm long from the valve will increase top end on a standard FXR. Then you have to shut it up. Bigger is better. Hamish mentioned Steve's muffler being quite. I gave that to him a while ago. Its good to know it works. It is an old oval scorpion sports bike slip on. Straight through with a 48 50mm bore. It was about 450 long when he got it might be shorter now. Very similar to Gavin V's setup. Any mega boom / resonator would have to be matched to cams and intake. Not much point as you can run a shorter pipe to gain top end. Unlike dirt bikes. If you want to develop a system you would want to be adding a carb and intake to the package. Header muffler and a Akunar 30mm PWK knock off with a trumpet taking it to 205 / 210 from valve. If you can prove it makes more power and is under 95db then people will be keen to make the effort.

**TZ350** · 3rd July 2012, 08:06

Originally Posted by richban

If you can prove it makes more power and is under 95db then people will be keen to make the effort.

Thanks for the info.

I think those specks are what Giggles has been working to and he has 18rwhp.

We are doing some more dyno work on his FXR soon and will post the results.

**hmurphy** · 3rd July 2012, 08:52

I also think it would be a good idea to not scare everyone off touching their mufflers with all this science talk. I just cut my header pipe where it suited me, and banged on a muffler where it could fit and not hit the ground mid corner. The bike goes completely fine. No issues and is fast enough. I am sure that it could be better, but surely not by a huuuugely different amount.

So if you're scared about touching your muffler and you don't want to spend lots of money, don't let that stop you from going racing if all you need to do is cut your header pipe and put a decent capacity muffler on there. I'm not going racing at Kaitoke until my bike is a lot quieter but it's not a big deal modifying mufflers if you aren't looking for that last 1% of power which I'm not.

**bucketracer** · 3rd July 2012, 09:04

Originally Posted by hmurphy

I also think it would be a good idea to not scare everyone off touching their mufflers with all this science talk. I just cut my header pipe where it suited me, and banged on a muffler where it could fit and not hit the ground mid corner. The bike goes completely fine. No issues and is fast enough. I am sure that it could be better, but surely not by a huuuugely different amount.

Yes your right, we don't want to scare anyone off from having a go, but we dont want to stuff around either.

We have the gear to test things properly and when its all finished those that want to have a go at least have an idea of what something thats quiet and proven to work looks like.

**kel** · 3rd July 2012, 12:50

Originally Posted by F5 Dave

Now I think of it here's a place to recommend a Local muffler expert.

Im sure your man is very good at his trade but ...
After trying and failing miserably to quiten my megaphone exhaust it was tossed out and replaced with a unit made by a local exhaust manufacturer, and guess what, I was told it was the loudest in A grade at Kaitoke. Point is you need to be specific about noise even with the guys that make exhausts for a living.
TZ your idea and offer is excellent but the pipe mentioned above has proved OK on a standard camed motor but noisey as hell on mine. That said we're putting cams into giggles bike next weekend so if you can effectively quiten it then the design should apply to most FXR's

**Pumba** · 3rd July 2012, 13:16

Originally Posted by richban

Very similar to Gavin V's setup.

Gavin's muffler is a aftermarket muffler that was off a damaged speed triple that was just lying around (if he is to be believed

)

**TZ350** · 3rd July 2012, 13:37

Originally Posted by kel

That said we're putting cams into giggles bike next weekend so if you can effectively quiten it then the design should apply to most FXR's

I am away again, back next Monday and looking forward to seeing what we can do. Giggles got his after market muffler from a local muffler shop I think and he says it was reasonably priced. PS Kel I have fitted a TPS to the Beast so we will get that back on the dyno too.

**richban** · 3rd July 2012, 14:26

Originally Posted by Pumba

Gavin's muffler is a aftermarket muffler that was off a damaged speed triple that was just lying around (if he is to be believed

)

Seems to work a treat. Can't really remember but its is not the loud right?

**Pumba** · 3rd July 2012, 15:34

Originally Posted by richban

Seems to work a treat. Can't really remember but its is not the loud right?

Yell it was a shit load quieter than mine was (note the was) so yea it did the job. Based on my limited knowledge on the subject I suspect it is because of the large volume of the pipe.

For the same reason I suspect mine was loud because it did not have enough volume and a large opening. But it has been quietened down with a baffle insert, that hasn't appeared to reduce any power.

**Gigglebutton** · 3rd July 2012, 17:25

I got a carbon can from Chase on (Maurice Rd Penrose) just up from work. $180 + GST I think. Chinese but really well made and real pretty. They supply car bits but have a box of these for some reason out the back. They sell the bits needed to make up exhausts at trade prices.