What muffler to use?

[bnt5]

I pulled the stock muffler box off my robin subaru 9 hp and am welding up a new pipe to replace it, couple of questions for the pros:

1. exhaust I.D. is .8" what size pipe should I use?

2. Is there a certain length the overall muffler pipe should be for max performance?

3. What muffler end should I buy to put on the pipe? (I want something quiet and relatively inexpensive since my wife or son will probably back the go kart into something and damage it)

Thanks Bill

 

[devino246]

If your adventurous, you could do what Toystory_4wd and I did and make a muffler.

http://diygokarts.com/vb/showthread.php?t=6887&highlight=homemade+muffler

 

[racerc2000]

max performance doesnt include the word muffler.

but if you want quiet. larger will in most cases mean quieter to a point.

ie: on a 5hp using 3/4" pipe into a 4" chamber section. with a 3/4" pref pipe in the middle and fiberglass packing.

5" long muffler may do the trick. under would be louder but over may just decrease power while sound stays the same.

distance of pipe between the valve and muffler could change this also.

if your not up for the trial and error.

a simple very small car muffler would work or a muffler of a larger then 50cc scooter or moped.

you can choose the exit direction depending on who the noise was bothering. if it was you point it strait back or to a side. for others a turndown pointing at ground works.

you can also take the stock muffler. and stuff it with stainless steel pot scrubbers for a cheap and quiet fix. for more performance you can add in some pipe to gain some distance from the valve.

 

[bnt5]

Thanks for the ideas, I never thought about making one. I will look into a little scooter muffler if I can find one, right now I just have to find a parts store that sells 1 1/8" dia. pipe.

 

[racerc2000]

if this is in your price range and you wan to weld up a header pipe.

this has a 1.10" (28mm) ID flange

http://www.ebay.com/itm/Muffler-Pip...ies&vxp=mtr&hash=item4cfb065d36#ht_707wt_1031