OzVMX Forum

Marque Remarks => Yamaha => Topic started by: Tahitian_Red on December 07, 2015, 01:08:00 pm

Title: Yamaha 360 Stinger
Post by: Tahitian_Red on December 07, 2015, 01:08:00 pm

What is the ideal stinger diameter for a 360 Motocrosser (RT-1 thru 360MX)?  How does length effect the power?

Thanks!

J

Title: Re: Yamaha 360 Stinger
Post by: Rossvickicampbell on December 07, 2015, 02:25:56 pm

other guys will comment with numbers but the standard YZ360 one goes from thin through fat through thin again - and can measure if you need.

Doesn't help but thought I would say  ;D

Title: Re: Yamaha 360 Stinger
Post by: Tahitian_Red on December 08, 2015, 01:38:57 pm

Thanks I have the Hooker pipe on my RT-1 MX and the silencer is tiny.  I was thinking a maybe cutting it off and replacing it with a stinger and bolt on an aftermarket silencer (Skyway, J&R, Answer).

Title: Re: Yamaha 360 Stinger
Post by: Rossvickicampbell on December 08, 2015, 01:58:53 pm

Geoff Morris does a YZ360 silencer - not sure about mountings etc.  Physical size is larger, and is quieter, not sure about pipe diameter though but must be similar as fits straight onto existing pipe.

Title: Re: Yamaha 360 Stinger
Post by: Lozza on December 08, 2015, 10:37:51 pm

Quote from: Tahitian_Red on December 07, 2015, 01:08:00 pm

What is the ideal stinger diameter for a 360 Motocrosser (RT-1 thru 360MX)?  How does length effect the power?

Thanks!

J

Around 27-28mm. Some say longer is more top end and shorter is more mid. I think that is just perception and not reality. As I have made pipes with tailpipes about 20mm long and they make heaps of top end.......and mid range  ;D

Title: Re: Yamaha 360 Stinger
Post by: Tahitian_Red on December 11, 2015, 12:18:26 pm

Thanks Lozza!

The length will probably be determined by the aftermarket silencer I find. :-)

Title: Re: Yamaha 360 Stinger
Post by: Rossvickicampbell on December 11, 2015, 01:44:15 pm

as Lozza says - the one on my 360 - the GMC silencer measures very close to the 27mm mark inpipe, 200mm long silencer at 55mm diameter (repackable), with a 20mm ID discharge.

Title: Re: Yamaha 360 Stinger
Post by: GMC on December 11, 2015, 09:23:46 pm

Open class stingers can vary from 25 to 32mm ID
Your 360 would be best in the lower scale of that, as Lozza says around the 28 mark
Length plays a minor role in power output compared to diameter

Don't pay any attention to what the Yamaha engineers designed for the B model YZ, they were on drugs the day they designed the B model exhaust :o

Title: Re: Yamaha 360 Stinger
Post by: Freakshow on December 14, 2015, 11:21:49 am

circle F in the states sell the stingers for like $30

Title: Re: Yamaha 360 Stinger
Post by: shelpi on December 14, 2015, 11:39:29 am

Quote from: Lozza on December 08, 2015, 10:37:51 pm

Quote from: Tahitian_Red on December 07, 2015, 01:08:00 pm

What is the ideal stinger diameter for a 360 Motocrosser (RT-1 thru 360MX)?  How does length effect the power?

Thanks!

J

Around 27-28mm. Some say longer is more top end and shorter is more mid. I think that is just perception and not reality. As I have made pipes with tailpipes about 20mm long and they make heaps of top end.......and mid range  ;D

yep flow rate is dictated by the orifice diameter and length only causes frictional loss

Title: Re: Yamaha 360 Stinger
Post by: Rossvickicampbell on December 14, 2015, 11:55:25 am

and quietens the bike????

Title: Re: Yamaha 360 Stinger
Post by: shelpi on December 14, 2015, 12:02:11 pm

there is a tune length wich starts at the piston wall (exhaust ) to the tail pipe orifice 
its lenght of header pipe, convergance cone, belly (centre) section, divergance cone to tail pipe inside diameter and how many stage that dictate the power spread 
of course the overall diameter plays its part in the design/ tuneing performance curve attempting to achieve
and makes it louder  ;D until we put a muffler on it :(