Shortened Silencer

[troybilt]

I was reading on twostrokemotorcross.com claiming that a shortened silencer adds low-end snap to the powerband on a 2 stroke. Any truth to this? Anybody with experience shortening a silencer... obviously would need repacked etc... But I'm intrigued about the low-end enhancements... and why a shortened silencer would have any effect other than making it louder.

[muddymess]

iv heard from some old gncc racers that they used to shorten the silencer to keep it from getting hit during a race and smashing the pipe but never anything about it changing the performance. Im pretty sure the silencer doesn't do anything but that, silence the motor.

[troybilt]

I didn't think so either, that's why I'm asking. An article on twostrokemotocross mentions it does.

This article: http://twostrokemotocross.com/2009/09/2010-honda-cr250-elsinore/

from article, this is the author's rebuilt rendition of a 2010 Elisnore CR250r



For 2010 Original Equipment Honda silencer, shortened to add low-end snap, packed and sealed.

[atvmxr]

i have heard rumors about the short silencer, I guess the theory is that it will alter the wave pulse. But after modifying mine I couldnt tell any difference and am about to install another full length silencer because it is louder for sure...

[derby]

Originally posted by atvmxr
i have heard rumors about the short silencer, I guess the theory is that it will alter the wave pulse. But after modifying mine I couldnt tell any difference and am about to install another full length silencer because it is louder for sure...

Stinger length and diameter are critical in pipe building. Exactly the idea with ESR using the centermount over the standard 250r silencer setup. They are able to shorten the stinger length which has an effect on performance and also temps. ESR also made 30 really short center mount silencers for higher profile customers with 370's.

[derby]

:)

[troybilt]

What does stinger length and diameter effect as far as performance?

[MOVIN32]

YES IT DOES MATTER , SAME AS ON A 4STK BUT HEAD PIPE HAS ALOT TO DO WITH THAT ALSO ,LOOK AT OLD SCHOOL SILENCER ,BILLS MOST DG CT ECT

[muddymess]

I'm assuming everyone that's saying it works is referring to the stock silencer like the guy in the article.

I couldn't image chopping up an aftermarket silencer. Especially for something that would equal out to be a gain equal to you changing the spark plug if any.

[86 Quad R]

ive ran the shortened ct and fmf on the same quad with the same pipe and compared it with the longer versions and the only seat of the pants differences were the sound

[derby]

Originally posted by troybilt
What does stinger length and diameter effect as far as performance?

There are so many factors to look at in pipe building. The main thing you will see in modifying the stinger is a drop in temp as you go down in stinger length and as you increase the inside diameter of the stinger. But what is considered ideal for lets say a 250 cc is a stinger that measures 11.02-12.0079 inches with a diameter of 1.063 inches.

The problem with getting the stinger length to 11-12 inches is that you have to run a centermount and also the silencer will look like the one I have in the picture. Plus it is much louder. Hope this helps a little to answer your question. Answering the performance question would be much harder to explain due to all the different variables.



http://i46.tinypic.com/2vaxph0.jpg

[troybilt]

Yes, that explains alot. Thanks.