Merlin Man

Hi,

I have just obtained a inverted Slimline muffler for my 1.8 Moki, and was wondering if anyone has any data about the stinger pipes' length?

The two pipes are 4" long and protude about 2.5" of this out the bottom of the cowl on my P51. I would like to reduce the length outside the cowl, but I understand that just cutting them off is not going to be without its problems.

I presume that the length of the pipes affect noise levels and back pressure? If they are cut, does this mean that back pressure is reduced proportionally?Could this reduction in back pressure be accounted for by inserting a narrower pipe piece ( restrictor) in the end of the stingers?

Any info or ideas on this would be appreciated.

Cheers,
Merlin Man.

David Bathe

Just cut away IMO.
If you get problems just crimp the pipes or block one off.
In my experience (and thats mainly with BMC ((I consider SL's to be a superiour)) Pitts mufflers) many engines tends to run better with one stinger totally blocked.
What I've done in the past (because I've used them on many different applications over the years) is to cut them down to say 2cm in lenght and then use silcon tube cut to lenght to suite.

Merlin Man

Hi David,

Thanks for your reply . I have thought of this approach but didn't want to rush it not knowing.

I'll see if anyone else might offer opinions.
Cheers,

M.M.