New 3 chamber tuned exhaust tuning?

[Scotty Rex X]

hi there,

bought myself a 3 chamber tuned exhaust for my rex x on a .21 engine.

put the exhaust on and took it on a run and it was so down on power and really boggy, so i put the old exhaust on problem solved.

how would i go about tuning the engine to the exhaust and is this a good idea otherwise il send it back.

will the engine temp increase what do i need to consider worry about ??

cheers

Alex

[1981robbo]

It'll probably run differently, so a quick retune may be in order, sounds like ur lsn may need 1/32 of a turn lean. The top end may be affected also as your pipe may let your engine rev higher, thus needing a 1/32 rich on the hsn.

[Rich8]

The tuned pipe works by maximising the amount of exhaust gasses (containing unburnt fuel - a 2 stroke nitro engine isn't very efficient) that are forced back into the cylinder. That unburnt fuel that is normally wasted flying out of the exhaust goes back into the combustion chamber with the new fresh fuel coming in from the carb. So all of a sudden you have more fuel in the combustion chamber than before, so your engine is running a bit richer.

If you've changed to a tuned pipe best bet is to reset your carb to factory settings (expecting it to be even richer than they would normally be), and lean/tune from there.

Edit: that is reset both HSN and LSN to factory and lean from there.

Edited February 12, 2013 by Rich8

[Scotty Rex X]

cheers for the reply lads very helpful.

quick question is running well now would i need to go back to factory setting or just tweak the HSN and see were that gets me ?

Cheers

Alex

[mugen mark]

just a tweak,there aint a lot of difference,when adding/changing pipes airfilters ect they ussally only need a small adjustment.

[Scotty Rex X]

lovely, cheers for the infomation.

Just need to pluck up the courage to tune it know. its running lovely on the standard pipe would hate to mess it up

Cheers for the uselfull answer there much appreciated

Alex