Exhaust Throttle

EatMyShortsRacing · Feb 12, 2003

Ian,

Yeah we are famous for getting off topic I bet!!! Might be easier to follow if we raise new issues in new threads... and maybe title them so they can be more specific...

EM.. you know the rest

Ian Inverarity · Feb 12, 2003

Craig,

Yeah. I think we should start a dyno thread....

Nitrocrazed racing: Gentlemen-Start your dynos....

Atious · Feb 12, 2003

Heck no, you guys are doing a great job answering the question. You've helped me to determine that the exhaust throttle is getting tossed for now. Rather than mess around tring to figure the correct venturi diameter for the engine I'm going to stick with a mild carburetor. I live in the middle of Maine and the temp and humidity alter greatly, not only day to day, but hourly as well. Determining a proper venturi would be rather difficult within these conditions. A simple twist of the needle to tune would be much more preferable.

Propjockey · Feb 12, 2003

Atious--the only true benefit I have seen for an exhaust throttle is INSTANT throttle response. The only limitation is how fast your servo can open it!

Ian--flapper valve sucked! Awesome top end--almost impossible to get consistant low end. Too much 'slop'. And leaks like a sieve!

The rotating barrel on the 7.5 works much better. I didn't find it any harder to adjust than a normal carb.

EMS--to the best of my knowledge, both venturi(s)--what IS plural for venturi?--are original K&B parts. The machined piece on the 7.5 is epoxied on (an experiment). I can measure 'em if you want.

For anyone considering an exhaust throttle--MAKE SURE your cooling system works! At anything less than full throttle, the engine heats up FAST!

Ian Inverarity · Feb 12, 2003

Propjockey,

Thanks for the info! Sometimes the simplest ideas are the best..... sometimes they really suck! ;D

Nitrocrazed racing: Something else that old Walbro is no good for....