Thread: Exhaust valves
View Single Post
Old 10-17-2015, 03:35 PM   #3 (permalink)
RustyLugNut
Master EcoModder
 
Join Date: Nov 2012
Location: San Diego, California
Posts: 982
Thanks: 271
Thanked 385 Times in 259 Posts
Or you can use in-cylinder pressure sensors.

Quote:
Originally Posted by aerohead View Post
At least one production motorcycle incorporated a 'smart' muffler which had a computer-controlled butterfly valve inside.
The motorcycle engine underwent a full-spectrum dynamometer test to evaluate it's best performance at all rpm's as a function of exhaust back-pressure,then a look-up menu was burned into the ROM chip which allowed the computer to modulate a servo motor linked to the muffler's valve; enabling the engine to always remain in the sweet-spot.
If you've got a loose $100,000 you want to throw at a chassis dyno,you'd be able to do this to your car.
For roughly 10,000 USD, you can purchase an array of pressure sensing spark plugs and the attendant data logging. A set of well thought out acceleration runs will get you most of what you desire.

If you are doing a single cylinder engine, you can purchase the sensing spark plug for about $1K and cludge your own data logger using slower commonly available electronics and do multiple cycle overlays.

But, that's just what I would do.
  Reply With Quote
The Following 3 Users Say Thank You to RustyLugNut For This Useful Post:
aerohead (10-21-2015), oldtamiyaphile (10-17-2015), pgfpro (10-21-2015)