I recently started as a sales rep fopr Bosal USA. many of you may or may not know that Bosal is an exhaust company with a line called Brospeed. well speaking with the usa president he mentioned that they have a bunch of exhaust tips (the fart can or so) that they want to get rid of ....I can sell these for like 12 each and shipping...retail is over 60 on most. we also have the oe accessory Mazda 3 dressup tip(ewe made them for mazda) I will get pictures if there is any interest. these would look great on lots of cars i think there is pictures on www.bosalperformance.com let me know and i will hook you guys up

Hey, they look great, for them kinda things!




M

That suction wave theory is... interesting. Hmmm... timing at different RPMs and different pipe lengths, considerable pressure coming out of an exhaust... wave travelling from end of muffler back to the valves, timed exactly with the opening of the exhaust valve? Can someone explain to me how that could really work? Sorry to sound skeptical - just wanna understand it. Is there more info? Dyno results?

Pictures are always a good thing. Saw several tips I might be interested in but none listed as "fart can" design.(hahaha)

Thanks for thinking of us.

Perhaps one of these?

http://www.bosalperformance.com/catalog/ex...t_tips_cat.html

QUOTE

Can someone explain to me how that could really work? Sorry to sound skeptical - just wanna understand it. Is there more info? Dyno results?

Isn't this similar to the Varioram induction only applied to the exhaust?

However, I think that when Porsche did this with the intake, that they ended up with two different "lengths" for different RPM ranges.

they add like 5 hp... if you are into that kind of thing(i am not) but i figured i'd let you guys know

QUOTE (RandyLok @ Mar 18 2005, 06:16 PM)

That suction wave theory is... interesting. Hmmm... timing at different RPMs and different pipe lengths, considerable pressure coming out of an exhaust... wave travelling from end of muffler back to the valves, timed exactly with the opening of the exhaust valve? Can someone explain to me how that could really work? Sorry to sound skeptical - just wanna understand it. Is there more info? Dyno results?

Looks like these guys are engineering the resonant frequency of their exhausts so the reflected wave (low pressure) hits the exhaust valve just as the next exhaust cycle is starting thus helping the exhaust gases exit the engine. Travelling waves and their reflections are very important in high frequency electronics. Works the same with mechanical systems. When a wave (in this case exhaust gases exiting the engine) hits a discontinuity like the inside of a muffler or even a sharp bend or exhaust connector, a reflected wave is generated in the opposite direction (back to the engine).

You can do a simple experiment to visualize this phenomenon. Get a corded wall telephone with a long coiled type cord, or even a heavy rope with one end secured, pull it tight, and quickly snap or flick the end you're holding. You'll see a wave travel to the other end of the cord, and then an opposite wave come back to you. Do this continuously at just the right frequency and you'll see standing waves which represents the resonant frequency or multiples of it. Since the RPM range of an engine is quite limited (1K - 6K), a single resonant frequency of an exhaust adjusted to, say 3K-5K RPM could serve the engine well throughout its enire RPM band.

Spoke