Originally posted by ferrealb16
bends take away from flow. mandrel bends creat an odd shaped figure. because of this, the exhaust flow doesnt flow as smoothly as it would if it were being pulled/pushed thru a constant radius bend. and how do you get constant radius bends? you contact a tubing fabrication house and buy either 90 deg bends or donuts.
:eh: A mandrel bend is accomplished by inserting a mandrel the same size as your exhaust and using it to guarantee the inside diameter doesn't change. Are you thinking of crush-bent tubing? The difference between formed elbows and mandrel bends is so slight it's almost laughable.
you stay current huh and dont give history a second thought? ever heard the phrase history repeats itself or you could learn from your elders? well hello, learned something from highly competetive superbike racing and applied it to import racing.
Let me put it this way. If it was so great, it would still be used in racing. As far as engines and competitive racing goes, history is all apart of the recipe for making power, where you learn what to add and what to leave out. If you want to talk about highly competative, look into the world of kart racing. It's gotten to the point in 4 cycle karting that high HP engines have about a 15* bend coming out of the head on an otherwise straight pipe. Why? Because they figured out that's the angle needed for the naturally swirling gases to exit with the least back pressure, which is a necessity on a flat-head engine. If you get into the restrictor plate classes, they're using 360* bugle style pipes because they run stronger with the added length that you can only fit within the rules by turning that much. Back to motorcycles, or 2-cycles in general, to make the most power you need to be able to handle the sound energy from the exhaust port the most effectively, with your divergence and convergence cones after the tunable section of flex piping. The header pipes are still mandrel bent.
take a look at ericks racing, check out his header that he has properly tuned and make your car fast.
My car does fine, it won't break any records, but it will get me to work with some fun, and still pull over 35 mpg. That's what we do here, talk about streetable engines because most people can't afford to spend all their money on engines that last less than 20,000 miles.
what is up with the gang mentality on this board? i simply come here to ask a question, give my advice/opinion and you jump on me like i were a virus! you must all be liberal democratic dictators, meanin if its not what you think, its wrong.
Well, lemme see. You come in here spouting off things that no street engine builder would ever consider doing, trying to drop names and cite professional techniques, and pretty much use those as your only basis for your suggestions. I'm all for new ideas, but your suggestions just don't add up to logical thinking.