Giving my '94 heritage a complete rebuild, and want to go away from the retro look with 2-into-2 fishtail exhaust. Want to make a hotrod out of it, and want to get as much performance as I can. Good deep sound is important too. The engine is stock 80" evo except fora slightly hotter-than-stock cam and SE aircleaner kit. Current exhaust is the OEM header (think itwas made byKerker) with sampson fishtails. No baffles anywhere.

I would consider thunderheader or another two-into-one system. However, I like the old-school staggered duals look, and have been cruising the catalogs looking at dozens of alternatives. Too many choices. Can anyone help me with techie-talk about back-pressure, reversion, and some of the other terms that mean nothing to me yet?

Thanks all,

Stoner

 

2into 1 usually produce a little more torque. Vance and Hines make a 2 into 2 that has an equalized tube to make the motor "think" it's a 2 into 1 but with the look of a 2 inti 2. (power chamber)

 

ok. this will be a brief overview.every engine needs a certain amount of backpressure. if u loose too much back pressure ur torq will take a dramatic dive.

with drag pipes and even full length pipes w/o baffles reversion is possible but more common with drags. reversion is when the exhaust gasses are sucked back up the pipes on decell and go back into the motor. that air that is drawn back to the motor can burna hole in the valves. it can actually act like a welder and melt the valve. but this happens more with drag pipes with no bafflesthen anything. if ur motor is putiing down about 100 h/p at the wheel then u could run drags and bennefit from them. but only in the higher rpms range. u will always loose some torq with drags. drag pipes look awesome and sound even more awesome,but they are just for sound and looks on a street bike.

i happen to love a loud bike. so i am a fan of drag pipes. but i like power more which is why i don't have them.

so this is what i did. i got vance and hines big shot stagger with the power chamber. i have big city thunder baffles for them. i rode around like that for a couple of months. it was the closest i could come to no baffles at all.

well i took them out to see if i would have lost any torq or power. well i'll tell ya it pulls alot harder of the line and through the entire rpm rang then it did with the baffles in. i have a dyno sheet reading with the baffles in. i will this winter have it dynoed again the way it is now. if l lost anything it is not noticeable power, thus i will leave the baffles out.

i believe and my indy agrees with me that the power chamber desighn, wich is an X pipe that connects the top and bottom pipes together. is the reason i feel igained. it creates enough back pressure to allow me to run with no baffles in these pipes only. so only if the pipes u are running have a x chamber would i run it like this. and i do.
i've had V&H drags with the B.C.T. in them on my lowrider. and it lost alot of torq.

hope this helps.
jay.

 

Thanks for all the advice. I really like the look of the Donnie Smith staggered duals or python3's. What is the impact of going with the larger diameter pipes- like Donnie Smith 2.25"?

 

well that depends . do they come with baffles? if so then prolly nothing. they will sound deeper,but u could loose some torq b/c of the increased diam. i'm not sure. maybe u could do a search to see what the poeple who have them think. and see if they lost any power.

 

baffles are available. Does the diameter of the pipes matter?

 

yeah. to a point. to big a diameter is goin to kill ur torq like i said before. but with the baffles u will prolly be allright.
i really can't say with any certanty b/c i've never had them. i've seen them and they are bad *** but i can't say anything about the pros and cons.
u should really do a search and see what poeple are saying about them.
then let us know too.

 

I changed the exhaust system in my bike 4 times, last one I removed was a 2-2bigshots by V&H, Right now I have thunderheaders, nothing beats its performance and sound in my experience and I get a lot of jelous compliments on the deep sound.

Mimo.