[Uncle Bob]

A- What's the deal with performance pipes ? Everybody wants them to increase HP yet whenever I see a dynochart comparing stock to afermarket you need a magnifying glass to tell the lines apart. That is if you only change the pipes. If you go the 9 yards and go to a freer flowing air filter and a rejet or remap with the pipes then you'll see a difference.

My contention is that most of the power comes from the rejet or remap rather than the pipes. Aren't most carburated bikes delivered lean from the manufacturer to comply with EPA? If the bikes are already lean adding freer flowing filter and exhaust would actually decrease performance ( if you don't rejet ) causing a potentially harmfull situation for the engine ?.

So for bang for the buck wouldn't just rejetting increase hp without having to go for the filter and pipe ?.

In the case of FI and catalytic converters do they deliver them lean or do they go rich relying on the converter to clean up the emissions for EPA?.


B- Just for the heck of it , have you ever figured out how much it would cost if a customer asked you to order all the parts to a bike, let's say for the sake of argument. all the parts for a meanstreak and then have you assemble it rather than buying a preassembled one ?.

C- A lot of twp stroke riders complain about having a hard time starting their bikes and oil fouling of the plugs . Any tips ?.

 

[Freakinout]

you get a little increase with just pipes, but without rejetting you are running lean, you really have to go do everything, pipes, air intake and rejetting, or else you won't see enough power increase to make a difference.

a lot of people like to just make more noise by using slip ons and such.

 

[antiq]

Might be an association with car headers or just that it looks cool. The PO of my 750 put on 4-1 pipes and a new muffler. It does look better than rusted old chrome and one muffler to replace when needed seems a good thing to me. Stock bikes look great to me. But then again so do all the other bikes. My co worker has an old HD hand painted flat black and uglier than homemade sin. But I still like it.