What sort of gains can one expect by doing the typical drop in mods like a K&N air filter, new header/exhaust, etc?

About 3-4 HP gain.

http://gstwin.com/dyno_run.htm

lol
$1000 stuff for the 10% increase in HP? Hmmm... Does one feel the increase? The sound is definitely better agreed. But 

Psychologically, we automatically assume (Most) that if it's louder it must be faster.

put the airbox k&N filter (model that fits intpo airbox) and you will enjoy it.. its does make a better response
also if you have a pre-04 model change your ignition rotor (search for it) and you will get better response as well

loud pipes dont make a bike go faster.

But an R1 can certainly makes it cooler

I'll say this for what it's worth.I didn't see any seat of the pants power gains.It did broaden the power band, make the power smoother,and throttle response better.I have a Bob B.ignition advancer,K&N lunch box,D&D exhaust,rejetted to 40/142.5/1 washer and 2.5 turns on the mix screws.

5-10% gains with a Lunch box, and just sound and a bit of smoother driveability with just pipe. But in either case, its the mid range and the driveability ... useability that counts.
Cool.
Buddha.

I'm definitely down with modding,  just want to know what the potential really is.   Don't want to spend mega $ which should really go into a more powerful bike if that is what I want.   I like wrenching, machinist by trade, improving drivability is  certainly worth a few dollars.   I'd like to get a pipe and progressive FE or Katana FE eventually.   Later I'd like to snag an SV650, it seems sort of like an updated GS, or a Ninja 650r.    Kind of like that Triumph street triple or Thruxton too.

Quote from: commuterdude on July 13, 2008, 06:12:27 PM
I'm definitely down with modding,  just want to know what the potential really is.   Don't want to spend mega $ which should really go into a more powerful bike if that is what I want.   I like wrenching, machinist by trade, improving drivability is  certainly worth a few dollars.   I'd like to get a pipe and progressive FE or Katana FE eventually.   Later I'd like to snag an SV650, it seems sort of like an updated GS, or a Ninja 650r.    Kind of like that Triumph street triple or Thruxton too.

I have less than $100 in my rejet,K&N lunch box, and exhaust.Knowing a good deal when you see it goes a long way to lower the cost of mods.I read that here and it is correct.I have 95% of all the mods I wanted done to my bike.It took me a little over a year to obtain the parts and mod my bike.I won't sell her unless it's an absolute have to.