The recent thread about quarter mile times brings up the difference between the performance figures for the 01-02 and later GS500s vs the 89-00 GS500s.  The newer 01 and later GSs are about a second slower in quarter mile times.

http://www.gstwins.com/forum/viewtopic.php?t=16761

Although I've never found it spelled out anywhere, a check of the camshaft numbers in the parts fiches shows the same shafts in all GSs thru year 2000.  There is a new intake cam # for 01-02 models and a new exhaust cam # for 04 models.  Also starting with the 01 models we have the new 3 circuits carbs replacing the old 2 circuit carbs with the newer ones having a 1 mm larger bore.

As a result, the newer ones feel much smoother and stronger to ride and also start to pull at lower RPMs but show slower quarter mile times.  In the real world the newer ones are a great improvement for everyday use while in the numbers world they are the poorer performers.

When I got the 02 GS in Sept 03, I immediately felt the improvement in the ridability of it over my 97 model.  It was so much more pleasant to ride that I was reluctant to ride the old one.  It felt like it had 10 more HP in everyday use.  As far as I can tell both bikes are factory stock.  

While I was repairing my 02 GS recently, I was riding my old 97 daily again for about 3 weeks and I again became proficient in motivating it and it again felt like the bike I enjoyed so much for 80k miles.  Back on the 02 again now for about 2 weeks and the old 97 feels like a dud again.  

Both bikes seem like they run fastest maintaing the pace at about 7-9000 rpm on back road twisties and the test figures show both have their HP peak at about 8500 rpm.  Below 8500 rpm the 02 feels stronger all around, but the old 97 feels like it is pulling longer and stronger above 8500 rpm which accounts for the better measured quarter times, but I'd rather ride the 02 any day.

Can't help but feel that we would have much better all around everyday bikes to ride if we quit playing the numbers game.    

As a resident of Numbers World, I take offense to your post, Jack.  Over here, the pre-01's are way better.  Spec numbers all the way! :lol:

All joking aside, you make good points--sacrificing a tad on the 1/4 mi in order to smooth out an engine's performance and make it more enjoyable on the street is a worthy tradeoff for most streetbikes IMO--but I doubt anyone here is going to argue that the GS500 wasn't plenty "streetable" to begin with...

Well, I think that stinks.  

You guys with the newer GS's get all the pretty paint, pretty body work, etc.

Us guys with the older ratty GS's need SOMETHING to hang our hats on.  And with out looking, we've found it.   Our bikes our faster.  

"V-I-C-T-O-R-Y. . . You can't have it.  Nah-nah-nah-nah-nah." ~ Bushwick Bill, The Ghetto Boyz.

Dredging this back to the surface...

I'm doing 'production class' racing on a 91 GS500E.  I'm allowed to use parts from any year GS500E/F so the fact that the cam profiles changed in 01 has me intrigued.  Does anyone have lift and duration numbers for the two different cams profile sets?