small wheels/gearing

[Mike 99GSX]

If this should be in suspension tech then please move it but its more of a drag racing question. I want to get small wheels. I've been told that most 15" will clear stock 2g GSX brakes no problem. I've been told that the outer diamter of a stock 2g tire is 25". IF I run say a 225-55 15 tire then that would mean that my outer diameter would be less than stock which I believe would shorten my gearing somewhat. I'm wondering how significant this will be at the dragstrip. I'm currently at around 6000 RPM in 4th gear with my setup as I pass the traps. I assume this wouldn't be that significant enough to make me have to shift into 5th gear. Also, I was hoping to find out at what point down the "ET Chain" does it usually become necessary to shift into 5th. Big Dogs with experience please chime in.

 

[kpt4321]

If I can remember correctly, even Shep (158 mph traps) doesn't shift into fifth. With a raised rev limiter, stock sized wheels will get you to 130 in fourth. You should be fine, as long as you're not going way small.

 

[Mike 99GSX]

Good point on the rev limiter being raised which I will be doing as well this winter. That should definately keep me in 4th even with 15s. Shep does run 16x8 wheels. Maybe I shouldn't push it and just go with 16 instead of 15?

 

[psychlow]

Mike, why would you want a smaller wheel size? Is it just for looks?

 

[Mike 99GSX]

Originally posted by psychlow
Mike, why would you want a smaller wheel size? Is it just for looks?

Weight reduction and acceleration. If I got rid of my Baer brakes and went to 15" wheels, I could drop at least another 30 pounds on just the front wheels. The Baer Pro Kit is stupidly heavy.

 

[wret]

I believe the smaller tires you mentioned would be about 2% smaller. I don't think the change in gearing will be significant.