i put new wheels on my crx now it seems slower anyone else have that problem went from 14' to 17'

 

17s are going to be heavier then 14s... rubbers usually lighter then metal.

 

weight and size...takes a little more to turn a 17" wheel than a 14"..

 

Of course it's different. It's not because of the wheel weight either. By enlarging the wheel diameter, you change the final gear ratio. This means that the engine doesn't have to turn as fast as it did for any given wheel speed. It's not always a good thing, though, because with a bigger wheel diameter the engine is going to have to produce more torque at the wheels to overcome this change. Think of a bicycle. When you up shift, say when you are going downhill, this allows you to speed up the bike and not have to pedal as fast. But, you also notice that it gets much harder to pedal now that you changed the gear ratio. The problem is that you have changed the final gear ratio, which means the car is affected throughout every transmission gear. With bigger wheels, it is harder for your car to "pedal", in a sense.

 

/\+1

To counteract that, you've got to make sure that even though you're increasing your wheel size, your "rolling radius" stays the same.

Like:

Say your car come stock with 13 inch wheels with tires that have 2.5 inch sidewalls (just for example). That means that the whole diameter of the wheel and the tire is 18 inches, right?
Like:
|tire|==rim===|tire|
|2.5|===13===|2.5|

Your odometer, speedometer, and your gearing is set to this so when you plus size your wheels, you've got to make sure that the diameter stays 18 inches. So in THIS example, if you put on 17 inch wheels, you need to have 1 inch sidewalls.
Like:
|.5|====17=====|.5|


You can give or take a little, of course, since sidewalls are measured in mm instead of inches. You won't see much of a difference between 45s and 50s if you're in a spot where you want to keep your wheels but get some new tires. But if you're changing your whole set up, you'll want to definately keep it as close to the stock total as you can.
This also reduces the likelihood of rubbing (when your tires don't fit in the wheel well properly and scrape when you turn sharply).

 

Excellent point. I wouldn't say you are counteracting, just complementing (that's complement, with an "e"). I was about to add the same thing, but I couldn't have said it better myself. I could only assume that since the performance was affected as such, his original radius was not the same. Most don't realize how big a difference an inch or two can make.

 

Just adding to the excellent comments you've already got about the effects of such a big diameter change.... If your overall diameter is too much bigger, be ready to start replacing your brakes more often. Keep an eye on your front brakes every chance you get. The same laws of physics that are making your car seem slower are also going to make your brakes much less effective. It could even be dangerous if you have to stop suddenly. I went from 13" to 15" but kept my overall diameter within 2mm by using 50's with no problems.