In my honest opinion yes 17s are way too big, even 16s are too much. Takes away from your torque which is almost essential for autocross. Plus not many performance tires in 16s. Only 15s and 17s.

YOu can go lightweight all you want but 17s push the weight further out from the center of the driveline which takes more energy. If you have 15lbs 15" wheels and 15lb 17" wheels if will take more energy to turn the 15lb 17s.

For example take one of the merry-go-rounds you push. Take 10 people and put them close to the center of the merry-go-round and push them compared to those same people on the outer edges of the merry-go-round. It will take more work to push the people if they are hanging on the edges.

 

As always, your answers are very helpful! I like the merry go round reference, never really thought about it that way.

Thanks
rob

 

I'd like to thank those who've answered my questions. And about the rim size question, I have an article that you might like to read...

http://www.grassrootsmotorsports.com/plustest.html

I'm not sure if this article is true, but what is your input on this CivicSiRacer? Have you tried trying comparing times b/t 15,16,17 inch rims?

 

Well I think that test was a little biased. The times should drop throughout the day due to finding better lines as you switch from one size to the next. They went from 14s, 15s, 16s, then 17s. What they should have done was go to 16s to 15s and back to 14s.

In my personal experience I was quicker on 15s than I was on 17s.

 

Wasn't that test done by Tire Rack and Grassroots?

One thing I noticed when running 17's is the car feels much more responsive in turns. Would this lead to better times or is it still a matter of rotating weight?

Rob

 

Im thinking of swapping my cluster on my 93 civic dx 5sp
as it has no tach.How difficult is it to replace the odometer/
speedometer ONLY so the correct mileage will show on the
replacement cluster.Please elaborate on "how to" replace
that part only.


thanks in advance.

 

Yes the test was done by Tire Rack and Grassroots MOtorsports. But that doesn't mean it wasn't biased.

But yes the car with 17s will feel more responsive cause the sidewalls are stiffer. The same feeling can be felt with higher pressures in 15s.

 

Ok, I got all the parts to pull off this rear brake disc swap, but the brake lines because i was thinking of getting braided stainless steal lines, and i don't know whether i should get civic or integra brake lines. Any help there? Also, I've read that it would be more beneficial to have a larger bored master cylinder. I know that the EX will bolt right on, but is it the same bore as the DX? Could I put an integra's master cylinder in there? Would I have to do any major modifying of the brake lines or anything like that? Does the integra even have a larger bore on it's master cylinder? Thanks

 

The brakes lins you would want would be for the donator car. Not because it's an integra or whatever. It because the drum and disc brake lines are different. So get them for the car you pulled th rear disc brake stuff from.

As for the master cylinder. It would be a good idea to upgrade that and the proportionate valve. Do not buy an abs porportionate vavle. Get one off of a 99-00 civic si with out abs.
lots of people with ek's i know us the 99-00 civic si master cylinder. you can most probably use an integra one. i'm not sure on the ek stuff.


the integra sizes are bigger. you most probably have a 13/16, and the integra without abs have like 15/16 master cylinders, and the abs integra's have 1" master cylinders. using the 1" abs master cylinder usually requires bending and reflaring of the lines.

1" is the one to use i'd say but other have been happy with the 15/16's master cylinder.

 

what size bulbs (turn signal) go into the rear of 99-00 civic coupe taillights.

and please dont tell me its 7440 or any push in type bulb because its not. 99-00 seem to have different harnesses than 96-98 coupes