jhjc52

I know, this might sound dumb, put has anyone found that having too wide of a tire on an fc take away from traction and corning?

RETed

Not possible with street tires...


-Ted

adam c

iTrader: (2)

You can put too wide of a tire on a rim. Rims are designed to use tires in a range of widths. If you exceed the range, handleing will suffer, and it can be dangerous.

You wouldnt want to put a 245/45 series tire on a 6" rim.

CarmonColvin

RETed is correct, with street tires it really is not possible to hurt cornering and traction. But in a race tire where you deal with an optimal heat range you can put a tire so wide the weight/power of the car is not enough to get the tires up to their operating temps.

But wider tires CAN hurt overall performance. My first hand experience with this was on my race car. I switched from 8" wide Hoosier race tires to 10" wide Yokahoma slicks. The car cornered slightly better (not as much as expected because I could never get the slicks into their operating temps) but on the straights I was loosing a bit of top end speed. In short the speed I gained in the turns did not make up for the speed I lost in the straights and my lap times dropped.

The heavier weight (extra 4lbs per wheel between my 8" and 10" wheels/tires) and the increased resistance (rolling and wind) was costing me. My biggest regret with the car was spending the ~$1000 on wider wheels and tires that slowed me down.

adam c

iTrader: (2)

Sorry guys, I have to disagree. My example of a 245/50 tire on a 6" rim would be way too wide. The rims would "float" across the tire when cornering, and could even come off the tire under the right (wrong) circumstances.

ptrhahn

iTrader: (9)

Nobody is contradicting you. Most of the discussion of width assumes the proper sized rim for the tire in question.

CarmonColvin

I agree you can't put a 10" wide tire on a 6" wide wheel, even if it fits it will not be safe or give any performance advantage. But I don't beleive the question was about a tire too wide for a particular wheel. It was too wide of a tire on a type of car? I was under the assumption that whatever tire size would also have the appropriate wheel size.

In my previous post notice my mention of going from a 8" wide "wheel/tire" to a 10" wide "wheel/tire". At the time I had RealWheel Pro6 3 piece wheels and was able to change the width of the wheels in about 4 hours of work and $200 in new outer halves.

adam c

iTrader: (2)

I guess we were looking at his question differently. I thought he was just looking at wider tires. He didn't mention buying rims.

I guess that we both know what we are talking about. We are just answering a different question.

gnx7

iTrader: (10)

Since awesome rim/tire combo can cost some $$$'s here are some good options using production FC rims.

Convertible rims are 15x6.5" I believe and were made by BBS for Mazda. They are very light at around 12lbs. You can fit 225's all the way around which a lot of people autoX and roadrace with. I believe coilovers must be used.

Another alternative is the '89-91 Turbo 2 rim. It is 16lbs and is a 16x7" rim. You can fit 225/50/16's all the way around as well. I actually put 245/45/16's out back on mine and in hindsight would probably go back to 225's on the rear. It still handles well but it seems to be a little loose out back when doing evasive maneuvering.

I ran 17x8 TSW's with Toyo RA-1 235/17's at the track and they are the best setup I've used yet. I have coilovers which allows more tire up front. Car was awesome in the corners however in the straights the added weigh of the rims/tires I believe hurt the acceleration like others have stated. n/a 13B has very little torque so weight is everything and especially wheels and tire height.

Hope that helped,

-GNX7
suspension upgrades on a '87 FC with 100% stock 13B

RarestRX

Yo,


I have the same question:

https://www.rx7club.com/showthread.p...hreadid=263902

Kevin
1989 GTUs "When is too much of a good thing...too much?"