Last month I changed my completely worn out stock tires for Kumho 712's. I had the 712's on my highly modded MR2 turbo and honestly loved the tires, they were a great cross between performance and price.

This time I wanted to go with the Kumho MX's but finding them in the correct S2000 size is near impossible.

Anyway, with the new 712's, the car feels REALLY twitchy. Kind of like I have to pay much more attention when driving as the car is almost following the lines in the road. Also when shifting faster/harder than normal the back end doesn't feel as secure as it did even with completely worn S02's. Really hard downshifts even with rev matching get the rear slightly unsettled too.

In hard turns and rain the tires are much better than the worn out S02's and plant much better, but the car is still really twitchy in the previous mentioned situations.

Has anyone else experienced this?

BTW - My car was in an accident at one point and has not been completely repaired so this could be part of the problem, but I didn't have this problem before the tire switch.

 

I ran a set of 712's followed by a set of MX's on my Fbody. The 712's were definitely more sensitive to following the groves in the road. The MX's (same size and alignment settings) seemed less sensitive to this. All in all the MX's were a lot better and I wouldn't go back to the 712's. Perhaps getting you car aligned correctly might help but I doubt that it will cure the problem. I think it is a characteristic of this tire and it only gets worse the wider the tire is (I'm guessing that your MR2 tires were narrower.) However, the price-performance benefit of these tires is excellent and might be worth putting up with a few negative characteristics.

JeffA

 

I think I am going to take it in for an alignment, hopefully that will help some.


As for the tire size, my MR2 tires were significantly larger. I had Enkei RPO1's 17x8 front with 215's up front and 17x9 with 255's in the back.

 

My Fbody was setup with very aggressive autocross alignment settings which may have exacerbated the twitchy effect. Perhaps there are some particular alignment settings that would help reduce this? Maybe a little toe in and more caster? I'm not sure; you might want to ask someone more knowledgeable on what these cars like as far as alignment adjustments. Good luck.

JeffA

 

If you mean twitchy at the limit, the S2k is more prone to that behaviour than say, an E36 M3. The limits are high, but with the 50-50 weight split and neutral handling, you can't afford to be careless at or over the limits of handling.

Get to the limit in an EVO8 FQ-330 or similar, and the whizz-bang electrohydraulic diffs give you lots of room for error (or fun).

I notice that even with my S02s, the car tramlines a decent amount. I was under the impression that staggered tyres don't exhibit this behaviour.

Previously I ran Dunlop SP9000s in 205/225 sizes on the car. Tramlining was there, too. Those tyres squealed a lot more and had ultimately less grip, rain or shine. In fact, in the wet under heavy acceleration, the Dunlops in the rear really made the tail end waggle quite a bit.

///Robin

 

I don't really have the problems in the turns, it's just really at moderate speeds on 2 lane around town highways.

I don't have any problems holding a line through turns and it is actually a little more forgiving at the limit than my MR2.

This is why I'm so confused. Could it just be that these tires are just following the grooves in the road that badly??

 

Give it a little more time. If you just got these tires, you may need to wait until the thread wears out a little bit and settles and forms contact patch according to your camber setting.

 

What size tires are you using?

Stock S02's are 205 Front 225 Rear, but if you buy non-OE tires your suppose to use 205 Front 245's Rear.

 

I just checked my invoice on the tires:

2 225/50WR-16 Kumho ECSTA Supra 712



I called and ordered these from Jim at TireRack, I SWEAR I asked if it was the correct size because I know the S02's are sized slightly different.

This does NOT make me happy.

 

You have the wrong tire in the back and will make the car feel less planted to ground. You should've checked the alignment when you mounted tires. Did you check the alignment after your accident?