Well not what I thought

I got new tires the other day. Toyo proxes FZ4 215/45/17. I had Bridgestones 225/45/17 Potenza So3 in the front and the factory runflats in the rear.

Now the change greatly softened the ride almost like a real car rather than a go cart. BUT I lost that go cart feelin', oh whoa that go cart feelin, Ive lost that go cart feeling now its gone gone gone whoa whoa whoa........

And I am the type of guy who would rather have a rough ride rather than lose that unbelievable responsivness and handling.

Dont get me wrong the new tires handle good and are rated ultra high performance but I will go back to either pirellis or bridgestones

 

this thread should be under tire&wheels

 

Dibber Dobber! Dibber Dobber!

 

Who put the tires on? When I got new Falkens, they (tire people) had the pressure way too low and I had to fill 'em at the gas station. Went from slushy ride to go-cart in one stop. dan

 

When you had the S03's on the front and the factory runflats on the rear, you had VERY different types of tires. Your front tires gripped very very very well compared to your rear tires. So that made it feel like you could take quick turns and have your rear end just spin right around.

Now all 4 tires match eachother (as they probably should). That go-cart feeling can be restored by getting a stiffer sway bar (if you don't already have one).

There was a thread a few months back where a guy totaled his MINI because he had the same sort of setup . . . . high performance tires in front that did not match the runflats he still had in the rear.

Some people think that your rear tires should always have the same amount of grip as your front tires.

 

Tire pressure. There is nothing "high performance" about the stock runflats.

 

Not being a tire expert I have a question about the runflats. I always thought the go-kart feeling came from very low profile tires and/or stiff sidewalls, both of which prevent much tire flexing in the corners.

Wouldn't a run-flat tire add to the go-kart feeling due to the stiff sidewalls necessary to "run flat"?

 

I equate the "go-kart" feeling with light weight and quick steering. The harsh ride of the runflats is just that, a harsh ride. Tread compound on runflats also seems to be less than high performance, at least compared to the conventional ones available. Go test drive an Elise to witness "go-kart" feeling that's really like a go-kart. Teeth rattling, back breaking, no suspension feel.

 

I agree there are many factors that contribute to the go-kart feeling of the MINI, or any car. Tires with low profiles, and now with very low profiles, were developed to reduce the tire flex or squirm in corners that affected the older, higher profile tires. This is especially good if the intent is to maximize cornering ability. Low profile runflats have a stiffer sidewall which compliments the low profile, making them even less likely to flex while cornering. This adds to the go-kart feeling but worsens the ride.

I'm sure the tread compound on most run-flats, and most tires for that matter, is a compromise designed to provide a reasonable tread life and decent "stickyness". If you want tires that really stick expect to replace then very often.

 

Is there some proof out there (that I'm unaware of) that shows a runflat is less "high performance" than a non-runflat? It's obvious that many people don't like them. Whatever. But to state the tires are less capable or less of a performer than a non-runflat version of the same tire is an assertion based without fact. If the assertion is that non-runflats, due to greater choice, gives you higher performance options, then that's OK and accurate in some cases, but not all. But the same can be said of comparisons between non-runflats. My stock Dunlop SP Sport 9000 runflats are just as capable (wet/dry) as the stock Dunlop SP Sport 9000 non-runflats I had on my Audi A4 quattro. I can't tell any difference in grip levels or wear rates. I wish someone would do a closed circuit comparison with the same tire (both versions) to see if one outperformed the other.

 

Shack! (Air Force speak for excellent commentary that you completely agree with)

 

There will be no "Shack" here

 

The go-kart feeling comes from the 'car' and no one individual component...in my opinion. That feeling can either be enhanced or diluted by the addition or removal of good or bad stuff.

 

hear! hear! ( or is that here! here! ? ) i've had both the runflat sp9000, the non runflat sp9000 dunlops, and the pirelli runflats on my mcs. for the non racing, non autocross, fun off ramp driving i do, i couldn't tell the difference in grip. BUT i could really tell the difference in the turn in "squirm." i've stuck with the runflats because i like that very stiff turn in feel. the non run flats felt like 80 profile marshmellows in comparison and indeed did ruin the go-cart like feel for me.

there obviously are higher grip tires, but the dunlop runflats are not all bad compared to stock dunlops. and they give a MUCH softer ride that the pirellis.

 

Well
the stiff side wall is what I will attribute the go cart feel to I am runnign 38 lbs in all 4 tires and like I said it still handles good but some performance was lost.
Before if I was in a turn the car didnt roll much body wise, and if I was in a turn and then tightend the turn it was like a roller coaster because the car would make the turn and the g force pushing you out was intense. IT WAS GREAT. now you can feel the tire flex and I might actually be affraid to tighten up while already turning.
It FEELS different than what I was use to so it will take a while to get comfortable again.
Like i said Ill take the rough ride in order to get the turning ability

 

Thanks for the Shack and especially for your service in the USAF.

 

What...someone agrees with me??? "Elizabeth...it's the big one...I'm comin' to join ya...."