I have a good friend running Kinesis 17s which I assume are at least as wide as the stock fitment wheels. Car has been professionally lowered on Konis.

Anyone care to share what the "no issues" upsize tire fitment would be for a car that sees mostly street w/ some track in the future.

Thanks and Best,

Matt

 

Forgot to mention - it's a 968.

Very tasty...

 

Crickets?

Come on over to the 964 or 993 forum - we love chatting about nonsense like this!

 

Matt i have 18" X 8.5" and 18" X 10" wheels.

let's assume your front wheels are 17" X 8.5" in the front and 17" X 10" in the rear..... i would try to find anywhere from a 25.5" to 25.7" diameter tire for the rear. that will help you get near a true speedometer reading. therefore, i would run anywhere from a 225-45-17 all the way up to a 255-40-17 (ideal) up front and run a straight 275-40 or start with slightly worn 285-40-17s in the rear. your speedo will read very close to true and your performance will be very good.

try to minimize your tire stagger width as much as possible.

example: for our cars running 245-35-18s in the front and 265-35-18s in the rear will produce a better handling car than running 225-40-18s in the front and 275-35-18s in the rear.

i'm running Dunlop 255-35-18s in the front and i've had 275-35-18s and now run slightly worn, 285-35-18s in the rear.

 

Like most guys here I'm running 225-45 ZR 17" front & 255-40 ZR 17" rear w/ Falken 452 tires.The car is street driven only but sometime will see speed up to 140/150 MPH & until now never had any problems.Maybe if tracked another choice of tires will better,I'll let peoples who do track their car answer that.

 

back in late June, Van took me for a ride in my car through the twisties somewhere near the Hudson River. i'll never again get in the car with this man.... but, suffice it to say, Ernies cute little Falken's would have been cut down to the nubs.... Van is also the only living Rennlister outside of myself who can tell you what a 968 with a perfect exhaust note sounds like.

we will make a video of the exhaust soundstage before the engine comes out. there are others of Earth's inhabitants who've heard this symphony of a properly breathing 968 exhaust, without that horrible angry lawnmower side-effect, but they simply bowed and offered money (and unfortunately, they don't frequent the Rennlist chat pages).

 

Ernie cute little Falken's are just doing fine,show me a set of Falken which are cut to the **** after just one ride then I'll believe you ,but please I want you to include pics of them.Don't want to be smart here,but if you think you guys are the only one that can throw a 968 around you must be going on a heck of an ego trip. BTW - QUOTE from mhr (RL S2 owner) Eric (951 also RL who track his 951) told me about the ride you gave him Sound Sick! just happen I gave give Eric 951 a little ride in my 968 running cute little Falken.

 

Those were the stock sizes on the optional 17" wheels and will work fine for a street/track application. If desired you can go up to 245/40 front and 275/40 rear on the stock 17" wheel widths. This setup will work fine on street and track. I used this setup on my race car for a number of years.

If you go with wider wheels you can increase tire width even further. 255's will fit up front with no problems, and you can even get 275's and 285's up front with only minor, correctable issues. Currently on my race car I run 8.5" wheels up front with 255's and 10" wheels rear with 285's. When I run under NASA rules I run 10" wheels with 285's all around.

 

aww Ernie, please don't get mad. i was just ribbin' ya.

of course your falken's are fine for spirited driving,


it's just an opinion, but it goes something like this;

Porsche 911s have since about the mid-'90s, come with wheels and tires that can be described as very close to 'max-performance' for the street... our cars did not. while your wheels and tires are surely 'very good,' our cars are a bit large... and while the 968 is not as heavy as a 928, the 968 is still, fairly heavy, and came detuned from the factory, first by not adding a turbo option for an engine that needs a turbo (if Subaru can do it, than Porsche could have done for a few more 968s with a base price almost double the wrx's, which HAD the turbo, and was introduced in the same year as the 968)... and also by not running 'max street performance' wheels and tires, the cars were kept at a safer distance from the 911's 'performance...' that is to say that the wheels and tires that came with our cars can be designated in the 'extended performance' range, about 1~1.5 inches narrower the equivalent tires given to an even lighter 911, and while i'm just stating my personal tastes, i'm also specifically referring to the load / (cm of tire width) that each tire will see when being stressed under spirited driving.

when i changed to my wider wheels and tires, the smoothness of the ride on poor quality roadways decreased, and the increased grip, while less noticable at slower speeds, became quite dramatic at higher speeds. after 120~125 mph the feeling of maximum grip that was most surely absent before moving up to the wider tires, was now decisively 'there....' my conclusions are that the narrower 225 fronts/245 rear tires certainly were good, but considering the increased loads that our cars make, the 968 can easily take advantage of increasing to 235, 245, or 255 mm front tires and 275 or 285 mm rear tires...

and if our heavier cars can take advantage of wider tires so easily, by definition, this demonstates that the stock tires offer less grip, get hotter, etc.....


there's a Walter Rohrl video where he talks about tires... trying to locate that.

no luck.


/

 

The change in ride quality that you noticed was more likely due to the lower profile tires on the 18" wheels than the increased widths. Lower profile tires have stiffer sidewalls, which effectively increases your spring rates. When I moved from 17" to 18" wheels on my race car I had to make compensating adjustments in my shock settings.