PDA

View Full Version : Tire questions



RacerBill
05-02-2006, 10:42 AM
Two questions about tires. I am driving a 83 Dodge Shelby Charger.

1) The dry tires that I have are 205/50 15 Kumho V700's. I have just acquired a pair of 195/55/15 Yoko H4S's, well worn (3/32's). Would they be good to put on the back axle to decrease understeer?

2) I have the opportunity to pick up some Kumho V710's 205/60 15 at an absolutely rediculously low price (new, from a dealer...). Would these make good rain tires, even with the 60 aspect ratio?

Thanks for your thoughts.

planet6racing
05-02-2006, 10:51 AM
1) Probably car dependent. Have you tried addressing the understeer in other way (rear sway bar, shocks, etc)?

2) The V710s have just two circumferential grooves and are molded at 4/32". These WOULD NOT be suitable rain tires.

RSTPerformance
05-02-2006, 11:12 AM
Bill-

We mix and match tire sizes, treads, compounds, and makes all the time now to help with balancing the car... Works unbelievably well and I think others would also start to give it a try.

Raymond "The front aint the same as the back, and the right aint the same as the left" Blethen

PS: I know "aint" aint a word... :rolleyes:

RacerBill
05-02-2006, 11:16 AM
Bill:
2) My bad V710's should have been V700's


1) Dodge Shelby Charger has a monterous solid rear axle. Polybushings make a rear sway bar, but the inner fittings bolt to the axle and the outer fittings bolt to the trailing arm up near where the front mounts to the chassis, but not directly to the chassis. Don't know how much that would help. Development plans call for installing Ground Control all around with 400's up front and 450's in the back.

zracre
05-02-2006, 11:53 AM
I have run hoosiers on the front and ra-1's on the rear...car definitely rotates better...your results may vary! depends on the track surface and your car setup. Maybe get a set of springs up 100# in the rear?

RacerBill
05-02-2006, 12:55 PM
Ray: Thanks for the thoughts.

How about the 60 series for rains? Supply a good response and I'll share the source and price.

planet6racing
05-02-2006, 01:43 PM
I think it really depends on the rain. I've always treated my full tread V700s as intermediates and, if it was really wet, went to something with more tread (i.e. deeper tread with blocks).

The advantage is that, if it starts to dry, you are ahead of the game (full rains can go off quite quickly).

As for the 60 series tire, that could be beneficial in the rain in that it raises your gear ratio and reduces the amount of torque being put down, thereby decreasing the amount of wheelspin you'll experience on exit. I don't think the 60 height is that big a deal in rain conditions.

Gary L
05-02-2006, 02:33 PM
2) I have the opportunity to pick up some Kumho V710's 205/60 15 at an absolutely rediculously low price (new, from a dealer...). Would these make good rain tires, even with the 60 aspect ratio?[/b]

This makes me really nervous... V710's at ridiculously low prices smells like 2004 recall tires. I'd be checking to be sure the tire labeling shows polyester as part of the construction. If the polyester isn't there, the tires are most likely part of the batch that was recalled by Kumho about 2 years ago.

http://www.scca.com/News/News.asp?Ref=84

RacerBill
05-02-2006, 03:10 PM
Gary: I mistyped - they are Escta 700's, not 710's. The aspect ratio is 60 instead of 55 or 50. That may be the cause of the price. I was thinking of them as rain tires.

RSTPerformance
05-02-2006, 04:29 PM
When I think rain, I think Ice (not snow, snow is like dirt). Look at any Ice Racing Tire and you will see HUGE sidewalls on these little skinny tires. Must be made that way for a reason!!! My nontraditional thinking would say to my mind (what really matters is what you think behind the wheel right?) that 60 series tires have a bigger sidewall, thus theoreticaly (sp?) have a softer sidewal that will move and countour (?) to the road better... IE will stick to the pavement longer before loosing grip.

If that makes any sence at all I have no idea... but it would make mee feel good :-P

Ok- Time for someone else to share some real technical answer with data!!!

Raymond

joeg
05-02-2006, 06:05 PM
Raymond--A skinny tire (for ice) puts more weight on a smaller tire patch area, thereby increasing whatever available traction there is. It doesn't have as much to do with contouring the sidewalls, but that could play some role.

However, I had a set of Michelin ice tires for the old rally car and the sidewalls were so stiff (and the tread so narrow) that they were difficult--if not impossible--to mount. I think they were labled "C-4" or something like that.

For ice racing I bought many many Menards, but they were just 80 series Firestone recaps with a bunch of wierd studs molded in. A lot more expensive than Hoosiers.

They also needed to be "aged" or the studs would come flying out rather quickly.

Cheers.

RSTPerformance
05-02-2006, 07:33 PM
Raymond--A skinny tire (for ice) puts more weight on a smaller tire patch area, thereby increasing whatever available traction there is. It doesn't have as much to do with contouring the sidewalls, but that could play some role.

However, I had a set of Michelin ice tires for the old rally car and the sidewalls were so stiff (and the tread so narrow) that they were difficult--if not impossible--to mount. I think they were labled "C-4" or something like that.

For ice racing I bought many many Menards, but they were just 80 series Firestone recaps with a bunch of wierd studs molded in. A lot more expensive than Hoosiers.

They also needed to be "aged" or the studs would come flying out rather quickly.

Cheers.
[/b]

I have some Menards (Thanks again Steve M, they are a blast on a lake!!!). I put them on the race car and went out onto the lake for some practive at a BMWCCA club event... Had a blast and learned a lot especially about left foot trail-braking with a quaiffe on ice... The ice tires on ice was to me a lot like rain tires in the rain road racing... I think your points are good, those sidewalls are stiff.

Raymond

SteveMc
05-03-2006, 11:33 AM
Glad you got a chance to try them out Raymond. They are a hoot, aren't they.

Steve Mc

RSTPerformance
05-11-2006, 08:32 PM
Steve-

Thought you might enjoy a shot of the Audi equiped with Menards!!!

Raymond