Good morning all, I was wondering what compounds by brand you are running for those of you with slicks? Also what style of slick would allow me the largest tire on a 17x9.5" rim? What experiences has anyone had with takeoff slicks(qualifying tires, used one race tires etc.)? I also wanted to get a feel for the differences in suspension setup vs dot tires. Tims has spent a little time with me on this but I'm in need of a refresher. Any input, flames, and abuse is appreciated Carl Byck

 

17" rims are not the easiest to outfit especially with take offs. 18" is the most popular since it is used extensively in pro racing. lots of radial and bias slicks available from many manufactureres. 15" is also very popular since it is probably the most used diameter in SCCA GT cars, e-production, and alot of stock cars. you need to look through the Hoosier and Goodyear's size charts for the 17" wheels and see what tires can run on the 9,5" wide rims. you might need a wider rim. as for setup, I would change all the alignment specs. I run my car basicly straight up. 1* or less front and rear negative camber, 1/16" toe out on the front, and 1/16" toe in on the rear. shock and spring settings are the same as I use for DOT's but I am running the front and rear sway bars at full stiff(probably need a stiffer front bar). tires are great for the first 3 or 4 heat cycles and will last maybe 2 weekends if you rotate and swap them on the rims. I have only used the Hoosier bias ply tires in the 16x22.5x10.5. this is the smallest 16" slick that I have been able to find(works out similair to a 245/45/16 DOT). never have found any take offs and new they are $220 each plus mounting.

 

I hear Goodyear Slicks don't leak air nearly as fast as the Hoosiers. I have Hoosier 21x9.5x13" rim tires on the rear of my 1st gen and, well, Hoosier Dot R's on the front since that's what I got. Those slicks start leaking air as soon as you fill them up!

As for wear, it depends on the car's weight and power. Less of both and tire lasts longer. More of both and tire lasts less. I have talked to convertible british car owners who can get a whole season on slicks if they're rotated all the time but a slick will have most stick in it's first few heat cycles. That's why Nationally competetive slick users will go thru two SETS of slicks a weekend! Must be nice to afford that!

Lots of folks use much stiffer springs with slicks. Their sidewalls just don't flex as much.

-bp-

 

Ok, so how much differnce is there between DOT approved race tires and race slicks?

 

IMO, there's not very much difference between a Hoosier R3S03 DOT race slick and a true race slick...

 

I don't know what or where your using these tires but in my experience there is a tremendous difference. Acceleration and braking are dramaticly different and the cornering is also noticable improved. I can apply throttle much earlier in turns and can brake much later. the car is about 5-7 seconds a lap faster on the tracks I race at(about 1:30-1:50 lap times).

 

I agree with tims. Slicks add gobs of cornering power, and seeing that they're lighter than DOTR's the car accelerates and stops quicker too.
-bp-

 

I run Dunlop Slicks (265/650x18) all around on my car. I run a 252 compound and get about 6 track days out of them before they lose significant grip. You will not wear them out before they lose grip. They are also MUCH lighter than Hoo-hoos.

The difference between Hoosiers and these slicks are like night and day. At Texas World Speedway, the first session I knocked a whopping 2.5 seconds off my personal best without really trying. Honestly, they are worth about 1.5 seconds per minute easy.

I buy mine from Porsche Grand-Am and Club Racing teams for about $90 each.

 

like I stated earlier in the 18" rim size there are alot more options and brands available from pro teams

 

could someone explain the sizing system on the slicks, i notice it's different than what we're used to on the DOT tires.

when you say you get them used from teams, is this via a connection, or is there some internet or retail source you are using?

thanks
fabian

 

with both goodyear and hoosier, a 23x9x15 would be 23in. tall, 9in. wide,and uses a 15in. rim

 

Fabian there are several sources in the back of Grassroots motorsports, I'll be checking on the elusive 17s. My best bet is the Panos series,they use a slick that is roughly equivelant to a 275-40-17.

 

Anyone have any luck in finding the 17's ?

 

Try Bob Woodman tires, he gets all the Grand Am takeoffs, he told me 17s not a problem, Carl. He also can do BBS 3 piece racing wheels, new centers, used rim halves for 2200.00 a set any 17" size. A 17x10 weighs around 15lbs !!!

 

What class or series do you plan on racing? That makes deciding what you want easier because slicks aren't legal in certain classes and then your sometimes limited on the max rim size allowed. You might want to check the rules if you haven't done so already.

 

He's running an unlimited class, slicks are a-ok.

PaulC

 

Thanks Leather, I am building a 25000.00 race car,One would hope I knew where I was going to race it That said, you are right on both counts. I am running NASA Super unlimited, I will be running 17x10fr/17x12rr, I will primarily run DOT tires, but I will run slicks when I autocross, since the 17x12 puts me in a prepared class anyway. Carl Byck

 

A true slick in any size puts you into Prepared as well.

 

I run Yokahoma slicks on my 10x15" wheels. They are take off tires from Formula Atlantic cars (fronts). Because they are designed to be on a vehicle that weighes only 1100 lbs my 2400 lb car chords them fairly quickly. Luckily I can buy them with full tread for around $50.00 each.

 

I thought a true non-DOT approved slick put you into a Modified class because tires run in Prepared had to meet the requirements of Section 13.3 of the SCCA National Solo rules, which state:

C. ... The tire model must have Department of Transportation approval.

http://www.moutons.org/sccasolo/Rules/index.html

 

You can use slicks in Prepared, and everyone does.

Slicks are not DOT approved. No idea about that 13.3 rule but slicks move you to Prepared at a minimum. Mod if you have, well, more modifications than allowed in Prepared.

 

Im looking for some take offs for tha size rim too. Where do you get them?

Thanks,

-Mark

 

It is just some guy that advertises in the back of Sports Car Magazine. His ads read like this..

Used Goodyear Racing Tires And other brands. All 10in, 13in, 14in, 15in, 16in, 17in and 18in sizes. Latest Compounds, 1/2 to full rubber. Low prices, quick service. Phone anytime (262) 740-0180. Wis.

I highly recommend buying from him. I have bought from him 4 or 5 times now. I think he runs this business out of his house but he has always had the brand/size I need. He once gave me two free tires because he accidently shipped them to the wrong address and it delayed my delivery by a week.