What is the Dominant Street Tire in CAM Competition?

The debate over who has the fastest tire in the “200 treadwear wars” rages on forums, in magazines, through social media and within race grids in SCCA, Optima, Goodguys, ChumpCar, Lemons, and WRL competition events. There are some magazine tests done on the current leaders in the 200 treadware tires: BFGoodrich Rival-S, Bridgestone RE-71R, Khumo V720, Dunlop Direzza Star Spec II, Falken RT615K, Hankook RS3V2, Yokohama Advan AD08R, and the Toyo Proxes R1R.

The problem is – the magazines tend to only perform their tires tests on light, small cars that don’t have any power (Miatas and Hondas). These cars have bigger “weight-to-tire” width ratios than most, which don’t correlate well to a bigger, heavier cars. Then there is the fact that many of these tire brands don’t make sizes large enough for the bigger cars – most top out at 275mm, which just isn’t adequate enough on a 3000 pound car, if the class allows unlimited sizing.

I am going to ignore the endurance road racing series that use 200 treadware tires, because their use is very different than CAM/Optima/Goodguys autocross or even Optima’s time trial events. We are also going to ignore Street Touring and Street classes, as these classes have either tire or wheel width limits, plus most of those classes tend to favor smaller and lighter cars.

Today we are going to just look at the SCCA CAM classes (which translates well to Goodguys and Optima events), which are based around full sized cars with weights generally above 3000 pounds. These cars also have substantially more power than the “little cars” often used in head-to-head tire tests or other 200 TW classes. We just came back from competing at the 2016 SCCA Solo Nationals in a CAM car, so this set of classes is fresh on our minds.

Vorshlag has also performed its own 200 treadwear tire tests with multiple brands on V8 RWD pony cars in the past. One trend we kept seeing was as widths increased (from 255 to 265 to 275 to 295 to 315 to 335) time kept dropping and the cars became easier to drive. There seemed to be no limit in increased performance with ever wider tires on these 3000+ pound, 400+ whp cars. This means that we now tend to use the widest tires available on these heavier cars racing in 200 treadwear classes. We will do whatever is necessary to make them fit, if the class allows it.

We have been proponents of moving to wider tires in 200 treadwear classes for over a decade, and even advised folks to “go big” in classes that allowed R-compound DOTs. We have seen the same trends on BMWs and Corvettes and Mustangs alike: as we went to ever wider tires, times kept dropping. Yes even with the internet experts saying “you’ll never get that wide tire hot enough” we got faster and faster, on autocross and road courses both.

CAM cars have a different set of criteria than some autocross classes that use this style of tire. CAM cars include old and late model pony cars as well as Corvettes, Cobras and other one-off builds. CAM classes have moved to ever wider tires – 315mm and 335mm are common – that are only available from one or two of the tire companies in these 200 treadwear ringer tires. BFGoodrich and Falken make a 315mm, BFG makes a 335mm, and up until very recently Bridgestone topped out at a 285mm. The AD08R has some larger sizes (285, 295 & 305), as does the Hankook RS3V2 (305), but they don’t seem to be on the pace of the Rival-S or RE-71R.

Most of the other top 200 TW tires top out at 265 or 275mm. Right before the 2016 Solo Nationals Bridgestone released a 305/30/19, which some racers quickly purchased to run on. On the C5 Corvette we were taking to Nationals the owner had run it all year on 18×11″ wheels and 315mm Rival-S tires, but we noted a lack of rear grip on corner exit. Right before Nationals we switched to an 18×12″ Forgestar wheel and 335/30/18 Rival-S tires out back – damn the poke! And it was easier to drive and faster.

It has been said that the BFGoodrich Rival-S was “terrible in the wet”, but we have data that says otherwise. The Bridgestone was favored by many 200 treadware racers at the 2016 Solo Nationals but if you look at these results sheets for CAM classes you will notice one thing: BFGoodrich dominated the top of every CAM class.

And during the second day’s run heat on East Course the entire CAM category had to run in the wet for all 3 runs. It was drying but still wet, and the BFGoodrich still dominated every CAM class. This isn’t the first time that BFG has won in the wet, either.

We have marked up the top half of the class results in CAM. As you can see above, BFGoodrich took 6 of the 8 trophy spots in CAM-C, including 1st-3rd places. Also in CAM-T (below) the BFG took 5 of the top 6 places including 1st-3rd. The only Falkens we saw in the top 10 in any CAM class was 7th and 9th in CAM-T, which only had 11 cars. These were popular a few years ago in Goodguys, but seemingly only when they were used on sponsored cars. When it became clear that the Rival-S was faster, most racers stopped using the Falken – even with a lower price tag or when given these tires for free. So when widths are the same, the tire’s construction and compound still matters.

Finally, in CAM-S – where we raced in a C5 Corvette this year – BFGoodrich swept all 6 trophy spots and even cleared all of the top 12 finishing positions. That’s a big sample of modern Corvettes, Cobras, old Corvettes and more.

Is this a perfect scientific study? No, but it does show a trend that is hard to ignore. Will this trend change in the future? Maybe, if Bridgestone would ever make larger sizes like 315/30/18 or 335/30/18 tires that CAM racers need, we might see a shift to that tire. Or there could be another brand the makes wider tires emerge – but the bottom line is, to be competitive in CAM you need to have at least a 315 to be in the hunt for CAM wins.

For now, due to wider available sizes and a superior compound compared to the Falken, the BFGoodrich Rival-S tire is proving to be the dominant tire in CAM competition. We have noticed this trend from looking at this Nationals results as well as finishes from CAM Invitational and Optima events. Even in the wet.

Our advice is simple: ALWAYS GO BIG! If your racing class allows unlimited tire widths, get the widest tire available (in an appropriate compound and height) that money can buy. Make them fit.