CTS-V mods for racing

[Bruce Nunnally]

CTS-V info & comments from a Technical official of the SCCA, the

racing series that the CTS-V's are in this year.

http://www.theracesite.com/index.cfm?paget...rm_article=6513

The current series champion is Audi's RS-6.

SCCA Pro Racing's Aaron Coalwell on the Cadillac CTS-V

"Cadillac came to us at Sebring last year and told us they were interested at running the CTS-V in WC," said Aaron Coalwell Technical Director for the World Challenge Series. "The choice of the car was decided by upper management and marketing. The Corvette is the 2-seat sportscar that GM wants to support, so the only other car Cadillac had that they thought could be made to be competitive was the CTS-V."

"We set up a meeting in April to view the test mule they had built and review their proposed configuration, as well as looking at their marketing campaign," Aaron continued. "They supplied us with valid reasoning for most of the changes they requested along with supporting documentation comparing the CTS-V to the Corvette, the Audi RS-6, the Porsche GT-3, and BMW M3. This information included Cd (coefficient of drag), Cg (center of gravity), weight distribution, etc."

"They (GM) also stated that one of the requisites for this program was to use as many next generation engine parts as possible so that they could test for problems on the track and fix them before the parts went into production," Coalwell explained. "They have already had several instances where this technology transfer has worked as planned. However, this is essentially a Corvette drive train, even if it is the next generation Corvette drive train."

"Therefore, the chassis needed to be changed enough to allow the CTS-V to handle as well as the Corvette for it to be competitive," said Coalwell. "The CTS-V (as configured for WCGT) does now handle almost equally to the Corvette. It still has a higher Cg, more frontal area, and more drag than the Corvette. All of the modifications allowed will be specified on the VTS sheet and all of them are simple enough that any decent race shop could easily make the same changes to build their own WC spec CTS-V."

As to the seemingly extreme body modifications Coalwell said, "the only unfortunate thing is that the CTS-V has such a high stock ride height and the "flat-sided" body, the race body looks quite a bit different from stock because when they lowered the car the 5" to get down to the permitted 3" minimum ride height they had to move the wheel arch up the side of the fenders and trim the bottom of the bodywork so that it did not drag on the ground."

"The wide fender flares were necessary for two reasons," he continued. "First, the stock CTS-V comes with very narrow wheels/tires without much room for wider ones. Second, with the tires we are using in the GT class, most cars need wider fenders than stock. This is largely due to current vehicle design which minimizes the amount of under-fender area available for mounting wider wheels/tires."

"When we first saw the test car, there were several items on it that we made them remove," Coalwell concluded.

Personally I agree with Louis Milone that WC fans and competitors have to have a certain amount of faith in the WC technical staff that a 'best effort' configuration was derived as a starting point. Aaron and Mitch have previously demonstrated that they aren't about to let one manufacturer dominate the competition so let's all see what transpires when the racing starts for real in March at Sebring.

[Bob D]

Well, It's going to be interesting Bruce..I've already got rooms reserved in Napa for July's race, and Monterey for October's, when hopefully by then there'll be a few wins on thier record. I'll have my laptop and dialy trackside reports.

Interesting footnote...Volvo has entered this series with four factory works cars. Thats a first for American racing.