In mid-February, post-Daytona “Balance of Performance” rules changes were made for Sebring, where SRT/Riley Motorsports is fielding two teams. A multi-day testing session at Sebring followed those rules changes, and from that session, IMSA has issued a final document for the 12 Hours of Sebring and possibly the rest of the season. It has only minor changes in both of the production based classes.
Most of the GTLM cars will see another slight reduction in fuel capacity; the Corvette C7.R was cut by 7 liters, while both the SRT Viper GTS-R and Aston Martin Vantage V8 will be allowed two liters less. The Porsche 911 RSR, meanwhile, has been given a 1-liter decrease. There are no changes in fuel capacity for the Ferrari F458 or the BMW Z4. BMW’z Z4 GTE car will be allowed to use a 10mm taller gurney and modified door sills, according to IMSA homologation.
It is our understanding that Aston Martin has withdrawn from GTLM competition at Sebring, but has been given a 30kg weight break should they decide to return.
In GTD, the entire class gained in fuel capacity:
- Porsche GT-America: From 68 L to 83 L
- Ferrari F458: From 75 L to 92 L
- Audi R8 LMS: From 75 L to 94 L
- BMW Z4: From 84 L to 89 L
- Aston Martin Vantage: 81 L to 97 L
- SRT Viper: 85 L to 104 L
The next change for GTD is interesting: the single standardized rear wing location has been dropped for all cars, which now have a range for their rear spoilers. The window for the rear wing setback is from 77mm to 101.5mm from the rearmost body point of the race car, instead of a fixed 100mm. The Porsche 911 GT America will be allowed to use the DP spec Crawford rear wing instead of the standard wing, which was used on the majority of GTD cars at Daytona; homologation has occurred to allow this change.
This competition bulletin is available at http://www.imsa.com/sites/default/files/uploads/Comp.%20Bulletin%20%2314-60.pdf