Audi 90 IMSA GTO: Some late-'80s madness here. Suspension geometry sketched up from our 3D model and photo reference; nothing too fancy going on. Gearbox is a mix of parts from the Group B WRC cars that came before it. Lovely little engine (coolest sounds ever) with little turbo lag and good for 720Nm / 720hp. Real car could be set up anywhere from 50:50 to 30:70 on the AWD torque split and I've used our hybrid system to land it somewhere in the middle. I know some people feel icky about doing it this way, but it really is a nice, effective simulation of AWD torque biasing that we can do now before spending the time on code for a fully adjustable, three-differential physics model. Aero is not lovely; typical mid/late-80s stuff here. While Group C cars were getting into underbody tunnels and crazy downforce numbers, the airflow management in GT was still quite crude and, at best, gave very modest downforce numbers. Means the car is very quick, but can feel a little unbalanced in performance. Not great in cornering, but it sure grips up and rockets out of the exits as few others can. Matches up quite well with the Trans-Am Mustang, or new GT3 stuff even. Huge power, light weight and super wide tires can do a lot for you.
Audi R8 LMP900: Nothing too fancy about this one, and maybe that’s why it was so dominant over its lifetime. Simple, effective suspension; aero package with strong downforce at expense of slightly higher drag; powerful engine with little to no turbo-lag. Can run fast laps all day long in this without feeling stressed. No traction control allowed when this car ran back in 2000-2006, so it’s all up to you to manage that 625hp. Great competitor for the Bentley Speed 8. Will have the measure of the BMW V12 LMR at most tracks - there was big progress in LMP900 performance from ‘99 to 2002 - but it could be a fun matchup with the right drivers.
Audi R18 e-tron quattro: This was a particularly exciting car to work on after it won Le Mans last year. The new hybrid regulations provide some very cool engineering challenges and the teams are, unsurprisingly, reluctant to share much data which could be used to work out where advantages may exist. That meant lots of work on our side to examine the data that was available and do some reverse engineering to figure out the details. Here’s an overview of all the essential areas and what we found.
What's it like to drive? Quite a bit different from the 2011-2013-era LMPs we've modeled so far. The narrower tires mean there is a lot less mechanical grip available and you end up hustling the car more at low speed. At the same time, the new aero/chassis rules mean more downforce on less mass, so high speed corners are an even more intense experience. Cruising to hit a good fuel number and maximize hybrid use is a very different experience and makes for a very interesting drive. Best laps here so far are a 3:26.3 at Le Mans, a 2:01.8 at Spa with high downforce and a 2:02.7 with low downforce. Can't wait to hear what you guys think of it.
