The QRP SLC owned by Chris Durbin, is over 2700lbs in endurance trim. That doesn't include up to 40 gal of fuel.
The SCCA lap record from Thunderhill was using the crows nest over the top of the hill, and was our 2nd race ever.
In this years 25hr of TH race, Mike turned a 1:43:9 with almost full tanks, in traffic, using the bypass track configuration. These times were accomplished with Hoosier A/6/7s not even race slicks.
The Wolf V/8 Hyabusa that Al Unser ran, was faster than us, but 5-7 times more expensive, and very unreliable.
We hope to build out the LeMans we have this year as a track day race car, with a 650 hp LS7, and hopefully less than 2300lbs. It should be faster than the Coupe, how much will be interesting.
Bottom line is you can buy a used DSR with modified Suzuki for less than a SLC.
You will spend way more $ on racing/running costs in tires, engines etc. The SLC is a safer, more reliable package, as you will be running your DSR against full sized race cars, unless you only race in the SCCA P1, P2 class.
Bottom line is that most of us will never even reach the potential of either type of car, as it takes an extremely experienced, talented and/or Pro driver to reach this high level of performance.
Just build a standard LS crate motor, and go out and scare the sh#t out of yourself, you don't need anything else.