The race is in Russia.
The GTR has the Switzer P800 turbo upgrade.
I could be wrong, and flame suit on, but I think the only reason why the ZR1 kept up w/ the GTR in the 1st race was because of the camera man passenger. Looks like the weight of the passenger in the ZR1 made a huge difference in its performance.
Don't get me wrong WOW @ both cars, but the P800>LPE, IMHO.