I agree with Vancehu. It depends on the car. Front vs mid-engine really makes no difference. In SCCA club racing people win races and championships with front engined cars all the time. The mid-engine cars rarely do well on road courses. A friend of mine, Michael Pettiford has won many races and championships with a 1996 V-8 Camaro Z-28. He now races a Pontiac Solstice and they beat the Lotus Elises all day long. The NSX is a neat car, but a new Z-06.......hell even an old C-5 regular Corvette would beat an NSX silly on a race track easily. Even the V-6 Camaros will give a stock NSX all it can handle and would most likely beat it. The NSX is a great sports car, looks good, handles well etc., but it is not a race car. Truly, the king of stock "race cars" would be the new Z-06. And, dollar for dollar is the best all around performance/race/sports car in the world. I just got my SCCA racing national certificate and in talking with many folks about a race car, all of them think of a V-8 Camaro very fondly and all rave about the Solstice. No one has ever raced an NSX with any kind of real success. It's in the T1 class and gets its ass kicked. Jeff Jenson raced one, but any success he had was because of him and not the car.
It seems to me racing is like golf. You can spend $1,200 on a set of clubs and look good but not win, or you can spend $300 on clubs and $900 on lessons and win.
The next NSX or whatever name it has should try to be a true sports car, whether mid or front engined. The GT-R seems to be that way. The Z-06 is. Hopefully Honda can build one of that same caliber. I love my NSX, but no way do I think it is truly a race car. It just isn't.