Car and Driver
Supercar Challenge
Nov 2004

10,000-HP Slugfest
Photos by Rich Chenet and Jeffery G. Russell

Review by Mike Stenhouse

The Superformance MK III did well in the last Car and Driver Supercar Challenge. But the blunt shape took its toll in the high speed tests. So it was a natural that Dennis Olthoff would enter the ultra sleek Superformance Coupe in this year's Challenge.

Alas, the Roush 402RC engine swallowed a valve on a missed shift very early in the first run. Dennis finished the run, but the times with the crippled engine were not up to snuff.

Too bad. It would have been interesting to see how the normally aspirated (un-blown) Coupe at $88,000 would have stacked up against the turbocharged front runners:
  Hennessey Twin Turbo Viper $162,000
  Lingfelter 427 Twin Turbo Corvette $141,000
  RSI SR Twin Turbo Viper $137,000

Well, at it turns out, we have a pretty good idea.  Dennis returned to Mt. Ulla, pulled the bent Roush motor and T-56 transmission and replaced them with an RDI all aluminum 427 Windsor and the new Tremec TKO-600 5-speed.

The RDI 427 Windsor is very similar to the engine in my Mk III (SP 218) as reported in Second Strike Volume 5 Number 1 and Number 2. Except... The cam has over 20 degrees additional duration (facilitated by Jessel shaft mounted rockers and titanium keepers). It has a single plane manifold milled for hood clearance. And a couple of points of additional compression.  The result is 629 horsepower at 6500 rpm. The engine is 80 pounds lighter than the iron block engine and the transmission is 30 pounds lighter than the T-56, a total of 110 pounds - mostly off the front end.

Dennis took the updated Coupe to Run and Gun in September and won handily. The Coupe clocked 11.1 seconds at 131 mph in the quarter. That would have tied it for first place in the initial acceleration run at the Supercar Challenge. This Coupe can also do 100-150 mph in under 7.5 seconds (actually 7.2 seconds in a 4th gear roll-on), which would have made it first in that acceleration category.

The Supercar Challenge contained other segments as well, so it isn't possible to draw a definitive conclusion that the RDI 427 Windsor powered Coupe would have been the winner. But it certainly would have been a strong contender for first. And without turbos. Even with the additional cost of the engine upgrade, you could buy this Coupe and a Mk III for the price of the winning Viper. Interesting thought....

By the way, if you see a Coupe at the stoplight, watch out. About forty percent of the Coupes on the street have a 427 Windsor under the hood.

The full story on the Supercar Challenge is at:

http://www.caranddriver.com/article.asp?section_id=15&article_id=8719

If this link doesn't work, go to:

http://www.caranddriver.com

and take it from there.

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