Foto,
Information I have states that the 500SL rally cars (developed from the 500SLC rally cars of 1980 and the 450SLC 5.0 rally cars of 1978 and 1979) that were developed for the 1981 season were good for 370hp and still had the 4 speed auto transmission.
I have had a quick look through various publications I have and came across an article in "Mercedes Enthusiast" magazine Issue 37 (Nov. 2004) page 40 discussing the Colorado Grand event in which one of the 500SL rally cars was driven. That article suggests it is good for 320hp although I suspect that figure to be incorrect given that the last of the 500SLC rally cars were good for 340hp. The article also states that the 4 speed auto had first blanked out and was set up only change manually effectively making it a 3 speed clutchless manual. The short rear axle ratio meant that most of the time only 3rd and fourth were used.
Apparently the car was noisy and unforgiving and was really only set up to be driven hard. The writer, Tim Slade, commented that it brought out the hooligan in him and remarked "At the end of the day I thought the only casualties had been my hearing and my reputation. However, later I realised that my shoes had melted!" What a beast!
This article at least confirms one of the 500SL rally cars still exists and also includes a few photos of it. One photo, an almost two page spread of the front, shows no less than ten lights! The are the four headlights of the US style but with what appear to be halogen inserts, a pair of spread beam and a pair of spot beam Cibie Super Oscars (as were usually fitted to the 500SLC rally cars), and a pair of equally large Bosch fog lights. The car resembles the 500SLC rally car in most respects except that it is an SL.
Greg
