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Old 30th April 2016, 05:18 PM
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Styria Styria is offline
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Join Date: Feb 2008
Location: Sydney
Posts: 8,498
Default Re: 450sl diff ratio

Mark, it's been done, but in the reverse. SEL69L had a 450 diff. fitted to his 6.9 and he reckoned that it improved his acceleration quite markedly. After the conversion, I did drive his car on a number of occasions and, quite frankly, I did notice only a slight improvement in acceleration - hardly worth the cost involved in doing the conversion. I know, he would disagree with me, but really until one would utilize a stopwatch to check the times, it all becomes a little hazy.

I prefer to go the other way - certainly with a 6.9. The torque is such that the engine will comfortably accommodate the higher gearing, such as you would find in an early 500 differential. I think the ratio is about 2.47:1 as opposed to the 6.9"s 2.65:1. In your case, I do think that the M117 450 engine would cope with the lower/higher (?) ratio - I never know which terminology to use, and if I were you, I would chose the higher gearing. I have a rebuilt 500 differential that, as yet, I have not fitted to Gleaming Beauty. I could be persuaded to part with it. I tend to agree with C107's comments, but am not sure. If I remember correctly, our doctor Bill Babe has gone through this exercise, and you should be able to find it in the Archive section, under Mechanical Repairs. Regards Styria
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