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Re: Exciting News!

To: "Datsun Roadster List" <Datsun-roadsters@autox.team.net>
Subject: Re: Exciting News!
From: Ronnie Day <ronday@home.com>
Date: Tue, 1 May 2001 22:10:42 -0500
>I have driven both.  IMO, the induction sound and high end oomph are
>worth 
>the extra work, finickiness and poor gas mileage.  A higher (1600) rear
>end definitely helps, too.  None of these are a deterrent to street
>driving.  I'll keep the Solexes, especially in view of the PO having
>traded away the SUs in 1971... 

Trust me folks, the biggest performance gains in this mix are almost 
certainly come from the lower rear gears. The biggest difference in how 
the warmed over L-16 in our first 510 responded came when we started 
racing on 22 inch tall Goodyear slicks compared to the 185/70-13 radials 
that we had been using. I'd need to measure a typical 185/70-13 if I 
could still find one, but if memory serves I think the 185/70s are about 
23.5 inches. I was also running a station wagon 4 speed with 3.657 first 
and 2.117 second gears compared to the OEM tranny's 3.382 first and 2.013 
second gears.

Even not changing from the stock 3.90, the difference in diameter and the 
different gears in the SW trans had the same effect as putting in a set 
of 4.44 rear gears. Not only did it rev more quickly, but you could go a 
lot deeper into turns because of increased engine braking effect. The 
fact that the head had been ported a bit, that we were running a longer 
duration/higher lift (than stock) cam didn't hurt either. Neither did the 
larger exhaust system and the massaged and rejetted carb. Heck I even ran 
a single 42 DCOE on it for a while, but it never really worked right. 
Still most of the performance gains came from the total gearing package. 
Bolt on the short slicks and the change in the performance was tremendous.

Wouldn't want to drive with this stuff on the street all of the time, but 
it's fun and very effective in competition. 

FWIW, Ron

Ronnie Day
ronday@home.com
Dallas/Ft. Worth
'71 510 2-dr (Prepared Class Autocrosser)
'73 510 2-dr (Street Toy)

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