Hello Jim,
Tomorrow I'm going to run out and find the new Classic Motor sports. The
article is just the sort of thing that interests me.
Right up front you need to know that I manufacture Throttle Body Injection
(TBI) parts for the TR6 and couldn't resist adding my two cents. When
Classic finished with the mods they measured 100HP and 115lbs of torque.
Nearly the same mods except using TBI rather than the Webers, Dave Murray is
seeing 125HP and 130 lbs of torque. You can read his story on
http://sidedrafttbi.com/dave.htm
Rick Patton
Brunswick, Maine
75 TR6sci
http://sidedrafttbi.com
> -----Original Message-----
> From: owner-6pack@Autox.Team.Net [mailto:owner-6pack@Autox.Team.Net]On
> Behalf Of Jim Jones
> Sent: Thursday, January 04, 2007 11:15 AM
> To: 6pack@autox.team.net
> Subject: article in Classic Mortor Sports
>
>
> In the most recent issue of Classic Motorsports there was an
> article about improving the engine performance of a 75 TR6. As
> you might suspect, the mods were head modification (grind to
> 9.2;1 ratio, porting), Goodparts GP2 cam, Pertronix ignition,
> rebuilt distributor, and improved carbs. In this case they used
> two Weber 45MCHH sidedraft carbs, which they say are essentially
> a single throat version of the classic 45DCOE. They come in a kit
> that included adapters, linkage, etc. They acknowledged that well
> tuned ZS carbs can perform very well, they wanted to try out a
> new product - which they no doubt got for free. While that was
> interesting, what got my attention was the fact they used a
> rolling dyno to measure stock horsepower at the wheels and then
> measured the effect of subsequent modifications. Using the dyno
> to tune it added another 6 HP & 5 lb/ft and reduced 0-60 from 9
> seconds to 8.4 seconds.
>
> They stressed that doing only one of the modifications would
> probably not do much good by itself. Rather, to get the benefit
> the motor needs to be considered a complete system from the time
> air enters the carbs to the exhaust tips. Reading between the
> lines it's obvious that taking the trouble to locate a dyno shop
> and tuning your existing car might uncork more power without any
> modifications.
>
> The stock horsepower was measured at 74 HP with peak torque at
> 95 lb/ft. 0-60 time was 13.4 seconds. Pretty anemic. By the time
> they finished the car measured 100 HP and 115 lb/ft with 8.4
> seconds 0-60. The use of the dyno to precisely tune the ignition
> and air fuel mixture was very insightful. The final settings were
> 12.5:1 mixture and ignition timing of 37 degrees BTDC at 4000 RPM
> (vacuum retard disconnected).
>
> The article was pretty instructive to a bone head like me.
> While I'm not a big fan of the magazine (too many ads and fluff
> photos, not enough content), this article was quite useful for
> anyone considering improving his own motor.
>
> Hope this helps someone.
>
> Jim
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