Hi Paul,

   Do we have a cross reference chart showing Torque and Rpm. ?
   I want to increase the power of the 13B in my Oscar SK90 racer,
   \but there is a limit to the torque the gearbox will handle.

   cheers,

   Russ Ward

   Torque and RPM are mathematically related.

     It is a law of physics.

   It is not just an idea it is the LAW!! :-)

   1. HP  = torque times RPM divided by 5252

   1a. HP = T * RPM / 5252

   2. 5252 * HP = T * RPM

   3.. 5252 * HP / RPM = T

   3a. T =  5252  * HP / RPM

   Increase the RPM and the gear box will live with more horse power.
   Use equation 1a.

   What RPM are you running now? Do you have a p-port?
   The peak torque is a function of the intake runner length.
   Shorten the runners and the same torque will move up
   the RPM curve.  14 or 13 inches long will be about right.

   What is an Oscar SK90? Do you have a picture?

   Paul Lamar




    Paul,


   Thanks for that. I was concerned about the gearbox not being able to withstand the torque.
    Its a Hewland Mk 5, which  will stand 260n-m, which is 191ft lbs.

   Taking equation3a T =  5252  * HP / RPMT=5252 * 200/7000 gives me 150 ft lbs

   260 HP  @ 8000 gives me 170 ft lbs, which is still pretty safe.

   The limiting factor is the gearbox casing, an Enkei, which is a strengthened VW.

   I am not allowed to run a P Port in the sports racer class - might embarrass a few folks.

   I attached a few photos of my car, though you might have seen them before.

   cheers,

   Russ Ward

   Nice car should be pretty quick. Too bad the wing is not movable and
   attached directly to the hub carriers :-).  Have you measured the down
   force front and rear? Does it under steer on fast corners? That is a good
   thing. But not too much :-)

   That is too bad about the p-port but is typical of these road racing organizations.

   I was thinking about starting a new road racing organization allowing people
   to run what they brung like the old Canam. No rules other than seat belts,
   roll over bars and fire extinguishers.

   An all aluminum  four rotor turbo would put the lap records out of site
   for everything except another four rotor turbo :-)

   Paul Lamar


Can Am had minimal rules. Open cockpit, capacity for two seats. Wheel base may have been another as they all were short in that respect. Seems something like 90 inches.
I would support another class like that but no power adders such as supercharging, turbo-charging and NOS. Power recovery systems allowed.
One of the issues of pro motor sports is R&D costs like F1 which falls into the ridiculous category. Thus something to limit costs would help get grids up. In my opinion, limiting the tires is the best way to efficiently accomplish this. Mandating a DOT spec tire available to the public would be effective to restrict costs and keep competition close.

Dale Davies



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