Ultimate Spyder

Image courtesy Warren Leveque.

This is Warren's latest purpose built competition car. He recently changed the supercharger to a Roots type blower:

The positive displacement roots type blower is from a Buick 3800 SC. It is the smaller of the two blowers available and designed for higher RPM. I had to fabricate every thing. The only thing that was close was the Corvair displacement of 3100cc.

I used the power steering pulley and idlers from the turbo Pontiac GP in my back yard. The crank drive pulley was too large for the space in my engine between fan drive belts. The belt alignment was the largest job, the serpentine belt must be very precisely aligned with the crank pulley. There is no surface relative to the blower. Many turn buckles and rod end links had to be used.

It seems to work fine now after a disastous first attempt, in public of course. The postive displacement, linear boost, is in the range of 6 to 10 psi averaging about 8 psi. Boost is instaneous and drivability is great. This is just fine for a 10/1 comp engine.

This is the best this engine has run in 8 years of trying. Now it's worn out and will get a complete rebuild; especially since the cam gear is now gone. I attribute the good running to the less horsepower required to drive the blower. I would estimate about 20 hp used for the Paxton and less than 5hp. for the Roots type. The Paxton sheared belts under quick engine acceleration. I tried a Turbo also this year, but the drivability was terrible for a small, light car in autocrosses -- would have beeen great on a race track.

I made a 45 DCOE Weber out of a 40 DCOE and made it progressive for driveability. It mounts on the rear end of the blower where a throttle body would be and is completely contained under the flat body work. It is sooty rich now but runs great -- erred on the safe side.

I had to leave the engine reversed to accomadate the blower's rotation. Using the 1.4 boost factor this engine is equivalent to 4300 and still legal (4.5L max) for the lower weight in E Modified. With a 3.27 axle and 22" x 13,10" wide slicks I now take off and run in 2nd gear. I had to add weight for the new EM rules so the weight might as well make power.

I can't believe at this Senior citizen point in my life that I'm this excited about a project.

Warren

BTW, if you look closely at the back of Warren's race cars, you'll see:

Corinthians 9:24

From the Contemporary English Version of the Bible:

You know that many runners enter a race, and only one of them wins the prize. So run to win!