Jim & Cindy Griggs | Karting Part Two - Need for Speed

Karting Part Two - Need for Speed

December 01, 2014  •  Leave a Comment

I really learned a lot from that old kart.  Caster and Camber as well as Toe-in and Toe-out were added to my vocabulary in the 8th grade.  I really understood the implications of these critical setting.  I really wanted to be able to adjust Caster and Camber but they were fixed on karts.  Toe-in and Toe-out were possible but best left neutral if you didn't have suspension.  With Roger Ward doing the testing on the Hellcat during development I assumed it was set up fairly neutral and for best handling.  I spent a lot of time in the library reading about steering geometry, trying to figure out why the inside tire turned sharper than the outside tire on the front; it is to insure that the center of rotation for all three axles was the same going around a corner.  Why did cars have differentials?  That was easy to learn the first time I pushed my kart and turned the steering wheel.  With a solid rear axle, one tire had to slip since it was traveling a different path than the other.  Having a solid rear axle ate up horsepower going around corners but it was rare to go around a corner on a kart and not have all four tires slipping!  There were times in tight turns when the inside front tire was completely off the surface.  I learned that chassis flex can be a good thing AND a bad thing depending on the situation.

 

What really came to light was engines.  The West Bend engines I had were "under-square".  By definition an engine that is square will have the bore of the cylinder equal to the stroke of the crankshaft.  The West Bend 580 had a long stroke and small bore.  That was great for low RPM torque but limited the top RPM of the engine.  Most of the newer karts had McCulloch engines which started off life as chainsaw power plants.  These were "over square" with larger bores and shorter strokes.  Those little engines were turning 9,000+ RPM at full song.  On a tight, twisty course, the West Bend with its low speed torque had an advantage.  Coming off a tight corner onto a long straight, the West Bend powered karts would pull away until about halfway down the straight.  Midway on the straight and the McCulloch powered karts would come by screaming at high RPM's.  Higher RPM meant higher horsepower.  It was a simple fact of physics.  I was learning stuff that would stick with me to this day.  Not bad for an 8th grader.  All this interest drove me to want to major in Engineering.  I took all the math and science classes I could.  I literally loved geometry!  Why?  Because I could go home after learning something in school and apply it to my kart.  I bought books on race car chassis and suspension design.  Most of it was beyond me but I read them anyway figuring that when I learned the physics later on it would all fall into place.  It did.

 

One Spring Sunday after a long morning shower we decided to go to the parking lot and do some driving.  There were huge puddles of water everywhere.  I decided it would be OK so we unloaded the kart and I fueled it up, put on my helmet and fired it up.  I thought it would be really cool to run thru the puddles at really high speed and see how far the water would spray out from the tires.  I learned a couple of valuable lessons that day.  One, slicks and wet are not compatible and two, when you drive a car thru a puddle and watch the water spray out it is cool, BUT when you drive a kart thru a puddle the water does indeed spray out but it also sprays IN!  Without fenders it is really damp for the driver.  I was doing about 50 when I hit the first long and fairly deep puddle of water.  I watched in horror as two huge waves of water came gushing into my face from the inside of the tires.  Helmet and goggles help but having water sprayed up your nose and into your helmet and mouth are not too cool.  I thought I was going to drown.  By the time I got my eyes open again I noticed I was traveling sideways in the puddle at about 45 miles per hour headed for dry pavement.  Steering had no effect, those slicks were essentially useless and hydroplaned very well.  As soon as the tires hit pavement and dried a bit they grabbed.  I felt like the kart was going to flip.  In actuality it came up about 15 degrees and bounced back down, whipped around and slid to a halt.  I gingerly added throttle and mostly crept back to the truck to go home.  I was soaked from head to toe and I need to uh, change clothes.

 

I really liked Indy Car racing and wanted to go see the 500 so badly but it was a long ways from Houston and it was expensive.  Walking thru the grocery store I spotted a magazine, Sports Car Graphic, and there on the cover was a Lotus Formula One car with a guy named Innes Ireland driving. This thing was small nimble and looked like a go kart on steroids.  I bought the magazine and started reading.  From they point forward I was a huge F-1 fan (still am to this day).  My friends in school had their heroes, mostly sports figures who played baseball or football.  My heroes had names like Phil Hill, Dan Gurney, Innes Ireland, Bruce McLaren, Jimmy Clark and a host of other F-1 drivers.  Technically, there is no other class of car built that can match an F-1 car for performance around a road course.  And the technology!  It was all about simplicity and suspension design, chassis stiffness and a small engine cranking out huge amounts of horsepower via crazy RPM's.  The cars of that era was fitted with a small engine of only 1.5 liters (roughly 90 cubic inches for those not in the know), with carburetors but turning maybe 11,000 RPM and pumping out 400+ horsepower!  WOW!!!  I was totally amazed.  I learned all about tuned exhaust, multiple valves per cylinder, hemispherical combustion chambers (most current Dodge owners don't even know what the word Hemi stands for but they have one and brag about it) and close ratio 6 speed transmissions.  One thing my kart had in common with those F-1 cars?  We could both do four wheel drifts.  Not the smoking tires that is called drifting now but sliding along at crazy speeds basically floating on a small patch of slipping rubber on all four tires.  Four wheel drifts were so cool when they happened and just felt like a ballet at speed!

 

Another installment coming soon, as the Need for Speed continues!


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