Nerd’s Eye View: The Cars of PRI


Part of what makes the Cobra Jets such great racers is a new rear end package for the S550 Mustang that replaces everything behind the driveshaft.  It’s a very clever package, bolting right into the S550’s chassis with no cutting or welding.  It replaces the OEM diff housing with one that accepts Ford 9” differentials (making gear and diff options plentiful for the experienced Ford racer).  It also saves over 100 lbs from the rear end and retains the factory IRS design, beefing everything up for dragstrip abuse.  The brakes are also moved inboard to reduce unsprung weight.  Watson developed this rear end in-house and are now offering it to all Mustang owners.
Speaking of factory drag cars, Chevrolet were showing off their latest Copo Camaro.  This specific car is the Hot Wheels 50th anniversary spec, but Chevy builds 69 Copos a year.  The latest cars are based off the 2016+ 6th gen platform and are offered with either a supercharged small block LSX, big block LSX, or an LT based engine (the latter two are naturally aspirated).
To complete the trio of American factory built dragsters, here is the Dodge Charger Drag Pak.  Essentially a lightened Hellcat, but with a 1,000 horsepower engine, now is a great time to be an amateur drag racer looking to break into a competitive and budget friendly sector.  The Cobra Jet Mustang, Copo Camaro, and Challenger Drag Pak are all eligible for the NHRA’s Factory Stock Showdown class, a class built specifically for the factory specials.  Hmmm, I wonder if Toyota, Nissan, and Mazda would be interested in doing factory stock drift racing…
Moving to super-high end muscle cars, can someone explain to me Pro-Mods?  This “1969” Camaro is a full tube frame racecar with an NHRA legal roll cage and not a single 1969 part inside of it.  The chassis was actually built in 2012 by Larry Jeffers Racecars and the entire body is made of carbon fiber.  It’s a full on racecar, but some people try to pretend these are street cars (in states with very loose registration laws like Michigan).
The tech in these engines is insane.  Running a 555ci (9.1L) Hemi engine and a Procharger F-3X-143 crank driven supercharger big enough to swallow a child, this Camaro makes over 3,500 horsepower.  The supercharger is pretty interesting.  One of the newer trends in supercharging (which is actually an old trend) is to spin the supercharger directly off the crankshaft with a reduction gearbox in the middle.  This both allows the supercharger to spin faster, and remove the possibility of belt slip or stretch.  It also allows for the supercharger to be mounted very low.  Crank mounting is how superchargers used to be in the 1930s and 40s when they first became popular in cars.

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