I have always told people that moving the position of an engine does not make that much of a difference in the car’s weight distribution and that moving a battery from the engine compartment to the truck can make more difference than moving the engine quite a bit. We showed how just how much moving the battery affects corner weight and weight distribution a few years back here.
Now we did a similar experiment on Dai Yoshihara’s unlimited drift car to show just how much of an effect moving the engine can make. The unlimited car has a semi-tube frame and an unequal-length A-arm front suspension that Chris Eimer built, kinda as a fun project, it would not be legal in Formula Drift and Dai drives this car for appearances and exhibitions.
Because of the tube frame construction, it was easy to build a simple aluminum rail to temporarily move the Chevy LS-based V8 engine around quickly for the experiment. The bare engine weighs about 460 lbs without its accessories, turbo, and intake manifold. When the car was in FD legal trim, it had a 51/49 weight distribution and weighed 3180 lbs. Now it weighs 2700 lbs and has a little bit more weight in the rear than the front. As a note, to be simpler, we did this experiment with no clutch or transmission in the car and that weight would have added 0.03% or so to the total front weight.
When Chris built the tube frame front end, He clipped the car, fabricated a new more rearward firewall, and set the engine back a full 6.5″ in the chassis to turn the car into a front-mid engine configuration. On the Subaru BRZ chassis, this is a pretty huge difference as the car had a pretty short flat 4 FA20 engine from the factory and a short engine compartment. The LS engine is now entirely in the back of the front axle centerline.
With the bare engine, 49.93% of the car’s total weight is on the front wheels. 50,07% is on the back wheels. With a fully dressed engine with a turbo system, clutch, and transmission, it is still a bit shy of 50/50. For the sake of this experiment, only the first number is important.
Next, we slid the engine forward on the temporary aluminum rails Chris had built for the experiment to see what effect that would have on the weight distribution.
We slid the engine 3.5″ forward, this is a pretty decent amount and you would think it would make a huge difference.