Under the Hood – David’s Winning Opel
If you have watched or read anything from the first two rounds of the Texas Slot It DTM Proxy Shootout you have seen one car at the front with a commanding lead over the other 13 cars. What is it that makes this car so much faster than the others? To answer this question, we take a look “Under the Hood” to see exactly what David did to make this car so much quicker than the rest.
It should be said before we go any further that David is one of the fastest runners at the Austin Slot Car Club and his car builds are usually some of the best so it’s not unusual to see him running at the sharp end of the field.
Like most of the runners from the Austin Club, David started building his Opel by stripping it down to each individual part then baking the chassis to make sure it was as flat and straight as possible before building it up.
After baking the chassis, the next step was to rebuild the car using a mix of the stock and non-stock parts to give David the feel and performance he was looking for. The list below shows exactly what parts were used with items in blue being the ones that have been changed from the stock part.
Guide – Slot It wood guide, CH07
Motor Pod – Stock
Motor Pod Bushings – Stock
Pod Screws – Slot It short, small head, CH53
Pod Screw Washers – yes, stock
Motor – Stock, with circuit board removed
Motor Fixing Screws – Slot It, CH41
Pinion – 10t brass
Crown – 24t brass, non-offset
Crown Grub Screw – stock
Ft Wheels – Slot It Aluminum 15×8, W15808215A, ex PA24-Als
Ft Wheel Grub Screws – stock
Ft Tires – Slot It Zero Grip 17”, PT07
Rr Wheels – Stock
Rr Wheel Grub Screws – stock
Wheel Inserts – Stock
Rr Tires – Slot It F30, PT28, glued to the wheels with ShoeGoo
Body Screws – Ft-Slot It long, small head, CH51, Rr-Slot It short, small head, CH53
Body Screw Washers – yes, stock
Braid – Slot It
Motor Wire – Thin white, glued to the chassis
Ft Axle – Stock, 48mm
Rr Axle – Stock, 48mm
Ft Axle Grub Screws-Top – Slot Car Corner oval point
Ft Axle Grub Screws-Bottom – Slot Car Corner oval point
Ft Axle Holder – Slot It bushing, CH56b
Ft Axle Spacers – Slot Car Corner plastic combined with brass spacers
Motor Pod Weight – Slot It Tungsten, SP23, only in the front slot
Chassis Weight – small lead weights, mounted to the outside and center of the chassis
Weight – 74.7gr
Ft – 31.70gr/42.44%
Rr – 43.00gr/57.56%
Height – 37.15mm
Ft Track – 58.85mm
Rr Track – 57.16mm
Wheel RPM – 8,485
Calculated Motor RPM – 20,[email protected]
As you can see from the list above there were many things David changed on his Opel but the ones that had the biggest impact would have to be the wheel RPM combined with the weight distribution. Usually a car that has a wheel RPM of 8,485 it would be hard to control on our track but this car is so well balanced it’s a joy to drive for a wide range of drivers. That is the key to a good proxy car – one that is easy to drive by everyone. It doesn’t hurt that David’s car is super fast as well – just check out the YouTube video of the race and watch his car walk away from the others in the turns and on the straights.
I believe the take away from all of this information is not just the parts David used but the attention to every little detail. From baking the chassis to the proper amount and distribution of weight, to gluing the rear tires to reduce chatter – everything that was done was done with the purpose of making the Opel the fastest car in the proxy. After two rounds I would have to say David did exactly what he set out to do. Congratulations on a great car build.