Project SEMA Scion Tuner Challenge FR-S: Easy Power with an Unorthodox Racing Pulley

Project SEMA Scion Tuner Challenge FR-S: Easy Power with an Unorthodox Racing Pulley

by Mike Kojima

In previous installments of Project SEMA Scion Tuner Challenge FR-S, we’ve worked on improving the suspension, braking and improved the grip with a new set of wheels and tires.  Now we will start focusing on getting more power out of the engine.  We will begin with simple modifications and start to ramp things up in our quest for power.

Our first step is perhaps the most basic, adding a lightweight Unorthodox Racing front pulley. The Unorthodox pulley is not an underdrive pulley but a lightweight pulley that takes several pounds off the engine’s reciprocating mass. Spinning up extra mass takes power and a lightweight pulley can free up some of that power to reach the rear wheels.

Normally this sort of power gain is more easily seen on an inertia type dyno like a Dynojet but our conservative Superflow dyno is an eddy current load type dyno with a slow ramp up so a power gain due to lower mass might not be so easy to spot.  Unorthodox claims a gain of 6-10 whp and we were curious if we would see anything close to that.

The Unorthodox pulley is CNC machined from 6061 aircraft grade aluminum and weighs 1 pound, 0.7 ounces.  This is about 3-4 lbs lighter than the stock iron pulley. The Unorthodox pulley keeps the same drive ratio as stock which was very important as we plan to supercharge our FA20 engine later on down the road.

Some people may be concerned that the solid lightweight pulley might have an adverse effect on engine life due to the removal of the damping element of the stock pulley. We feel that this is not going to be an issue. The FA20 engine is internally balanced and fully counterweighted and the damper in the pulley is mostly for the reduction of NVH and not something that is essential for engine life.

We have run Unorthodox pulleys on many different engines from high powered turbocharged race cars to street cars with over 100,000 miles on the pulleys and we have never ever had any sort of long term durability issues with any engine due to the pulley.

Don’t forget to check out the rest of the articles on our SEMA Tuner Challenge FR-S

The Unorthodox Pulley kit comes complete with a high quality Gates Belt.  Our sample car had quite a few hard press pool miles on it so it was greatly appreciated.
The Unorthodox pulley itself  is CNC machined from a solid piece of 6061 billet.  The folks at Unorthodox used a CNC machine to carve out the backside of the pulley and added lightening holes to even further reduce its weight.  The aluminum pulley weighs in at a feathery 1 pound, 0.7 ounces.
Getting the tooth contours just right is important for long term belt life and to keep the belt from being thrown off.
As a pure dress up item we could not resist this Unorthodox Racing billet oil filler cap.  The machine work is so intricate.  Normally we pass on billet caps and stuff because they get burning hot and are heavy.  The Unorthodox part is cored out to the max to make it light and the design actually acts like cooling fins so it does not get as burning hot as others we have experienced.

Leave a Reply

Your email address will not be published. Required fields are marked *