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.

Read about MotoIQ's Two Project FR-S's Here!

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. 
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Tuesday, November 25, 2014 6:44 AM
Dang, I was hoping you could do a full install on the oil cap. Any chance of doing that in the future? ;-p
Very cool piece even for those not into "bling". Is there any worry about dampening with the UR part? I know that has been a concern in the past.
Tuesday, November 25, 2014 9:15 AM
An 11% gain just from removing a perfectly good harmonic damper and replacing it with a chunk of billet? Colour me skeptical.

I've seen/read about a test that showed a 5% gain from removing the entire serpentine belt. Did you remove the serpentine belt for the dyno run with the UR pulley?
Tuesday, November 25, 2014 10:51 AM
Sorry, brain fart. You also had a 5% gain.
Mike Kojima
Mike Kojimalink
Tuesday, November 25, 2014 12:02 PM
The gain is typical of what I have experienced before. I have also NEVER had a problem with Unorthodox Pulleys in any of many applications including endurance road race cars and high powered turbo race cars. For instance when you put a drysump system on a race motor you get rid of the damper.
Ron Wood
Ron Woodlink
Tuesday, November 25, 2014 5:44 PM
Unorthodox pulleys (or any underdrive pulley that deletes the crank damper) have been the cause of countless oil pump failures in Miatas.

Seriously, don't run an undamped crank pulley.
Mike Kojima
Mike Kojimalink
Tuesday, November 25, 2014 8:20 PM
Seriously, I have been involved in lots of racing programs, real racing under tough conditions using these pulleys and have never experienced an oil pump failure, crank failure or bearing issues. I have never been involved with a racing program with a Miata or used one of their engines in a racing program nor have I ever modified one for street use but I do know that oil pump failures are an issue with Miata engines in bone stock condition which has nothing to do with the pulley. The oil pump gears are made using sintered metal which is brittle and tends to shatter. In fact there are billet replacement gears made for this engine. There are many documented cases of the gears shattering on stock engines and modified engines with stock balancers.
Mike Hawken
Mike Hawkenlink
Tuesday, November 25, 2014 10:10 PM
Dang, Mike laying down the factual information
Ron Wood
Ron Woodlink
Tuesday, November 25, 2014 11:18 PM
Miata oil pump gear failures w/ stock dampers are nearly always on tired old high mile engines with beat down worn out dampers. The Unorthodox pulley failures were documented way back starting about 20 years ago when the engines were still fresh... it is nothing new.

Crank dampers are categorically not "just for NVH." Even if the oil pump manages to live wih an undamped underdrive pulley, you are transmitting crank-borne torsional vibrations through the valvetrain drive (less of a problem on belt drives, more of a problem in chain drives), not to mention inducing errors in crankshaft position sensing. Measure the spark scatter before and after an underdrive pulley install, you will be surprised. And not in a good way.
Wednesday, November 26, 2014 12:42 AM
I have used pulleys on many different cars and have never had a problem as well. The very fact that these pulleys are not press fitted to the crank should tell you that they have nothing to do with damping harmonics.
Mike Kojima
Mike Kojimalink
Wednesday, November 26, 2014 2:21 AM
Ok you are talking in huge generalites, I am talking about actual experience in actual racing. One endurance race is probably the equivalent of a lifetime of near redline dwell time. A season of road racing is probably several lifetimes of wear and high rpm dwell time. A season of Formula D is like many lifetimes of abuse. I have not been involved with racing Miata's but it is common knowledge that they have weak oil pump gears and there are several aftermarket solutions for oil pump breakage which lends me to believe that this is an endemic problem for this engine type. Some engines like the SR20, need underdriven pulleys to live under racing conditions and we have been using Unorthodox pulleys in every single race SR20 powered project for years and we have yet to see a crank, bearing or oil pump failure in any engine, some of which have run through stuff like an E2 endurance championship including the 25 hours of T hill. This is just one example out of scores. We commonly replace the front pulley with a solid hub version when we dry sump a car for 100% race use and we don't see crank or bearing problems. We have even done it on stupid engines like the QR25DE which has a ridiculously long stroke and poor rod ratio. For instance that Ed Pink built version the Cunningham Racing ran in World Challenge. That the underdrive pulley causes failures and will hurt your engine is for the most part an internet myth. Sure there is a second harmonic where an engine will see a lot of torsional whip but for most 4 cylinder engines this is above 8k rpm. If we were seeing a lot of spark scatter, we would see a big reduction in power and I have yet to see a case where an Unorthodox Pulley did not gain at least 4 whp. This is what happens in the real world. Like I said I have not built Miata engines or raced them, but I have built and raced with many other types of engines and have never had a problem.
Wednesday, November 26, 2014 7:26 AM
Is the engine any smoother or coarser after this mod? Quicker to rev?

I agree with Mike, not all engines are the same in respect to harmonics. Miata's (which I own) aren't good candidates for these types of pulleys in boosted form but seem to work just OK if kept NA. Miata BP engines also destroy their throttle bodies at higher than stock rpm to give you an idea of their inherent balance...

I'd run an ATI style damper on a miata.
Mike Kojima
Mike Kojimalink
Wednesday, November 26, 2014 8:51 AM
An interesting point is ATI dampers seem to destroy the oil pumps in RB26's. Not a 100% correlation but at lot of RB's lost the pump right after installing an ATI. One of the reasons why we started to go dry sump on any RB making lots of power. RB's have notoriously weak oil pump gears and the inline 6 reaches the second harmonic at around 7k.
Ron Wood
Ron Woodlink
Wednesday, November 26, 2014 1:27 PM
I should add that the spark scatter issue is seen where trigger is on the outboard crank end and not the flywheel end.

Definitely the torsional vibration situation is application specific which is why just bolting on an undamped underdrive pulley and hoping for the best is pretty foolish. Racing engines (esp 4cyls) you can often get away without a damper (whether knowingly or just by luck) because you can do things to drive the first mode freq out of the rev range. Ed Pink knows what they are doing, I would bet they had next to no flywheel in that engine (helps a ton), tiny low inertia clutch (ditto), lighter recip weights (helps) & a stiffer crank (helps) with less counterweighting (helps).

It goes the other way too, modified race driven BMW S50/52 with light flywheels and stock dampers have broken oil pumps and cranks since the mode freqs have been altered so the stock damper is ineffectual. Toyota ZZ cranks with stock dampers are bombproof torsionally pretty much no matter what, the only broken cranks have deleted dampers.

But for sure the number of guys installing these Unorthodox pulleys & putting a torsiograph on their engines is effectively zero, just rolling the dice.
Thursday, November 27, 2014 9:55 AM
Oil pump failures are a function of the inherent weakness of the gerotor oil pump design. The factories do not over design the stock oiling systems, primarily from a cost standpoint. The gear materials are usually sintered or powdered metal which have a finite capability for increased acceleration as such the oil systems and a number of other components (injectors, fuel pumps, etc) are only intended for a small range above stock parameters (HP/TQ and rev limit).

So when you hear about oil pump or bearing failures we guarantee it has nothing to do with the stock crank pulley being replaced with a UR crank pulley. The failures are always a function of exceeding the capability of the stock oil pump causing the oil pump gears to shatter. This is why we have advocated the use of external dry and wet sump oiling systems for engines exceeding roughly 25% normally aspirated and 50% for forced induction over stock output. The problem with these external oil systems is their expense, the bulk of enthusiasts choose to risk it with the stock pump. In the end an upgraded oil system would be less expensive than a serious engine failure. Billet pump gears are also not a solution as the gear sizes (thickness and diameter) do not allow for enough additional strength over the inferior stock materials.

If the stock crank pulley were a protective engine damper the crankshaft would crack or other driveline components would crack. The problem with current aftermarket dampers is they are heavier, both in effective and non-effective weight, than the stock dampers adding significantly more stress to the crankshaft. This stress of the additional weight has a hammering effect on the engine internals which will lead to oil pump and bearing failures. Lastly a true damper must be interference fit onto the crankshaft and no engine UR has ever made pulley for has ever had a stock crank pulley that was interference fit.

For more on these facts about the stock crank pulley and what it does plus more info about UR pulleys check out http://www.unorthodoxracing.com/university
Thursday, November 27, 2014 10:42 AM
Actually our test Miata back in 1997 was a friend of the founder. It was a 1990 just after the front snout change done by Mazda. The founder tracked (Lime Rock and Pocono) and extensively autcrossed that car over 8 years. The engine had our crank pulley, adjustable cam gears a cold air intake, header, high flow cat, our lite weight flywheel and more. We never saw a problem once, in fact we also did the head gasket replacement which we bumped compression slightly. Yet the engine performed flawlessly. We never exceeded the limits of the stock internals.

The problem is too many modders were bolting on super/turbochargers or nitrous and expecting the engine to stay whole. Even the improved snout was still too weak for the forced induction and this was seen in many engine failures showing wiped bearings, broken oil pumps and of course bent rods, broken ring lands and melted pistons. The problem back then and even today is many consumers would rather blame something easy then really analyze and solve the problem. This is how the urban legend of the solid crank pulley being bad has sadly been perpetuated. 18 years later with billions of street miles and trillions track hours accumulated UR is still going strong.

Wednesday, December 03, 2014 11:22 AM
Ouch on the "stupid qr25" comment. Agreed, but still......ouch. :P
-A head in the sand, solid pulley, QD27DE-T, driver.
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