Long term feedback on those with lightweight crank pulleys?

[Nickel]

Happy Friday, people! After 10+ years, I'm STILL going back and forth with myself on a lightweight crank pulley from either Perrin or NST or even Tomioka Racing. We all know the arguments for both the pros and cons to them, but is there anyone here with an exceptional amount of mileage on one and still running strong? Or multiple?

I appreciate any feedback in advance! Hope everyone has a stellar weekend.
-Nickel-

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Originally Posted by Nickel

Happy Friday, people! After 10+ years, I'm STILL going back and forth with myself on a lightweight crank pulley from either Perrin or NST or even Tomioka Racing. We all know the arguments for both the pros and cons to them, but is there anyone here with an exceptional amount of mileage on one and still running strong? Or multiple?

I appreciate any feedback in advance! Hope everyone has a stellar weekend.
-Nickel-

Hey Nickel,

TLDR; Go big or go home!

Seriously though, I can give you first-hand, long term experience (60k+ miles) from a car that was used for daily driving, Auto-X, and track days at an instructor level.

I installed the old complete Perrin Pulley kits (PSP-ENG-101BK Crank / PSP-ENG-120BK *discontinued* Water Pump & Alternator ) simultaneously at 3,646 mi on the car. There was a marginal improvement in feel/response. It was there but you really had to have pre/post install driving experience to notice it. Anyone driving the car for the first time would likely have no clue they were installed, thinking the car to be completely stock. They did subtract about 4.3lbs from the car's total weight and it was rotating mass on the drivetrain, so there's that.

At 4,633mi I added the Driveshaft Shop aluminum driveshaft (TOSH86). This took another 11.5lbs off the driveline and definitely perked things up. RPMs were starting to come up much quicker as well as having a more direct feel to the power application. Unfortunately, this part does add some extra driveline clunk/rattle around town at low speeds.

It wasn't until I installed the SPEC Stage 2+ clutch (SU333H) and lightweight flywheel (SU33A) at 30,554mi that the car really woke up. This shed another 9.84lbs off the driveline directly at the crank. At this point, with over 25lbs of total rotating mass removed, it was the same feeling as if you were wearing ankle weights all day then took them off at night. It didn't feel more powerful but instead like it had a huge restriction lifted and the revs would really move. Car was an absolute dream to drive in a spirited fashion. The down side of this last piece however is that the RPMs would drop so fast that a mildly rapid stop with the clutch in could stall the car as the factory ECU (car was not tuned) could not compensate for the rev drop quick enough. This is highly frustrating on the street if you don't feel like engine braking EVERYWHERE. Through enough drive cycles, the ECU learned and was better-ish, but the problem could still happen and any time the battery was disconnected, the relearn process had to start all over again. There are ways to drive around the issue, like always using engine braking or tuning the car to better compensate, but now you're compromising driveability and need to give instructions and disclaimers to anyone you give the keys to. Definitely not ideal.

I ran this combo every day over several years both commuting and performance driving until 45,720mi when the engine suffered an unfortunately fatal and completely unrelated water ingestion. Until that point, there were absolutely no issues with all of these components from idle all the way up to the factory limiter. The engine ran smooth as a finely tuned sewing machine. I enjoyed the feeling so much that when I put a replacement engine in the car, I transplanted these parts and have gone another 20kmi without issue and still going strong. Also, the new car I'm building has all the exact same modifications above with the Cusco full pulley kit replacing the discontinued Perrin components.

So, all this to say;
Are there any long-term ill effects to the crank pulley? I haven't found a single one and I beat the bejesus out of the engine.
Is it worth replacing ONLY your crank pulley? IMO, no. Only do this if you have money to burn and/or get some sort of warm-fuzzy feeling from showing or telling people you have it. That's the only way it's going to make any noticeable difference. Even if you are sensitive enough to feel the negligible change in performance, you would quickly become accustomed to it and forget all about it.
Are there some compromises to wringing out every last bit of performance? Yes. If you want to liven things up by going down the path of driveline mass reduction, you'll need some complimentary supporting mods that come with their own down sides.

Hope that helps.

[MJones_RB]

Lightweight crank pulleys are like pierced nipples; your mileage may vary.

I went the opposite route and got a Fluidampr Pulley which is actually heavier than stock. The difference is noticeable, smoothing out revs and making the engine feel more balanced.