G_Money

Vivid Racing has the Agency Power underdrive crank pulley on sale for $480 from $600. Is this worth it? Are there pulleys that are reccomended over the Agency Power brand?

Thanks!

chrisridebike8

worth it compared to what? whistle tips? for $600 you are better off spending a little more and getting a tune. don't waste money on a pulley. the negatives far outweigh the maybe 5 whp you would get.

shardul

iTrader: (1)

We have the UPD under drive crank pulleys for $449 shipped.

JimGnitecki

Underdrive pulleys are not a good idea on any car that uses any significant amount of electrical power, and our C63s have LOTS of electrical accessories. It can also adversely affect the effectiveness of your air conditioning compressor.

Having done an underdrive setup on a U.S. made car some time ago, I found the power difference was undetectable and the negatives were very evident. I would never do it again.

Jim G

G_Money

Thanks for the tips, I guess ill keep the stock crank pulley as this is my daily!

Shardul, do you also make a billet replacement idler kit like for the M113ks? I can't believe AMG is putting plastic pulleys on motors LOL!

Celicasaur

He does and his ones are just as good + about 20-25% cheaper than the competition. Highly recommended.

CaptnCharisma

I have an under drive pulley and have not seen any electrical issues with it. I've even tested the alternator and was just fine with a smaller crank pulley. I have the Agency Power and I think UPD has the evosport pulley.

SactownP31

I have a lightweight one on my clk. Car revs faster and picked up 13 whp when i dynoed 4 years ago. Id say post some dyno numbers but even with that you'll still find blind eyes and deaf ears and possibly still get told you're a fool.

CaptnCharisma

It definitely feels like it shifts faster and more aggressive when I get on it. Unfortunately I never did a before and after dyno with it. I did dyno last year and managed to get 475 whp with it, e85, ROW boxes and filters, tune, and a secondary cat delete so not bad numbers for not having long tube headers.

SactownP31

Not bad at all. But believe me, opening up about having put a lightweight or underdrive pulley on this forum is like openly admitting you're a Republican in California. Better get your flame suit on. LOL.

Infiniti

The pulley is on my list and when i do it, i’ll get it from shardul

betrezra

There is a trade off when ud a crank pulley, but if you are ok w that then yes there is a sm hp inc.

however, going to be hard to detect 10hp on a 500 hp engine.

most spend that mod $. Elsewhere

CaptnCharisma

So I've enjoyed having the agency crank pulley but I have hit a big snag due to it after rebuilding my engine. The under drive crank pulley does not have any markings for 40 degrees TDC so while trying to get the timing set there isn't really anywhere to reference other than where I took the cams off when I started tearing the engine apart. I've been able to get the engine in the ballpark and run but it sounds like a lawnmower. Off to the shop it goes.
Anyways if you get an aftermarket crank pulley you may want to get it the crank position etched on it during install.

JimGnitecki

Good advice!

Jim G

Celicasaur

I had this problem on my Celica many years ago. Of course, I was able to get around it easily because to time the engine, cylinder #1 needs to simply be at TDC. The 40 degree thing on the M156 makes it an issue.

I suppose your only alternative for now is to use an oem pulley to time it up and then swap the pulley back out again?

Vladds

With the M156, the crank pulley doesn't have a harmonic balancer in it?
The only thing I would look into is what the M159 has. And that's easy enough with part numbers.

Celicasaur

I'm pretty sure it does....nothing special really, but that hardened rubber certainly serves it's purpose I suppose.

I was considering the pulley for a good while myself tbh, but seeing as I'm going to raise the rev limit, i'll keep all the balance that i can get