Underdrive Crank Pulley
 

Hi guys my first time on the forum I am from Cape Town South Africa I am currently on the look out for a new/ used underdrive crank pulley .. Evosport used to sell them but they went out of business a year or 2 ago , and really don't trust these new kids on the block . Agency power also sell but never heard anyone talking about thier pulleys.
I am also looking for a price on LSD my car is highly modded and traction is just my worst nightmare at the moment I am running Pirelli Pzero 265/30/19 at the rear and they are just not up to the job 😔 any help will be appreciated
Thanks
https://cimg3.ibsrv.net/gimg/www.mbw...46cf7659f.jpeg


My Stallion

What do you think you'll gain from an under driven pulley?

I have the Agency under drive pulley. It's fun but most of the time not noticeable if your car is your daily driver. Otherwise it makes for some wicked downshifts when you get on it. I've had no issues with any other belt driven accessories from it. Also I'm running 275's for my rears and usually don't lose traction that often unless I'm actually trying to slay my tires. Honestly I would get the LSD first. I've heard plenty of people talk about how much they enjoy having the wavetrac LSD even if their car had the stock LSD.

P Zero's are pretty awful for wheelspin control off the line.

For a DD I'd vouch for RE05A's and I've heard nothing but great things about Michelin PSS.


Crank pulley...have you had first hand experience of one previously? I'd like to know if it's worth buying too tbh. I spoke with Agency power and they insist that it's worth 20hp. I just can't see it though. I'd like to take the plunge one day, but I've spent major recently and need to chill out for a bit.

The review from CaptnCharisma tells me that it's something that you'll only slightly notice, so only do it at the end of your main mods and you're just trying to eek out every last bit.

Out of curiosity...you say your car is highly modded....what have you done to it? What kind of power are we talking here?

Another Capetonian on the forums. Welcome.
I assume your car has been tuned by Motronix.

Agency Power is fairly well regarded. As much as Evosport, I would think.

How a crank pulley can add a horsepower?? Can someone explain this?

Google

Google is good, in addition, my experience with an under pulley comes from a lesser car. It doesn't add hp, but it frees up existing hp. Less rotational mass on the pulleys allows more crank to the wheels. The engine felt 'lighter' as I floored it through the gears.

what's the weight difference? 1lb at best?

Mine was 5 lb difference.

rotational mass is a completely separate ball game from just straight up weight.

Curious as to what the OP means by he is highly modded? S/C? Headers?

It doesn't add horsepower per say, less rotation mass = less weight which means the engine will spin faster.

@ savage yes my car is Motronix tuned buddy the under drive pulley doesn't add hp but allows the engine to rev much quicker and with less restriction

The under drive pulley adds power by get this under driving the accessories ... It spins the accessories less per rotation of crank this taking less power to run the accessories....

So will this add additional stress to the engine? Will this also increase the engine temperature too?

Some say that an OEM crank pulley with harmonic dampener shouldn't be touched. If a replacement pulley isn't balanced spot-on, you're likely to increase crank bearing wear. If you look around on different forums there are plenty of experiences either way. You don't see a lot of reviews here for a reason. Most people don't need the extra 5hp with the possible risk, so leave them alone.

I just started reading these links to better educate myself. Probably worth a look.
http://www.unorthodoxracing.com/faq
http://www.civicforums.com/forums/17...k-pulleys.html

Thanks for the reply! I'll read the links too. I've been indifferent about doing this installation too.

I totally agree with you man. I've had an engine on a different car after installing a solid crank pulley. The oil pump gear shattered....it wasn't pretty.

However what makes me wonder is that loadssss of the M113K guys ran aftermarket big crank pullies with a rubber core to act as the damper and you'd struggle to find any bottom end issues with those motors. This Agency Power pulley is effectively the same thing....so I'm on the fence for the moment. But just not all that brave.