anybody use the MR pulley set?

[WILDACEX187]

i saw that these are considerably cheaper than the greddy ones and they are nearly identical. i was talking to my friend and he said he wouldnt trust them since it could mess up the crank because they have to be machine very precisely. anybody had them? will anybody trust them?

[Rusker]

I didn't even know MR came out with a pulley set.

[s14turbosilvia]

Originally Posted by WILDACEX187

i saw that these are considerably cheaper than the greddy ones and they are nearly identical. i was talking to my friend and he said he wouldnt trust them since it could mess up the crank because they have to be machine very precisely. anybody had them? will anybody trust them?

1) A pulley is a pulley, if machined good enough. I think MR has made a good enough reputation for themselves of supplying decently built parts identical to their higher priced counterparts.

2) It definately wouldn't mess up the crank. The pulley is driven by that crank, and basically all thats driven by the belts around a crank pulley is accessories. Timing on the SR is done with a timing chain competely seperate from the pulley.

[WILDACEX187]

thank u s14turbo. http://www.srparts.com/pulleys.html <~rusker there u go

[bing]

dont worry about them Antony,

they are probably made in the very same factory as Greddy.

you'd be amazed at who makes what.

JIC has no representation in Canada but some of their exhuasts are made an hour from me. the same facility produces 5zigen equipment i think it was too. Yet this facility it owned by another company that has their own brand name altogether that is associated with fancy shifters and taillights... i wont reveal who...lol

[WILDACEX187]

APC!!!!!!!!!!!!?!?!?!? lmao

[Rusker]

APC
Made in Canada


lol

[Rusker]

Thanks wildacex187,

I was going to buy the Greddy, but I really didn't like the blue. Guess this way I can save a few bucks as well.

[Angel]

Originally Posted by s14turbosilvia

1) A pulley is a pulley, if machined good enough. I think MR has made a good enough reputation for themselves of supplying decently built parts identical to their higher priced counterparts.

2) It definately wouldn't mess up the crank. The pulley is driven by that crank, and basically all thats driven by the belts around a crank pulley is accessories. Timing on the SR is done with a timing chain competely seperate from the pulley.

A pulley can certainly mess up a crank.... if it isn't balanced correctly or if the stock pulley acts as a harmonic dampener.... which many of them do. Unless you are sure that these two things are either addressed or not an issue on your paticular application, then stay away as it isn't worth the small gain.

[S14DB]

Originally Posted by Angel

A pulley can certainly mess up a crank.... if it isn't balanced correctly or if the stock pulley acts as a harmonic dampener.... which many of them do. Unless you are sure that these two things are either addressed or not an issue on your paticular application, then stay away as it isn't worth the small gain.

1) These aren't crank pulleys, they are for the accessories.
2) SR's don't have Dampeners.

[wootwoot]

Those arent even underdrive are they? just lightened? I would like to find a full underdrive set INCLUDING crank pully

[Rusker]

I'm guessing just lightened.. I tried finding the weight on these compared to the Greddy. Anyone know?

[WILDACEX187]

call them and find out

[wootwoot]

I bet you a dollar they are identical. As in they found out who made the Greddy ones, and then bought them from that company.

[WILDACEX187]

they certainly look the same.

[Angel]

Originally Posted by S14DB

1) These aren't crank pulleys, they are for the accessories.
2) SR's don't have Dampeners.

Only wrote that because someone stated that a pully can't hurt the crank... which it can, didn't look at the link. Naturally assumed since the crank was brought up that the kit included a crank pulley. And if you look at an sr crank pully you will notice that there are two halves seperated by rubber.... what do you think that is for?

[S14DB]

Originally Posted by Angel

Only wrote that because someone stated that a pully can't hurt the crank... which it can, didn't look at the link. Naturally assumed since the crank was brought up that the kit included a crank pulley. And if you look at an sr crank pully you will notice that there are two halves seperated by rubber.... what do you think that is for?

To reduce A/C clutch NVH.

[WILDACEX187]

sorry nvh stands for?

[S14DB]

Noise, Vibration, Harshness

[97DubTruck]

Unorthodox makes a crank pulley. It's 200 something. Accessory pullies do nothing. The crank pully is what gets you the power.

[WILDACEX187]

Originally Posted by 97DubTruck

Unorthodox makes a crank pulley. It's 200 something. Accessory pullies do nothing. The crank pully is what gets you the power.

is this true? will anybody contradict this person/?

[90RS13]

In most apps the crank pulley is what makes the power cause it is the item that actually underdrives the accessories. That's why you get power cause the engines is underdriving (using less power on) the Accessories.

[WILDACEX187]

so getting one of these sets is pointless?

[Rezlo]

No its not pointless, less weight = less rotating mass = more free'd HP

Bad things about UDP's are they slow your waterpump down, which in a hot motor like the SR that probably isnt the best Idea.

You make power from pullies 2 ways, Rotating mass and slowing accessories down, slowing the alternator or PS down a little rarely causes problems unless you are in a very cold climate or have a large sound system, but the SR's water pump will be slowed down with a UDP so best try avoid that.

[WILDACEX187]

kool thanx.

[90RS13]

Actually underdriving the water pump can help on high rpm engines. It can help reduce cavitation. Also, lightened pulleys will let the engine rev more freely, but you aren't going to get a good hp gain without underdriving.


EDIT: Just incase people don't know what cavitation is. Cavitation occurs when the impeller in a pump, (or propellers on a ship) goes to fast. When the blades move too fast, low pressure areas form around the blades as the water passes through. If pressure becomes to negative the water will reach it's "vapor pressure". When that happens the water vaporizes and bubbles of gas are formed. Now the bubbles are the problem. When a bubble is formed in the cooling system, water can't carry heat away from the area the bubble is occupying. So you get severe hot spots in the engine. Also when the bubbles
collapse, they make little shock waves, damaging the impeller.

-matt

[WILDACEX187]

will redline water cooler help this cavitation u speak off?

[90RS13]

I believe you're talking about Redline Water Wetter. Water wetter is good at keeping an engine cool. It lowers the surface tension of the fluid, so that when bubbles do form they are smaller. Also, you can get cooler temps with it and can safely raise the pressure of the cooling system which will help stop vaporization. But that's where the impeller spinning at high rpm's comes into play. Redline will even tell you that Water Wetter doesn't raise the boiling point much at all. The main way that Redline actually advertises it's effectiveness is in the fact that it allows you to raise you're cooling systems pressure. This doesn't really help the water pump problem, because the impeller is causing severe low pressure area's as fluid passes through the blades.

So in short, Redline Water Wetter will help engine temps and is an awsome product. But if a water pump is experiancing cavitation due to high rpm's. The only way to stop it is to lower the rpm's. Actually, there are companies that make water pulley's specifically to underdrive the water pump. And more hp isn't there goal it's stopping cavitation. Nissan Motorsports (north america) makes a kit for the KA. But if you get an underdriving crank pulley it will underdrive the water pump. Good for sustained high rpm's, (like drifting) where cavitation could be very bad.

-matt


EDIT: I don't want people to read this and get scared and think they need a underdrive pulley, or their engine will blow. The stock SR water pump should be good to 8k. They're aren't many cars with cavitation problems at factory set redline. They're are some, but not many, and I doubt Nissan underengineered the SR20DET powerplant. I'm just showing that underdriving won't hurt and if you plan on revving to 8k+. It's a good idea.

[autobahNESSA]

"97DubTruck --Unorthodox makes a crank pulley. It's 200 something. Accessory pullies do nothing. The crank pully is what gets you the power. "

Does anyone here know of anybody with a rwd sr20det that put the unorthodox crank pully on. Any dyno charts. I seen the charts for fwd non turbo sr's, and seen about 5hp increase, just wondering what a turbo sr would do.

[Rusker]

If you doing this just to make HP, there are better, and more inexpensive ways to make 5hp.

Although, I'm looking into getting a set myself.