Thinking of buying a UR underdrive pulley... Some questions and concerns..

[OM3GA]

Im going to buy a Unorthodox racing crank pulley soon and im wondering if it is going to hurt any of the accessories such as the water pump.. Since the pulley is smaller then stock that causes the accessories to spin faster then stock.. I dont want any problems from this. Also does anyone else out there have one that knows what size belts you need? (im assuming it will come with info about the belts but id like to get them beforehand) Also how can you tighten the crank bolt without hurting the pulley? And without using an impact gun... For the stock pulley we used a chan type device with a bar but it left a small indent in the pulley, not a really big deal but the UR pulley is aluminum and i imagine it will be alot worse then the stock one..

[scole]

Since the pulley is smaller then stock that causes the accessories to spin faster then stock.. I dont want any problems from this.

Smaller pinion = slower spur, hence underdrive.

[OM3GA]

The smaller the pulley is the closer it is to spinning the same speed as the crank... Normally it spins alot slower then the crank as you shorten the circumference of the pulley the faster it will spin causing the accessories to spin faster... Am i mistaken?

[scole]

Am i mistaken?

Yes.

[OM3GA]

How exactly does it work then because i see it as being smaller and spinning faster then the larger stock pulley.... So your saying it does not spin any of the accessories faster? I cant believe that... Its smaller so it should be spinning faster then before, Or since its attached to the crank its spinning the same speed? but what about the accessories wouldnt they spin the same speed as well?? even though the pulley is smaller..??

[Soravia]

Water pump is connected to the fan clutch. By that, it is designed to slip after certain torque difference is applied to it.Meaning, it cannot over-spin.

[OM3GA]

The water pump pulley does not slip.. what are you talking about? The fan clutch slips is that what you mean? As the engine gets hotter the clutch in the fan clutch grabs harder basically causing the fan to spin faster and cool the engine down.. As the temp of the engine drops the pressure from the thermal part of the fan clutch is lessened thus causing it to spin slower or "slip" like you described..

Im just wondering how the accessories are spinning "slower" as it explains on their site.. The main thing im worried about is an increase in cooling system pressure causing problems.. After my friend installed this pulley his radiator hose started to leak at the clamps and now his heater core is leaking. Whether or not this pulley increased cooling system pressure i still find it a weird coincidence... Also how do you tighten the crank bolt without an impact? I need a way to grip the pulley without hurting it..

[Kalypso]

Water pump is connected to the fan clutch. By that, it is designed to slip after certain torque difference is applied to it.Meaning, it cannot over-spin.

there is your answer, well said and articulate.

[98s14inaz]

The smaller the pulley is the closer it is to spinning the same speed as the crank... Normally it spins alot slower then the crank as you shorten the circumference of the pulley the faster it will spin causing the accessories to spin faster... Am i mistaken?

Wow.

[Kalypso]

now that we established a smaller crank pulley wont make the world spin faster.

is the only benefit the weight reduction, and an easier spin?

this thread is full of but it would be nice to turn it into useful info for less experienced people.

[OM3GA]

So this pulley could not cause any problems or quicker wearing or an increase in cooling system pressure?

Also how do you recommend tightening the crank bolt without chewing up the pulley? And without using an impact?

[White Comet]

this thread is full of but it would be nice to turn it into useful info for less experienced people.

dont worry, im here to save it with knowledge . seriously, i enjoyed the UR pulley on my ka. it worked very nicely, didnt over or under work anything, and made a noticeable difference. it wont have any adverse effect, i say go for it

[gregfarz78]

I stay clear of underdrive pullys, lightened pullys are a different story I'd go with one of those instead

[JStrateger]

Also how do you recommend tightening the crank bolt without chewing up the pulley? And without using an impact?

What do you mean? I tightened mine with an impact wrench and it didn't chew my pully up. As long as you have the tourqe settings right, you should be fine. I think it's 105 ft-lbs.

[98s14inaz]

now that we established a smaller crank pulley wont make the world spin faster.

is the only benefit the weight reduction, and an easier spin?

this thread is full of but it would be nice to turn it into useful info for less experienced people.

This has been covered ad nauseum, if the noobie would have searched he could have avoided all the

[Kalypso]

well then!

on to bigger business

[Soravia]

Lightened 11LB flywheel is the way to go. Pullys don't weight crap to make much of a difference.

[sunnys14]

Lightened 11LB flywheel is the way to go. Pullys don't weight crap to make much of a difference.

Wow are you serious? Please tell me you're joking.

Pulley sets are a great way to gain power. A G35 gained 9whp across the powerband with a ljust ighter crank pulley. A 240 gained 8whp across the powerband with just a lighter crank pulley. Please dont DUMB this forum up with idiotic remarks.

[maroon240]

What side

Wow are you serious? Please tell me you're joking.

Pulley sets are a great way to gain power. A G35 gained 9whp across the powerband with a ljust ighter crank pulley. A 240 gained 8whp across the powerband with just a lighter crank pulley. Please dont DUMB this forum up with idiotic remarks.

What side scurts are those on ya whip, yes thread jack.

[mitcheyismyname]

i believe a smaller circumference pulley would make other things slower, and a bigger pully make things faster...... same principle as wheel/tire size and how simply an inch bigger wheel or tire will make the car accel faster....in some cases...

[White Comet]

Lightened 11LB flywheel is the way to go. Pullys don't weight crap to make much of a difference.

dude, i dont mean to be rude, but your posts are really starting to get on my nerves. its like you dont think before you type

[EazyBreazy]

A larger crank pulley or smaller accessory pulleys would increase the speed at which the accesories rotate.

As for the 11 pound flywheel, that allows the engine to rev freer as it has less momentum to overcome during a change in acceleration.

[Kalypso]

As for the 11 pound flywheel, that allows the engine to rev freer as it has less momentum to overcome during a change in acceleration.

the sweet sound of knowledge...

people please relax, once my money$ is tight, im certainly getting the flywheel and pulley kit. and eventually a twin turbo dodge viper.

"the greatest strength comes from accepting uncertainty" Deepak chopra

[OM3GA]

I have been just sitting here and watching peoples replies... Anyways to turn this into useful information let me break it down for you because me and a friend of mine thought about it more and figured it out, Basically visualize the pulleys in your head... on the ka there is the Alternator pulley, Water pump pulley, power steering pulley and the Crank pulley.So hypothetically speaking im just going to say the Crank pulley is 4 inches in diameter The alternator pulley is 1 inch in diameter the water pump pulley is 2 inches in diameter and the power steering pump pulley is 1 inch in diameter.

Ok so if the crank pulley rotates one time it rotates the alternator and the power steering pump pulley 4 times, and the water pump pulley 2 times.

If you were in fact going to decrease the Crank pulley size to (hypothetically) 3 inches in diameter while leaving the other pulleys the same size with one rotation of the crank pulley it would rotate the alternator and power steering pump 3 times and the water pump 1.5 times. So that is how the Smaller underdrive pulley actually UNDERDRIVES the accessories in a way that is so minor for the accessories that they will still function as they normally should but its alot less work for the engine to do. Which is why it gives you more horsepower/torque.

On another note i have the lightweight flywheel already, The 11lb fidanza, Pulley sets and light flywheels are both really good for power, Any weight taken off the crank is good and noticable, I remember driving my friends 240 with a DE that was completely stock besides catback and mishimoto radiator and that pulley was installed and WOW it was noticable so you people saying its not noticable need to leave and stop spreading useless information... Also You dont really have to worry about it messing up the engine because import motors are INTERNALLY BALANCED which means that what you do to the outside such as the crank pulley isnt going to really hurt it.. Unless the pulley is not balanced and or is wobbling everywhere then you have some serious issues.

You people really need to stop talking about SEARCH SEARCH SEARCH... Do you really think i would take the time to post a thread about something without searching first? Give me a break do us all a favor and reset your post counter so us people who actually post threads look like we know what we are talking about, I could easily post whore by going in to every thread telling people to search. Did you try searching yourself and find anything useful? If so please direct me and slap my A$$.

[cbt240sx]

I'm putting mine on when my belts get here.

[ADF932]

I got a laugh out of it but its so true. I have an underdrive pulley on my KA, I did notice a power difference. The KA is a little more rev friendly with the underdrive. While your changing your pulley you should replace the front main engine oil seal, cheap insurance and will save you a hassle of removing your pulley a second time because the old seal started to leak.

[EazyBreazy]

lots of words i already explained just in further detail

A larger crank pulley or smaller accessory pulleys would increase the speed at which the accesories rotate. OR VISE VERSAAs for the 11 pound flywheel, that allows the engine to rev freer as it has less momentum to overcome during a change in acceleration.

The only thing I would change about anything I said earlier is in bold above.

blanket statements such as you people are unnecessary, The people whom know what they're talking about are easily distinguishable from the idiots because they're post have content in them. I've learned that the longer I frequent the internet and forums, the more bs I have to sort through in threads to get information as well as more bs to sort through when searching. It can become extremely frustrating.

[OM3GA]

That is why all the threads with useful info get stickied or used somewhere that they will be seen more. I hate looking through all kinds of bs trying to find something useful.

While your changing your pulley you should replace the front main engine oil seal, cheap insurance and will save you a hassle of removing your pulley a second time because the old seal started to leak.

Yeah im changing my front main seal which is actually why im doing this pulley lol, I had the front seal done not too long ago maybe like 3k miles.. And its starting to leak again Very Very little though like i only noticed because the car was on a lift and i looked up there with a flashlight... But i figure itll get worse so i might as well replace it now. Im replacing the pulley at the same time because im thinking maybe the stock pulley has a groove in it that is causing the seals to fail.. Well see but ill get some more power out of it too so thats cool.

[ken240sx]

Yea, to clear it up for anyone who still doesn't understand the concept of a smaller crank pulley making you accessories spin slower...here we go.

If they are the same size then they will spin at the same speed.If you replace your crank pulley with one that has 2 inches less diameter, then for one revolution of the crank, your belt is traveling 2 inches less...thus transferring to less rotation of the other pulleys.

think of a yo yo, yes a GD yo yo.....If you have a big yo yo, more string will wrap around it with one full rotation. Get a smaller yo yo and you'll end up wrapping up less string in one full rotation. Now wrap one end of a string around a large yo yo and the other end around a small yo yo. turn the small yo yo one revolution...and there you have it you now mentally capable children, your larger yo yo didn't spin a full rotation. The smaller your crank pulley, the slower acc. pulley rotation and visa versa.

[scole]

Yea, to clear it up for anyone who still doesn't understand the concept of a smaller crank pulley making you accessories spin slower...here we go.

If they are the same size then they will spin at the same speed.If you replace your crank pulley with one that has 2 inches less diameter, then for one revolution of the crank, your belt is traveling 2 inches less...thus transferring to less rotation of the other pulleys.

No not 2" less, it is 2"*pi, or ~6.28" less.