Underdrive Pulleys

[The Necessary]

Originally posted by fabianyee@Mar 15 2006, 05:26 AM
actually underdrive pulley is smaller in diameter.

Visualize the front ring gears on the bicycle. the bigger the ring gear, the more effort u need to pedal it. the smaller the front ring gear the lesseffort required to pedal.

Smaller pulley on the crank means smaller circumferrence, hence less belt travel for every revolution, hence 'underdriving' the alternator, powersteering pump, fan clutch and waterpump.

As for the case of the bigger pulley on the MCS, it's to increase the boost on the supercharger. There are 2 ways of doing that. one is bigger crank pulley, the other is smaller supercharger pulley.

Dude, you've got it the round way around.

Think about the gearset behind.

I think Break is not looking for a crank pulley.

 

[Breakpopin]

Aiyo Fab u're confusing me now LOL.

Anyway, was browsing over the net and most of them are selling the pulleys in sets. The pulley for the water pump, alternator, powersteering, fan clutch bla bla bla..

So is it ok if say, the upgrade is to be done in phases? Or its better to do all at one go since the process to dismantle parts over and over again will be a hassle?

 

[Alvin]

Pulley for the Fan clutch should be larger for the after market ones.

 

[gwumpkus]

er...i read this thread twice over in order to understand..hehhe..

but i'm resigned to the fact that nO ONE makes even lightened pulleys for my puny M40b18 engine...sigh..

 

[teejay]

Originally posted by Breakpopin@Mar 15 2006, 07:02 PM
Aiyo Fab u're confusing me now LOL.

Anyway, was browsing over the net and most of them are selling the pulleys in sets. The pulley for the water pump, alternator, powersteering, fan clutch bla bla bla..

So is it ok if say, the upgrade is to be done in phases? Or its better to do all at one go since the process to dismantle parts over and over again will be a hassle?

Vic,
it's always sold in a set because it is a set that goes with it

don't think its appropriate just adding one by one, as you have have more problems then gains

suggest either get a proper set from aftermarket tuners, or not at all
these are somethings you don't wanna mess with by using or thinking you can use whatever is appropriate, cause this is related to your heart of the engine, the crankshaft...... :huh:


*when you joining us for tennis......?

necc,
i wann see and feel that serve of yours.......hahahah!!! :rofl:

 

[Breakpopin]

*when you joining us for tennis......?

Oii Teejay brudder! I'm still in the penang island for work lah!! been here for months already. Will definitely join u all when im back to KL for good.

necc,
i wann see and feel that serve of yours.......hahahah!!! :rofl:

Necc knows how to play tennis wan meh? :rofl: :rofl: hahaha miss playing with him too lol.

Ok thanks all for the info on the pulleys, was really informative!

 

[fabianyee]

Originally posted by The Necessary+Mar 15 2006, 06:47 PM-->QUOTE (The Necessary @ Mar 15 2006, 06:47 PM)

 

[adliz]

Originally posted by teejay@Mar 15 2006, 09:10 AM
don't think its appropriate just adding one by one, as you have have more problems then gains

hi,

not to mention u'd need to change the belt everytime u do so..

i've had a set on my 325 previously.. power gain is similar to when u have the aircon off, a bit more in fact.. as mine underdrive the power steering pump, steering felt a bit heavier, which is a gud thing..

the other underdrive the alternator.. never had any issue with battery running weak.. but be cautious if u are running heavy ICE, then it wudnt be recommended..

 

[Breakpopin]

Originally posted by adliz@Mar 15 2006, 04:42 PM
but be cautious if u are running heavy ICE, then it wudnt be recommended..

Ahhh, so how heavy is heavy? Are there any sort of calculations or judgements that i can refer to?

Power similar or slightly more to having the air cond switched off... now that is tempting

 

[DanPromote]

Originally posted by gwumpkus@Mar 15 2006, 09:16 PM
er...i read this thread twice over in order to understand..hehhe..

but i'm resigned to the fact that nO ONE makes even lightened pulleys for my puny M40b18 engine...sigh..

gwumpkus, actually there are custom made ones but the problem is that a sample needs to be used so far I haven't got time to leave my car for a few days to get it done. Perhaps my next overseas trip I'll remove my crankpully and have it customised. It is made using Anodized Aluminium T7 (the highest grade which is used for Aircraft (lightest and strongest among all grades).

The construction will be 100% like the original but weights 70% less. Hopefully it offers some improvement, I'm also using the same engine as yours

 

[DanPromote]

Originally posted by Breakpopin@Mar 15 2006, 02:18 PM
hi Dan,

mmm so i guess there IS such a problem as the battery havin difficulties charging eh. You did mentioned having a higher fuel Consumption.. why is that?

On a different note, the undersized pulleys on your proton may be too undersized LOL, since its more like a product defect than a purposely manufactured undersized pulley hehe.

Lightened pulleys, anyone here has tried them on BMWs then? Any info on where to get them?

Break, this was on my friend's Proton I just tested it before and after installation. He drove the car for 7 years without knowing the Proton defect

After changing to the standard size but lightweight material, all the problems dissapeared. The acceleration was as good as using the undersized pully but the car does not shut down during corners anymore and there is no more power drain.

 

[Alvin]

Originally posted by DanPromote+Mar 15 2006, 05:54 PM-->QUOTE (DanPromote @ Mar 15 2006, 05:54 PM)

 

[gwumpkus]

hmm..another tempting mod..

as i understand, underdriving the crank pulley is discouraged, cos it affects the harmonic dampening of the crankshaft with potentially disastrous result...of course anecdotal evidence migt point otherwise..

really, i'm happy with a set of ligtened pulleys, if only so that i dun have to change to DIFFERENT length belts....heheh..

Dan: when u get around to it, i'm IN...hahha.... us puny engines need all the power we can get eh?.... ehhheh

Alvin: what kind price are we lookign at indicatively? i mean..there MSUT be more than TWO of us puny enines around....

 

[3er]

Originally posted by Breakpopin@Mar 15 2006, 02:11 PM
Ahhh Thanks for the swift response 3er.

Which brand of pulleys are you using currently? And which pulley does the set contains? Water Pump, aircond, alternator etc etc..

I'm using UUC underdrive pulleys. It includes pulleys for water pump and power steering pump. No alternator pulley so you dont get battery charging issues.


For more details, check out their website. They explain it better than i can.

http://www.uucmotorwerks.com/

 

[Breakpopin]

Thank you all for the information. !Danke danke.

Adliz, you mentioned that you underdrove your pulleys in your previous ride, which brand were you using? I assume that yours is the set that contains 3 pulleys?

 

[DanPromote]

Thanks Alvin, any idea on the price?

The quote I got now is +/- RM350 for small qty anodized aluminium T7. Is that considered cheap or expensive?

 

[Breakpopin]

Originally posted by DanPromote@Mar 16 2006, 03:28 AM
The quote I got now is +/- RM350 for small qty anodized aluminium T7.

wah.. Dan! so fast get quotation already ah?? hehe

RM 350 +/- per pulley ?

 

[adliz]

Originally posted by Breakpopin@Mar 15 2006, 10:27 PM
Thank you all for the information. !Danke danke.

Adliz, you mentioned that you underdrove your pulleys in your previous ride, which brand were you using? I assume that yours is the set that contains 3 pulleys?

emm.. come to think of it, i am now not sure about the alternator pullley.. i cud be water pump.. :dunno: i bought from UUC, same as 3er.. must have mixed-up my memory from what is on sale, and which one i bought 3 yrs ago..!! sorry if that confuses u..

anyhow, i recently got another set from VPD for my s54.. underdrive, and lightened.. for steering pump and water pump.. power delivery is more instantaneous and the engine revs up quicker.. calvin tan got a same set.. u can ask him what he thinks oso..

so far, water temp and oil temp stays similar as before.. same effect on the steering as the UUC..

 

[Breakpopin]

Ah thanks adliz, btw your PM box is full lah. hehe

 

[DanPromote]

Originally posted by Breakpopin+Mar 16 2006, 11:30 AM-->QUOTE (Breakpopin @ Mar 16 2006, 11:30 AM)