eggy790

iTrader: (20)

hi guys

looking at aztek performances crank pulley.. but was wondering if their are any negative effects of these? as i heard some can ruin your engine etc.?

is that referring to the same style of pulley or a different sort?

read mixed stuff on it, so dont want it to mess the car up of i change it. suppose to be a nice lil performance mod aswell as looking loads better.

cheers

http://www.superhids.co.uk/lightweig...i-uk-jdm-.html

prodriverules

iTrader: (52)

No con's all pro's mate,looks the nuts and helps to lift rotational mass off the crank[weight]

eggy790

iTrader: (20)

serious? so what is this underdriven stuff i keep seeing pop here and there when i search crank pulley?

prodriverules

iTrader: (52)

If you brought a cheap one then it may not be machined to well and put the crank out of balance but by **** it would have to be bad when you compare it to the weight of the flywheel clutch assembly bolted to the other end of the crank and that doesn't effect things unless really out of balance.
I have a light weight flywheel and crank pulley and it doesn't half allow the motor to rev more freely

Wagon Gaz

iTrader: (18)

CDF set on mine no probs and as has been said removes a load of roational mass

eggy790

iTrader: (20)

cool anyone on here using one of bobs?

alcazar

iTrader: (2)

Got CDF on mine, underdriven, means they are smaller, so a shorter belt.
The whole lot moves more slowly.

eggy790

iTrader: (20)

ok cool, so as long as i go with a reputable company, they are no cons really? just on badly machines ones.

prodriverules

iTrader: (52)

Shorter would be faster not slower

Wagon Gaz

iTrader: (18)

On my Hawk with the fly by wire throttle, it had a tendancy to want to stall at junctions but not since the pulley swap, bit of a chew getting the old off but otherwise

Cannon Fodder

iTrader: (100)

I have a set of 4 CDF lightweight pulleys on my Spec C, I thought they were all made to standard size?

BTW it's one of the best mods you can do, it really allows the engine revs to pick up quicker.

Wagon Gaz

iTrader: (18)

CDF ones are standard size just lighter, I believe you can get smaller underdriven ones but there are some probs with these.

eggy790

iTrader: (20)

ok i'll stick with the standard size one.. would i need the full set? heard the performance gain is from the crank pulley? azteks is 510 gramms, how much does the cdf one weigh?

Wagon Gaz

iTrader: (18)

If you look on here when CDF had a group buy on these, I am sure Chris gave the weights.

Wagon Gaz

iTrader: (18)

When you take the crank pulley off its a monster its well heavy.

Scooby329

Launching from standstill needs more revs with lightweight crank pulley.

CDF Racing

iTrader: (49)

Guys,
I can't stress enough to keep away from those cheap ones on ebay (not ours of course ) Go for a decent set it's not worth the risk to your engine,.

Buy from a reputable dealer .... there are people that have brought our pulleys and tried coping them,.. beware

Wagon Gaz

iTrader: (18)

It certainly dont seem that way with my setup, with less weight on the end of the crank it revs much freer.

alcazar

iTrader: (2)

I see......so when I drop into the smaller chainwheel, the others go faster?

JohnD

iTrader: (5)

The crank pully will rotate at the same revs irrespective of the diameter - it's bolted to the crankshaft! A smaller crank pully will turn the other pullies slower


JohnD

crazyspeedfreakz

iTrader: (92)

sorry to hijack the thread but just bought a 4 peice pulley kit from chris at cdf yesterday and was hoping if any of you guys could tell me how hard it is going to b to remove the oe pulleys or if im gonna need any specialist tools to remove from a 95 wrx ... thanks

prodriverules

iTrader: (52)

My bad,on the pop last night

Wagon Gaz

iTrader: (18)

The main crank pulley nut is tricky long breaker bar needed and someone to stand on the brakes with the car in a high gear. To be honest for me the alternator one was the worst, ended up cutting it off

crazyspeedfreakz

iTrader: (92)

errmm small problem then as the engine is currently on a engine stand
in the garage ... sounds like im gonna have as much fun takin off the pulleys as i did trying to remove the down pipe from the turbo and that took some time hmmm what to do ?

Scooby329

I need maybe 500-1000rpm more now,when launching car sidestepping clutch.
But i have ej207 and you may have ej257

harvey

iTrader: (48)

Eggy: I have run underdriven lightweight and OE size lightweight (from CDF) and I can tell you there is no measurable difference in your quarter mile time or 0-100 time with running these lightweight pullies but they do look nice and they do take around 2.5kg off the weight of your car. The underdriven will be a miniscule amount less drag on the engine.
When stood still and you blip the throttle the engine will rev that bit quicker because there is less inertia just in the same way that a lightweight flywheel allows the engine to rev freer under no load when the throttle is blipped.
Underdriven crank ie. smaller diameter may require a smaller belt depending how much underdriven they are but don't believe any stories about the alternator not putting out enough power. In any case, the power steering and alternator pulley diameter is often reduced to compensate.
Chris at CDF does OE size and in addition to the lightweight pulleys he can also do the lightweight idler.

harvey

iTrader: (48)

If you are using 500-1000 rpm more when launching and attributing this to lightweight pulleys I suggest you have a rethink. Did you replace the flywheel at the same time?

bigarf

iTrader: (67)

Scooby329

All i know,is that after i replaced crank pulley(1.7kg lighter than stock),car stumps easier,when launching.But i am not pro with these things.Stock flywheel.

I have launched ej257 couple of times..easier with more torque.And car had grippier tires than mine.

harvey

iTrader: (48)

O/E crank 2.54 kg. O/E P.S. .37kg. O/E Alternator .17kg. Total = 3.08kg.
CDF Alloy pulley set 0.720....0.235....0.055kg. Total = 1.01kg. Saving over O/E = 2.07kg.
Under driven aluminium : 0.310...0.150...0.060... Total = 0.520. Saving on O/E = 2.56kg.