(steel ) crankshaft sprocket

[volcano rs]

The Original is made of a very soft and weak metal.
Good for standard and mildly modified applications.
But once its been used and removed, it seems to loose the tightness of the "Fitt" it was meant to have. This is not good for high HP applications.

Some Pictures of the damaged pulley from my car. GT3076 maybe 600Nm torque ..
It bent the valves as well.
Note that when the pulley slipped it scoured and lost some of its metal that ended up on the crank. I had to rub the crank down with some fine sandpaper b4 fitting my own crank pulley.

http://members.audiclubsa.org.za/d/1...rankPulley.jpg

faheemo have got a steel one on yours ?and if so how long have you had it and what do you think ?

[A80Avant]

see,if id spent 200euro for the sprocket id want it to be able to stay in for 2 cambelt changes at least.But who can guarentee something like that?

[volcano rs]

see,if id spent 200euro for the sprocket id want it to be able to stay in for 2 cambelt changes at least.But who can guarentee something like that?

you can wait for me to finish experimenting but that might take about 15 to 20 years to do 2 belt changes .
no car manufacturer spends extra money than they need to to build a car .they are in it to make profit .
if they were to use the best materials the car would last a life time they certainly don't want that .
its like having uprated rods can you gurantee they would never break ? of course not
something else might fail and cause them to break.
remember the gears are under a lot more stress than a crank sprocket and this sprocket is made from gear material.
why don't manufacturers make stainless steel exhausts standard on most cars ? would it last you a life time ? possible .
its all to do with being cost efective .
i certainly believe this would last more then 2 belt changes because its so much better of a material.

[A80Avant]

its not the same comparison you are making with the exhaust or the rods.Both of these have been tested and at least there are ways to test them before they are sold.For the rods to go bad,that would mean that either they are used above their spec,or their spec wasnt as it should to begin with.

In this case though,if there was a machine that the sprocket could be tested on for its hardness and strength i would be more confident in fitting one for more than 2 cambelt changes.In any case to say that you already have it on for 9 months without problems doesnt really say anything cause if i understand correctly it is fatigue that makes these things break as well as engine power.

I had mine changed on the rebuilt over a year now,pushing around 400hp and without issues.Do i need one for safety? and if i do,do i have to still change it every cambelt change?And if i do,will you be around to get another one???

edit: by the way,your item seems good value,and i wouldnt mind changing it every cambelt.However there are sprockets out there that cost 200euro which you cannot be buying and changing every cambelt just for 'a piece of mind!!'!! the cambelt change budget scyrockets then!

if the immence torgue is what causes this damage,would a transisional mapping to the boost help things?

[volcano rs]

if you use standard one and change it everytime you do a belt change you should be ok .
i changed mine because it caused damage to my engine and after talking to the engineer we come to a conclusion that original one wasn't strong enough .its difficult to test it except with time .
thats why i said you can wait for me to do a couple of belt changes before i can prove to you that this is stronger than the original .
or you could buy one of me take it get it tested along with the original one from whoever you want and if you are still not happy i'll refund you your money .i'm not here to rip people off .
i was asked for this so i put a post if anyone else wanted them while i was having them made .
why do people use silicone hoses when standard last for years ? why do people use urethane and aluminium bushes when standard last for years? why didn't s2 come with better brakes from factory ? or exhaust ? you could argue the case for a lots of bits .
end of the day audi or any other manufacturer is not going to use best materials .
and making the pullys from cast must be a very cheap way then to have them made from steel .

[A80Avant]

My query and questions are not to judge why you went along and produced a stronger part,nor am i questioning your motives.Im sorry if it sounded that way.

Changing to silicone hoses is not only done because they tend to last longer than original ones,but also for better engine looks(at least one of the reasons).

We are not questioning why Audi didn put bigger brakes or better exhaust in their cars,and to be honest there is always going to be a better aftermarket item out there.You get 4piston brakes on your car,next thing you know you got a 16piston caliper for your applicaton etc etc...

Urathane and aluminium bushes is an improvement for some that like their car to be tracked or are OK with firm suspension.Not for everyone.

Im only answering to the examples you are giving because the item in this case is not the same as the examples you are giving.The engine will not brake down,or produce a siginificant failure if there is a torn boost hose,or a water hose(especially since all alarms go off from the sensors),if there is a worn bush or a worn shock,and also if the brakes are not as effective after some use.

However as you have noticed yourself,it can be caused with a malfunctioning sprocket,or a fatigued one.

I am very happy that people like you take the time to produce something like this,im only questioning for whom is it designated for?It is usual for everyone to get excited on a forum and buy the best stuff for his beloved car so that it is more mechanically secured especially after mishaps that he or others have faced,but sometimes there are no boundaries to that.
I find myself buying stuff lots of times that turn out that are not really needed,and other times i dont spend money on things i really do need.Hence my questions for this item,because it seems to be very very crucial!!!So with you guys producing all these parts,makes me wonder...am i going to be counting my bent valves anytime soon???Is my car SO modifed to be worried about?

I am probably going to buy it,even if i never had any problem with the OEM part,AND im probably going to be replacing it on every cambelt,even if it is ok not to.However when there are units out there that cost 3 times the one you have(and the OEM one for that matter) i do wonder how are they sooo much better,and at least if they are,should they be changed as well?

Finally a tecnical question.
Why is that tooth removable?Is it like that on the original one as well?


PS: sorry for all the questions,i just want what is best for my car,as always

[Jonas_R]

No the original one used a woodruf key

[A80Avant]

does it have any special way to be fitted since it is made this way?any chances of falling off?is it only secured by squeezing it in?

[Flat on my back]

.

It's made in 2 parts cos it's easier to machine like this...could it fall out...no chance, the slot is curved at one end and the other is the back of the pulley.

Unless you forget to torque the pulley up right and it all falls apart...which is the real reason peeps keep breaking the front sprocket.

[Faheemo]

^^ Agreed - Probably the Most important thing is to Torque that crank bolt correctly, no matter which pulley you use.

[Faheemo]

faheemo have got a steel one on yours ?and if so how long have you had it and what do you think ?

Yes i have installed my hi strenth version, it's been in ther for about 3 months now i think.
Problem was when my original one broke it caused alot of damage, 10 valves plus the valve seats and the flywheel some how came loose
and not to mention the ongoing Clutch issues.
So my car has not been used so often.
I have pulled out the damper pulley to have a look at the crank pulley sprocket, and it looked 100% fine to me.
Happy so far, but i think some people that i have supplied have more torque then me and they are the ones that are proving the product to its limit.

[volcano rs]

Yes i have installed my hi strenth version, it's been in ther for about 3 months now i think.
Problem was when my original one broke it caused alot of damage, 10 valves plus the valve seats and the flywheel some how came loose
and not to mention the ongoing Clutch issues.
So my car has not been used so often.
I have pulled out the damper pulley to have a look at the crank pulley sprocket, and it looked 100% fine to me.
Happy so far, but i think some people that i have supplied have more torque then me and they are the ones that are proving the product to its limit.

good to hear that .the pullys i'm having made are in en8 grade steel and case hardened which is hardening the surface only so not to make them too hard and brittle.

[merlin's S4]

@ volcano rs... Do you have any of these ready yet? Thanks!

[goodall]

i cant see now high power outputs would cause this part to fail, as the power it transmits is relative to engine speed to drive the cams and ancillaries. maybe if the angular acceleration increases enough the power transmitted would increase due to more energy needed to speed parts up quicker being transmitted, but how much faster are you guys getting your engines to rev??

[merlin's S4]

i cant see now high power outputs would cause this part to fail, as the power it transmits is relative to engine speed to drive the cams and ancillaries. maybe if the angular acceleration increases enough the power transmitted would increase due to more energy needed to speed parts up quicker being transmitted, but how much faster are you guys getting your engines to rev??

This isn't really about high power as far as I can tell. The standard sprocket has been known to crack and fail on standard and mildly tuned cars. Using a stronger part such as this makes sense to me if (like me) you're replacing the sprocket anyway!