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Underdrive pulleys for 9x6 and 9x7

jimk04

Well-known member
Joined
10 Dec 2013
Messages
85
I am having another batch of 4" pulleys made. This will be the 3rd run.
Hopefully back from the cnc shop next week and then to the anodisers.
Maybe 3 weeks until available.

****only suitable for pre .2 cars.....not for later cars with harmonic damper crank pulley******.

Will be 90gbp.

Please log any interest

Thankyou
 
Jim, will these work on a manual 997.2 if so very interested ,also do you have access to the shorter belts. :thumb: :thumb:
 
Hi Phil

I should have added more detail to the initial post. Sorry.

I don't think these are suitable for any 9x7.2 as they changed to a harmonic damper style pulley.

Regards

James
 
4"underpully

Hi Jim

I take it that it would be suitable for my 996.1 tip?

As per Phil too, do you have access to shorter belts?

Regards

John
 
Hi John.

Fine for 996.

I can provide a belt or can give you the details for you to get one from wherever. Readily available.
 
Poor picture I'm afraid.....I am another disgruntled ex photobucketeer.


CjOvwZI.jpg


New ones may not be laser engraved.
 
Interested - Could you comment on if these differ from the RSS items?

Is the diameter the same?

Cheers
 
jimk04 said:
Hi Phil

I should have added more detail to the initial post. Sorry.

I don't think these are suitable for any 9x7.2 as they changed to a harmonic damper style pulley.

Regards

James

Dam, thought that might be the case Jim thanks for the reply though . :thumb:
 
Jim

Would these work on a 996.2 gt3 mezger engine?

Also what do they help with? Reducing resistance and helping to spin engine faster?

Thanks nick
 
Mick.

Sorry no the gt3 is a different fitment.
I'm not sure if the Mezger has a dampener on the pulley as well. ..meaning your'e best leaving it alone.

The principal is you are slowing down the auxiliary consumers such as pas/ac/alternator. ..therefore reducing parasitic losses on the engine.
 
jimk04 said:
The principal is you are slowing down the auxiliary consumers such as pas/ac/alternator. ..therefore reducing parasitic losses on the engine.

I have thought about this mod many times.
Are there are any published figures to show any increase in power?

Adrian
 
I have read reports from some that proclaim a revelation after fitting one of these.
I however don't buy into that. If you are doing a few cheap bolt on upgrades. .....throttle body....sports cats.....light flywheel......I think it all adds up to a sum greater than the parts.....which is what I have done.
But please don't think your car will feel a different animal for fitting an under drive pulley.

Another benefit is you are slowing down the pas pump which is known to overheat on hot track days....admittedly not a problem for most people.

I guess if you are the type of person that can't leave cars alone you will do this regardless. But I understand it isn't for everyone.
 
jimk04 said:
I have read reports from some that proclaim a revelation after fitting one of these.
I however don't buy into that. If you are doing a few cheap bolt on upgrades. .....throttle body....sports cats.....light flywheel......I think it all adds up to a sum greater than the parts.....which is what I have done.
But please don't think your car will feel a different animal for fitting an under drive pulley.

Another benefit is you are slowing down the pas pump which is known to overheat on hot track days....admittedly not a problem for most people.

I guess if you are the type of person that can't leave cars alone you will do this regardless. But I understand it isn't for everyone.
Ok thanks for that.
 

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