First for those of you out there looking for easy mods to do yourself look somewhere else. Now for the ? Do you really have to pull the supergharger or could you pull the nose of the charger off, or second but less likley take motor mounts loose and get the motor high enough to use the puller. Next question There are lots of pullers out there in the world and none of them work? I see why most will not work but there are lots of special pullers for lets say power steering pulleys get my drift . The SNAP ON man would not have something that would work? I have not started the job and must say I am a little intimidated by the looks of it. I am ASE certified and have never been intimidated by a job before so any step by step help would be great.

kite-surfer,

An in-depth how-to will follow shortly. It doesn't look like you can do it any other way but pulling the whole supercharger. From what I've been told, it takes a conventional gear puller with the specialized tool (which I just got from jlm - thanks!) and about 40 horsepower to get the pulley off.

Randy

Thanx! I thought it was worth asking even though I pretty much knew the answer. Now, should I wait for the how to or just go 4 it. I dont really need the full in depth step by step just what parts need to come off if there is a site with an overview of how to pull the charger that is what I need. Last where does one get "THE TOOL".

New question. I know with the new pulley it will be at 17000 RPM+ and I know the intake charge is hot but how hot does the pulley and shaft get? Any numbers out there? The reason I ask is in a different post about the install someone says to heat the pulley to 300 degrees and this will allow you to get the new pulley on. Well with the mini mania pulley being aluminium and the shaft being steel what temp the shaft and likewise the pulley get can have the same affect as to loosen the pulley correct? That seems bad an 17000 RPM. Just a thought. Any mini mania testing on this part yet? Any advice or tech support on this issue would be helpfull.

BMP is putting the new pullied SC back on the car as I'm writing this. And, since that's the case, I don't think there's been any testing done yet on it...

what pulley and let us know how it is when you go run it.

"Well with the mini mania pulley being aluminium and the shaft being steel what temp the shaft and likewise the pulley get can have the same affect as to loosen the pulley correct?"

press fits are tricky, since close tolerances have to be held, but with an aluminum/steel combo, since the aluminum expands at about double to triple the rate of steel and assuming the shaft and pulley heat up to block temp, that would be about a 250 degree rise, so you can calculate the mount of interference you would still have and make sure you bore accordingly. You will have to get enough expansion with install pre-heating to still get it on.

as I mentioned, I was more comfortable with the steel/steel fit, especiially give that the aluminum is on the outside and would only get looser. I'll run some numbers and re-post.

Does anybody out there have an infered tool to read temps? If so go drive your car hard for 5-10 min and take a reading on the pulley. O but dont speed ha ha.

some data:

assuming a 300 degree F temp rise, the expansions are:

Aluminum alloy: 13 x 10^-6 in/in/deg F
Steel alloys: 6.5 x 10^-6 in/in/deg F.

using a bore of .75 in:
1. heating the steel hub 300 degrees hotter than the shaft will cause the bore to grow about .0015 (we made the hubs with a .001-.002 interference fit)
2. under normal HOT operating conditions, say 300 degrees (a very conservative temp for the purpose of this calculation), the aluminum pulley would grow twice as much as the steel shaft it was pressed onto, about .0015". so if you machined the aluminum to a .001-.002 interference (sme as the steel example), it might slip if the installed unit could get up to 300 deg F.
3. because of 2.), the aluminum pulley must be made with .002-.003 interference fit, requiring that you heat the pulley to 300 def F so you can press it on. 300 deg F is getting pretty hot for a 6061-T65 aluminum alloy and if you get up to 400 deg F, you start to change the tensile strength.

I prefer the steel hub method, even though it is highly unlikely anything attached to the water cooled block ever gets higher than 250 degrees, except the header and these can easily get into the 1500 degree range. I do have an infrared temp device, so when I get the chance, I will report on the temps.

Thanx Mini mania says they have tested the set up Dyno and track.Plus they say it's on a few daily drivers. No reports of problems. They also say its .003 interference fit so all that said, should be OK. I did something just to get a feel for how hot the pulley gets. I put my hand on the pulley after a short drive it was not so hot that I could not keep my hand there for a few seconds so it was not over 150 degrees. Like I said just to get a feel for how hot it gets. No exact #'s nor was it at peek temp but just a reference. Dont try this at home your results may very bla bla bla. Mini mania says to remove the snout on the charger ( they may have said neck or front half) and then press off/on the pulley others say cut/heat what do I do? Of those of you that have done it with the heat method does it just slip on as long as you hurry?

What is this special tool used, and why don't they sell it to those who purchase the upgraded pulley?
:wink: Aimee

>>some data:
>>
>>assuming a 300 degree F temp rise, the expansions are:
>>
>>Aluminum alloy: 13 x 10^-6 in/in/deg F
>>Steel alloys: 6.5 x 10^-6 in/in/deg F.
>>
>>using a bore of .75 in:
>>1. heating the steel hub 300 degrees hotter than the shaft will cause the bore to grow about .0015 (we made the hubs with a .001-.002 interference fit)
>>2. under normal HOT operating conditions, say 300 degrees (a very conservative temp for the purpose of this calculation), the aluminum pulley would grow twice as much as the steel shaft it was pressed onto, about .0015". so if you machined the aluminum to a .001-.002 interference (sme as the steel example), it might slip if the installed unit could get up to 300 deg F.
>>3. because of 2.), the aluminum pulley must be made with .002-.003 interference fit, requiring that you heat the pulley to 300 def F so you can press it on. 300 deg F is getting pretty hot for a 6061-T65 aluminum alloy and if you get up to 400 deg F, you start to change the tensile strength.
>>
>>I prefer the steel hub method, even though it is highly unlikely anything attached to the water cooled block ever gets higher than 250 degrees, except the header and these can easily get into the 1500 degree range. I do have an infrared temp device, so when I get the chance, I will report on the temps.
>>
WHAT ???? You should change your name to Einstein.

Thank God for Einstein's!!! Just thought I would pull this post back up to the front page.

youbeat me to it...I just repeatd the calcs and was going to re-post!

6061 T6 aluminum starts to get soft when heated to 400 degrees F and loses 30% of its tensile strength when cooled back down. Weldments are a problem and typically need re-heat treating

So non Einstein person like myself a .003 interference fit aluminium pulley heated too what temp as to get it on easy and not hurt the pulley?

So kite-surfer, I guess we're working this topic in two different threads; poor thread management on our part. :wink:

See my answer to your question here:
Pulley install thread

James