Pully size for a M112

kenewagner

kenewagner

Registered User
Anyone know off hand what the stock diameter of the the pully on a stock M112? Or what sizes are available? Thanks

Ken
 
Cobra & Lightning forums

kenewagner said:
Anyone know off hand what the stock diameter of the the pully on a stock M112? Or what sizes are available? Ken
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Check some of the Cobra & Lightning forums. You'll probably get your answer there, faster than you will here.

68COUGAR
 
The Stock 03 Cobra is around 3.7". You can get them all the way down to 2.75. Their quick change setups are about $80 with the hub.
 
cougarsc said:
The Stock 03 Cobra is around 3.7". You can get them all the way down to 2.75. Their quick change setups are about $80 with the hub.
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Thanks I am trying to figure out what size pully to install on this M112 I have in process. I went to some of the forums but there can be a lot of them to read through.

Ken
 
What you want to find first Ken is a pulley that is as close to the stock M90 pulley as you can. Simply measure that diameter, then start your hunt for something as close to that as you can find. That'll get you close to the stock drive ratio of the supercharger. What may be an overdrive pulley for them, may be exactly what you need to keep that supercharger spinning at 12,000 rpm at 6,000 rpm engine speed. Anything smaller than our stock pulley and you'll be OD the supercharger. I can get with you offline on this if you'd like. Just give me a call.
 
007_SuperCoupe said:
What you want to find first Ken is a pulley that is as close to the stock M90 pulley as you can. Simply measure that diameter, then start your hunt for something as close to that as you can find. That'll get you close to the stock drive ratio of the supercharger. What may be an overdrive pulley for them, may be exactly what you need to keep that supercharger spinning at 12,000 rpm at 6,000 rpm engine speed. Anything smaller than our stock pulley and you'll be OD the supercharger. I can get with you offline on this if you'd like. Just give me a call.
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My thoughts Sam are this. According to other threads a stock SC pully for our M90 is 3.135, or 3.275 if it is a 94-95. The M112 moves 22% more air so if I use a stock sized pully it will be like I am overdriving a M90 22%. I would perfer to get, if available, 3.4 or something it that size so maybe I would be only about 15% over a stock M90. Thats my logic and if I am wrong someone can chime in here and get me going in the right direction. In the end it is Feld who will make that decision. And yes I need to get the diameter of the pulley on the blower at the moment but it is nice to know there are pulleys sized to get me where I need to go.

Ken
 
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There are different stock size pullies for M112 usage:

Ford Lightning - 2.93", Cobra - 3.55", Harley Davidson - 3.16"

You can also buy them in 2.7, 2.8, 2.9, 3.0, 3.1, 3.2 and 3.3" diameters.


Bird963
 
bird963 said:
There are different stock size pullies for M112 usage:

Ford Lightning - 2.93", Cobra - 3.55", Harley Davidson - 3.16"

You can also buy them in 2.7, 2.8, 2.9, 3.0, 3.1, 3.2 and 3.3" diameters.


Bird963
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thanks a smorgasbord of choices
 
112 / 90 = 1.4 X 100 = 140%

If you get a pulley that is 140% the size of the M90 pulley, the M112 will flow the same amount of air as an M90 at the same speed.

68COUGAR
 
+22% & Cooler output temp

kenewagner said:
The M112 moves 22% more air so if I use a stock sized pully it will be like I am overdriving a M90 22%. Ken
Click to expand...
Yes like over driving 22%, BUT at a lower output temp. because the M112 doesn't have to work as hard or spin as fast, to make the same boost as the M90.

68COUGAR
 
68COUGAR said:
If you get a pulley that is 140% the size of the M90 pulley, the M112 will flow the same amount of air as an M90 at the same speed.

68COUGAR
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Never was very good at math. I am figuring on the cobra pulley at 3.55. That should still be a lot more than a stock M90 and hopefully not blow the heads off the block. 140% over the stock 3.135 is 4.389 on my calculator. 3.55 seem to be the largest I can buy at this time. Thanks for all the input guys

Ken
 
68COUGAR said:
If you get a pulley that is 140% the size of the M90 pulley, the M112 will flow the same amount of air as an M90 at the same speed.

68COUGAR
Click to expand...

112/90 = 1.4x100 = 140%

I don't follow your math. Can you explain it? I would think 124%
 
Are the Cobra, Lightning, and Jaguar M112 pullies the same, because if they were interchangable I may have an easier time finding pullies. ;)
 
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He was dividing the cubic inch displacement difference between the two blowers.

112 cui as opposed to 90 cui which somehow game him a difference of 1.4, hence the 140%.
 
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