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3 tower vs 4 tower on a M1000 turbo?

J

JSCC

Well-known member
Nov 26, 2004
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Huntsville,Ut
A three tower will have better grab at engagement and lower rpm. Atleast in my opinion.
However, like Shain stated, you will need more weight than the three tower can give you once you hit a certain hp level. I have ran up to 16lbs with my three tower. Takes a different setup to make it work, and the rpms are still too high, but it is doable.
 

RACINSTATION

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Jan 14, 2003
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Idaho
The 4 tower contained all different parts from the 3 tower which added to production costs and I believe it was built by Comet, which shut down at that time.
 

spoon

Wrenching to ride is half the fun
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Dec 2, 2007
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I found the 4 tower more reliable, I have 2 turbo 1000s and 1 had a 3T and the other a 4T. The 4T has over 3000 miles and still is in good shape, my 3T had only 800 miles and I was having belt issues, inner sheave bushing was very loose and rollers were all very loose. Checked a few other 3T on other M1 stockers that went through my shop and inner bushing very loose on those as well. I have acquired a few spare 4 towers and I will stick with them. BTW the extras are not for sale.
 
W
Sep 23, 2008
188
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43
Morgan, Utah
Spoon, When you run the 4 tower do you shim the rear clutch at all? I run both a 3 and 4 tower and have a few 4 towers stashed away as well. I was wondering if there was a difference in alignment at all.

And in theroy "the three tower engages better" is not what the engineers will tell you.... They say the 4 tower engages better and holds onto the belt tighter because you have 4 points of engagement instead of three. Which means more points of pressure on the belt at any given time.... But I have seen a lot of 4 towers break the spider.

I really like the three tower a lot....

Does anyone run a 4 tower with offset weights? Like 2 80grams and 2 68grams? Just wondering....
 

BigAir

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Nov 26, 2007
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Spoon, what are you running for spiders in your 4 towers? I assume it isn't the stock spider since Cat has problems with them breaking.
 
S

SnowDevil

Well-known member
Nov 26, 2007
390
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Portland
Ran the 3 and 4 tower at ten pounds and up the 4 always outperformed the 3 on the the top end. The 3 seemed to come out of the fist fifty feet better. On the 4 tower I would stagger weights around 84 74 and would adjust the smaller ones.
 

spoon

Wrenching to ride is half the fun
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Dec 2, 2007
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Kootenays, BC
My 4 towers are all stock spider and no issues. Run anywhere from 72-79 gram weights in them depending on my target boost that ride. Easier to swap clutches than to change weights. I won't run offset weights. Using SLP blu/pnk or Blu/gry springs. Shim the secondary using stock offset tool and little to no belt issues.
 
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