6-71 vs 8-71 blower

[Silver R/T]

Which blower would be best for street driven 440 and occasional track. 8-71 would provide more power but would be slower turning? What are pros/cons of both

[moparguy01]

well the 8-71 is a bigger number so it must be better.....

[firefighter3931]

Bigger blower produces less heat. Either way you'll need to upgrade the cooling system to accomodate the forced induction package. 

Ron

[Blown70]

Which blower would be best for street driven 440 and occasional track. 8-71 would provide more power but would be slower turning? What are pros/cons of both

Well you could look at a couple of options.  a 6/71 will do what you need.  Esp for a largely street driven car with the cubes you are speaking.  You could also look at a BIG bore 6/71 which will move more air.

Can you do an 8/71 sure... But for that application it would not be necessary. 

I agree however that it would not have to be turned as much and thus a cooler charge. Less heat.  And heck they are an inch longer in the case...  I guess you could buy the 8/71 so you can underdrive it rather than 1/1 it on the street.

Tom

[Chryco Psycho]

slower speed to move the same amouint of air is a benefit for sure & it gives you more potential later on as well

[Ghoste]

Are you just curious Silver or is this something you really intend to install?

[Silver R/T]

I do intend to supercharge my 440 but havent decided yet which one to get yet. centrifugal or roots,

centrifugal will make more hp and would still make power in higher rpm range than roots
fits under hood so I dont have to worry about weather or asshole cop pulling me over (sleeper look)

Roots.,... well it just looks simply BAD ASS on 2nd gen
Has power in low rpm range and faster

[Ghoste]

Personally I like the sleeper aspect of the underhood, althought the whine kind of negates the sleeper part.

[Blown70]

centrifugal will make more hp and would still make power in higher rpm range than roots

Then you do not know how to tune a ROOTS....

[Chryco Psycho]

 
the Roots will not lay down at top end over a centrifugal , the roots will make more power anywhere & is more reponsive

[Blown70]

the Roots will not lay down at top end over a centrifugal , the roots will make more power anywhere & is more reponsive

This true with high helix and some of the other designs by Kobelco?  And define the tip end here? 

Tom

[Chryco Psycho]

everything has a top end , the reason for a 14 71 blower is to slow down the rotor speed to keep it from going overspeed & developing more turbulence then pressure & of course as you increase the helix the hp to turn the blower decreases freeing up more output power

[Black and Blown]

Nobody mentioned this, so I'll stick my neck out here.  I have a 6-71, and surely I'd take an 8-71 if it showed up on the doorstep.  However, there is one nice thing about the smaller blower... you can adjust it more subtley than an 8-71.  Changing a pulley by one tooth will make a smaller increase/decrease in boost on a 6-71 vs. an 8-71.  From spring to summer to fall I change pulleys 3 times because of air density.  And I just run it on the street.  When it's super hot out I can push more boost without detonation.  Hope that makes sense.