CJ Thunder

What is it in relation to the engine? is it 1:1? Quick question then you may delete.

Thanks.

D4u2s0t

not sure what the formula is but the super spins much faster than the engine

CJ Thunder

At say 1,000 RPMs of the engine its 10,000 RPMs of the super? I know its different based on the pulley size as well. But just any close number would help.

Also whats the RPMs of say a comparable, boost wise or powerwise turbocharger.

ItalianJoe1

iTrader: (10)

Crank pulley is 6.0", so if you have a 3" S/C pulley, you are at 2:1
Other ratios would depend on pulley size

Turbos cant compare, at full spool, a turbo can reach near 100,000 rpms or more, depending on the turbo in question. Even Centrifical blowers spin at 50-80,000 rpms

The twinscrew blowers have differential drive, that is one rotor spins faster than the other at a 3:5 ratio. I heard it quoted somewhere as 21,000:35,000 at full speed, so I guess thats a good idea of where they land as far as RPMs are concerned. You could spin the M62 over 20,000 rpms with upgraded bearings.

D4u2s0t

curious as to why you want to know this.

CJ Thunder

Great, one more: What is RPMs of engine at peak HP & TQ, and boost?


An idea I have...don't want to say more right now hahaha...

D4u2s0t

as long as you're not trying to spin the engine as fast as the super

ItalianJoe1

iTrader: (10)

From my stock dyno sheets, which are all I have on this computer, power is still going up at 6500 rpms and torque was pretty much a table from 3000-5000, so figure on 4500 or so as peak TQ.

Please do elaborate as to why you want to know this. I love hearing about new ideas and I may be able to help further given more relevent info.

CJ Thunder

Well if I say something and its able to make money I don't want to blow that on a public forum. Thanks for the help though.

Sharkey

iTrader: (1)

[QUOTE=ItalianJoe1;1737997]

The twinscrew blowers have differential drive, that is one rotor spins faster than the other at a 3:5 ratio. I heard it quoted somewhere as 21,000:35,000 at full speed, so I guess thats a good idea of where they land as far as RPMs are concernedQUOTE]


ive worked with screw blowers lots with top alcohol dragsters and funny cars, (PSI blowers and whipple chargers) and i can say thats not the case. both gears in the drive are the same size, and timing of the rotors is critical. furthermore, if the rotors turned at different speeds, the blower would bind up.

ItalianJoe1

iTrader: (10)

PM me then. I'd love to help someone tap the potential of the blower.

[QUOTE=Sharkey;1738132]I know I saw it, can't remember where, i'll have to find it again. The TS one I saw anyway had one rotor with 3 lobes and one with 5, that was the reason for the different speeds. I thought it was on a lysholm, but I could be mistake. I'll try to find a reference later when I have time.

http://www.kennebell.net/techinfo/ge...romcatalog.pdf

go there, every one they show is different, either 5:6 or 4:5 lobes. There is a male/female arrangement that is completely different from the roots setup. Like you said, different speeds would destroy an eaton, but if there are different mesh patters on the rotors they would have to be driven at different speeds. Thats the whole deal with the compression IN the blower instead of after the blower.

Sharkey

iTrader: (1)

double post

ItalianJoe1

iTrader: (10)

http://www.whipplesuperchargers.com/....asp?PageID=67

Ok, it was a Whipple that I originally saw.

HunterKiller89

iTrader: (1)

based off of this info, its a 4:1. You gotta remember, its Pi(3)˛:Pi(6)˛,

Sharkey

iTrader: (1)

when calculating the drive ratio you go off the diameter of the pulley, not the circumfrence.

ItalianJoe1

iTrader: (10)

Its ok, his forumla was wrong anyway its PI(r*r), pi x radius squared. He used diameter.

HunterKiller89

iTrader: (1)

oops...ur right, i did diameter...but you definitely go by circumfrence and not diameter. try it for yourself...this is why you can also compare # of teeth on one gear to another, because the teeth are along the circumfrence of the gears 9assuming the teeth have the same spacing on both gears)

Sharkey

iTrader: (1)

going by that formula

crank pulley- PI(3x3)=28.26
blower pulley (3")- PI(1.5x1.5)=7.065

28.26/7.065=4.0

and it doesnt matter in this case if i do PI(d*d), it still came out to 4

thats 4:1, meaning when the engine is at 7000rpm, the blower is spinning 28,000rpm. now iirc, the max rpm on an m62 is around 18,000rpm, meaning with a 4:1 ratio the blower is maxed out at 4500rpm.

its done by the diameter. go out to your car, jack it up and turn the crank pulley 1 full rotation and see how many turns the blower pulley turns. garuntee, itll be around a 2:1 ratio depending on what blower pulley you have.

ItalianJoe1

iTrader: (10)

Thats the only way to be sure. I can't guarantee that the crank pulley is exactly 6.000" either, it may be off a little. Can't always account for the actual diameter at where the belt sits.

HunterKiller89

iTrader: (1)

i caught my mistake...its still based off of circumference...so im right in that area...however, its also still a 2:1 ratio, so you are right as well...i was using the formula for the area of a circle instead of a circumference. My mistake