Blower Thermodynamics

[ACCEPTENCE]

[/qb][/QUOTE]I have 2 11.5 gallon side tanks and 1 5.5 gallon "T" tank. It is a lake boat. The injection was designed for alcohol. I starve it for fuel on the ramp after pulling it out of the water. I drain the system from the "T" tank and WD-40 the pump and barrel valve after I use it. I have a Holley pump to keep the "T" tank full. I drain and WD-40 it also after each use. It is not designed for alcohol and has lasted 2 seasons so far. [/QB][/QUOTE]
I got a question?????

[ACCEPTENCE]

Fiat48:
Infomaniac: Try a product called Pro Blend Alcohol lube. 1 can to 55 gallons. It works so well, that I only WD40 the system when the engine sits 3 months or more. I don't even drain the tank between races. I discovered how good it was by total accident. We left a race with the alcohol still in the system, was going to WD40 the system when we got home. We had an engine failure in our tow vehicle in the middle of nowhere. In all the confusion, the alcohol got left in for 6 weeks before we remembered. System was clean, no damage, no corrosion. wink Dear Sir, Where to get this wonder stuff??? Thanks, Greg

[Unchained]

Whipple Charged:
This really depends on blower design, blower size, etc, but in an ideal situation, this would answer your question in rough form:
screw:75
roots:225
centrifugal90
Thanks,Dustin [/QB]Wow, What a range of drive HP's required . I had no idea the roots blower could take that much HP to drive it.
Thanks, Mark

[78Eliminator]

Unchained:
Whipple Charged:
This really depends on blower design, blower size, etc, but in an ideal situation, this would answer your question in rough form:
screw:75
roots:225
centrifugal90
Thanks,Dustin Wow, What a range of drive HP's required . I had no idea the roots blower could take that much HP to drive it.
Thanks, Mark [/QB]I find this hard to believe. You're saying if an engine doesn't pump out 225 HP, it won't spin a roots blower? I can spin the thing with my hand. I must be a lot stronger than I think...

[Liberator TJ1984]

Justin there is a relative curve it takes..boost# is a big factor I read somewhere if you run a roots blower under 15# it is effecient once you start getting over that is when it starts to "eat up" some of the power it is actually making say instead of producing 200hp you are getting 150hp taking 50HP just to make desired boost...wish someone in here could come up with a grap to illustrate this ??? a blower has alot more mass to move than say a belt driven turbo and therefore robs more HP.
[ January 21, 2003, 10:37 AM: Message edited by: Liberator TJ1984 ]

[Infomaniac]

I honestly doubt those numbers are all under the same engine operating conditions.
For example put the screw blower on a specific engine - test it - put the roots blower on the same engine etc.
I know a roots blower can take 220 HP to turn but the HP required to turn the others in the same conditions?
If I am wrong I will gladly admit so and shut up.

[Fiat48]

ACCEPTENCE:
Fiat48:
Infomaniac: Try a product called Pro Blend Alcohol lube. 1 can to 55 gallons. It works so well, that I only WD40 the system when the engine sits 3 months or more. I don't even drain the tank between races. I discovered how good it was by total accident. We left a race with the alcohol still in the system, was going to WD40 the system when we got home. We had an engine failure in our tow vehicle in the middle of nowhere. In all the confusion, the alcohol got left in for 6 weeks before we remembered. System was clean, no damage, no corrosion. wink Dear Sir, Where to get this wonder stuff??? Thanks, Greg Info and can buy here http://www.pro-blend.com/tech8400.html

[Whipple Charged]

The question was, 500ci engine, 15lbs. of boost, but under ideal conditions meaning properly sized compressors, proper amount of airflow on the inlet. Turning a supercharger by hand gives you little information about 15lbs. of boost. A roots should never be run at a level above 12lbs., typically speaking, you will not gain anymore HP with anymore than 12. You will net more torque, but not HP. At 40lbs, theres over a 300hp differential between the properly sized screw vs. roots on a 500ci engine. That would be comparing a high helix/teflon stripped roots. It's been proven many, many times.
Dustin

[Blown 472]

Whipple Charged:
The question was, 500ci engine, 15lbs. of boost, but under ideal conditions meaning properly sized compressors, proper amount of airflow on the inlet. Turning a supercharger by hand gives you little information about 15lbs. of boost. A roots should never be run at a level above 12lbs., typically speaking, you will not gain anymore HP with anymore than 12. You will net more torque, but not HP. At 40lbs, theres over a 300hp differential between the properly sized screw vs. roots on a 500ci engine. That would be comparing a high helix/teflon stripped roots. It's been proven many, many times.
Dustin Dont the fuel cars run roots at 40 to 50 psi??

[Infomaniac]

They used to. I think they are screw blowers now.