big_ben

I in no way personally attacked anyone else. I didn't use anyone's name. I just defended the person that started this thread when others were bashing him just b/c he asked a question about something he didn't know about. Yes, I know this electric thing was a piece of crap, but I didn't make fun of him for not knowing that. Correct me if I'm wrong but didn't psuedorealityx say to me "If you understood the simple math behind how an engine works". So I can't defend myself. Man there sure are some egotistical dictators on this board. And no, a sixth semester studend isn't a junior. Two semesters per year, one summer session. If a person goes all year long for two years, thats 6 semesters, hence early to late sophmore. Do you expect me to sit back like a bitch and take it when someone directly insults me? And I will say this again, I didn't start this, I just defended the person you all were bashing just b/c he thought this might work. I never said that it would work, but you people started putting words in my mouth and started bashing me. And the last thing, I'm sure some turbos or super chargers spin that fast, but as a aerospace student, the most important factor in getting more air through the turbo isn't the rpm, it is the design of the turbine blades. I'm sure psuedorealityx and myself can at least agree on that. But again I only defended the guy that people were bashing to begin with. FOR FUTURE NOTICE, IF SOMEONE IS ASKING A QUESTION ABOUT SOMETHING, IT'S PROBABLY B/C THEY DON'T KNOW ANYTHING ABOUT THE SUBJECT. That is just about all I have to say to all of you. Thank you for your time.

Shawn

I still agree with GNO's calculations but think whatever you want.

Well, now that that's over. I have a question about turbos and stuff.

What is the difference between a roots-type blower and a centrifugal turbo. I've seen other posts comparing the performance of these but they never mentioned the key differences. I think I am familiar with the centrifugal turbo, the roots-type is new to me though.

neuromancer

While I am sure that you had good intentions with your defense, please don't do it again. I am perfectly able to defend myself.

In any event I don't think that I needed to be defended. I wasn't attacked, sure some of the comments were a little on the smart assed side but no one called my mother a ***** or anything like that.

Thanks to those that added information to this thread.

And I did attach a hair dryer (no leaf blower handy) to my intake to see what it would be like (low heat setting of course). I swear I got at least a 20hp gain! Dyno to follow.

-Jay

big_ben

My bad. I just see this happen a lot throughout these sites and it pisses me off. I think this whole thing went a little too far though, everyone started insulting everyone else. So if any one out there cares,....I'm sorry if I have insulted or pissed any of you off. But by the way, I hooked a bellow up to my intake and got a bunch of fat kids to jump up an down on it. It got a little ugly when I got up to about 80mph though. One of the little fat girls started crying and screaming to slow down but I just told her to shut the hell up and keep jumping.

neuromancer

Well I now get the smell of burning hair when I drive my car. But that is of little consiquence considering the power I get from it!



-Jay

big_ben

I don't know if you are talking to me, but one of the little fat girls dropped her popsicle in my fuse box and blew a few relays.

GNO

Superchargers are simply air pumps. Turbochargers are turbine driven superchargers, usually centrifugal. Pumps usually can fall into two categories - Positive Displacement and non-Positive Displacement.

Positive displacement pumps take fluid from one volume and transfer the fluid into another volume. The volumetric flowrate is directly proportionate to the pump speed.

Non-Positive displacement pumps still transfer the fluid but the volumetric flowrate is not directly proportionate to the pump speed.

Roots-type blowers are the most common positive displacement pump used in the automotive industry. They can consist of screws, lobes, or helixs, which mesh together to transfer air from a near infinite volume (atmosphere) to a fixed volume (intake manifold). Since the the air is transferred from a large volume to a small volume it becomes compressed. Another type of positive displacement pump is the piston-type, like what is used in air compressors and bicycle pumps.

Centrifugal pumps are like a fan in a casing. The casing is disigned so that fluid enters near the center and is forced to the outer edge from the spinning motion in the vanes. Compression,for gases - like air, occurs as the fluid is forced to the outer edge.

I'll try to get into more detail are it comes to mind, but I hope this helps for now.

njaremka

good question.

a root blower is a positive displacement pump, which means that for every rotation the rotors make, they displace a certain amount of air (or whatever). a centrifugal turbo is considered a dynamic pump. it moves air based on it's speed and provides energy to the substance that surrounds it. as i am a centrifugal pump engineer, i know more about these things than a lot of people do, but i do not know that much specifically about turbos (and i will admit that). by nature, centrifugal pumps (or turbos) are more efficient than are positive displacement pumps (or superchargers). however, thare are different variations of each that would be exceptions to that rule.

on a side note, my company sells centrifugal pumps that are up to 85% efficient, where as turbos can be up to 92% efficient(?)

Shawn

That sounds about right. I was watching Junkyard Wars once and they had to make a water pump to put out a fire. One team made a centrifugal pump where the water came into the middle of the fan, and got shot out a valve on the side of the casing. It was hella powerful. The fan was powered by a car engine. The other teams pump must have been a positive displacement pump. They used one engine to drive another engines cylanders up and down. They used those cylanders to pump water. That means X amount of displacement per cycle which is what you guys said. Hmm, the answer was somewhat under my nose but I never put it together.

neuromancer

Everything you need to know about life can be learned from Junkyard Wars. It's true, I read that on the internet.

-Jay

MAD323

does the junkyard wars have a website ?

njaremka

what else:

http://www.junkyard-wars.com/