Roots type Blower

**scott5** · 12-21-2007, 07:14 AM

Well we just sold an 08 California Special last night and of course i am the one that has to be responsible for it so i was just pulling it in when the customer came back and looked at the car for the first time and we started talking and he told me that he wanted to put a Roots blower on it, i think he has his mind set on a whipple, but not sure thats what he said, he was going ot have the dealership do it, bu ti mentioned that i knew some guys who own mustang shops and he got interested and i am going to see him today so i was wondering if anyone of you guys would like me to give him your name and numbers? I check this through out the day so Just let me know by 4.. Thanks guys

**Rodeheaver's** · 12-21-2007, 01:07 PM

That is no problem for my shop have em call me, 724-737-5088, thanks

**scott5** · 12-21-2007, 01:29 PM

Originally Posted by Rodeheaver's

That is no problem for my shop have em call me, 724-737-5088, thanks

Ok.. cool.. i will let him know..

**Wolfpack Speed** · 12-21-2007, 06:01 PM

funny you mentioned this, i was just having a beer with one of my customers last night...california gt coupe. he's itching to do the same thing!!! don't ever hesitate to give out my name and number, of course we want to do the work. we can also handle the tuning for him so his car is running right when it leaves the shop!

thanks

mike

**low12lightning** · 12-21-2007, 06:52 PM

Whipple and Kenne Bell are both twin screw blowers, not roots. Roots are Eaton, and GM style blowers.

**scott5** · 12-21-2007, 07:43 PM

my fault... i thought that the twin screw a type of roots blower.. my fault..

**scott5** · 12-21-2007, 07:45 PM

Originally Posted by Wolfpack Speed

funny you mentioned this, i was just having a beer with one of my customers last night...california gt coupe. he's itching to do the same thing!!! don't ever hesitate to give out my name and number, of course we want to do the work. we can also handle the tuning for him so his car is running right when it leaves the shop!

thanks

mike

I gave him your card that i got off ya up at the party

**Wolfpack Speed** · 12-21-2007, 09:50 PM

Originally Posted by scott5

I gave him your card that i got off ya up at the party

thanks man, i really appreciate that and it was good to meet you at the party

**SonofaBish** · 12-21-2007, 10:10 PM

Originally Posted by scott5

my fault... i thought that the twin screw a type of roots blower.. my fault..

they're both positive displacement blowers, but work a little bit differently...

**scott5** · 12-21-2007, 10:48 PM

i thought that the blowers that replaced the intake or the upper intake was considered roots?

**SonofaBish** · 12-21-2007, 10:57 PM

Originally Posted by scott5

i thought that the blowers that replaced the intake or the upper intake was considered roots?

nahh, not necessarily... its called a roots b/c the original guys that came up with the idea were brothers with the last name Roots...

The difference b/w the two are how they compress air... twin screws compress the air inside the housing of the blower, where the pockets between the lobes decrease in size.... roots blowers use the rotors to rapidly pull air into the intake manifold, therefore compressing it there....

So, they both replace the intake, but work differently....
I did a lot of looking into this a long time ago, and found www.howstuffworks.com to be a great resource on how different superchargers and turbos work...

**low12lightning** · 12-27-2007, 11:25 AM

Bish is kinda right, twin screws compress between the rotors. Roots compress between the rotors and the case. Because of this, the roots stye make alot more heat. Since the blower is the upper manifold, it has to compress the air in the blower, before it hits the lower intake or it would not be considered a "positive displacment blower" it would be a centrifigual blower. (I think that is how you spell that.)

**One Sweet Day** · 12-27-2007, 08:38 PM

Originally Posted by low12lightning

Bish is kinda right, twin screws compress between the rotors. Roots compress between the rotors and the case. Because of this, the roots stye make alot more heat. Since the blower is the upper manifold, it has to compress the air in the blower, before it hits the lower intake or it would not be considered a "positive displacment blower" it would be a centrifigual blower. (I think that is how you spell that.)

centrifugal blower

**SVTGT** · 12-28-2007, 10:35 PM

If we wanna talk tech here it goes. all superchargers fall under 2 catagorys, fixed displasment and non-fixed. fixed displacment charger like the Roots and twin-screw pump a specific amount of air per revolution. non fixed like centrifugal push an unpecified amount of air along, much like a fan blade, so air can flow backward if condition warrant.. o then we get to compression. the twin screw and centrifugal compress air inside the screw between the rotors and the centri, in the housing. if anyone want more info ide recomend checkin out the book Supercharged by Corky Bell alot of good info and history.

**low12lightning** · 12-29-2007, 12:25 AM

Originally Posted by SVTGT

If we wanna talk tech here it goes. all superchargers fall under 2 catagorys, fixed displasment and non-fixed. fixed displacment charger like the Roots and twin-screw pump a specific amount of air per revolution. non fixed like centrifugal push an unpecified amount of air along, much like a fan blade, so air can flow backward if condition warrant.. o then we get to compression. the twin screw and centrifugal compress air inside the screw between the rotors and the centri, in the housing. if anyone want more info ide recomend checkin out the book Supercharged by Corky Bell alot of good info and history.

The centri??? I'm not sure what you mean. twin screws compress between both screws. I've heard of positive displacement, i guess fixed would be the same thing.

**u1arunit** · 12-29-2007, 12:33 AM

To me the Centri would be positive as well since it turns with the crank rpms just like the roots/twins. The only way I see other wise if there is an air leak in the intake tract between the blower and engine. Recirculating bypass valve notwithstanding or course. What do I know though? I didn't write a book. lol

**low12lightning** · 12-29-2007, 01:09 AM

Centrifugal compress more air at higher rpm, becuase they have more power to "squeeze" the air. Roots and Twin screws grab a predetermined amount of air each revolution, and force it through to the blower outlet, not letting it "backflow" as a centrifugal would when it is not spinning fast enough to overcome the restriction. Roots, and twin screws make more power at low to mid boost levels becuase they are inefficent at high boost. Centirfugal blowers are made to spin faster making most power at high boost levels.

**u1arunit** · 12-29-2007, 01:18 AM

Boy this brings a tear to my eye. We actually have a nice tech thread going here on SCS!

**SonofaBish** · 12-29-2007, 01:20 AM

this seems to be a pretty good, quick rundown if anyone wants to know... rather than reitterating what it says, i'll just post a link...

http://en.wikipedia.org/wiki/Supercharger

i love topics liek this... learn more and more just by looking for answers to others questions

**SonofaBish** · 12-29-2007, 01:22 AM

it seems as if TJ might be on to something as to why a centrifugal blower isnt considered positive displacement... positive displacement blowers push a predetermined amount of air per revolution, no matter what speed....

Centrifugals are like belt driven turbos, they rely on the speed of the crank to be able to compress the air and feed the engine