Roots screw type supercharger
- Thread starter 40th Sonic GT
- Start date
kirkyg
Founding Member
Roots create boost off idle like the twin screw does. However the roots style has a lower efficiency rate as compared to both twin screw and centrifugal. Basically the roots creates more heat which means you cant run as much boost and there is less power / pound of boost. The twin screw however creates boost off idle and has a better efficiency meaning its going to put out alot of power. You get what you pay for though. An intercooled Kenne Bell kit will cost you 4900 bucks but most think its worth it 
Both roots and twin screw will create more torque down low.
kirkyg
Both roots and twin screw will create more torque down low.
kirkyg
Roots/Twin Screw superchargers are "positive displacement" blowers, and make X amount of PSI (full boost) by a certain RPM. They build boost fast, and at a low rpm, so they give more tq then centrifugel blowers, and can carry that "full boost" that hits low all the way to redline, or close to it, depending on the efficiency of the blower.
Centrifugel superchargers boost building is RPM dependant. Building them with more aggressive internals can spool the boost faster, but doesn't change their overall characteristics. They generally produce no power below 2000rpm, unless you are running an insanely small pulley. They are, however, much more efficient than your typical roots blower, meaning they love making lots of PSI, where as a positive displacement blower heats up real fast and can only make soo much boost. Centrifugel blowers reign supreme over all other superchargers on the dyno as far as peak HP is concerned. These types of blowers are ideal for the track, because of the smooth power delivery and the fact that they keep on building power as the rpms increase.
I've had both types of blowers on my old Maxima, both a Vortech SQ trim V1 blower @10psi, and an Eaton M90 roots @8psi. The Eaton had more punch down low, but ran out of steam around 5500rpm, where the Vortech shined.
Anyways, theres my .02.
Centrifugel superchargers boost building is RPM dependant. Building them with more aggressive internals can spool the boost faster, but doesn't change their overall characteristics. They generally produce no power below 2000rpm, unless you are running an insanely small pulley. They are, however, much more efficient than your typical roots blower, meaning they love making lots of PSI, where as a positive displacement blower heats up real fast and can only make soo much boost. Centrifugel blowers reign supreme over all other superchargers on the dyno as far as peak HP is concerned. These types of blowers are ideal for the track, because of the smooth power delivery and the fact that they keep on building power as the rpms increase.
I've had both types of blowers on my old Maxima, both a Vortech SQ trim V1 blower @10psi, and an Eaton M90 roots @8psi. The Eaton had more punch down low, but ran out of steam around 5500rpm, where the Vortech shined.
Anyways, theres my .02.
Saleen claims 100hp at the flywheel. with a properly tuned Vortech S trim, you can gain over 100rwhp. and the S trim is the smallest blower being installed on the 4.6L. a Paxton NOVI 2000 or Vortech JT will produce more. i don't know what the KB is putting out, so i can't really compare it to anything.
Defleshed
Satanic Mechanic
kirkyg
Founding Member
Craig Mack said:
misconception #1...twin screw and roots are the same type supercharger & twin screw is positive displacement. NEITHER is true. Twin screw is the best of both worlds.
kirkyg
White360RFnSwee
Founding Member
Bottom Line.. Twin Screw doesnt give as much upper RPM power as the Centi.. Centi make boost all the way to 8000 rpms with these carss
stallion98gt
New Member
kirkyg
Founding Member
White360RFnSwee said:
8000 rpms??? lmao youd have to put 10k in the motor to get it to spin that fast. Your a moron man. I could bring up plenty of private mesages between you and i about how the twin screw was better in many ways and now your just doing a 180 and saying the twin screwi s **** and the centri is god sent. Your just full of it.
kirkyg
kirkyg said:
No, not to be a dick but they are actually different than each other, the roots uses fan type things to push air in and creates a lot of heat, but twin screws use "screws" and they are intercooled. If I would go with any I would go with a twin screw myself. The Saleen blower is a Whipple supercharger which is only using about 8 psi. If you were to get a higher psi verison, you'd make as much or more power than a the other superchager types, plus you'd have the power instantly.
kirkyg
Founding Member
jordan, reread what i was saying...i said specifically that THEY ARE NOT THE SAME LOL. Again twin screw is better, and you get what you pay for.
kirkyg
kirkyg
Jordan_J said:
Read more closely....he is saying what I said is a misconception....so he is refuting what I said. So you should save yourself the embarrassement and delete your above post.
My bad for grouping them together in the positive displacement catagory, but they both deliver their power in a similer fashion. (not mechanically)
I did not have it dyno tuned. This is KB tune. My first run the dyno I saw 373 rwhp becuase there was in issue with my speed (shaft) limit. I reported the results back to KB and they sent ma new chip to fix the problem. With the new chip I'm at 398 rwhp on the power mode and 418 on the shootout mode. I have the switch chip by the way.drexebo said:
kirkyg
Founding Member
I type pretty fast but i tend to make errors sometimes.
00s281sc368
New Member
Mine made 433rwhp @9psi on 91 pump gas with the standard KB chip. I haven't seen yet a Vortech or Novi that gives as much HP and torque for the same boost.
The KB twin-screw is the best for low end power and high end power as well.
The KB twin-screw is the best for low end power and high end power as well.
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