Centrifugal vs. Roots
08-02-2007, 09:31 PM
#1
2nd Gear Member
Thread Starter
Join Date: Sep 2006
Location:
Posts: 183
Centrifugal vs. Roots
I want to know the numbers. I know the roots has slightly lower hp numbers but better torque through the rpms. But I want to know, the acceleration numbers. I want to know how fast a 400hp roots blower is and how fast a 400hp centrifugal is. Quarter mile times or 0-60 times. I don't care. I want to know which is right for me. I'm hoping that 400 ish RWHP is going to be enough for me. But I do road racing and I want to know, which choice is right for me.
08-02-2007, 10:00 PM
#2
3rd Gear Member
Join Date: Aug 2006
Location: CT
Posts: 747
RE: Centrifugal vs. Roots
both can easily make 400rwhp at around 8psi with a good tune and a few boltons.
what doesnt make sense is you're asking about 1/4 mile times then mention that you're into road racing.
if you were into road racing i would imagine that NO blower would be your best option and to just build one hell of an engine that can handle that type of abuse. The type of driving thats required for road racing (and i assume you mean cones-on-a-parking-lot type stuff, and not highway racing) would just cause most blowers to suffer from severe heat soak and after a few laps or runs or whatever with no cooldown period, your performance would basically suffer. Plus with the type of driving you do, you dont really have enough time to build and hold boost to make it worth while.
Someone please correct me if i'm wrong, but I cant think of any real successful road-race oriented cars that have a blower. I think your money would be better spent on a built motor and some serious suspension upgrades as opposed to 4k on a blower that doesnt really help you at all.
what doesnt make sense is you're asking about 1/4 mile times then mention that you're into road racing.
if you were into road racing i would imagine that NO blower would be your best option and to just build one hell of an engine that can handle that type of abuse. The type of driving thats required for road racing (and i assume you mean cones-on-a-parking-lot type stuff, and not highway racing) would just cause most blowers to suffer from severe heat soak and after a few laps or runs or whatever with no cooldown period, your performance would basically suffer. Plus with the type of driving you do, you dont really have enough time to build and hold boost to make it worth while.
Someone please correct me if i'm wrong, but I cant think of any real successful road-race oriented cars that have a blower. I think your money would be better spent on a built motor and some serious suspension upgrades as opposed to 4k on a blower that doesnt really help you at all.
08-02-2007, 11:42 PM
#3
5th Gear Member
Join Date: Sep 2006
Location: CA
Posts: 4,039
RE: Centrifugal vs. Roots
+1 First, I would figure out what you will be mainly using this car for. Is it a 1/4 mile car that you will occasionally road race, or visa versa. Or the most realistic scenario: is this a daily driver that you will sometimes take to either track? Figure out your ultimate goals for the car, then choose a blower or build a motor that most suits your type of driving.
08-03-2007, 12:12 AM
#4
5th Gear Member
Join Date: May 2007
Location: Michigan
Posts: 2,795
RE: Centrifugal vs. Roots
ORIGINAL: ajmodelski
I want to know the numbers. I know the roots has slightly lower hp numbers but better torque through the rpms. But I want to know, the acceleration numbers. I want to know how fast a 400hp roots blower is and how fast a 400hp centrifugal is. Quarter mile times or 0-60 times. I don't care. I want to know which is right for me. I'm hoping that 400 ish RWHP is going to be enough for me. But I do road racing and I want to know, which choice is right for me.
I want to know the numbers. I know the roots has slightly lower hp numbers but better torque through the rpms. But I want to know, the acceleration numbers. I want to know how fast a 400hp roots blower is and how fast a 400hp centrifugal is. Quarter mile times or 0-60 times. I don't care. I want to know which is right for me. I'm hoping that 400 ish RWHP is going to be enough for me. But I do road racing and I want to know, which choice is right for me.
[sm=dontgetit.gif]
08-03-2007, 12:16 AM
#5
6th Gear Member
Join Date: Jan 2004
Location: United States
Posts: 12,575
RE: Centrifugal vs. Roots
ORIGINAL: GT03 TJS
both can easily make 400rwhp at around 8psi with a good tune and a few boltons.
what doesnt make sense is you're asking about 1/4 mile times then mention that you're into road racing.
if you were into road racing i would imagine that NO blower would be your best option and to just build one hell of an engine that can handle that type of abuse. The type of driving thats required for road racing (and i assume you mean cones-on-a-parking-lot type stuff, and not highway racing) would just cause most blowers to suffer from severe heat soak and after a few laps or runs or whatever with no cooldown period, your performance would basically suffer. Plus with the type of driving you do, you dont really have enough time to build and hold boost to make it worth while.
Someone please correct me if i'm wrong, but I cant think of any real successful road-race oriented cars that have a blower. I think your money would be better spent on a built motor and some serious suspension upgrades as opposed to 4k on a blower that doesnt really help you at all.
both can easily make 400rwhp at around 8psi with a good tune and a few boltons.
what doesnt make sense is you're asking about 1/4 mile times then mention that you're into road racing.
if you were into road racing i would imagine that NO blower would be your best option and to just build one hell of an engine that can handle that type of abuse. The type of driving thats required for road racing (and i assume you mean cones-on-a-parking-lot type stuff, and not highway racing) would just cause most blowers to suffer from severe heat soak and after a few laps or runs or whatever with no cooldown period, your performance would basically suffer. Plus with the type of driving you do, you dont really have enough time to build and hold boost to make it worth while.
Someone please correct me if i'm wrong, but I cant think of any real successful road-race oriented cars that have a blower. I think your money would be better spent on a built motor and some serious suspension upgrades as opposed to 4k on a blower that doesnt really help you at all.
Roots sucks. You may be thinking of a twin screw, which is much more efficent and doesn't fall off up top. The roots blowers for our cars are lucky to make 360ish WHP with 8 PSI + full boltons and custom tune, let alone 400 WHP.
In every single way, other than torque from 2000-3500 RPM, the centri is superior. A centri powered car, with all else being equal (same boltons etc) is going to W A L K away from a roots car. Its not even going to be a race.
Roots ftl!
08-03-2007, 12:32 AM
#7
6th Gear Member
Join Date: Jan 2004
Location: United States
Posts: 12,575
RE: Centrifugal vs. Roots
BTW, if your wanting a mean road race car, a blower can definatly help. However, for road racing only I would probably go with a twin screw, of if I had no other option, a roots style. From what I have seen though, the roots kits are dammed near as much as a KB setup.
The reason I would not go with a centri on a road race setup is the lack of power down low. Unless you can keep your rpm in the 3000-redline range your going to have bad results with a centri on the road course. On a twin screw/roots setup it makes max boost down low, and will make lots of low end torque, so you wouldn't be so busy with the shifter. AKA, you come out of a turn and instead of having to upshift just apply throttle and the car will pull thru the bottom of the gear.
With the right suspension setup and a twin screw you would have one mean road race machine.
The reason I would not go with a centri on a road race setup is the lack of power down low. Unless you can keep your rpm in the 3000-redline range your going to have bad results with a centri on the road course. On a twin screw/roots setup it makes max boost down low, and will make lots of low end torque, so you wouldn't be so busy with the shifter. AKA, you come out of a turn and instead of having to upshift just apply throttle and the car will pull thru the bottom of the gear.
With the right suspension setup and a twin screw you would have one mean road race machine.
08-03-2007, 10:45 AM
#8
3rd Gear Member
Join Date: Apr 2006
Location: Florida
Posts: 628
RE: Centrifugal vs. Roots
ORIGINAL: 2000GT4.6
BTW, if your wanting a mean road race car, a blower can definatly help. However, for road racing only I would probably go with a twin screw, of if I had no other option, a roots style. From what I have seen though, the roots kits are dammed near as much as a KB setup.
The reason I would not go with a centri on a road race setup is the lack of power down low. Unless you can keep your rpm in the 3000-redline range your going to have bad results with a centri on the road course. On a twin screw/roots setup it makes max boost down low, and will make lots of low end torque, so you wouldn't be so busy with the shifter. AKA, you come out of a turn and instead of having to upshift just apply throttle and the car will pull thru the bottom of the gear.
With the right suspension setup and a twin screw you would have one mean road race machine.
BTW, if your wanting a mean road race car, a blower can definatly help. However, for road racing only I would probably go with a twin screw, of if I had no other option, a roots style. From what I have seen though, the roots kits are dammed near as much as a KB setup.
The reason I would not go with a centri on a road race setup is the lack of power down low. Unless you can keep your rpm in the 3000-redline range your going to have bad results with a centri on the road course. On a twin screw/roots setup it makes max boost down low, and will make lots of low end torque, so you wouldn't be so busy with the shifter. AKA, you come out of a turn and instead of having to upshift just apply throttle and the car will pull thru the bottom of the gear.
With the right suspension setup and a twin screw you would have one mean road race machine.
08-03-2007, 11:25 AM
#9
5th Gear Member
Join Date: Mar 2007
Location:
Posts: 2,441
RE: Centrifugal vs. Roots
yeah, id say with a centri.. it NEEDS to be intercooled and you might want to consider other methods to keep the temperature down... id maybe consider getting a stock cobra hood to pull some of the heat out, if there are clearance issues then a cowl hood that is functional. honestly, for road racing your best bet is to build one hell of a motor with the suspension to boot, and maybe get nitrous for the straight aways...
