Got Boost? We know JonK does!

[Johntee540]

Check this out! It is a great idea. http://www.fastcar.co.uk/New_superch...nJoa2rmWw.html

It is the answer to Turbos 2 stage setup from the Super charger side - JT

[Jon K]

Thats kind of neat but there are two flaws -

1) The use of a rotrex blower - those units are only able to make about 10 - 11 psi before they hit their ceiling

2) a supercharger already exists with instand boost all the way through the RPM range - these are referred to as twinscrew superchargers. They use a male and female rotor to compress air rather than an impeller - the efficiency is exponentially better albeit larger and more expensive.


Rustam please come in here and tell me I am wrong on all accounts, that'd be great thanks.

[632 Regal]

Children play nice!

Thats kind of neat but there are two flaws -

1) The use of a rotrex blower - those units are only able to make about 10 - 11 psi before they hit their ceiling

2) a supercharger already exists with instand boost all the way through the RPM range - these are referred to as twinscrew superchargers. They use a male and female rotor to compress air rather than an impeller - the efficiency is exponentially better albeit larger and more expensive.


Rustam please come in here and tell me I am wrong on all accounts, that'd be great thanks.

[kyleN20]

that is verry neat, not what if the hooked a gearbox to a twin screw? and what if it wasent a 2 speed, but a 5 speed? what if the put one inbetween a turbo? it seems that this will sone be the next step

[kyleN20]

and jon, yer sig is giving me epiletic seizers

[Jon K]

You don't put them in a turbo because a turbo intrinsically has more torque - it's a characteristic of a turbo. Also, a turbo makes its max spool at lower rpm than a CF blower - well, when the turbo is sized properly.

For instance, my CF blower makes ~9.5 psi at 6500rpm, but only like 2 or 3 psi @ 3800 rpm. So, they probably have a transmission that changes the effective "pulley size" or internal ratio of the gears while the input wheel is spinning < 4000 rpm or so, then once it reaches 4000 rpm it switches to the 1:1 input wheel and runs the Rotrex on the default ratio which I think is 10:1 or so. My asa blower is 15:1 so when you turn the input pulled one rotation the impeller spins 15 times. This means that theoretical max boost is higher, but you have to be careful how fast you spin the impeller. My unit runs a 150mm input pulley which is MUCH larger than the ~2.5" input pulley on the Rotrex which is lower internal ratio of 10 or 9:1.

You wouldn't bother with a transmission system on a twinscrew because they are positive displacement blowers... meaning they move amounts of air even at idle... they acheieve max boost by ~2500 on the Eurosport units we've driven. This means that 8 or 9 psi comes on at 2500 and stays there til redline. This makes the car handle more like a big block V8 than a 3.0L inline 6.

Also, you wouldn't really need more than 2 gearings... because either the supercharger is making good boost or its not. The nature of a CF blower is that theres little boost below 3000 rpm and max boost at redline... you wouldn't want 5 gears swapping around because lets say gear 1 is from idle til 2500, gear two comes on at 2600... well what happens at 2550? Not to mention, if you really want your boost to be present throughout the entire RPM range, you buy a twin screw or a turbo

[kyleN20]

they ought to just put a cvt on there

[Jon K]

lol - or just use a turbo/twin screw

[kyleN20]

why not do it ll at once, a small turbo, a twin screw, and a asa with a cvt on it. that fits the bill for a 1200whp super e34 doesent it?

[Rustam]

Thats kind of neat but there are two flaws -

1) The use of a rotrex blower - those units are only able to make about 10 - 11 psi before they hit their ceiling

2) a supercharger already exists with instand boost all the way through the RPM range - these are referred to as twinscrew superchargers. They use a male and female rotor to compress air rather than an impeller - the efficiency is exponentially better albeit larger and more expensive.


Rustam please come in here and tell me I am wrong on all accounts, that'd be great thanks.

Just read the PM that I addressed to you... As far as being wrong look up the messages that others have provided in support of my point on intercooling...