Got Boost? We know JonK does!

[Johntee540]

Check this out! It is a great idea. http://www.fastcar.co.uk/New_supercharger_really_shifts.YTW4rnJoa2rmWw.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...

[Rustam]

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

Juvenile...
You're a child, Jon K, as much a child as one can be at 21 - and you show it here very inadvertently...

[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.

It would take you to say something deserving greater depth of analysis to make me interested in commenting on your opinion - this superficial information bares no significance to delve into. Of course I understand - you feel compelled to invite me to a discussion over these statements because you find them being expressive of some big knowledge and not being superficial at all.
Oh well...
Some choose to study the material, and others - are just pretentious...

[onewhippedpuppy]

All other BS aside, it does make sense that you could use a transmission to effectively vary the pulley side depending on the RPM. If a CVT type set-up could be made compact enough, it seems it would be ideal. You could essentially keep the rotors moving at the same angular velocity at all engine RPMs, allowing the same boost level from idle to redline.

Cool stuff, I think technology will continue to make FI more appealing, with far less compromises. Variable geometry for turbo vanes has performed much of the same task for turbos, allowing close to instant boost.

[Rustam]

All other BS aside, it does make sense that you could use a transmission to effectively vary the pulley side depending on the RPM. If a CVT type set-up could be made compact enough, it seems it would be ideal. You could essentially keep the rotors moving at the same angular velocity at all engine RPMs, allowing the same boost level from idle to redline.

Cool stuff, I think technology will continue to make FI more appealing, with far less compromises. Variable geometry for turbo vanes has performed much of the same task for turbos, allowing close to instant boost.

yes, it makes sense to do this...
But I would still prefer a bi-turbo setup.

[onewhippedpuppy]

True, there's no parasitic drag with turbos, if you can make them lag-free and package them efficiently they're tough to beat. Nice to reclaim some of that otherwise lost energy inherent to the internal combustion engine. The new 997 TT has twin turbos with the variable vane geometry, supposed to have nearly instant boost. Yeah, I'll just take one of those.;)

[Jon K]

Rustam - do you realize that you post 3, 4, 5+ times consecutively without someone saying a damned thing to you or does your feverish attempt of making someone look dumb distract you?

It's not even that - you also send ... 9 PMs to me... as if I am going to read the first one.

http://e34.digital7.com/wtf.jpg

OneWhippedPuppy - a company called Holset has been making variable vane turbo chargers for a long while available on turbo trucks.


Some choose to study the material, and others - are just pretentious...

You got the quote wrong - some people choose to sit on their **** all day and read books, misunderstand the points being made, and dictate it to other people on the interweb. Other people actually build cars with applied knowledge and experience - you do not fit into the latter. Thanks for playing.

[onewhippedpuppy]

OneWhippedPuppy - a company called Holset has been making variable vane turbo chargers for a long while available on turbo trucks.


Before I got smart and went back to school, I was a diesel tech for a while at Detroit Diesel, and had the opportunity to train on their variable vane turbos. At the time Mercedes also had the technology on their big diesels, adopted from DD (Detroit Diesel is owned by Daimler Chrysler). Regardless, it's cool stuff, essentially instant boost.

[Jon K]

Before I got smart and went back to school, I was a diesel tech for a while at Detroit Diesel, and had the opportunity to train on their variable vane turbos. At the time Mercedes also had the technology on their big diesels, adopted from DD (Detroit Diesel is owned by Daimler Chrysler). Regardless, it's cool stuff, essentially instant boost.


Yea the truck we tow my friends racecar with is a F250 superduty. The thing only tuns like 4500 rpm absolute max, but makes full boost at like 1200rpm and man does it pull. Pretty sick.