As stated before, the only difference between the stock 05 and JCW supercharger is the pulley. I too have seen a side-by-side comparison and there is no difference between lobe shapes, and there is no difference in the water pump drive gears. The lobes on an early model stock supercharger will appear different because they are smooth and shiny; that may give the impression of smaller diameter lobes due to the reflective properties of the coating. The later model rough textured non-reflective mat lobe coating may create an illusion of looking fatter, but the shape is the same. I have not seen a 06 build date for either models but reason dictates (although this is a potential fallacy) that a change of lobe geometries would generate some marketing hype which would have made it to press by now.

 

 

You may have hit on something here. I may have been comparing apples to oranges. As you can see in the sig, the 2 SCs I was comparing were an '02 MCS and an '05 JCW.

 

yeh, cos i heard that 02 and 04 JCW's had the teflon coating or whatever, and then they introduced that on the 05 SCs. I wonder if the JCW 05's SC are different to the stock 05 MCS's SC

 

Does anyone have more info on that RMS stuff from a few posts back? What is the supercharger capable of supporting versus stock? I tried calling this morning but I don't think ANYONE that works there speaks English...lol.

Also will this work with an air to air such as the new M7 unit?

 

whats the deal on the one from RMS? Is it a twin screw?

 

i think it is a twinscrew. randy webb was developing a kit a while back that never made it to market. it was probably too expensive to R and D, then to produce.

 

Have you guys not seen that the 62 is a reality.... there are two threads going on it now

 

How about this, to make it even easier to find.....
https://www.northamericanmotoring.co...ad.php?t=77790

peter
Team M7
562-608-8123

 

thanks for the link i would have been lost without you guys

 

A centirfical SC like a vortech should be thought of as a mechanically driven turbo. IT's nice on a lot of V8s that have cam limit high up, and most V8s aren't lacking for low end torque. These don't have turbo lag, as the are coupled to the crank. The lack of the low end is because the turbines don't really work well till they are spinning fast. Turbo lag is from the fact thatit doesn't really start to spin until a bunch of exhaust gas goes past it. Xisor had it right, easy to place on a car. Just move the alternator or some other accessory, and plop it in!

The twin screw has much better thermal efficiency than a roots, but is more to make, as it has much tighter tolerences in the "screws". Also, a lot of the suppliers (all?) are European based, and we're getting killed on the exchange rates. So don't expect to see one offered anytime soon. don't know if Wipple or Jackson will do one, as the Mini is a much smaller market than the honda or ford applications.

The roots is the worst from an efficiency standpoint, but good from a cost standpoint.

Matt

 

My suggestion is to take a test ride in the M7 demo car and see if you think you need "more"..... you may be very happy with the 62 or you may want more but I would check this out first

 

but the differences of the SC types are what they are. It probably does make sense to do the 62 as opposed to a twin screw, as everyone in the US that started a twinscrew project for the Mini dropped it over costs. The 62 isn't the best technology, but at least it's affordable, and it's coming to market. The other technologies can't claim that...

Matt

 

YEP

 

The much maligned Roots also, I think, has the best low-end torque (of the blowers), right?

 

Honors go to the twinscrew...

Only reason it's still used in drag racing is you HAVE to use a roots!

Matt

 

I was thinking that vectored thrust is a great technology but there are lots of cool planes that still use traditional control surfaces.... somethings just work and the cost to value ratios make sense

 

Third paragraph sort of jives with what I read some time ago:

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

Heading home. Be back online later...

 

the twinscrew is more thermally efficient and has less leakage at low RPMs. All the articles connected to your link say the roots is good down low and also express some advantages of it's simplicity (read cost). But none actually comments directly on the comparison with a twinscrew other than noting the compression happens inside a twinscrew, and outside a roots.

But there are some excellent discriptions in the links. Moreso in the two links at the bottom than the actual wikipedia entry.

Matt

 

Supercharger 101


Good heads up on superchargers in general with good design comparisons.

 

Just seems like throwing in a bigger SC like the M62, doesn't solve the efficency problems. What is the Efficency of the M62 versus the one we have? How much extra power will it take to build up for the extra. Guess I'm always a fan of something that has higher efficencies then just throwing bigger things at a problem.

Reason I like the DFIC, the efficency of it is quite nice. O_o.

 

Matt can certainly do better but the real advanatge is that the M62 has to work less hard to produce a specific volume of air. Less work means less heat.
Something alse I can't remember being mentioned is the advanatge of the M62 in parasitic loss. I don't know what it is but have the feeling there is an advantage there as well.

 

Idealistically though, we would be increasing the amount of volume of air possible, since we are increasing boost no? *shrugs*

 

Boost in a roots and the available work are 2 different aspects and can be maniplulated independently.

More air does not mean, absolutely, more boost.
In identical applications at identical supercharger rpms the M62 will move more air. Given idential restrictions to the flow path the M62 will show more boost.

 

Well the chambers inside the engine can only except a finite amount of air. Even if it's compressed to a degree, there is a finite amount. Something has to give. Meaning more boost.

I still think there has to be another answer then throwing another roots S/C at the mini. Maybe I'm the odd man out. I would rather see the whipple. O_o