Mostly because there is so little room on the driver's side. All the components block it. A hotside supercharger was developed, not sure progress on that. lol now that I want to sell my car all the new FI kits are finally comming out.

 

And it is for one simple reason - he can't use the Eatons anymore. Oscar Jackson just split off from Moss Motors and Moss have a deal with Magnuson about their Eaton blowers. So Jackson had to find something else to use.

If you want your car to have extra power only at the top of the RPM range - you can go with a Rotrex (centrifugal "junk" like the Vortech and the like). Your car won't be fast but you will still have a good peak horsepower number to brag with (and most people who have no idea about performance will pay attention to just that peak hp number)

But if you want your car to be absolute beast - you better get kit with a positive displacement supercharger - either the Eaton units or a twinscrew one (Opcon/Whipple or Autotor). It will eat alive one with similar peak hp and centrifugal blower.

 

Nobody makes roots blowers nowadays.
The Eatons which people call roots are actually twin-screw/roots hybrids.
And at less than 20 psi of boost you'll get similar results no matter using an Eaton or a twin screw Opcon/Whipple/Autorotor. Either one of these will work great under the hood of your car

 

I refer to the Roots style blower or basically the Eaton/Magnussen units. Of course it is more advanced that the Roots blowers of old, but it still does not harness internal compression.

You will not get similar results between an Eaton/Magnussen and Whipple/Autorotor at almost any boost level. The latter will consistently out-performn the former due to the same big word I've been throwing around: internal compression. This really is the limiting factor of the Eaton/Magnussen unit or any Roots style blower for that matter. The only downside to this is that you are ALWAYS compressing air when the blower is spinning, whether you use it or vent it to atmosphere. Less efficient when off boost, more efficient when on.

Turbos/Centrifugals/Twin Screws each fall into both the compressor and air pump category, some more than others. The Roots style unit is ONLY an air pump. It does not have the ability to compress the charge on it's own.

 

I think the buzz on the street is that the ROTREX drive system is supposed to mimic more closely a PD-SC performance at lower RPM. I have no experience with them, but will be interested to see how they perform.

 

The Rotrex unit is interesting. It uses a planetary traction drive vs. gears or belts. The drive allows MUCH higher RPM vs. a typical centrifugal blower, so the Rotrex can use turbo impellers. These are more efficient due to higher RPM, smaller diameter for the same boost (less rotary inertia). Of course there is still parasitic load to spin it, but the dyno plots show the unit to be less peaky than a normal centri. HKS and www.w2wpowertrain.com have dyno plots of various motors.

-Doug

 

This thing could be a pretty pimp low boost plug and play solution...

Good low end torque, good high rpm power

at 5-7 psi just a basis plug and play ems

no headgasket

no oil tapping, engine oil is still a sealed system


at those boost levels would it even need an after/intercooler?

if this put around 300whp down with a good power curve and a price take around 5k I 'd rock this....


Matt

 

Yes, you will - unless you've tried some crazy boost levels and you found some big difference.

One of the cheapest examples - the Miata world. Lots of experience there and almoste any form of forced induction has been tried and compared vs the others in real life. There are kits using: the Eaton blowers (MP62 from BRP/SOT); the Swedish Opcon (sold in USA by Whipple) by Flyin' Miata in the past and now BEGI; Autorotor in the Kenne Bell kits.

People use these in their Miatas and at similar boost/flow levels get similar hp results. The twin-screws' avertisements sound like these blowers are much more advanced but the Eatons are no slouches either. There is no day and night difference. Even if a twin screw makes a couple more hp than an Eaton it is not the end of the world - the quality of the whole kit is much more important.

Btw, still the highest sc Miata hp crown is held by an Eaton equipped Miata - RJW had a homemade Eaton MP62 kit, running 20+ psi, W/I intercooler plus water injection and boosting the stock 100 rwhp Miata output to over 340 rwhp. Here is his 7000 rpm dyno run, later he was running his built engine to 8700 rpm redline





The centrifugal blowers also have been used in the Miata world by some manifacturers but with these folks got peak hp numbers at high rpm and weak power below that ... so noone was buying these

 

Here

One more company that is going to give the roots style a chance on the S2000.

 

What I don't like about that one is that it puts the supercharger on the driver's side of a LHD car. Of course it is not a deal breaker but IMO the supercharger should live on the passenger side of the engine bay for better weight distribution