Quote Originally Posted by aLmk View Post
So basically with the twin chargers you can get to higher boost levels earlier in the rpm band? Is that what I'm gathering? Rather than a typical super charger that builds boost absolutely linearly through the rpm band? If so, that's really neat and a great use, that to me was always the downfall of the superchargers is that you have to wait till rev limit to get to full boost.
Thanks for your questions, and interest. It depends on how you do the twin charge layout. If you run parallel Rotrex boost climbs the same as a single Rotrex in a linear fashion.

Quote Originally Posted by Adm_rsx View Post
No. There have been a few twin charged cars before I found about jaydee. The guy I bought my first setup from at TTS PERFORMANCE had twin charged his s2k. And hondatas rsx has twin chargers as well.

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You are correct these cars were twin Rotrex, however when I spoke to Doug and Richard they had only ever tried running the Rotrex in parallel.

So to my knowledge almost everyone has twin charged Rotrex or turbo's in parallel to increase the air flow available for more top end boost.

My concept is totally different. The first Rotrex is a big C38-91 which takes atmospheric pressure (14.7psi) and increases this at a pressure ratio dependant on rpm. At 4000rpm the pressure ratio is x1.35 so 14.7psi becomes 19.8psi absolute or 5psi boost (this is the same as a single Rotrex will produce). This 19.8psi absolute then feeds our 2nd series Rotrex which is a smaller C38 unit as it does not need to be as big as both inlet/outlet are at a raised pressure compared to atmosphere. The 2nd unit has a x1.3 pressure ratio but due to the air density drop due to the hot inlet air the outlet pressure is 24.5psi absolute or about 9psi boost.

However we have almost doubled our boost at 4000rpm over a single Rotrex from 5psi to 9psi and the torque increase is 35% more than the single Rotrex from 235Ft/lbs to 315Ft/Lbs. As I said in the previous post acceleration times are 30% quicker now. So yes, you are correct "higher boost levels earlier in the rpm band". If we add another intercooler between the 2 Rotrex's we will pickup 3 to 5 psi more boost, however our fuel system, driveline, tyre grip and other components on the car are pretty much maxed out already and the car is already quick enough. So our efforts are now focused on the Jaydee Quantum 700.

It would be great if Top Gear did a shoot out on our modified Atom's. As they say the BS stops when the flag drops...
They will be in Australia in March 2014 for the http://www.topgearfestivalsydney.com.au/