Stephan

Sorted, bought the Vortech kit from Kwiatu from this forum. Thanks! Got me 320hp and a nice, linear torque curve as I wanted. I race usually on my local track in Gdansk in Poland. OK, a mini track in UK standards. I'm finally happy with the setup. Won my class yesterday. Ready for bigger tracks now. Gt86 seria...pdf

True, when I looked at RaceChrono the revs rarely drop below 3500rpm. I drive on the small technical tracks, between second and third gear. With torque down low, I could use third gear more, shaving off some time on shifts. Also, I’m not planning to change engine internals or modify the exhaust (ok, possibly new manifold and remove cat 1) so I don’t think I will get to the high peak power that centrifugal superchargers offer. I drive GT86 because I love steering with throttle. Biggest fun I get on track is to make the car oversteer mid corner and exit with the opposite lock, gently controlling the angle (I know it is not the fastest way, I know, just can’t help). I feel that with non-linear torque surge from turbo, it will be harder to do that. When I started using semi slicks (currently toyo r888r 225/45/17), I felt I lost this feature. With sticky rubber in the back, stock power feels not enough to break traction in the rear. So yes, my left foot braking needs some work. I sense 240-250 WHP will get me my throttle steering back. So twin screw will be plenty enough. Lastly, because of the low peak power, I assumed people will want to sell their SC in order to upgrade to higher power centrifugal/turbo units. Might not be true, but I assumed used centrifugal charger kits are more expensive.

Thanks Varelco, all that is roots or twin screw is fine with me. No rotrex type though. I track my GT86 so I need a fat torque down low. Peak power is less important.

I'm looking for a used roots type supercharger, has to be an intercooled unit. No brand preference. Of course a working unit. Ready to pay around £2000, I will pick it up myself, some time in January 2018.