Wanted roots type supercharger (used)

[Stephan 4]

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. 

 

[Lauren 2259]

I'm not sure if it's useful to add, but there aren't really any Roots type superchargers for the GT. They are all Twin Screw (which is not the same), if you mean Sprintex, Harrop, Cosworth then it might be worth changing your thread title. 

[Varelco 211]

 

17 hours ago, Lauren said:

I'm not sure if it's useful to add, but there aren't really any Roots type superchargers for the GT. They are all Twin Screw (which is not the same), if you mean Sprintex, Harrop, Cosworth then it might be worth changing your thread title. 

Thats not true. The Harrop, Edelbrock and Cosworth supercharger are all Root type supercharger

Sprintex/innovate is twin screw hence the noise.

 

 

[Stephan 4]

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. 

[Lauren 2259]

3 hours ago, Stephan said:

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 stand corrected on the Cossie/Harrop stuff as it is positive displacement. 

I don't get why you want low down torque if you are on track though? You'll be driving in the higher reaches of the rev rang all the time on track and using peak power more. 

[Kodename47 446]

Aye. PD blowers tend to shine on the road more so than the track. That's not to say that a Centri is better on track, the Harrop and Cosworth blowers have definitely shown their worth.

[Cerastes 204]

What about a turbo?

[Varelco 211]

13 hours ago, Lauren said:

I stand corrected on the Cossie/Harrop stuff as it is positive displacement. 

I don't get why you want low down torque if you are on track though? You'll be driving in the higher reaches of the rev rang all the time on track and using peak power more. 

I thought this also. OP its top end power you will want on track seeing as the car is pretty much sat above 4k for the entirety. For that you are better off with a centrifugal supercharger. For one its going to be more affordable, i'm sorry but are never going to pick up a Cosworth, Harrop or similar supercharger on your budget. A Sprintex yes, but on track its know that these can get hot and struggle to keep intake temps down. The advantage of a centrigufal blower is they tend to be cheaper, so will fit your budget, and use an air to air intercooler which is going to keep those intake temps lower on track.

[Stephan 4]

10 hours ago, Varelco said:

I thought this also. OP its top end power you will want on track seeing as the car is pretty much sat above 4k for the entirety. For that you are better off with a centrifugal supercharger. For one its going to be more affordable, i'm sorry but are never going to pick up a Cosworth, Harrop or similar supercharger on your budget. A Sprintex yes, but on track its know that these can get hot and struggle to keep intake temps down. The advantage of a centrigufal blower is they tend to be cheaper, so will fit your budget, and use an air to air intercooler which is going to keep those intake temps lower on track.

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. 

[Lauren 2259]

Centrifugal kits are cheaper generally. A bit less engineering compared to twin screw, positive displacement units and also a less complicated and more efficient front mounted intercooler, rather than the water/air intercooler of the Cosworth, Harrop and Sprintex units. 

As Matt has said, realistically only the Sprintex will come within your budget. It was one of the first SC kits out, but I don't like it as all it's power is low down and mid-range, it lacks top end punch I found. 

What tracks do you actually use? I must admit, I can't think of any that are just second and third gear only. Are you sprinting? 

[Stephan 4]

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