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Locost supercharging
Benzine - 25/1/08 at 10:08 PM

Are the only relatively affordable superchargers available roots type? What would a new/used centrifugal type cost? I see plenty of eaton M45s, M62s and M112s on ebay but I've not seen a centrifugal type on ebay. (not been looking for that long though)

NeilP - 25/1/08 at 11:01 PM

The centrifugals are usually a bomb - I'd like the Rotrex fairy to visit but don't think that's going to happen any time soon.

With a small Eaton at low boost you might be able to get away with no intercooler and if you do need to alter the comp ratio then a thicker head gasket might do...

carpmart - 26/1/08 at 12:24 AM

quote:
Originally posted by NeilP
The centrifugals are usually a bomb - I'd like the Rotrex fairy to visit but don't think that's going to happen any time soon.

With a small Eaton at low boost you might be able to get away with no intercooler and if you do need to alter the comp ratio then a thicker head gasket might do...


Why would you not use an intercooler? It adds very little by way of complexity and the extra weight is minimal. The return in power for the reduction in charge temp can be very significant!

RazMan - 26/1/08 at 04:52 AM

Agreed, the complicated / expensive part is strapping the s/c on so the i/c can then follow without too much extra fuss.
The choice between air / air or air / water can hike prices up a bit though

bimbleuk - 26/1/08 at 07:34 AM

Hi before I finally took the plunge on the Rotrex I was a watching ebay regularly for superchargers. So yes 9 out of 10 on ebay are roots type. The majority being M45 BMW Mini (I bought n sold 5 of those myself!) units then m62 and M90s from Jags. Some RO yank V8 blowers. Occassionally a sprintex twin screw from Rover V8s and I even bought and sold a twin screw from a SL55 AMG twin screw which was huge!

In that time I saw two Rotrex SCs one in Belgium and a ropey one in the UK. Both went for around the £750 mark!

Just had a look and as usual plenty of Mini superchargers on there and now the listings are swamped with those ridiculus electric supercharger rip offs!

Roots are easy to mount and don't necessarily need an intercooler to work at low boost. Twin screws can actually be the easiest to mount but do need an intercooler to work efficiantly. Twin screws can be treated like a roots. You could get away without an iontercooler at low boost but ideally needs one. Main thing is the mounting on a twin screw as it only takes a tiny amount of distortion for the rotors to touch and destroy the unit!

[Edited on 27/1/08 by bimbleuk]

stevec - 26/1/08 at 08:27 AM

Guess what I do for a job now,
This is my workbench.
Steve.

Richard Quinn - 26/1/08 at 09:13 AM

quote:
Originally posted by stevec
Guess what I do for a job now,
This is my workbench.
Steve.


Sweep up using the brushes that come with instruction labels attached?

stevec - 26/1/08 at 09:54 AM

quote:
Originally posted by Richard Quinn
quote:
Originally posted by stevec
Guess what I do for a job now,
This is my workbench.
Steve.


Sweep up using the brushes that come with instruction labels attached?




Well spotted, but they are actually mops.

billynomates - 26/1/08 at 11:13 AM

quote:
Originally posted by stevec
Guess what I do for a job now,
This is my workbench.
Steve.


Did you know there was a ghost on the other side of that window?

Guinness - 26/1/08 at 12:25 PM

quote:
Originally posted by billynomates
Did you know there was a ghost on the other side of that window?


Spooky!

bimbleuk - 27/1/08 at 07:27 AM

Is that a Rotrex with the Antonov gearbox on the workbench?

thomas4age - 27/1/08 at 08:11 AM

I'd say the workbench is somewhere on the TTS building/site.

looks like the antonov electrical box, justin but can't tell really good.

would love to have 2 of those on the lexus.

grtz thomas

bimbleuk - 27/1/08 at 01:50 PM

Well maybe but when I was at TTS last time they showed me a dyno of the two speed Rotrex and at the time the transition was too harsh for hard drivng. Was some time a go so things may have changed.