Centrifugal / Rotrex Supercharger Oil

[KTMsm]

I need to top up my HKS supercharger

It's a centrifugal type

I thought Eaton took the piss with their oil at around £30 for 100ml

However HKS want £345 for 800ml !

I struggle to believe it requires anything better than fully synthetic motor oil

If an exhaust driven turbo can run on it, which is a harsher environment, I find it hard to believe a belt driven one can't

However does anyone know the requirement or justification for the price ?

[The Rotrex Kid]

Short answer. No

Longer answer, it’s because of the gears inside. Have a look inside a centrifugal charger and it’s a lot more than a ‘belt driven turbo’

I use the genuine Rotrex stuff, it’s about £125 per litre I think.

It’s soooooooooo thin. Not like an oil at all.

[poppopbangbang]

The HKS supercharger is a planetary traction drive system somewhat similar to a Rotrex supercharger where there is no physical connection between the compressor and drive pulley. The transfer of drive between the two is achieved via a specific fluid with some pretty unique properties, in that it is the fluid that determines the friction between driven and undriven components / rolling elements and therefore directly impacts the drive between the two.

Basically don't put "normal" oil in it, it won't work as the function of the oil is not just lubricity and cooling as it is in, for example, a turbo charger. You may be able to use the Rotrex SX150 traction fluid in place of the HKS version (which is a lot cheaper at £100 a L) as the drives are similar, but research this first.

Super low volume complex lubricants are, unfortunately, really expensive as you're having to amalgamate the lab, mixing, post batch test etc. across a really small volume of product. See the price of the more exotic Klubrer greases for another example of this.

[KTMsm]

Thanks gents - I did have a google before asking but couldn't find anything useful

The HKS is only similar to a rotrex ? I assumed it would be identical

[The Rotrex Kid]

IIRC the HKS is not as complicated inside as the Rotrex, I don’t know any more than that!

As PPBB says, the oil (sorry, ‘traction fluid’ ) is quite important? A rebuild will cost a fortune and I’ve seen a few where the oil has been run low and killed the charger.

You could ask this guy about the oil - https://www.instagram.com/uksuperchargerrepairs?ig... he might have some knowledge!