Eaton M24 on 1275.
Turbo Mini Forums

Hi Guys,

Just writing up a feature on a 1275 Mini using the Eaton M24 from a VW twincharged FSI engine.

I've seen enough on here to suggest its better on a 998 engine. However, I've since read this unit has internal step-up gearing of 1.93:1, and a max rpm limit of 17,370 rpm (according to Eaton). Could this mean it could have enough about it to make it a worthwhile addition to a 1275? The guy is running an intercooler too.

Could the m24 be a better alternative to the m45? I know many of you don't like Roots chargers, but I'd appreciate your opinions. It is a very compact charger, after all.

Many thanks,

Jeff

Edited by Jeff R on 20th Oct, 2011.

My M24, from a VW is not internally geared. The pulley rotates at the same speed as the rotors.

We were advised by Eaton, via TD, that the maximum speed is 15000rpm.

The M24 pushes 24 cu. in or 393cc per rev. So if you gear it at say 2.5:1, it will pass 1966cc per engine cycle.

Hence on a 1275cc it will try and pass 1966cc and therefore give around 7.5psi boost if intercooled efficienctly, higher if not.

Mine is still for sale, although I have just seen some slight damage to the rotor coating whilst checking for gearing. I can include a nice ladies dress if you are interested.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Thanks Paul for the speedy reply. So, would an internally stepped-up M24 be a better bet? I believe this particular unit is a stepped-up charger.

Unfortunately I'm not looking to buy one. I'm a turbo man!

Edited by Jeff R on 20th Oct, 2011.

No, it's the rotor speed that is the limiting factor.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Hmm, I've been told nearly 17,500 rpm. Maybe the stepped-up charger is rated differently?

What boost is he seeing ??

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I've yet to find that out. It makes 112 bhp though, all standard other than a lowered CR. It's an MPi with a foreign aftermarket ECU.
Would i be right in thinking a stepped-up, small charger could work nicely though?

112hp would be right for the M24.

Most superchargers are usually "stepped up" by the pulleys to the appropriate speed. There is a physical limit as the how fast you can run the rotors before they start to disintegrate.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Eaton's reply is that the pulley would ned to be tiny to acheive what the internal stepping of the M24 does, so i guess that makes sense. I'd imagine its pretty good and a bit better than a standrd M24. Mind you, its probably well out of puff after about 4000 rpm.

Well, you will have to get the data and some pictures for us to have a look at :)

Here's mine:


Obviously no internal gearing other than the mesh gears.

And here is a map showing 15,390rpm:

Edited by Paul S on 20th Oct, 2011.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I'll find out what boost he's running too.