K series - lightweight alternator (Brise / Denso / Daihatsu)

[573]

The standard Rover / Magneti Marelli alternator on my Superlight R has died. In the spirit of upgrading rather than just replacing I've been looking at lighter alternatives.

Brise list a Denso unit. From the part number (5020) this appears to be a standard Denso unit that appears in numerous Daihatsus and I think also Suzukis. The Brise unit is £240 whereas the Daihatsu unit seems to be readily available for under £100.

I guess I'm not the first to notice this... has anyone fitted a Daihatsu souirced Denso?

Second part of my question - the Denso unit has a 3 pin plug. Does anyone have an idiot proof wiring diagram for the swap?

Thanks.

[573]

I’ve got sorted. I’ve bought a Denso and also a lightweight mount, tensioner and pulley kit.

Is there a Caterham forum with more traffic that people would recommend?

[573]

I'll share details in here once I've fitted it. The mount and kit I've bought is for an Elise but I don't see why it won't fit.

[573]

573 said:

I'll share details in here once I've fitted it.

I forgot to share, so here we are:

Initial searches led me to a Brise alternator that seemed to be ~3kg compared to the ~5kg of the original. The Brise unit was £300. More searching unearthed that the Brise unit is made by Nippon Denso and is used on numerous things including Kubota tractors and Daihatsu hatchbacks. These seem to retail for around £99. Better than that, I know Dan Webster who runs HPE http://www.hpeauto.co.uk (the people that put the K20 in the back of my Elise) and he thought he had one of the Denso units in his workshop. Sure enough he did, and he stuck it in the post for me free of charge.

I then tracked down a guy in Austria, under the name of 'Carlos Racing' who makes lightweight mounts and tensioners in order to fit the Denso unit to the K series. Buying from him couldn't have been easier; getting the parts to me proved much harder. The parts made it across Europe and as far as my local distribution centre. I then tracked them onto a van where they then reported the address was incomplete. Despite me contacting them numerous times, they held them for a week and then lost them. Amazingly, the seller, who is a man knocking these out for fun, not a large commercial enterprise, stuck me another set in the post on overnight TNT.

Weight for original bits:

Alternator: 4848g
Pulley: 192g
Mount and tensioner: 1193g
Total 6.23kg

New smaller Denso alternator and lighter pulley:


@2997g

New mount and tensioner:


@547g

Total 3.54kg, which is a loss of: 2.69kg

It's a much better design, simpler to adjust and is now further from the 4th primary too.



I started a thread on the car in reader's rides if anyone's interested: https://www.pistonheads.com/gassing/topic.asp?h=0&...

[573]

Cheers. Unfortunately (fortunately?) I'm not on facebook.

[573]

I joined a few weeks ago. Still need to read the literature and log-in to othe forums though.

I was told it was good for cheap trackdays - offers on Brands GP for instance. Was a bit annoyed to join and find they all seem to be sessioned days shared with other clubs.

[573]

Ah cool, sounds good. Stick some pics up when you're done, I'm keen to see your solution.