Lightweight alternators....

Re: Lightweight alternators.... (kameleon)

Mon, 03 Oct 2016 22:06:03 GMT

Please do. I have ordered a 3mm thick sheet of carbon fibre to make a bracket.

Re: Lightweight alternators.... (MCT_MR2)

Sun, 02 Oct 2016 16:00:21 GMT

I doubt it, he has been busy raiding the motec catalogue. On a side note trav, old mate beams master runs a 90a unit from a dihatsu. Tiny lightweight unit. He had to underdive the **** out of it for the amount of revs he is using though. I can find out more info if you need.

Re: Lightweight alternators.... (kameleon)

Sun, 02 Oct 2016 11:46:01 GMT

Thread from the dead.....

Did you end up doing anything with yours Brendan?

Re: Lightweight alternators.... (WIDEMR)

Tue, 30 Apr 2013 10:54:29 GMT

Nothing lockwire cant fix " />

Re: Lightweight alternators.... (kameleon)

Tue, 30 Apr 2013 10:36:00 GMT

Yeah there is a reason manufacturers do thing like that. Just wish they did a hollow cast alloy one instead.

Re: Lightweight alternators.... (kameleon)

Tue, 30 Apr 2013 10:36:00 GMT

Yeah there is a reason manufacturers do thing like that. Just wish they did a hollow cast alloy one instead.

Re: Lightweight alternators.... (Reddtarga)

Tue, 30 Apr 2013 09:43:15 GMT

Re lightweight alt mounting brackets:
There must be a lot more stress on the bracket than I imagined, because I just checked all the mounting bolts on my lightweight fabricated bracket and tensioner assy and found some of them loose with a couple missing.
They certainly weren't that way when I fitted it, and I will have to check them more often in future or use a bit of Loctite.
Maybe Toyota knew what they were doing with the stock heavy cast one lol.

Re: Lightweight alternators.... (kameleon)

Wed, 24 Apr 2013 18:46:53 GMT

Might be time to go 80A and see what happens....

Re: Lightweight alternators.... (MCT_MR2)

Fri, 19 Apr 2013 20:42:51 GMT

otherwise look at light aircraft 100a alternators, you'd have to check on the speed you can run them at and sort an appropriate pulley, but one i quickly looked at comes in at 12lb, or 5.45kgish.
http://www.nationalairpar...small-case-alternator/

Re: Lightweight alternators.... (MCT_MR2)

Fri, 19 Apr 2013 20:39:28 GMT

http://www.lynxae.co.uk/Products-alternators.htm

Dunno if you have seen these guys before, but their 140a alternator weighs in at 6kg, and they make their stuff with denso parts for most things.

As for "switching off" an alternator, i would only attempt it on a 3 wire alternator with a l-ion battery, as the voltage drop would be catastrophic otherwise.

Depending on ecu choice, you could switch to a 4 wire off a later model car to duty cycle control the alternator, so it doesn't load up when you don't need it to, and i'm assuming this is what Brendan is referring to, as thats how a lot of modern cars are. For example with a pnp m800 for sti's and evos the computer will switch off the aircon compressor and run the alternator at minimum duty to maintain voltage at high throttle inputs.

Ultimately your 100a requirement will be the killer, you can find some 3kg 80a 4 wire alternators fairly easily. Maybe you should adapt a suzuki swift or similar steering coloumn into your car and run a manual rack.....

Re: Lightweight alternators.... (kameleon)

Wed, 10 Apr 2013 20:42:14 GMT

looks like its just a matter of going to a place that have lots of options with some scales.

Re: Lightweight alternators.... (WIDEMR)

Mon, 08 Apr 2013 16:31:55 GMT

Racer X Aluminium bracket (bottom, top and adjustment rod) 846 grams

Re: Lightweight alternators.... (Reddtarga)

Mon, 08 Apr 2013 09:57:53 GMT

WIDEMR
Yeah biggest saving will be the bracket for sure.

I will be running a smaller alternator then the 100 yes.

From factory, can the 80 and 100 be swapped? or do they have different thickness mounting?

Ian are you able to measure the thickness of the bottom mounting tab/bolt location? The 100A i have is 58mm.

The bottom tab on both the 80 amp alternators I have is exactly 57 mm wide.
If the turbo one is 58 mm that is not much difference, but comparing it to the NA alt as you say there is a difference between the hole centers of that mounting tab and the adjustment tab so you can't fit an NA alt to a stock turbo bracket.

A while ago I found these weights but I'm not sure if they are exact:
Camry 70 amp alternator 9 lbs 11 oz. (4.3kg)
MR2 turbo alternator 13 lbs. 8 oz. (6.1 kg)
MR2 NA alternator 5 kg
MR2 NA bracket 6 kg.
MR2 turbo bracket?
Hux bracket stock position 1 lbs 15 oz. (.87 kg)
MR2OC (USA) aluminum billet bracket 1 lb 7 oz. (.65kg)

You're right about the bracket.
The bracket I use that I fabricated from mild steel for the stock mounting position saved about 4 kg over the stock NA bracket.

Re: Lightweight alternators.... (WIDEMR)

Sun, 07 Apr 2013 20:58:47 GMT

Also a smaller output alternator will have smaller and, generally, lighter rotor, meaning less reciprocating mass, light weight fly wheel lovers will be all over this, so will spool up faster.

Under load tho i dunno how its affected.

Re: Lightweight alternators.... (WIDEMR)

Sun, 07 Apr 2013 20:51:07 GMT

For factory size options for guys Ill have a look at some alternator catalogues when im down at dads old shop soon, see what has weights, altho doubt they will be accurate. Just had a look at one site i know i have a cat for, it does show weights, but again single digits weights, hard to compare, prob just shipping weights.

Looking at Denso, factory size specs, shows a 70A at 5kg (Ians says his 80 was less then 5kg) and a 100A at 6KG.

like very very common Sv21 camry http://www.pinpoint.aea.com.au/Guest_pc_alt.aspx?pn=ALT1091&id=5072&ptbl=Alternator
Hole centres i think are 1mm out, shouldnt matter on factory bracket, deff wont matter with racer x light bracket which has rose joints and threaded rod. Battery stud is on the side (boot side)

Need to get a 80, or camry 70 and a 100 or other alt and put them on the same scale, not different ones all around the world.