Alternative Alternators ?

[Holden202T]

yeah I think that is the one I have, but its not an issue now I have upgraded the charge wire to something decent, at idle at least its holding 14.15v in the boot, and the issue I was having was while racing it would drop, so that's certainly not the idle current ... but I will be able to confirm for sure in 1.5 weeks time after I race again

[The1]

yeh perhaps your wire wasn't big enough, i have confirmed in both my VS and VX the drop is a constant 0.3v at any load between alternator and battery with factory wire, adding wire doesn't decrease the drop, so im guessing it's enough. I want to try and borrow a current clamp multimeter from work so i can measure the amperage at different loads, would be good to see.

I did hear that you can put a diode between D+ & B+ the D+ runs the sense circuit so it thinks it's got a drop of 0.5v and will try and bump it up another 0.5v via the reg, but most of the time anyway these alternators never hold 14.4v so i doubt it would do much. The 40 or 60amp at low RPM should be enough for 99% of purposes.

[Holden202T]

yeah that's the other thing I have the sense wire in the engine bay not at the battery so I could maybe gain more from that, but the fact its now holding 14.15v at idle with fans and such on and it couldn't do that before with the smaller wire makes me think that was the only issue .... I was seeing 11.9V while racing so anything in the 13's and i'll be happy

[delcowizzid]

are you running gilmor drive cause we thought belt slip was causing the vb to drop volts as boost hit or maybe its just too much alternator rpm geared for low rpm charging of a street car LOL

[Holden202T]

nah just running from crank to alternator and water pump like stock 202 with serpentine belt.

P1100880.jpg (358.5 KiB) Viewed 4711 times

and here you can see the volts dropping a fair chunk when I get off the 2 step, I have set the second pump to activate on 4 psi boost, and I get 3psi on the 2 step, so just after launch it comes on and the volts drop .... anyways going to run it as it is with the new wire and see what results I get before I do anything else.

battery volts log.jpg (356.91 KiB) Viewed 4711 times

[The1]

i found this on the bosch tech site, the bearings are rated for 12,000 rpm and the unit for 18,000rpm
http://apps.bosch.com.au/AAExtranet_Tec ... -A0003.PDF

I guess it'd be getting up there being less than half the size of the other pullies?

I think some V8 ones had larger pullies? Might help perhaps. But yeh even at 12.7volts you above the battery charge voltage so safe.

[Holden202T]

hahahaha I don't think I want to work that ratio out cause I'm not surprised if I'm turning it to 13,000 or more!

[immortality]

Does anybody know what sort of amperage the sensing wire would pull?

Might have a play around with a diode and see how well it works. I have read a few different things that suggest it does indeed work.

I did see something about automotive blade fuses that incorporate a diode which would be ideal for this sort of thing although I haven't found a NZ supplier yet

[VL400]

Current is low and pretty much any old diode can do. I have a fuse with some back to back SMD diodes soldered in (so it can be installed without worrying about polarity) while keeping the fuse part.

Worked well but cold you get a touch over 15V which was not ideal, its no longer installed.

[Holden202T]

sounds like its easier and more beneficial to run the sense wire to the boot