Stronger altenator options?

[mcandmar]

Funny you should mention it i had a good discussion with the company rebuilding my alternator about them. He asked me if i did track days as it had been cooked and suspected sustained high revs. As it came from my 7A and had to admit to frequent thrashing. His take was an alternator has a sweet spot where it works best and the manufactures gear them so the shaft speed stays in this range while cruising. Typically 2-3000rpms engine speed when your cruising along at 50-60. So in theory for track day cars that really only see 4-7000rpms your better off gearing down the alternator so it runs within its sweet spot in terms of speed shaft. Over spinning them produces a lot of heat from what he was saying.

[Ross]

Ross - you 'working' again today?

Yup, I've got dual screens here. s2forum on one, tennis on the other. Alt+Tab is my saving grace

[A80Avant]

If your having idling problems, it may well be your alternator is faultly or regulator.

Only reason to fit a higher rated one is if your fitting even more lecky options to the car or if the car should have had the higher rated one to start with.

If the 90 amp alt and reg turn out ok, the poor idling is due to something else.

As Paul says,im running VEMS and the ISV settings although able to cater 90% of all situations as well as the motronic does, it might get into a bit of trouble creating a bouncing effect on the idle(dipping) when lots of electrics are on like lights, rear defoger and A/C for example.I know that the situations where all these need to be on are very rare,but since i want to eliminate all factors i want to have settings for everything and if there is something that can help mechanically i would like to use it.

Unfortunatelly, VEMS does not have a specific secondary settings that you can go to once for example VOlts go lower than 12 or A/C is on etc. If something like that was available, then i could use different settings for that and everything would be fine. SO for the time being,as my setup currently works for 90% as i said, i would like to minimise that 10% with better cableing and alternator if possible, thus maintaining as stable as possible the volts that the ECU reads.

First thought was to run a separate cable to the ecu through ignition directly from the battery.

Then i could also replace the cable that goes from the alternator to the battery.All these need to be tested with a voltometer to see where the drain is happening and how much it is cable based,(small cables, lots of separations etc.) Hopefully that way i may gain half or 1 volt or so, which is all i need really