Friday, May 19, 2006

Visitors and alternator findings

Had Carruthers, Dawson and Bowler down today. Fiddled with Dawsons Dellorto and he left with a rather different car to the one he arrived in, it was in need some attention, partly my fault with a batch of funny float valves I had about that time, also some hardcore salt corrosion on the pump arm, which was a bit siezed, chain lube it mate, smoother it and alloy shield needed!

Was driving perfectly through progression, idling well and when i tested it was a complete pleasure after full check over and static idle jetting. For a stock motor and such, it was surely putting out most of what it had to give, a little more time on the mains it'll go better again I'd say 10%! It came to me easily and the jetting and was very close - bar tiny fluff in the mid range, upper range, rich I thought. Needed more time than we had so he left with some jets and advise!! So that was pleasing. I have never seen a rain shower so heavy as when they left, hail, snow, sleet and someone with a firehose spraying from the heavens!

Good to sort something out so easily and keep someone happy!

I tested the alternator it works, it will drain FAR less power than the old one, the idle doesn't drop at all really when the fan comes on. The old one dragged 100-120rpm off the idle speed due to load. So I guess its worth a HP or two- at the highend...Also the rotating mass is under half as much as the A127, so the drag of the alternators centre spinning about 15000rpm at 6K rpm must cain hp, its under drag too.... That weights about half? the mass of the alternator...? You have to accelerate that mass , decelerate it and its under drag. So I'd expect it to make a small difference, like ditching the water pump for the EWP, but less so..That made a "good" difference, especially on the 4.11 in 2nd, it was noticeable right away, but small in effect, less stuff to rotate, more spin up speed.

The lighter you make the car the faster it can get going, so the spin up speed on the engine and drivetrain becomes even more noticeable and effective, it really starts to add up...Punches like a boxer!

Alternator doesnt load up at idle much, as its a generator that is more scaled it doesnt give max volts, output at idle? At 2000rpm it gives about 14.7Volts which is the same as the A127 I didnt compare amps yet, the A127 gave 14.7V all the time when needed, also it loaded up alot lower in the rpm, dragging idle down....I am sure the new one can cope with my fan, ewp, high power headlights and such, the A127 had no problems, overkill but extremely good for battery charge!

No comments: