LetsTurboSomething

I have a shitty reman alt on it right now that won't put out over 14.0v. The thing stops charging at 5300RPM... If I under drive it I only have a couple possible outcomes. Is a pulley going to give me 2000 more RPM? Is it going to cut out still at 6900 rpm and blow my motor?

If I get it to work better, its going to get tuned for the extra fuel pressure. The Mechman will go to 9000rpm without cutting out. If it cuts out of the reman alt its going to lose so much fuel after this I'm afraid I won't just see the wideband angry. I'm afraid the engine will go before I can tell it happened.


On top of that I cannot find any underdrive pulley on ebay except the $50 billet one. I searched as many ways as I could and could not find that steel one in the picture above.

Forcefed86

iTrader: (4)

Thought I put a link directly to it? search "6 groove 17mm pulley" pops right up. All kinds of different sizes. But I hear ya. No need to under-drive the mechman.

AwesomeAuto

My stock DR44G holds 13.8volts at 7400 RPM.
A buddy of mine with the same alt had to use the larger 2.85" pulley to get his to hold voltage above 5500. We both run the exact same ECU with the same resistor going to the alternator.
Its strange how it works out some times.

jayyyw

$300 JS Alternators 250amp alt holds 14.5v to 8250rpms. I'm even over-driving it, slightly.

LetsTurboSomething

So I got the new pulley installed and got a new belt on it. It raised the limit to 6400 from 5400. But it didn't really change anything, when the voltage drops, the pressure is the same. When I went past the old point where it stopped charging and dropped voltage it didn't actually raise the fuel pressure when it had full voltage. So even with a full 14v supplied to it the pressure is still steadily dropping from 58psi after for boost over 6psi...

When it drops voltage at 6400 now, you can't even notice a fuel pressure change along with it and its going from 14v to 11.5v.

47ford

a lot of times the most over looked part of an electrical system is the size of the battery cables. When I relocated my battery to the trunk I used 2/0 wire to the starter and a 2 gauge cable to the alt. Also I found a fuel pressure drop because I had the relay too far away from the fuel pump. Something to think about, hope this helps !

tblentrprz

If measuring 14V at fuel pump and fuel pressure is dropping under higher fuel demand, possibly pump can't keep up or fuel delivery restriction (filter, lines, etc). Maybe regulator issue? Reg after rails and boost referenced?

Forcefed86

iTrader: (4)

pump/plumbing/filter must be an issue if it still drops with confirmed voltage at the pump. Try the filter,,, remove the element for a quick blast.