dax turbo

iTrader: (1)

got a cossie engine in a dax rush and after some advice on here i thought i'd better check the pump voltage under load especially as i'm running a 044 and a feeder pump to a swirl pot in series. I've done the rewire as suggested on here and i'm seeing 11.5 - 11.9V at the pump..(lights on makes a difference 0f 0.4V ish) alternator may be the culprit as car only shows 11v after start up until minute or 2 of running then goes to 12.3V so slight voltage drop...however someone has said that should be charging at more like 13.5V.....

Questions;
1) is 11.5 - 11.9 too low at the pump?
2) do i need to get the voltage up to 13.5V when charging to increase v at pump?
3) if so what alternator do i need (loads at burtons!) as u can imagine only electrics in the car are lights and horn..no heated screens, radios etc...

thanks in advance,

oldford

Start by getting a new/revised alternator. You're not getting very far at night now.
Just to make sure: is the wiring for the alternator correct?
Does the warning light go on at ignition on and off when the engine is running?

dax turbo

iTrader: (1)

Oldford,

new alternator it is then...any recommendations? (don't need to power radio, screens etc...they just add weight)

tabetha

Use any alt that you can fit on, most jap cars run internally cooled alts so would be a good look.
The voltage ideally needs to be nearer to 13.4/13.8 once running with no lights.
A few oddball french cars have single phase alternators, these are super lightweight, less than 1/2 the weight of the cossie one, much much smaller, but only around 30amps, which is more than enough for your use.
tabetha

Stu @ M Developments

iTrader: (12)

You should measure the voltage under load and want to see in excess of 13 volts at 5000rpm under full boost in 3rd gear with the lights and heater on.

If you havent got it at teh pump but do have it at teh battery you need a simple pump circuit rewire. If you dont have it at the battery you need to asses the charging circuit for deficiencies.