Ballast resistor - Yes or No?
Turbo Mini Forums

Why is their a ballast resistor fitted in the fuel pump power supply to the MG Metro Turbo and the ERA Mini Turbo, after all it's a 12v pump fitted into a 12 supply?

Their seems to be two main theories
1. To extend pump life
2. To keep pump temperature down

Time to run some tests. After installing a ballast resister into the fuel pump circuit, the voltage to the pump dropped by 2.5/3 volts; this had an immediate effect of slowing the pump down, which in turn made the pump produce less noise and vibration.

The theoretical benefits of this:
1. Pump not straining as much, therefore should extended pump
life/reliability (obviously the pump is circulating less fuel).

2. Pump runs cooler, therefore not passing on as much heat into
the fuel system.

3. Pump pulls less current/voltage, therefore putting less strain on
the charging system, in turn taking less power from the engine.

So for a standard/mildly tuned road going A series Turbo engine I would recommend installing one for the above reasons, but for an out and out monster which require excessive fuel, probably not.

no one bothers!

alex

AlexF

True no one bothers - but if the engine is only developing 90bhp - then the fuel pump is wasting energy pumping an excess amount of fuel through the system.

On a standard road going car I think limiting the pump is a good idea.

i was reading a jap magazine and one of then had a raditor install under the seat to cool the fuel

is there much gain to running cool fuel?

what if you run the pump ballast resister on the fuel pump and fit a pressure switch on the plenum chamber so when on boost the switch bypass the resister for full pump out put on the pump

1293 Turbo mini

I tested my fuel pressure last week and it was 4psi with ballast resistor and with out,will leave it there as its quieter.....well till I get 20psi boost pressure then will change it to 12 volt

Metro turbo weekend driver,Mini turbo in the making again!