I need some guidance. What Id like to buy or create is something to step down the voltage to a pump. I would like it to be adjustable as well.

Its purpose. im running a remote setup on my car so I have a scavenge pump for the oil drain. I would like to drop the voltage to 6-8v while the cars not boosting. Then either at high rpm or as soon as it makes boost fire back up to 12-13.? volts.

 

blower motor switch or interior light dimmer switch

 

I'd say it depends on the current involved.

 

You'll burn out the pump. Best bet is PWM control, contact Dan Nicoson of www.myo-p.com. I dunno how far along his PWM controller is, but that is one of the things he is working on.

FYI, what sort of pump are you using? Most of those are expensive... and the cheap electric-hydraulic pumps I know of (all are electric PS pumps) are pretty bulky and heavy.

 

MR2 pump, 10 lbs, pick it up for 50 bucks used, draws quite a bit of current though.

 

As opposed to Subaru XT6 pump, 85 lbs, bigger than a starter on a '91 Ford F-150.

 

Holy ----, that's enormous.

RR/AutoX forum on H-T, thread should still be on the first page. I'll link it later if I remember to.

 

I am exaggerating the weight... XT6 PS pump is smaller OD, but longer, than Ford F-150 starter. Still very sizeable chunk. If I had to kill anybody with it, for speed and accuracy I'd insist on using two hands.

 

its an electric fuel pump low pressure unit. Its going to be used as the scavenge pump for my setup but I want to scale the voltage down when its not in boost/high rpms. Once i reach either boost or anything over 4g I want it to pump back up to full power.

 

get a rpm switch and run it to a relay for the 6 when on and 12 on at high rpm