jayswizz

Sooo I see on my datalogs that my voltage is dropping to 13.1 volts under full throttle. It should read 14 volts or above correct? It was at night so high beams were on. Also have a hardwired walbro 450. I leaned out on the dyno and I'm thinking this could be the culprit!

2kdrift

I am not sure what its supposed to be but my data logs show the same and my car is running fine.

what hp did u lean out at? injectors? aftermarket fuel lines or OEM? Type of fuel?

also not sure why you hard wired the fuel pump seems like a good way to overheat it, im on a walbro 250 @410 HP with factory wiring to pump

u sure u dont have one of those fake walbros ? If you are near the max of what your walbro can do its best to do the upgraded wiring with a relay

jayswizz

My fuel setup is NOT the issue. It should support well over 700. I leaned out at 500. The pump is real and also is wired straight to the battery with 8 awg wire and a big relay... not sure what you thought I meant when I said hardwired. From my understanding 1 volt to these pumps can make a difference of about 100hp

VegaS10

You need to find where the voltage is reading from.

Your alternator may be putting out 14.4 at high rpm, and as long as there is no connection issues, your battery should match the alternator's output. You should take your measurement from the input AND output side of your relay.

Some of the larger ones like the Stinger (AAMP) or PAC SR200 style relays have up to a .7 volt difference due to the internals on the relay contacts. I'm using a smaller Bosch style 40 amp relay on mine with no issues.

Read the voltage from both sides of the relay under the conditions you listed and get back with us.

jayswizz

i would imagine the datalog is taking the voltage from the ecu but i could be wrong. testing the alternator with a volt meter i have 14.4 volts at idle. voltage at the pump before and after the relay is 14.2 to 14.3 volts. when under wot since the datalog is saying 13.1 volts does that mean the pump is only seeing 13.1 volts? this is what i am wondering

2kdrift

I dont think this is the problem, I am on a fuel pump nearly half the size of your pump, I also have 13.1 in my data logs and im at @410 I would suggest looking elsewhere I really dont think its a voltage issue

VegaS10

You would have to take that voltage reading at the fuel pump side of the relay while at WOT.

I also believe your issue is not voltage related.

jayswizz

i am kinda doubting it being an issue as well, i just wanted to make sure before i get back on the dyno. i have changed the filter on the pump and the inline filter. sent my injectors out to be checked, which came back fine. i also flushed the gas tank and put in a new batch of e85. ill see what happens on tuesday