Testrun

As the title says. If I could get a could get a few "good" voltage logs to look at so I can compare to mine it would be majorly appreciated!!!

Thanks.

XanderCage

iTrader: (1)

Here's a general drive around. Standard alternator, nothing special with a Greddy underdrive pulley. Battery located under hood in stock location. Pretty stable.

Testrun

Thank you very much. Looks nice and solid!!

arghx

iTrader: (3)

you might want to specify where the voltage is being measured and any other important context such as condition of harness, ambient temperature, electrical load, etc.

Testrun

That's a good point. Wouldn't all the ecu measure from the same source?

Testrun

No one else?

DaleClark

iTrader: (55)

I'll do this at some point, may be a good excuse to get the FD out of the garage for a bit

Dale

Testrun

Now we're talking!!!

dk_davis

This was a 3000 - 7200 rpm pull during a drive at night. i.e. with head lights on. Also the radiator fans were on. The trace shows the voltage dropping as the load increases with dips when the second fuel pump kicks in (3 in total, Walbro 274's) and another dip when the water injection pumps starts. During the day these values are about 0.5 volts higher. This is the voltage as seen/reported by Haltech 2500 ECU. Stock FD alternator, Greddy under-drive pullies, 4 coil direct fire.

Testrun

Thanks DK. So that is very interesting to me as I would have heart palpitations if I saw my voltage drop that low.... if I am looking at it correctly. So your AFRs are solid and no issues with any of the spiking?

estevan62274

iTrader: (32)

He has a Haltech 2500 so I’m sure he’s running the injector dead times/voltage
table and such for his injectors.
Once you go with the a newer ECU you see all the benefits they can do👍

My voltage is about 12.8 to 13.2 and AFRs are good no matter the voltage.
Also fuel pressure is a key factor to log/monitor.
My fuel pressure under boost never falls off regardless of my noted voltage. If it falls off a certain amount in boost then engine protection kicks in… same with AFRs.
I’ll post a log up.
Steve

dk_davis

Yes, AFRs follow my target goals well and boost line is very smooth, but this is a parallel stock twins setup only going to 12ish psi.