Hello

I´ve been tuning my engine and logging it with TTS datamaster.
When I drive it normally or at idle the logged voltage is around 13-13,5 V which seems just ok, but when I floor it the voltage drops to around 11,5-12 V at WOT.
Has anyone had this kind of problems?

I used a multimeter and checked the alternator, the readings was at 14,4 V all the time at idle.
Is there any other good places to take measurements at?
Where does Datamaster take its readings? Is it alternator voltage or somewhere in the system?

The power seems a bit low considering the mods I have, maybe this is the problem?
My mods: Rebuilt motor, Brodix IK180 heads, flat tops, Hooker headers, full 3" exhaust no cat, fully ported base, AS&M runners, ported plenum, XFI268 cam, roller rockers, AFPR, 2200 rpm converter, 3.27 rear, custom tune.

I think this car should be pretty fast, but it feels like something is missing.

Thanks

 

Can't help you with the Datamaster but I would suspect maybe a problem with the Battery. The alternators primary function it to charge the battery and the battery supplies the power to the car. If the battery and alternator is good the voltage regulator should maintain the right voltage especially at speed. 13-13.5 might be a little on the low side of the scale most I recall run 13.8 to 14.5 or so. Have a good load test on the battery, preferably some who does not use the electronic tester, someone with a good carbon pile load tester to get an accurate result. If it is done right the battery should be charged at 2 amps for 18 to 24 hours to ensure a good full charge.

Hope this gives you a place to start.

 

Thanks, I´ll check that.

When I put the multimeter on the battery, car off, it reads 12,4 V. This looks ok but maybe something happens under load.

Will a WOT run put that much more stress on the battery to give these symptoms? Compared to "normal" driving.

BR

 

It will some due to more power required by the dist to burn the higher fuel volume you are putting to it. But the alternator should compensate with the higher RPM's. You might notice some with the datalogger but the drop you were seeing is too much, Unless you are running a big electrical load and plain overloading a 60amp or so alt you shouldn't see that big of a drop.

You might also check that you have good voltage to the plug on the alternator, that is what the regulator uses as its reference, could possibly be the alternator itself.