Just want to see if any one has a drop like this

14v all the way to peak boost 1.1bar ish then as it starts boosting it drops to 13.71v

 

Are you certain nothing else happened like the electric fans coming on?

 

The load on the fuel pump increases with boost which may result in a voltage drop as pump current increases.

 

If your alternator can't keep up with the load, it needs to be upgraded.

 

Perfect info guys
This test was a check over of evrything before i increas my boost
But i will sort this out i would prefer stable voltage at loads

The fans already on, headlights were on few min proior to this load test

I was leading into the fuel pump way to
But as you say the alternator should be able to keep up with the current demands
This is good thank you
Im gona put a amp clamp on battery and test how much current it draws under boost and ill get back with more info
It is a 20 year old alternator
Is there a way to modify the internals ?
For a little higher amps ?

 

This might help you out.

IRP 140 Amp Alternator | IRPerformance

 

Thanks for that im looking into better alternator
battery drained to 12.2v and using amp clamp on im getting 22amps

 

22 amps is a lot of draw.

 

22amps at 1,300 rpms? Sounds about right. I'm a Haltech guy and don't recognize the software. What ecu you running? How many ignition coils?

 

It says "MoTeC" at the top of the software window.

 

My idle is set to 1400rpm
I have 4x ignittion Aem smartcoils
Sorry its motec i2 software
Ecu is motec m2r