Right, so I have a Profec B Spec II. Im going to upgrade to an AVC-R or the EVC unit somewhat soon, but for now this sucker needs to work.

I run my car daily on a low boost setting (17-18psi) and I am getting boost spikes in 3rd gear. I typically spike to 1.3bar then settle to 1.15 to 1.2 bar.

Settings:

Set = 37%
Gain = 3
StartBoost = 1.10KPa
Warning = 1.60KPA

The odd thing is, I dont get boost spikes using my high settings which is like:

Set = 58%
Gain = 5
StartBoost = 1.10KPa
Warning = 1.60KPA

I have the third little cap removed and everything, any ideas what might be causing the spike?

 

Your start boost setting is causing the spike. If you don't open the wastegate until 1.1 kpa, it won't be able to stop building boost by 1.15-1.2. Try dropping that down to 1.0 or so, that should get rid of the spike.

-Paul

 

Oh jeez, good call. I didnt even think of this.

Thanks

 

You can set that gain to 10% trust me you will notice the difference

If you change it to psi here's what you need to do.

Set : 35%
Gain: 15%
Start Boost: 14 psi
Warning: 22 psi

IF YOU SET THE WARNING TOO CLOSE TO WHAT YOU WANT TO ACHIEVE IT WILL AUTO OPEN ITS SELENOID TO FULL DROPPING ALL THE BOOST.

 

I thought that if you set the gain above 5 it starts spiking?

 

It doesnt
IF you do not put your set that high

Remember the Set on the profect B is how much you want your turbo to work, if you put 35% thats how it will build boost at 35% efficiency, BUT by using the gain at 15-18% you get that turbo to spool like a maniac, spikes happen when you forget to set the (Set Gain) Start Boost if you put it too close to the boost you wish to run then it will spike as the internal seleniod wont open in time.

 

Interesting! I will try this out for my high (autox) settings tonight on the way home from work.