How to: MAFT Pro Boost Control

StefanLarsson

Viking
Jun 26, 2006
47
0
0
Sweden
I would really like this info too, but no matter how hard I want it I still think you are doing a great job for the community!
Keep up the good work...
 

drjonez

Supramania Contributor
Mar 31, 2005
3,061
0
0
18
the motor city
www.4cefed.com
in the interim, check out rich's writeup:

-Rich87Tx2 said:
I wrote this a while back. You might find some of it useful. It may be for ver. 4.4. I don't remember for sure.
-Rich

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The MAFT-PRO boost control is pretty easy to use. It's almost the same as the AVC-r. The 'problem' (for me) was that the start duty default was too low, like 20% and my actuator was too loose. I tightened the actuator to 13psi without the MAFTPRO. When the start duty was 20% (low), nothing seemed to work as described. I brought that up to 60-80% and everything started to work as the book described.

Based on what I know about the AVC-r and the MAFTPRO, I'll toss the following intot he mix and see what turns up:

What the MAFTPRO manual should say about boost control is set your actuator to the minimum boost you want to run WITHOUT MAFTPRO correction. Then set your target PSI to what you want (19psi), set Start PSI to 3 psi less than that (16psi), set start duty to 50%, set your TPS and RPM to slightly above normal cruise, set your gain to "10".

****This means you will build boost quick on the bottom (until Start PSI is met), but the actuator will start opening too soon, and too quickly. <- safe

Do a third gear pull and log your boost. The line for solenoid will spike when the turbo is trying to build boost (100% solenoid duty). AFTER THAT - If the line goes up raise your start duty. If the line goes down, lower your duty. Try to get a line that starts out fairly level. If you boost goes to target and then drops raise start duty. If you boost spikes, lower start duty.

****Adjusting start duty adjusts the amount of air getting to the solenoid/actuator *initially*. The gain controls how quick the solenoid can self adjust thereafter. For now, you want to adjust this percentage to get a level line after the spike.

Once the solenoid line is fairly level after the spike, raise the Start PSI until you get a little boost spike. Lower it a bit to remove the boost spike.

****Similar to the above. On a large, laggy turbo you can build boost fast, then slam the actuator with alot of air at the last minute to avoid a boost spike (High Start PSI, low start duty). Alternatively, you can apply less air initally but apply it earlier to prevent boost spike (low Start PSI, High start duty). It may be desireable to do the latter to take the edge off a really hard hitting turbo.

Lower your gain to ~4 and hopefully you'll enjoy stable boost.

**** Lower the gain to ~4 and make sure your boost stays stable. If the gain is too high, boost can fluctuate. If it's too low, boost may creep up/down.

That's my take on the AVC-r / MAFTPRO boost control. Comments welcome....
 

joeytvr

New Member
Apr 3, 2007
112
0
0
Louisiana
the above helped me alot running 15psi. However I have tried to turn things down to 10psi, i have a 8psi spring. Cannot stop it from spiking around 15psi?
 

JimR

Supramania Contributor
Mar 30, 2005
304
0
0
Canada
joeytvr said:
the above helped me alot running 15psi. However I have tried to turn things down to 10psi, i have a 8psi spring. Cannot stop it from spiking around 15psi?

I can't help myself because I don't have the boost control hooked up yet, however I'm pretty sure that if you posted all your bc settings, it would really help others to pinpoint.

Here's the list:
- TPS Spool:
- RPM Spool:
- TPS Start:
- PSI Start:
- DC% Start:
- DC% Aux:
- PSI Set:
- PSI Aux:
- Gain:
 

joeytvr

New Member
Apr 3, 2007
112
0
0
Louisiana
I had the DC% to high. lowered it to 25 and works much better. However I am going back to a manual controler and selling this one.