Boost duty drops to zero after activation

[Eaallred]

Hey all,

Is there a setting that i'm missing that controls how long the boost duty cycle stays up after launch? Last year it was staying on for about 30 seconds before dropping to zero, and now getting the car back together after a winter tear down it is only running for about 5 seconds before it shuts off.

What will cause the boost duty to shut off? I need to get the car on the dyno soon for tuning, but if it won't stay up on boost for a full pull it's going to be tough to get anything accomplished.

Anyone else have this issue? Know what might be causing it?

Thanks

[Eaallred]

Aaargh! I think I found it. If someone can confirm that would be great.

In my Boost %age after launch window the top left drop down box gives me "Set History Timeout".

Is this the number of seconds after launch that it will remain active before dropping back off to zero? Hope so, would make perfect sense.

Car is in the trailer, and trailer is backed up into storage so no easy to get it out and give it a quick run to check it out.

Thanks to anyone who can answer that, thanks again!

[Barton]

you launch boost duty es 0%, but why do you have 100% of duty (boost table) it will make the boost to rise until your boost hits the boost cut value.

first you need to set your boost table then set your boost duty % to get you desire boost at launch.

use overboost protection: both (4 sparks from 4 events).


I recommend to use closed loop 10000000000000% if it is cofigured right, with a big turbo is brutal.

[Eaallred]

I have it at 100% because it doesn't boost higher than 24-25 psi at 100% That's right where I need/want it to run

I just took it for a spin, I have the "History Timeout" set to 60, but the datalogging shows my boost duty go up for about 32 seconds then turn off. Inside the car I can hear the boost controller ticking for maybe a second is all (Last year I could hear it tick for a good thirty seconds or so). I've got to be missing something. I'm not getting any more than 10 psi (wastegate spring) out on the road. Most frustrating because it did used to work. It just doesn't work this season now.

[Eaallred]

Anybody?

Does having this boost controller (the one from DIY) go bad from vibration or heat very easily? If it is a boost controller failure, has anyone seen one that will tick for a second and then nothing? 'Is that the tell-tale sign that is' gone bad?

I've attatched my latest tune that I drove with and a datalog of a practice launch if it helps

[muythaibxr]

I'll try to take a look later this evening.

Ken

[Eaallred]

Small update:

Phil at DIY recommended I try some oil in the valve since the car sits for extended periods of time. I ran some PB Blaster oil through it but no change.

I trigger the launch control and the solenoid clicks for a second and stops. I can do this repeatedly over and over again.

Don't know if it's a 3X board issue (driver?) or a solenoid issue.

[chips60bug]

Does your datalog show the boost duty itself tapering off? Or just the pressure tapering off? can't see the log on my phone. Sorry. Didn't your old 3x do exactly the same thing. Or is this the only one you've really had running in the car since the rebuild? Have you tried the most recent code release? I think there were some boost control changes made that might be helpful. Might be time to give closed loop boost a shot since you know overboost isn't gonna hurt it

[jsmcortina]

Hey all,

Is there a setting that i'm missing that controls how long the boost duty cycle stays up after launch? Last year it was staying on for about 30 seconds before dropping to zero, and now getting the car back together after a winter tear down it is only running for about 5 seconds before it shuts off.

Where is this in the log?
The log you posted shows the boost duty ramping up to 100% and then dropping back to zero at ~30 seconds. That is a code bug, however, the "boost delay from launch" was primarily intended for a drag racing application and 30 seconds is too slow for the timing gear at most tracks...

Targetting full boost at 0% TPS seems like a strange idea too.

James

[chips60bug]

This is a drag car. I just saw your(James) comment on the after launch timers and was going to mention that, glad you did instead.
Main reason for bringing in the boost at low duty is to save our weak, yet expensive "built" ACVW transmissions. I'm betting that 100% duty at no throttle is just because the boost is meant to be full asap. Basically an electric 25psi spring in the wastegate.

[jsmcortina]

This will be working correctly for firmware 1.3.1.

James

[Eaallred]

Yes, this is the second 3X board I've had in this thing so far. The first one failed, not boost control, but I think it was a couple of ignition drivers conked out if I remember right.

I may just buy another 3X board and throw it in. Work on better vibration isolation to the MS while it's apart. I am suspecting that is the issue.

I have the whole table set to 100% because having it lower anywhere on the table doesn't' matter. It's all for the drag strip. If I get in and out of throttle, etc, I don't want things to change. I just want the boost controller to come on for about 30 seconds after launch at the ramped up rate that I have setup (or can tweak to get the car out of the hole).

[Eaallred]

Okay, here's my "DUH" moment.

Having the controller at 100% means it won't click because it's fully open. I'm an idiot. haha So when I hear it click for a second and then stop, it's the controller getting to the higher percentage and stops clicking to be wide open. I put everything down to 50% and can hear it click the whole time, no problem.

I am starting over with a new tune this year and it's still pig rich. I believe that is why I am not getting it to boost like it should. My tune is still way too far out. I'll get some dyno time in and it should be back to where it was.

Sorry for the false alarm. I appreciate the help guys!

[jsmcortina]

See:
http://msextra.com/forums/viewtopic.php?f=125&t=53611

James