MyE28.com DEV

Posted: **Apr 16, 2015 7:00 AM**

I am getting a bit of a surge (2-3 PSI) when the waste gate opens, I have this boost controller and it's setup for the external WG. Can anyone point me in the right direction?

http://www.diyautotune.com/catalog/ebc- ... p-285.html

Here are my settings.

Posted: **Apr 16, 2015 10:03 PM**

Screen shot one of your spikes.
There's this slight spike I could never really tune out but it was like 2psi pretty acceptable I think but
ya, it bothered me too.
you can just raise the target 2psi to keep it silky smooth.

I haven't tuned my car in a long ass time so this is all I have.

Before and after when I got the pid down.

Found this one when I was smoothing out the map. Notice no initial spike.

Good luck!! Not allot of people use this cheat mode upgrade for some reason.

Posted: **Apr 17, 2015 11:28 PM**

I put in your exact settings and it couldn't control it, I played around with it for a while and ended up at 32, 3, 11 and it seems to do better!

Posted: **Apr 18, 2015 12:43 AM**

At first the smallest numbers like you had in your first post will seem like you're really really close except for
an initial spike... The more you try to tune the spike out the more erratic it'll get then when you tune that out the spike will return.

So, after tuning and cycling through the same chaos you end up with big numbers but the spike will be no more.
I know you know how to tune it but just to help more people do this great mod.

http://www.e30tech.com/forum/showthread.php?t=117583

"P" will put boost in the target range, Start with 100 and work down.
Most people end up with 10-20.

"I" will flatten out the boost drop/tapper that you will see at the end,

and "D",
"D" will flatten out osculation that too much "I" creates.
You will see boost osculate when increasing the "I" so "D" will smooth
that out.

It's important to know when you increase "I"
then "P" will need to be increased because boost will rise.

Also, it's important to know when
adding "D", it would also need some "I", but when
increasing"I", then "D", needed to be brought up yet again.

Basically "I" made it osculate and "D" made it smooth
but tapered boost down. Never ending cycle.

So if there's a spike you can't really smooth out by acouple kpa it's ok.
it might look bad in logs but acouple kpa is nothing.
1-2psi spike is nothing.

Posted: **Apr 18, 2015 12:50 AM**

Shadow wrote:At first the smallest numbers like you had in your first post will seem like you're really really close except for
an initial spike... The more you try to tune the spike out the more erratic it'll get then when you tune that out the spike will return.

So, after tuning and cycling through the same chaos you end up with big numbers but the spike will be no more.
I know you know how to tune it but just to help more people do this great mod.

http://www.e30tech.com/forum/showthread.php?t=117583

"P" will put boost in the target range, Start with 100 and work down.
Most people end up with 10-20.

"I" will flatten out the boost drop/tapper that you will see at the end,

and "D",
"D" will flatten out osculation that too much "I" creates.
You will see boost osculate when increasing the "I" so "D" will smooth
that out.

It's important to know when you increase "I"
then "P" will need to be increased because boost will rise.

Also, it's important to know when
adding "D", it would also need some "I", but when
increasing"I", then "D", needed to be brought up yet again.

Basically "I" made it osculate and "D" made it smooth
but tapered boost down. Never ending cycle.

So if there's a spike you can't really smooth out by acouple kpa it's ok.
it might look bad in logs but acouple kpa is nothing.
1-2psi spike is nothing.

This is gold, thanks!

MyE28.com DEV

PID Boost control settings

PID Boost control settings

Re: PID Boost control settings

Re: PID Boost control settings

Re: PID Boost control settings

Re: PID Boost control settings