Greddy td04 Boost creep/spike
 

Hello again. I seem to be having a problem with boost creep or spiking, not sure which is the correct term.
Using closed loop, and also open loop the following happens. Using ms2pnp/mac valve.

Symptoms: On a 3rd gear pull from say 2000 itll hold 15ish psi roughly, with some fluctuation/occilation of around 1psi, mostly due to having minimal PID tuning. This is what I was expecting.
If i drop from say 4th to third, or roll on and hammer the throttle into 3rd however itll spike up to my boost cut of 225kpa, or 17.9psi.


Is this a tuning issue that I need to keep playing with PID? or a mechanical wastegate issue. If i switch the boost controller off itll start off at 6psi and settle on 8psi till redline. It doesnt look like it has the stock actuator, its the same style but has 2 ports. Would changing to a 3 port setup on the solanoid make any difference?


I have sensitivity on 0, P200, i10, d0 so far
Another thing is when the closed loop is set to "normal" the solanoid is always clicking, if i change it to inverted it stops, in open loop however its correct as more duty = more boost. Should I leave it on inverted?

the wastegate on the td04 is really small and tends to spike. My old GReddy setup would hold 15psi but with an initial 17-18psi spike.

Sounds like you need to tune the PID controls a lot more. There are some good posts on how to start in open loop and then progress into closed loop.

Did you resolve it at all? would porting wastegate help or is the spring too weak?

I would have thought a P value of 200 was pretty high and should stop spiking. I also had D and I 20 as well with no real change.

Moar tunnee!

I remember I had added a helper spring so that the gate would actually hold boost. The stock wg can was really bad. I did port the wg on the turbine housing and it helped the spiking issues to some extent. I think I ended up using a different wg can with a stronger spring and longer throw to open the flapper farther.

Sweet, going to pull it apart and see then.

Did a race meeting in the weekend and at ~13/14psi its not spiking under full acceleration but only on part throttle. So if im half throttle around a corner itll just keep spooling till it hits boost cut, not a nice feeling. But if i stomp on it itll be fine. So i was havign to use a higher gear, roll through the corner with foot flat and hope it spooled by the time i was around the corner and pointing in a straight line. Or leave it on wastegate for corners and flick to to high boost when i exited. Rather annoying.

What are you using for boost control? Manual or electric boost controller? That's odd it's over boosting at part throttle. I think you need a stronger wg can with a 1 bar spring. It'll hit 14-15psi without any assistance from a boost controller. Or if you want to run less maybe a can with a 12psi spring. I run a 14psi can on my gt2560r and it's great.

MAC valve like the diyautotune one to ECU on open loop. Yeah tis weird because it wont spike doing a 3/4/5 high boost pull on around 14psi, but will spike on partial throttle. I even drop the DC under 80% throttle position to like 10%, which should be about wastegate but still does it.