Brutal turbo transition 10-1-10 Log posted
 

I did some work on my RX7 over the winter. Everything seems to work well except the transition from primary to both turbos
I've attached my map and the relevant log

Do you guys see anything that should be changed from a tuning standpoint? Or anything fundamentally wrong with the way things are working?

The 2 winter modifications that may impact this are:
1) New fuel system. New pump/FFE fuel step-up kit/rewire. Kept the stock primaries. Fuel pressure is ~41psi

2) Replaced turbo control solenoids with 3 way MAC valves. Set up as per this thread - https://www.rx7club.com/3rd-generati...lenoid-531676/
I am no longer using any pills from the stock system. People say that with the MAC valves you don't need them, but maybe I should put some back in?

3) Silicone hose job. I tested the other solenoids, they all work properly. I was careful and I believe everything is hooked back up properly.

4) Air pump/ACV delete. I installed a delete kit from FFE and blocked off the ACV.


I know my AFRs need a lot of work, I just want to get things functional before tuning things properly.

The map couldn't upload as a .dat file so I changed the file type to .apk. Change it back to .dat to open it in FC-Edit.

Thanks!

I see only one PreControl reading in the log but the WasteGate has more.
I assume that your Settings 1 Turbo Transition values are stock and the Function Select Seq. Turbo Control is checked.
If so, your solenoids are nothing working properly.

This might be a weird question, but does the DL log the signals sent to the solenoids? Or does it log the actual activity of the solenoids?

And it looks like maybe the WG is behaving properly, but the PC is not?

I took the PC solenoid off (3-way MAC valve), took it apart and lubricated the inside. It seems to respond to 12V faster now than it did prior to lubrication.
I put the system back together and went for a couple pulls. Things seem to be improved, but they are still not very smooth.
Charts and log posted below
I might order another valve to replace this one to see if it fixes the problem

Current pattern is more like 11-7-11

Any other suggestions of what I should look at, based on the charts and log?

This time I see many pre-control values along with the waste-gate values.

The stock system used the pills as a way to fine tune pressure buildup for the stock PC and WG actuators. Most likely that is your problem! Read attachment. Either reinstall pills or install small water brass valves for fine tuning.

hey, just saw this thread. What are your current boost control settings and turbo transition settings? Looks like the secondary setting (after transition) boost is too low, so the feedback is wigging out.

I think they're the stock boost/transition settings (other than the "low" transition value, which shouldn't affect this)
It's been raining for a week here. Next time I take it out, I was planning to increase the primary and secondary boost settings, but decrease the duty cycle on both, to see if that's an issue
Maybe the car wants to boost creep and my solenoids are freaking out trying to keep the boost level in check?

Those duty cycle settings are probably way off for the MAC valves. They are meant for the stock 2 port solenoids with restricter pills. Try cutting them in half and adjust from there.

I adjusted the boost/duty settings and the terrible transition is gone :nod::icon_tup:
I need to tinker with it to get it exactly where I want it, but it doesn't fall on its face anymore

However, I'm now often getting the bouncing boost that I got last year (prior to installing the MAC solenoids, doing the vac hose job, testing the stock solenoids, installing DaleClark's check valves, removing the pills, eliminating the air pump/ACV, and doing some other work).
There are a minimum of vacuum lines involved now, and not many common relevant elements compared to the old setup :egrin:

Here are my boost settings and PFC charts :scratch:

Here's what you need to do. Put it in 2nd at 1500rpm and floor it up to 7500rpm. Set the Primary and secondary boost and duty the same for now. Run the following patterns:

Pr .70 25%
Sc .70 25%

Pr .70 30%
Sc .70 30%

Pr .70 35%
Sc .70 35%

Pr .75 25%
Sc .75 25%

Pr .75 30%
Sc .75 30%

Pr .75 35%
Sc .75 35%

Save a separate file for each pull. Go through each file. Make a spreadsheet and record the peak peak boost under primary boost operation and under secondary boost operation. Also make an assessment of whether it is oscillating (A lot/A little/No).

Post the chart here (screenshot of it is fine). This is what tuning is all about, when it's time to get more methodical than random guess and check.

Thanks again ARGHX, I'm slowly walking through it :icon_tup:
It takes a while because I need someone else competent to work the laptop while I drive :lol:

Here are 2 charts showing (I think) normal behavior of the solenoids. The charts for all of these runs looked fairly similar.
Also attached is the spreadsheet of info from all of the runs.
Obviously my boost is still lower than desired, so I'll need to keep working on getting things where I want them.

Do you suggest continuing (and logging) the increases of 0.05 in target boost? And maybe switching from logging 25/30/35 duty to 30/35/40 as well?

Should I have my secondary boost/duty settings slightly higher than primary to get the x-y-x pattern back, or should I wait until I get closer to my general target (13-14 stable psi) before being concerned about that?

Maybe I got my hopes up too soon :lol:
Looking at the logs with fresh eyes (and after doing 0.80 - 35 and 0.80 - 40) you can see the distinct waves in the secondary boost levels.
I imagine it would be more obvious in 3rd gear because I would be in gear longer, but you can see it (to some degree) in every one of these logs.



Pre-transition looks fine, but post-transition has bounces. No obvious cut-outs in WG/PC solenoids (like there used to be). I don't know what is going on with this. :scratch:
Are these bounces minor enough that I should disregard them?
The only other thing I can think of would be to remove the twins to check the physical wastegate solenoid/flapper, but that's a lot of work that I would rather not do

Here is the chart from the 0.80 - 40 run in 2nd gear
Bounce bounce bounce

Sort of talking to myself now, but next time I can take the car out, I'll try 0.85 - 35 and 0.90 - 35.
The bounce became more pronounced at 0.80 - 40, so maybe the duty was becoming too high for the target boost level.

Honestly, it doesn't look too bad to me, but a lot of that depends on the scaling of the map which can be deceiving. I mean I don't see anything "wrong" with your car. You can have slow response of the feedback system or a bit of overshoot (the bounce). Boost fluctuates all the time, but if you've got some autometer mechanical boost gauge you're eyeballing you're not going to see such a fast oscillation.

I mean that last one (0.75/35) in the chart it's hitting almost 11psi and tapering down to 9 after transition--which is basically what a stock car does. I'm reading your sig and it says you have a catback and intake. Is that it? I mean do you really want the boost to go higher?

You can slightly adjust the secondary boost by changing it individually from the primary, if you are happy with the primary. So you can do 0.75/35 primary (or whatever) and then do 0.80/40 secondary, and do the combinations again. It's a tedious thing, but tuning can be tedious.