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-   DIY Turbo Discussion (https://www.miataturbo.net/diy-turbo-discussion-14/)
-   -   Overboosting/boost creep (https://www.miataturbo.net/diy-turbo-discussion-14/overboosting-boost-creep-78400/)

Harv 04-11-2014 09:50 AM

Green red wire you say?

Well, that's fantastic since I'm red/green color blind. Wait, does the wire say BOOST on it or is that the pin selection in the software?

Braineack 04-11-2014 10:02 AM

the wire leading up to the MS should say it.

it's almost almost built like this:

spark c, spark d, fuel c, fuel d, blank, EBC, blank, o2
Y/G, Y/P, W/G, W/P, N/A, G/R, N/A, P

Harv 04-11-2014 10:51 AM

Okay, saw your PM. Lemme go look at what is coming off the harness then and take some pics. BRB.

Twodoor 04-11-2014 11:59 AM


Originally Posted by 18psi (Post 1120539)
that's moronic

that's like having a supermodel girlfriend and using a fleshlight while looking at her

I'm not recommending it, just saying if he don't want to port the WG or go external it is an option.

Keith

Harv 04-11-2014 12:04 PM

I've got the fueling and the computer to do 10psi no problem. The clutch might start letting go, but I've also got a new clutch waiting to go in once this one goes.

Harv 04-11-2014 01:07 PM

I'm amazed that I wired it correctly just completely by accident. Once I tested the boost output I could hear the solenoid clicking. Whoot! Who knew that Boost = Boost? :loser: :noob:

So, I loosened up the wastegate as the DIY folks say to lower wastegate boost down and then tune from around 2-3psi.

Harv 04-11-2014 02:18 PM

So, I think I have the boost solenoid setup properly. At least when I do a test in TS with the Boost the solenoid clicks.

The boost protection cutoff is set to 175kPa and the thing hits 176 at times in the log.

Isn't 175kPa = 25psi? Am I doing maths wrong, because the boost gauge never shows more than around 10psi.

Edit: Okay wait, I'm not accounting for the fact that sea level pressure is around 100kpa. Dumb da dumb.

I think I need to turn this cutoff up because I keep hitting it before I get to redline and I don't know how far it wants to go. I think I need to set the duty cycle real high in Open Loop mode at high throttle and RPM so that the solenoid opens more and leave it closed down low? This way when it starts to creep up top it will just match what was going on down low? (Am I reversing this? I don't think so).

Here is the latest log btw.

https://drive.google.com/file/d/0B-d...it?usp=sharing

I think I've got fueling at least under control if not optimized as I'm not really going above 11 at this point in boost.

Harv 04-11-2014 02:54 PM

Nevermind last post. Had the polarity set wrong so my boost table was acting in reverse.

Harv 04-11-2014 03:20 PM

I think I'm gonna take it to a dyno next before I start adding more boost. I saw some 14s in that last log where I was boosting up over 10psi. I really don't want to blow this thing up and I've probably been pushing my luck considering all the stupid runs I've done with the boost control not properly set.

sixshooter 04-11-2014 05:31 PM


Originally Posted by 18psi (Post 1120539)
that's moronic

that's like having a supermodel girlfriend and using a fleshlight while looking at her

Abso-fucking-lutely.

10psi or flaming pussy avatar.

Harv 04-14-2014 11:24 AM

I think I'm doing this wrong. Setup the boost control solenoid in open loop mode.

I made sure the polarity is set so that in the table 100 is fully open (ie normal wastegate mode)

Then I'm pretty sure I did the wrong thing in that because I'm overboosting at higher RPM and throttle levels I should be setting higher RPM/TPS values to 100 and lower values to below 100 to even things out. I instead made the table ramp upwards.

Gonna keep working on this. I'm not sure if getting a different wastegate can would help the overboosting, but I suppose it couldn't hurt.

Braineack 04-14-2014 12:09 PM

100% should be fully closed and full boost.

the thing should be wired/plumped in a manner so if the valve fails, it fails to wastegate. If you're suggesting that 100% DC is wastegate, that means you need the MS to actually intervene in order to limit the boost. that's dangerous.



and dont use open loop mode; do it right, bro. (although having the open loop table setup will be a great place to start when using the newest boost control code that uses an initial duty table before CL PID kicks in)

Harv 04-14-2014 01:17 PM

Well, I can change the polarity in the config so that it's 0 for no boost and 100 for full boost, I was just pointing out how I had it setup. The whole thing is a bit counter intuitive for me for some reason since essentially the solenoid being open means it's using just the wastegate and the solenoid 100% closed means super boost.

For some reason this isn't registering to me how it makes a difference I guess, but I suppose I'm not thinking about it from how the MS sees things.

How can I plumb the thing for said safety? Essentially it's just plumbed inline with the turbo and wastegate.

Also, everything I've seen says to tune open loop first then move to closed loop, but I suppose I might have missed some newer info? I was only doing open loop to get somewhat close to where I wanted to be, but quite honestly it all needs to change when I go to the dyno.

Harv 04-14-2014 01:44 PM

Also, I could be wrong, but I thought I was doing the table correctly in that 100% duty means no boost. I was basing that off of this page and the open loop tuning guidelines.

Boost Control

Harv 04-22-2014 02:00 PM

So, back to this again. I am still working off of open loop until I get fuel dialed in, but the problem is that the computer seems to forget that it is set to "inverted" in the options.

I noticed that starting the car up and running it initially it will overboost, just boost goes up until the cutoff hits. If I go into TS and flip the option from "inverted" to "normal" and back to "inverted" again it then starts working fine.

Should I just rewire the solenoid? Swap the wires so normal = boost solenoid all the way closed at 100. It says in the instructions that polarity doesn't matter, but I guess it might?

Everything else seems to check out. I mean, I can test the solenoid and hear it click and once I flip that option back and forth the control is fine after that, no overboosting, it's just this initial startup problem.

Maybe I wire things badly?

Harv 04-22-2014 03:47 PM

Okay, so I went back, looked at what Brain said, looked at what the tooltip was saying in the TS software, set the thing to "Normal" and made the table so that 0 = no boost and 100 = all boost and it seems to work consistently now each time I start and stop it, knock on wood.

Harv 05-05-2014 03:18 PM

Yeah, still having problems with boost control. I really cannot figure out what I am doing wrong.

I went out yesterday to tune the table under open loop conditions. I started slowly raising values in the table and boost slowly started coming up until I got to a number I was comfortable with around 10 or so PSI max. Drove around like that for 30 minutes or so, no issues. The thing held solid boost levels.

Today, I took the car out, overboosting right from the get go. Like I never even made the changes yesterday.

I wonder if I hooked up the solenoid wrong somehow? Whenever I test it at a stop using TS I can hear it clicking, so it seems like power is good, though I do have it spliced in with one other device. Could that cause an issue under load? But then again why would it react one way during one run and completely differently on another?

Harv 05-05-2014 03:27 PM

In case anyone has any suggestions here is a ZIP with the MSQ file and two logs. The 5-4 log is the one that was running fine, the 5-5 log (today) is where it was overboosting.

https://drive.google.com/file/d/0B-d...it?usp=sharing

Harv 05-05-2014 05:03 PM

Maybe I should just stop trying to get open loop to be consistent? I sort of assumed if I adjusted it in small increments it would end up being consistent, but is that not the case?

Onyxyth 05-05-2014 08:27 PM

Open loop is never going to be perfectly consistent, it can't compensate for air temp, humidity, etc. It just matches duty vs rpm and throttle.


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