Julian's '91 200 20vt

[88a5tq]

That's hilarious Chris. My brother's mechanic, Shelby, got a black eye last week while removing his shift knob to install the short shifter! Thanks for minimizing my embarrassment though.

On a slightly less retarded note, the guy "making" my shift boot hadn't gotten back to me in about a month now. No idea what he's doing hah. Probably will call for his big bucks while I'm handing my $200 cash to the safelite guy friday. It went from $35 on his FS thread to a sweet $80 on the phone with minimal options lol

[88a5tq]

Another beauty shot

20150826_202042.jpg (1.8 MiB) Viewed 27027 times

Everything all the time... my cell bill is due in 4 days, I need gas, I didn't put the 5k's shifter back in, it's freakin battery is f#cked even with it being on a float charger for a month lol, my data plan only has 100 mb left until Sept 7th bahaha, and my insurance payment is due on the 5k end of month. Heartbreak is all relative

[DE80q]

When it rains, it poor's! I'd say your about flooded out!

[88a5tq]

I was nitpicking on those things. At least they're routine problems.

Now for the potatoes of this whole thing. Am I going to have to search the earth for a replacement windshield? NLA?

[88a5tq]

Safelite had one in their warehouse. Everyone in the office that heard the p/n asked "wth is that for?" Lucky me

[themagellan]

I would love to see some drift action on digital media! Funny thread, always love checking in here to see whats going on.

I wonder what kind of power you're at right now.

[88a5tq]

Now I'm ju$t concerned about whether my chrome accent around the glass will be salvageable. BTDT's?

Sir, thank you for stopping in Right now I'm ignoring the "Flywheel Affect" and I'll just say that it's quicker than the 360 chp m3 currently Because, honestly, it's how quick it "feels" and not much more

I always find my urge to drift is spontaneous haha. I am always on the move, however, when I have someone along with a recorder (I hate admitting this), they always mess up! Everything gets confuc#ulated and the car starts running too hot to enjoy with confidence. We all just have to play along while I say it's over 800 at the wheels until proof surfaces I suppose

Someday I will do an autox with the brother and we will record both cars. I promise. I will never grow bored of this car, either.

Even at that euro car show, with 60% of the old fellas in their porsches, none of them were prepared for the symphony from Dave's brain-child turbo-stein. I wish I could record all the music while I wait for a good video.

[DE80q]

I can't take credit for the hybrid. I bought it a couple years ago unfinished. I just finished it with a good balance and the other little pieces I had to find. I'm glad it's responding well on your setup.

[88a5tq]

Yep good so far.
I went out today and the car felt lacking in the butt dyno department. Checked the log to see 255 kPa max and slow spool. WHYYYYYY me!? I'm about to do one of two things. Either I'm gonna rip the digital boost controller out of the 5k and put in 200 for use with the current MAC or revert back to the n75 for kicks. I just never could wrap my mind around the best control strategy being the use of the lowest port only.

When I tried out my last known ref DC table and mediocre PID settings, the car overboosted.

Chris, it might help me to see what PID #'s some people use. What #'s are just ridiculous? What's too low? For awhile I was using 30, 22, 30 which achieved 278 kPa yesterday. 6 F difference in weather resulted in the 255 kPa today.

When I was using P and the D (at 30) I was upping P until I hit boost cut, backing it down slightly and adding I to change DC based on error. From browsing, it appears that I is based on % and the 30 I used at one point was 30% of the error (difference) was added back to P in order to achieve the target during any ambient temperature.

What are all of you guys using? I'm may remove the restrictor from the bottom WG hose as well. I just know one of you is gonna a say "we'll that's your problem right there (i.e. restrictor or MAC valve)!" Lol

[88a5tq]

Also I noticed that my heavier PID numbers from yesterday only resulted in a max DC of 74%. For a P in the 20's I was expecting much more. Perhaps I should increase my boost cut to 300 kPa temporarily until I can master the D... effect

[loxxrider]

Yep good so far.
I went out today and the car felt lacking in the butt dyno department. Checked the log to see 255 kPa max and slow spool. WHYYYYYY me!? I'm about to do one of two things. Either I'm gonna rip the digital boost controller out of the 5k and put in 200 for use with the current MAC or revert back to the n75 for kicks. I just never could wrap my mind around the best control strategy being the use of the lowest port only.

When I tried out my last known ref DC table and mediocre PID settings, the car overboosted.

Chris, it might help me to see what PID #'s some people use. What #'s are just ridiculous? What's too low? For awhile I was using 30, 22, 30 which achieved 278 kPa yesterday. 6 F difference in weather resulted in the 255 kPa today.

When I was using P and the D (at 30) I was upping P until I hit boost cut, backing it down slightly and adding I to change DC based on error. From browsing, it appears that I is based on % and the 30 I used at one point was 30% of the error (difference) was added back to P in order to achieve the target during any ambient temperature.

What are all of you guys using? I'm may remove the restrictor from the bottom WG hose as well. I just know one of you is gonna a say "we'll that's your problem right there (i.e. restrictor or MAC valve)!" Lol

Oh boy, where to start!?

First of all, let me try to call this one... I'm calling boost leak. OR you changed a setting.

Nothing about the whether would change your boost that drastically if it was a problem with your PID tune. It should hold the same boost in 90F as it does at 0F as long as you're even remotely in the ballpark with the tune. The dynamics of the system don't change much depending on air density as far as the boost controller and related components are concerned.

Think about it. If you didn't change anything in the tune, but you're getting noticeably slower spool and lower boost... all signs point to boost leak! With VEMS, you won't notice any other symptoms with a boost leak. The car will run great (but slower) as long as the tune is right in the new, lower boost cells.

No, I don't have any PID numbers to give you because you are using a MAC valve. What works for that will not work for an N75 and vicea versa. Also, you aren't going to learn anything about closed loop control that way Have you read my DIY on tuning boost and tried to understand it thoroughly? If it's lacking something, let me know. Based on your description of how you tried to tune the PID controller, it sounds like you didn't read it.

First of all, it sounds like you need to get the boost tuned at a lower kPa. If you're hitting boost cut, you can't see the fully characterized boost response from your settings. So shoot for like 250 kPa and get that right. Then after you have tuned the closed loop controller correctly you can just increase the boost target and never touch it again.

"I" is not based on percent. If anything, "P" is based on percent (P stands for proportional). "I" stands for integral which is not a percentage of anything... at all. Go ahead and read through my thread on this. If you're having a hard time understanding it, then we might need to have a talk (you can call me ).

In my opinion, your whole wastegate port thing is just adding variables into the equation which don't need to be there. The stock N75 and stock wastegate configuration responds perfectly fine just the way it is.

Read my DIY (or read it again), and then... and only then... go back to tuning PID. Otherwise, just live with open loop control based off of your refDC table or let me tune it remotely. If you're up late, I can get back to you fairly quickly during the night (for now).

[88a5tq]

Ok ok ok. Chris, it's not what you said. It's how you SAID IT! Lol jk.

Sometimes I forget people read this Turns out I had a few things backwards from when I first read your walkthrough. I re-read it and I understand it more so since last time 6 months ago. Also my brain stir-fried all the info so it was useless to me.

I've since reverted to the n75 except spool was horrendous like before. Flooring at 3700 and 280 kPa by 5500 rpm was disappointing. I've also gone to 0 for PID and disabled the 100% until ceature. My ref DC table is 35 accRoss the board and I put a restrictor pill in the compressor pressure line going to the n75 to facilitate spool and less WG creep hopefully. I know it seems like I just want the answers but now that I see the control system correctly again, I feel less hopeless about it and more determined to correct it.

I'm diligently logging and testing with a better PID understanding.

I did want to ask about VE current though. During the logging, I'm seeing it only goes as low as 83% and maxes out at 157%. Is that way off course? Thanks.

[88a5tq]

I checked a log from the beginning of last month and saw the same (83 and 164 respectively). I wasn't sure if something else went bad along with the resistor in the iat circuit.

[loxxrider]

Hahaha I knew it was a little harsh, but I also knew you could take it!

I'm not sure what you mean by ve current...

Restrictor shouldn't be needed in the wg line. If you really want to eliminate variables and see how fast that turbo can spool with the n75,then put your ref DC at 100 everywhere

[88a5tq]

I tried that 100% and was slamming pretty hard into 293 kPa in midrange. I'll see if I can find the log.

VE current randomly showed up in one of the screens where lambda originally was. I don't think I changed it on purpose as I don't even know what it represents. I just saw it in my VT window that I was connected to the ecu in and already had the car off. It caught my eye because it was in the red on the gauge at 93% which I figured was from idle since that was the last known reading before shutdown. I tried finding info on Google and nothing related appeared. I'm not incredibly worried about it now but I thought it was related to a random idle lambda of 1.10 instead of the usual 0.98. Only started happening since I lowered my idle rpm. Actually, at first the problem manifested as a lambda of 0.84! I've adjusted fuel since then.

Haven't found any boost leaks so far either

[88a5tq]

This getting crazy. Or is it?

My P value is at 120 and I'm only seeing a max of 66.7% boost DC. My table is 45 across the board and I'm seeing 251 kPa max, which happens to be my requested boost level at the moment. I kicked P up to 140 for fun but haven't logged it again since. The last log shows my boost settles to 228 kPa at 6500 rpm. So maybe if I keep bumping P higher (what's the max!? Lol) I will soon be able to see a minimum of 251 at 6500 rpm. Once there, I can start adding D to reduce overshoot and then set my table back to 274 kPa. After that, I'll add I values to reduce error and literally hit my target.

Don't respond until I've checked my comments hah. I'm currently on the road

[loxxrider]

Send logz

[chaloux]

Yeah logs. Always logs. Just skimming through these last few pages, it seems like you're sorta doing a lot of random things all the time and seeing if anything works, but then it's hard to know because you change more than one thing at a time. It's hard to keep up with your posts, so I could be wrong about that, it's just the impression I get. Sorry, not trying to be a jerk.

I have not used the b big refdc table before, always just the small one with the curve. Using that to begin with makes it very easy to get the boost about where you want it at the given rpm (a bit less to let PID control it when you get to that point). From there start into PID.

[88a5tq]

Nope I can definitely see it appearing that way. Hell, I did it lol! I'm Working on my approach. I think that sometimes I don't make it apparent that I tried one thing with a quick test and log and when it didn't work out, I quickly moved on to the next thing. Sometimes both tests get run together in a sentence when presented on here though. Sorry guys . Ill work on it I do feel like I'm closing in on solving this though!

I think you're onto something there though. I started out using that simple approach long before I got my 2.2 bar spring installed. Perhaps Ill try that again if my current attempt goes bad. I'm always glad to read others thoughts so thanks.

I was going to upload a log just now but I found it wasn't 100% tps so I'm skipping.

[88a5tq]

Look what I made!!



Aside from a messed up idle which resulted from me believing I could tune my iac PID as well lol. I reverted the settings.

I also cant break the 75% boost DC now. Perhaps adding I will help? I turned it to 20 after this log. Didn't do anything else log-wise.

And before I did that log, I stopped to help carry a dead dog off the road before it got hit again with the owner watching in horror :( I think it died instantly fortunately. It wasn't far off my usual as I do removals of people for the funeral industry pretty often. But sad still.

Anyway, see what you think, thanks.

PS thinking about doing my front sway bar bushings after reading themagellan's thread and how well they stabilized his car in turns. Also, about to order the shifter bushing from 034. Maybe just one until I figure out how difficult to install.

[loxxrider]

I really hate that you can't turn off these control modifiers like PD control far from target and PI control close to target, etc. You can tell in your log that the "PD control (far from target)" is affecting the controller's response. You'd think it wouldn't matter since you have a PD controller going on (your value for I is zero), but you can see the sharp upswing in duty cycle right when you are 60 kPa away from your map target.

I haven't tried this yet because I don't have a car running VEMS at the moment, but I think if you set "PID overlap range" to "forever" it will turn those other things off and just use PID all the time. That'd be really nice because then you could eliminate several variables all at once. Use those settings later to fine tune things if needed. Try that, and send a log again I suspect you will see duty cycle ramp up much sooner and therefore should see spool much sooner.

On another note, you really need to lean that thing out at full boost. Your fueling does follow along nice and smoothly though. It's just that it's too rich the whole time

Also, your warmup enrichment is on constantly... might want to adjust that.

[88a5tq]

Oh crap I thought I turned that off! Sorry I really thought I did that last week.

Thanks, I'll lean it out. It's about .04 lambda richer than my target lambda due to w/m currently.

[88a5tq]

Ok I can explain. I guess I thought disabling "100% until" would also disable the next few settings since disable wasn't available in those drop down menus. Not the case I guess

[88a5tq]

Ok I understand your post's first part now. You basically said what my answer was to your post. lol, see I'm an idiot sometimes. I read it too fast before work.

Ill take that "warmup always on" part as a compliment. Or, the fueling part hah. Anyway, thanks

Will report later.

AAAnd apparently dead dogs don't pull heart strings Chris!! I kid I kid. Maybe ill go back and help bury it...

[loxxrider]

LOL I didn't reply to your post about turning that setting off because I knew you'd figure it out when you went in to change it

The dog thing is sad! I didn't have time to respond to that part this morning lol. I had a dog (my dog) get hit by a car and I was the one who found it too. It's incredibly sad! I'd hate to have to pull one off the road like that. Touching dead stuff is gross.