aaronc7

iTrader: (8)

No big updates here, just continuing to put miles on the car and enjoy it at 13-14psi. Got closed loop boost dialed in pretty well. Vdyno shows weak low end torque though. Probably a combination of 1.) Large turbine housing 2.) Honda intake mani and 3.) No VVT yet. I was waiting to get an electrical connector for the VVT oil control valve- it's here now and wired up. This week I plan to get it all hooked up and running.

Been browsing around looking for a good VVT map/table. y8s posted what appears to be a decent one that's been tested. Another option is just running DIY's and increasing the Y axis into boost. I'm not all that smart on VVT, only recently started paying attention to the nitty gritty details of those threads, now that they apply to me.

Thoughts?

Here's a quick vdyno and crappy video of said pull from tonight (been messing around new camera...audio is terrible from the vibes). I started the pull at about 3k RPMs in 3rd gear, so this is also about worst case scenario as far as showing turbo spool potential. I hope VVT will improve it as well.

18psi

iTrader: (76)

vvt should seriously improve that powerband.

I prefer y8s map to DIY's. Don't worry about the boosted rows, they won't matter.

what does your timing table look like?

aaronc7

iTrader: (8)

I still have the Mazdaspeed 3/6 Cobb ATR tuning software on this computer so I took a peek into their stock tune VVT values and some of the Cobb OTS tunes. More modern direct injection engine, etc., yes, but it may still provide some insight.

It more or less matches what y8s had going on with his table I believe. Little to zero of cam advance below 1k rpm and low load/MAP, for general 'stability' I presume. Then right around the transition into boost, start advancing the cam, full advance all the way from 1k to 3k RPM, then taper off by 5k or so. My takeaway was full advance before you expect the terbo to be spooled up, then start to taper it off.

I think in theory you want to run as much cam advance as possible such that intake manifold pressure > exhaust manifold pressure, to avoid reversion. Having a large turbine housing should allow you to run more advance in the higher RPMs, but I don't see a good way to approach this precisely without measuring exhaust manifold pressure, so screw that.

aaronc7

iTrader: (8)

Here's my timing table... open to criticism as always. I'm guessing there's plenty of be gained in the low end from this as well- IIRC most miata spark tunes come with a low point around 4k, with more advance both below and above 4k. Mine's more or less flat-lined till 5k, then I start ramping up slowly.

I've been in talks with a local tuner regarding a spark tune. I just need to get VVT up and running, table/values set before I want to *** with that. I really don't want to go crazy trying to optimize VVT vs timing... just want to get a reasonable VVT table and set it and forget it.

aaronc7

iTrader: (8)

VVT is up and running. Just fired it up, idled and varied RPM a bit to make sure the default PID values worked well- they did.

Here is the VVT table I just pulled out of my ***. Mainly based off of what I saw in the stock Mazdaspeed 3 VVT table and my above Vdyno plots. My thinking went something like this: Max advance below turbo 'fully spooled' point, to help spool, then taper off. I know a lot of you guys run zero advance below 3kish RPMs for jerkiness or whatever. I'll give this a go and see what happens, this is just revision 1.

18psi

iTrader: (76)

Not bad. now lets see the VD plot of what this did to your midrange

muoto

And can also you post your VD log file here? I get a boner when I’m comparing different setups in virtual dyno, and there's nothing shameful about that

aaronc7

iTrader: (8)

VVT stopped working, I'm guessing OCV went bad?

https://www.miataturbo.net/engine-pe...working-75693/

aaronc7

iTrader: (8)

Been dicking around with VVT for a few days, it's not working right. When the oil is cold, it works just fine, but when it gets hot and thins out, it can't advance the cam more than a few degrees. Solenoid appears to be fine, I think the actuator itself in the cam gear may be jacked up or some of the oil pathways leading into, or something.

Short term I don't feel like messing with it or tearing the engine back open, so screw it, I just miss out on some low end power, not the end of the world to me. Here at some point I'd like to pull my valvecover to paint it and get some bungs welded on for catch can setup... that might be a good time to address the VVT stuff as well.

Changed the oil last night to Rotella T 5w40 and calling "break in" complete. Time for moar boost!

18psi

iTrader: (76)

you may get it working with rotella. mine is actually SUPER sensitive and I think that's in part due to the rotella

Fireindc

iTrader: (13)

Rotella is where it's at anyways. I couldn't believe the hot oil pressure difference between the syn 5w30 i was using before and the rotella t6 i switched to. Went up a good 10psi of oil pressure when super hot. Awesome ****.

aaronc7

iTrader: (8)

Sadly the vvt test I did last night was with the rotella. I will look into the vvt issue in the future but not right now.

Reverent MS3 on the way as well :-)

aaronc7

iTrader: (8)

Well, looks like I might have to start using 4th gear if I want to do virtual dynos from now on. Tires must of slipped a little around 6k for a split second, I turned the smoothing all the way up to try and get rid of most of it. This is at 20psi.

I'm only running a 5psi spring in my external wastegate, but it's hitting 20psi at 50% duty cycle no problem. Think there's any benefit to swapping in a stiffer spring to bring on the boost on the boost a little quicker, and maybe easier to tune closed loop for a nice solid curve? I can't imagine a time when I would want or run less than about 15psi, so I might go ahead and swap in the 1 bar spring anyways.

18psi

iTrader: (76)

niceeee

yeah might wanna run over 10psi base spring if you're going to be over 20

aaronc7

iTrader: (8)

Still haven't gotten around to switching EWG springs yet... honestly not sure if it will even help since I am only hitting 50 duty cycle on the solenoid and the way I have it all plumbed it (at 100 duty cycle, equal pressure is applied to both sides of the EWG spring)... highly doubt the exhaust pressure is cracking it open, even if it's "just" a 5psi rated spring, would still require quite a bit of force.

Basic MS3 is here!!!!!!!!!!!!! Man, this thing looks so awesome. Blown away by the overall quality and fit/finish. HUGE step above his old MS2 enhanced units (not that they were bad).

Some of the wire colors don't match the documentation I got with it, so going to confirm what is what off the DB37 and more than likely move my MapDaddy 4 bar sensor over to it before I throw it on the car this weekend.

Fireindc

iTrader: (13)

DO WANT.

aaronc7

iTrader: (8)

Well, bad news today. Something is fucked on the engine. I was doing some 3rd gear pulls, dialing in boost today, in prep for some spirited driving tomorrow. The last pull I did was a full 3rd gear (was gonna virtual dyno it).... everything went fine. Then I proceeded to put the car in 6th gear and continue the small drive home.

Not too long after that, I noticed high oil temps for just cruising around.... around 250F. But I was thinking "eh, I just got done with some pulls, I'll give it a little time to see if it cools off"- this was driving at around 60 mph. It started to rise actually, which concerned me, and oil pressure was lower than normal. Now I was paying a lot closer attention to what was going on, I downshifted and heard a definite knock from the engine. At this point, I'm looked for the next side road and pulled off. I also noticed that oil pressure was now dropping like a rock if I gave it any sort of load.... like 2k rpm, just normally accelerating or whatever. Any sort of accelerating of the engine, free rev, etc., there is a definite, loud knock.

I let the oil cool down, checked again and it was all still there, just as loud. Left the car on the side of the road... gonna get it towed tomorrow (getting dark now and don't feel like dealing with it). I did check the oil level and yes, it's fine. I'm not sure smart on engine builds here, but probably some sort of bearing gone bad?

miata2fast

iTrader: (2)

Damn Aaron, that sucks so bad.

I would say there was a bearing issue. A spun bearing would be my guess.

aaronc7

iTrader: (8)

I guess I will be pulling the engine, and tearing it down myself or take it to Bogus and let the tear down begin to see what the issue is. Bogus did all of the assembly on the bottom end- but I guess it's too early to start speculating too much as to what happened. Feeling very unmotivated overall right now... but I'm going on a 3 month deployment here in a few weeks, I have some time to think it all over, lol.

Fireindc

iTrader: (13)

Holy **** dude, that really sucks. Sorry to hear it. In for postmortem pictures.