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Old 07-10-2012, 11:23 PM   #1
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Default Motor blew up, check out my tune.

So I got finally got my car back together with an MS3x the other day, spent 2 days auto-tuning it. Car ran pretty good, it had a hiccup when I'd get into boost real quick sometimes, but only happened maybe 6 times over two days of driving hard. AFR's seemed to be solid, I was running ~15psi on a GT2554R, unknown whp.

Then, I was on it hard through the twisties with a friend for ~20 sec of WOT, looked behind me, huge cloud of blue and white smoke. The motor was already a ticking time bomb as the compression was low and it burned oil all the time, I knew it wouldn't like going from 10psi to 15psi... I guess I just thought it'd last more than 2 days.

I can't get the MegaLog Viewer to open up on my laptop, but I did datalog one session. Can anyone check it out and see if it contributed to blowing my ---- up in any way? I haven't had time to dig into the motor yet, but I'm guessing it dropped a ring and/or headgasket let go.

Also, if anyone has any tips on what I should do/change in MS before I put things back together, that'd be great. It's a learning experience for me, and next time I'm putting on knock sensor in... however you tie that into MS.
Attached Files
File Type: msl 2012-07-05_17.47.28.msl (102.4 KB, 86 views)
File Type: msl 2012-07-06_21.24.10.msl (1.40 MB, 78 views)
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Old 07-11-2012, 02:33 AM   #2
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Uhhh

Maybe if your motor was already mostly dead the boost killed it?

Just maybe?

Btw burning oil makes your combustion mixture very detonatable.
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Old 07-11-2012, 08:01 AM   #3
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Looking at the logs with my noob eyes i'd say u were running lean, in some places only a little, but some places what i think is alot.

180kpa - 4.5krpm - 12.8/1
130kpa - 3.4krpm - 14.5/1
183kpa - 6.0krpm - 13.1/1

Im keen to see what others say, its totally possible engine just let go for no reason but im sideing with running lean over time.

Cheers
Scott
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Old 07-11-2012, 08:10 AM   #4
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Little turbo + 15psi = pretty good heat. So 13 to 1 AFRs at ~180kpa = boom. Detonation eminent.

I'm at ~11 to 1 at 185kpa.
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Old 07-11-2012, 08:13 AM   #5
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Six did you have a look at the log and come to that conclusion or just read what i posted? The above wernt "sustained" as such but for periods of 0.5-2secs. Just wont to be sure what u posted was what you saw rather than just from reading what i said.

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Old 07-11-2012, 09:32 AM   #6
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I didn't see the logs (at work), but if he really did go for 2 seconds @ 180kpa @12.8-13.0 that's stupid lean and probably melted a piston or something

I really don't get why people run these cars so lean. Where is everyone getting their "tuning info"?
We preach 11.25-11.80 afr's all day long over here, with the more ballzy people running 12.0 (which is lean IMO even with decent pump gas). I just don't get it.
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Old 07-11-2012, 09:58 AM   #7
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I dont see anything inherently wrong with the log other than what the others said, maybe a bit too lean in some situtations. But either you messed up the timing sync and you were like advanced 5-10 throughout or the raw power that the ms3x cpu unleashed was just too mighty for your crippled motor.


Tune for 11.8 at the leanest in boost, and maybe start with more ignition retard in boost and only add more under controlled tuning where you can verify it's not pushing the limits.
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Old 07-11-2012, 10:47 AM   #8
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Thanks for the responses everyone, its much appreciated.

I'll fatten it up next time around, auto tuning with low AFR targets. What kinda timing do people run on here? I'm pretty sure it was fairly retarded, but I didn't keep an eye on it when in boost.

Also, any idea on the big hiccup as I would get into boost? Maybe around 3k or 4k RPMs. Right as I would get into big boost it would cut and fall flat on its face. I don't have an EBC, just a cheap MBC, is there an over boost control or something? It happened enough to worry me.

I have a motor with a bad crank sitting in my parts Miata that I'm gonna take out, swap cranks with this one, and try this all over again. I don't see a need to build a motor as I don't expect to push over 240whp. Thoughts on that?
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Old 07-11-2012, 10:53 AM   #9
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is the cutout event on the logs? what's the overboost on your map set to? it's around 200kPa right?
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Old 07-11-2012, 10:58 AM   #10
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The hiccup is most likely boost cut.

Are you sure your other motor is in good shape? I would never EVER swap something like a crank without making sure all bearings are inspected and most likely swapped, as well as rings and a fresh hone. Its just common sense, and super cheap to do "while you're in there".

Start out with 10* @ peak boost and go from there for timing.
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Old 07-11-2012, 10:59 AM   #11
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Quote:
Originally Posted by Braineack View Post
is the cutout event on the logs? what's the overboost on your map set to? it's around 200kPa right?
I don't know if I got a log with it or not, can't remember if it happened during these two or not, but these two are all I have.

I'll see if I can check the settings on the map when I get home. What happens if it were over boosting in MS?
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Old 07-11-2012, 11:01 AM   #12
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it would cut out (stop injecting fuel/spark).
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Old 07-11-2012, 11:07 AM   #13
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Quote:
Originally Posted by 18psi View Post
The hiccup is most likely boost cut.

Are you sure your other motor is in good shape? I would never EVER swap something like a crank without making sure all bearings are inspected and most likely swapped, as well as rings and a fresh hone. Its just common sense, and super cheap to do "while you're in there".

Start out with 10* @ peak boost and go from there for timing.
What kinda price would that be? Your super cheap and mine could be very different lol. I've got a few options to ponder while I figure things out. I've got a daily so this is my project for the summer.

I'm hoping the hiccup was boost cut as well, and thanks for the starting point with the timing.
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Old 07-11-2012, 11:11 AM   #14
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rings are around 60-100 for a quality set.
rod bearings are like 30-40 iirc.
obviously you'll need a "gasket set" since you'll have to pull the head off/etc. so that's another 60 or so.

You can just do it right and have a semi-fresh motor in there, or just replace the crank and very likely end up with mediocrity or failure. The choice is always yours.



PS: and for another 200 you can throw rods in there. and have a motor that will easily hold 300.
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Old 07-11-2012, 11:22 AM   #15
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Quote:
Originally Posted by 18psi View Post
rings are around 60-100 for a quality set.
rod bearings are like 30-40 iirc.
obviously you'll need a "gasket set" since you'll have to pull the head off/etc. so that's another 60 or so.

You can just do it right and have a semi-fresh motor in there, or just replace the crank and very likely end up with mediocrity or failure. The choice is always yours.



PS: and for another 200 you can throw rods in there. and have a motor that will easily hold 300.
I might just do everything above. Then I should be limited to the transmission at ~250whp, correct? I have two 5-speeds... is the only fix swapping in a 6-speed?
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Old 07-11-2012, 11:23 AM   #16
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yeah, but you still need to be careful with the pistons...but you should be able to throw a bunch of power at them...but have to be spot on with timing/fuel.
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Old 07-11-2012, 11:36 AM   #17
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Quote:
Originally Posted by Braineack View Post
yeah, but you still need to be careful with the pistons...but you should be able to throw a bunch of power at them...but have to be spot on with timing/fuel.
I'd probably run ~240whp reliably and then see if I could get it dyno tuned to its safe limit. That's far down the line and a bigger turbo would be needed.

What happens to the transmission at ~250whp and how long would it last above that? There have to be people pushing more power with the 5 speeds, or maybe just beefed them up a bit. 6 speeds seem rare and expensive from my brief knowledge. Its almost a moot point right now but...
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Old 07-11-2012, 11:46 AM   #18
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there is no magic number. I keep saying this in every thread about both the motors and transmissions.

it depends strictly on:
1) condition of trans
2) torque curve
3) how you treat it (also see #1)

I've had mine at 300 for a year then the guy that bought my car blew the trans in a few weeks. I've seen people blow their trans at 200, and a couple dyno queens hit 400
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Old 07-11-2012, 12:04 PM   #19
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depends, you could see 300rwhp and it can be fine. dont abuse it.
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Old 07-11-2012, 01:50 PM   #20
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I couldn't open the logs from the computer I was on so was working from above afr examples. It can only take once detonating under load to crack rings/pistons/both.

How did you set your base timing when you added the MS?
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