collin

Hey all,

This initial post may be short but I will keep updating this thread as I tear my engine down.

I am also no looking for people to join and mock anything that rises out of this as useful information. I might have fucked up but I tune my car myself because these ****-ups are valuable learning experiences.

I will be posting pictures and videos of the tear down as well. I think it's all very interesting stuff.

Long story short, I was dialing in my turbo VVT saturday evening before AutoX on Sunday and sent a rod out both sides of my oil pan. I will post the logs that were running during the event for anyone interested but from what I could tell everything looked safe. I do have a few theories but I can't prove anything or come to a conclusion.

Context of the blown motor:
I turned onto a large empty road after repeatedly stopping to adjust boost duty to smooth out when boost was coming on.
I did a 2nd gear pull to ~6000RPM into a 3rd gear pull to ~6000RPM to a 4th gear pull where just as it was coming into boost it grenaded. (Very loud and scary)
Car felt really great up to that point and I am mostly certain I was within safe power levels according to many sources. I know data like this isn't conclusive and this is one of my theories.

Data I know from the logs:
Ignition timing at 7-10PSI was about 15 degrees (This was more conservative than the MS3 and trubokitty startup tune and was tested with homemade detcans.
AFR was low 12s on the pull
Mat was 72 Farenheight, 20 degrees over ambient (~52 Farenheight)
CLT was about 172 on average

Parts:
Turbo is a Pulsar 2860R
Mani is a Kraken lowmount
Intake mani was the shitty valved one (I forget the name) but I deleted the flaps from it.
3" exhaust to the cat where it was mated to a 2.5" from my old setup.
250WHP and 190WTQ estimates are from tons of collected data into virtual dyno on possibly the flattest road in Iowa.

My theories:
The early torque that I was repeatedly testing is what the rods don't like. My guess is the testing of that rev range on repeated did a quick number to the rods.
Cylinder 4 rod is what went. Data shows cooling isn't an issues but I don't have a reroute so maybe there is something there
Last theory from earlier is, maybe my engine was just on the brink of destruction at the ~250hp range

The log is attached.

The Incident is the very end of the log.
Also note, the oil pressure sensor wasn't not actively working is it had failed recently but the dash showed pressure even right after the thrown rod.

I am curious what peoples thoughts are who are interested to read and look this over. I need to get the MS3 folder completely uploaded too but I need to get it off my laptop first.

DNMakinson

iTrader: (3)

MAP went to 198. Possibly a bit high for a 2680. If your intention was 10psi max, then boost cut should have been set at 12, with a lot of timing pulled in that region of your map.

At what MAP were your VD runs of ~250 WHP / 190WTQ made?

Would be nice to see a tune. Presume 10:1 pistons (stock VVT). What gas?

DNM

collin

I am fairly certain I have boost cut at about 200 since I was messing with the spike at 3800 that I was seeing.

My 190 runs were arounf 10PSI. I can confirm from the tuning laptop since I am sure I still have the logs I used to make them.

Yes the stock 10.5:1 VVT pistons on only 93 ever. Best I can get without going ethanol and I didn't see a need since I wasn't squeezing for performance.

collin

I can't upload the project since it's over 20mb so here is a drive link to grab it from.

https://drive.google.com/file/d/12ve...ew?usp=sharing

Kboi12

You do get a small lean spike when going into boost on those last 3 pulls. You said you do auto c. Did you money shift recently or in the past? Some people get rod failure a after an event like that. Could also be as simple as bad gas.

collin

So the prep I was doing was for it's first AutoX

Yeah 93 at those timings felts safe but probably not safe enough without constant monitoring which I hadn't setup yet.

collin

Here were some of the tear down videos from last night as well.

I am not all the way into the engine but it's pretty obvious at this point.

Kboi12

I have got to review your tune and I hate to break it to you but it’s just all over the place. Now I am not trying to bash you but trying to teach you. You got zero smoothness, no resolution. You would want to have a much better resolution from 150kpa to 200kpa. I don't know what's going on with the spikes at 1100rpm and 70kpa on the VE table, nevertheless its a frat party in that entire table. Your ignition table as well. You’re letting the computer interpolate itself between 150-200kpa. from 15 degrees of timing to 12 degrees, you NEED resolution. Your AFR table looks fine. Your tune was not ready for the loads you were putting in IMO.
On the bright side you got a block to build to go harder next time.