MEGAsquirt A place to collectively sort out this megasquirt gizmo

Rate the Tune That Cracked My Piston

Thread Tools
 
Search this Thread
 
Old 05-12-2020, 10:22 PM
  #1  
Junior Member
Thread Starter
 
intenseapple's Avatar
 
Join Date: Mar 2017
Posts: 169
Total Cats: 10
Default Rate the Tune That Cracked My Piston

I've been running this tune for ~6 months without any issues -- until last week. I was at ~3k RPM on the highway when the car died on me. I just pulled the head off and found that a large chunk of piston #2 broke off and I suspect detonation was the cause despite the fact that I never heard any knock or pinging. I tuned the car myself and it is almost certainly a **** poor tune so I'd like some input so I can figure out what I'm doing wrong. I plan on rebuilding the motor with forged internals assuming that the block is recoverable and want to make sure a **** tune doesn't ruin another (much nicer) motor. I added my tune as well as a couple of logs I took while I was tuning my EBC, target was 12 psi, never got it to hover there perfectly before it blew up :/. Thanks in advance!
Attached Files
File Type: msq
CurrentTune.msq (117.3 KB, 54 views)
File Type: mlg
2020-04-29_21.10.40.mlg (138.4 KB, 32 views)
File Type: mlg
2020-04-29_21.03.38.mlg (47.2 KB, 32 views)

Last edited by intenseapple; 05-13-2020 at 12:30 AM.
intenseapple is offline  
Old 05-13-2020, 07:30 AM
  #2  
Retired Mech Design Engr
iTrader: (3)
 
DNMakinson's Avatar
 
Join Date: Jan 2013
Location: Seneca, SC
Posts: 5,009
Total Cats: 857
Default

Which engine, what fuel?
DNMakinson is offline  
Old 05-13-2020, 12:42 PM
  #3  
Junior Member
Thread Starter
 
intenseapple's Avatar
 
Join Date: Mar 2017
Posts: 169
Total Cats: 10
Default

Originally Posted by DNMakinson
Which engine, what fuel?
Bone stock 1.8, only 91 octane since being turbocharged.
intenseapple is offline  
Old 05-13-2020, 09:29 PM
  #4  
I'm Miserable!
 
user 8202's Avatar
 
Join Date: Mar 2020
Posts: 164
Total Cats: 4
Default

Im no pro, but your tune doesn't look too bad to me. Looks similar to what I run on a stock 1.8 on 12psi. I do run 93 octane though, not sure if that's a difference maker that the level of boost your at though. This makes me a little nervous about running 12-13 psi on mine. Did you do a hard pull right before it died at 3k rpm? Seems weird to go while just cruising at that rpm.
user 8202 is offline  
Old 05-13-2020, 09:36 PM
  #5  
Junior Member
Thread Starter
 
intenseapple's Avatar
 
Join Date: Mar 2017
Posts: 169
Total Cats: 10
Default

Originally Posted by Jmatt07
Im no pro, but your tune doesn't look too bad to me. Looks similar to what I run on a stock 1.8 on 12psi. I do run 93 octane though, not sure if that's a difference maker that the level of boost your at though. This makes me a little nervous about running 12-13 psi on mine. Did you do a hard pull right before it died at 3k rpm? Seems weird to go while just cruising at that rpm.
I did a 20-60 pull onto the highway about 5 minutes before it went out, but I didn't notice any odd noises and it ran perfectly right up until it died. I have no idea how I didn't hear a chunk of my piston fracturing off and bouncing around the combustion chamber... I also never actually found a significant amount of metal anywhere in the cylinder, head, intake, or turbo, plus the turbine blades look perfectly fine -- like no metal has ever passed through them. I'm still a little baffled. I'm tempted to just chalk it up as an old car and a bad tank of gas, but I'd really like to make sure my tune is bulletproof before I throw together a forged engine so thanks for looking!
intenseapple is offline  
Old 05-13-2020, 09:56 PM
  #6  
Senior Member
 
andym's Avatar
 
Join Date: May 2011
Location: Miami
Posts: 559
Total Cats: 77
Default

Dunno what to say. But, for the next engine run a stock nb knock sensor.
andym is offline  
Old 05-13-2020, 10:31 PM
  #7  
I'm Miserable!
 
user 8202's Avatar
 
Join Date: Mar 2020
Posts: 164
Total Cats: 4
Default

I plan on building mine forged in the future too. Please post your build and updates!
user 8202 is offline  
Old 05-13-2020, 11:44 PM
  #8  
Senior Member
 
SpartanSV's Avatar
 
Join Date: Apr 2017
Location: Greeley, CO
Posts: 1,226
Total Cats: 169
Default

Originally Posted by intenseapple
I did a 20-60 pull onto the highway about 5 minutes before it went out, but I didn't notice any odd noises and it ran perfectly right up until it died. I have no idea how I didn't hear a chunk of my piston fracturing off and bouncing around the combustion chamber... I also never actually found a significant amount of metal anywhere in the cylinder, head, intake, or turbo, plus the turbine blades look perfectly fine -- like no metal has ever passed through them. I'm still a little baffled. I'm tempted to just chalk it up as an old car and a bad tank of gas, but I'd really like to make sure my tune is bulletproof before I throw together a forged engine so thanks for looking!
You said in your other thread that your cam timing was off, and you were going to post pics. Where are they? Have you pulled the pistons out yet? I'm curious to see the ring lands.
SpartanSV is offline  
Old 05-14-2020, 12:01 AM
  #9  
Junior Member
Thread Starter
 
intenseapple's Avatar
 
Join Date: Mar 2017
Posts: 169
Total Cats: 10
Default

Originally Posted by SpartanSV
You said in your other thread that your cam timing was off, and you were going to post pics. Where are they? Have you pulled the pistons out yet? I'm curious to see the ring lands.
I just posted them. TLDR: both cams were off by 2 teeth. I havent had time to pull the motor and get the pistons out yet, gotta find somewhere that I can work on the car long-term before I start tearing the rest apart.
intenseapple is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
mj1176
MEGAsquirt
31
06-09-2020 08:23 PM
poormxdad
MEGAsquirt
11
04-28-2017 05:42 PM
PSI
MEGAsquirt
14
11-26-2016 07:43 PM
whinin
MEGAsquirt
0
09-15-2015 08:37 PM
Chowcow
MEGAsquirt
2
05-14-2015 05:21 PM



Quick Reply: Rate the Tune That Cracked My Piston



All times are GMT -4. The time now is 02:45 AM.