Detonation on 1 & 4
07-21-2018, 05:25 PM
#1
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Thread Starter
Join Date: Jul 2012
Location: Iowa
Posts: 33
Total Cats: 2
Detonation on 1 & 4
Short version:
MSM dedicated track car rebuilt last winter
MSM MS3Pro PnP ECU that has been in car for over 50 track hours PRIOR to rebuild
Wiseco 8.5:1 83.5mm pistons
Eagle rods
FlowForce 640ish injectors
Stock turbo
Stock ignition coils
93 octane
Some kind of Saab intercooler
13psi
about 218 whp
10.5-11 AFR
It ran about 10 track hours
cylinders 1 and 4 failed due to detonation
Why 1 & 4 ?
4 is on the left
4 and 1
1
4
1 on the left
2&3
MSM dedicated track car rebuilt last winter
MSM MS3Pro PnP ECU that has been in car for over 50 track hours PRIOR to rebuild
Wiseco 8.5:1 83.5mm pistons
Eagle rods
FlowForce 640ish injectors
Stock turbo
Stock ignition coils
93 octane
Some kind of Saab intercooler
13psi
about 218 whp
10.5-11 AFR
It ran about 10 track hours
cylinders 1 and 4 failed due to detonation
Why 1 & 4 ?
Last edited by Elmos hers; 07-21-2018 at 08:18 PM. Reason: added info
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07-21-2018, 09:36 PM
#5
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Join Date: Dec 2010
Location: Auckland, NZ
Posts: 992
Total Cats: 57
Im FAR from any kind of expert but your map seems pretty conservative to me.....MT crew pelase correct if im wrong.
Don't 1 and 4 share the same coil? perhaps a coil or ecu ignition failure?
We lost an engine once in simialr style when the battery terminal was loose after electricain didn't toghten it.
+ lead was coming on and off and ended up with detonation damage.
Don't 1 and 4 share the same coil? perhaps a coil or ecu ignition failure?
We lost an engine once in simialr style when the battery terminal was loose after electricain didn't toghten it.
+ lead was coming on and off and ended up with detonation damage.
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07-21-2018, 10:16 PM
#6
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Join Date: Jul 2012
Location: Iowa
Posts: 33
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Yes, 1 and 4 share a coil. I’m having trouble understanding how a loose connection would cause detonation. I’ve detected no misfire.
EGTs appeared to be lower on 1&4 than on 2&3
At this point I think that was due to the detonation.
EGTs appeared to be lower on 1&4 than on 2&3
At this point I think that was due to the detonation.
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07-21-2018, 11:00 PM
#7
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Join Date: Dec 2010
Location: Auckland, NZ
Posts: 992
Total Cats: 57
We figured the bad power supply was upsetting the ecu and its internal timing thus messing with the ignition timing. I felt nothing in that circumstance either (well until the engine failed, i felt that 
)
Its highly unlikely but worth checking.
Your map seems conservative and your efr's 'seem' quite rich so it has to be something putting the timing off....incorrect dwell, timing trigger setting or something liek that.
Anyway, im stretched already so hopefully someone with more experience can chip in.
)Its highly unlikely but worth checking.
Your map seems conservative and your efr's 'seem' quite rich so it has to be something putting the timing off....incorrect dwell, timing trigger setting or something liek that.
Anyway, im stretched already so hopefully someone with more experience can chip in.
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07-22-2018, 09:58 AM
#12
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Join Date: Jul 2012
Location: Iowa
Posts: 33
Total Cats: 2
I have a Chatterbox spliced into the OEM knock sensor to listen in.
Would anyone share a successful timing map for reference?
Any thoughts on why 1&4 are severely damaged and 2&3 have none?
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07-22-2018, 08:51 PM
#18
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Location: Jacksonville, FL
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As previously stated, your timing map is way way too advanced. Especially top two rows midrange rpms.
here is my timing map, which I consider pretty aggressive, and your map is way more advanced than mine.
Also check that broken piston chunks didn't damage your turbine wheel.
here is my timing map, which I consider pretty aggressive, and your map is way more advanced than mine.
Also check that broken piston chunks didn't damage your turbine wheel.
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07-22-2018, 09:47 PM
#19
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Join Date: Jul 2012
Location: Iowa
Posts: 33
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As previously stated, your timing map is way way too advanced. Especially top two rows midrange rpms.
here is my timing map, which I consider pretty aggressive, and your map is way more advanced than mine.
Also check that broken piston chunks didn't damage your turbine wheel.
here is my timing map, which I consider pretty aggressive, and your map is way more advanced than mine.
Also check that broken piston chunks didn't damage your turbine wheel.
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