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peter
Joined: 06 Mar 2009
Posts: 11
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 Posted: Wed Mar 10, 2010 6:17 pm Post subject: |
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Thanks for the great reply.
I guess the main thing I'm trying to find out is this:
When I map my car with normal gas I will monitor knock/detonation by using the head phones. If I here knocking I will back out and all is well. Can I use the same method with E85 or is it already too late if I hear the engine knocking through my head phones? I take it your friend's DSM didn't explode when he heard it detonating?
Just making sure.
Thanks
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2jzgte + 74gts |
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hotrod
Joined: 19 Apr 2005
Posts: 872
Location: Colorado
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| Posted: Fri Mar 12, 2010 4:21 pm Post subject: |
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Monitoring knock with head phones (det cans) is probably the most reliable way of doing it. The human ear is very good at picking up the sound of detonation (far better than conventional knock sensors). About the only superior way of tuning would be to use pressure transducers in each cylinder but that costs over $1000 per cylinder, and most of us who do not work for NASCAR or F1 teams can't afford to do that.
Yes I would say, find your first sign of knock and back off about 2 degrees in timing as a good place to start. Then load up the engine and run it under load and see if it wants to knock under long duration load, just to be sure.
| Quote: | | I take it your friend's DSM didn't explode when he heard it detonating? |
He never heard a thing (high rpm knock under load is not detectable by ear, on open header race engines).
He only noticed a sudden loss of engine power, and lots of smoke out the back. When he got it into the pits, the end of the plug was melted off, just like yours, he pulled the head and the top of the piston was melted and one valve was burned. Engine was running fine right up to the point it melted.
Here is a photo series of another car I took 2 years ago, from first sign of engine problems to total melt down. Pictures were shot about 1/2 second apart. Under high continuous load at Bonneville, it only takes a couple seconds to kill the engine from full power to won't run. At the 3 mile he was going about 225 mph when the first picture was taken.
===== DSM on E85 at Bonneville ===
Spark plugs -
His cylinder head -
Piston top -
Larry |
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peter
Joined: 06 Mar 2009
Posts: 11
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| Posted: Tue Mar 23, 2010 7:05 am Post subject: |
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That helps a lot - thanks. So basically mapping with E85 is very similar to mapping with normal gas.
btw my plugs didn't melt. I think you're confusing me with someone else? My 2jz engine failed because the rods started to bend and one of them snapped. The plugs were fine and no sign of detonation. Bearings were also ok.
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E drifto
Joined: 26 Mar 2010
Posts: 12
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murphinator
Joined: 08 Jan 2010
Posts: 93
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| Posted: Sat Mar 27, 2010 8:34 am Post subject: |
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thats a nice link. its linked to page 6 of 8 though - worth reading all 8 pages
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PB's 1/4 mi 12.209, 117.75 trap ,1/8 mi 7.76 ,93.99 trap , 1.949 short time 4.53 0-60
I tune with HP Tuners software |
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ron
Joined: 27 Feb 2009
Posts: 16
Location: NY
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| Posted: Tue Apr 06, 2010 11:13 am Post subject: |
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kpturbo Would not run this type of plug with the pointed tip in a race engine. You think you had a lean condition and with the alum specks on the plug's i would agree. This cylinder may been even leaner and with the extra heat, this plug tip would act like a glow plug and fire at will. This might be the reason this plug self destructed. The plug strap heat looks ok, may take 2 out. Just my 2. Ron
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