Blowed up the boosted 370ci!!!
Just over 11:1, 93/M1, ~17PSI, 13-14*, nothing special about cam, stock knock sensor settings. But I've done the same on stock L76's, LS2/3's, 5.3's of all sorts, some small cams some big cams, some meth some E85, just happens sometimes when making a pull that it goes rich especially on first few hits and doesn't knock. Not like I leave it there except maybe on a SBE running 25+ on E85 then a little richer then normal seems to work well. But I have had some rich misfire, especially in imports but if you know what knock sounds like it has a different sound.
Boost can certainly hurt things as it bends rods and lifts heads, stock engines like 7600rpm more then they like 35psi lol
Just for ***** I went out adjusted my tune to mid 9's AF and ran it up and down the road a few dozen times under boost... zero knock. So 10-10.5 certainly won't hurt anything and I haven't seen it hurt anything in the past.
Just for ***** I went out adjusted my tune to mid 9's AF and ran it up and down the road a few dozen times under boost... zero knock. So 10-10.5 certainly won't hurt anything and I haven't seen it hurt anything in the past.
No its raining here today, I was out messing with my car last night anyways so I threw tune in both directions on my little test track. I didn't see any knock at 10.5 or 10.25 so I kept going down into 9's just to see if it even would. There's really no reason to me to run leaner then 11.5:1 on a boosted setup, especially a turbo setup as boost control isn't always as consistent as a belt. When superchargers have an issue boost normally goes down, but when turbos have an issue boost often goes up. While you may have a boost cut in place its generally not exactly where your tune is and its a few PSI above, much like when weather is colder and you make a little more boost I'd rather be safe there then have it lean out anymore then needed.
thats about usually where I stop too, except for 1 time we went to 19 psi.
I tune mostly Dodge Hemis on the dyno. Never seen knock from too rich. Talking pump gas here. We get 92.
The interesting thing about this discussion is the simple fact that you aren’t logging actual knock. You are seeing the resultant retard the ecu applies to the timing after is sees the knock. Remember the knock has already happened. Retard is the result. And the retardant of course is the result of more than a few parameters in the tune you can change.
Back to the Hemis. In this setup, we can view the actual knock sensor volts in real time. Pretty interesting. You see the spike, then see the retard.
We run them 11:1 on pump fuel when boosted. No more than 7-8 psi if stock bottom end. The mighty Hemis are fragile! Ha!
We pretty much gave up on pump ****. Waste of time if serious about going fast with any sort of reliability
Back to the original story. Two bent rod bolts and the rod cap in the pan? I’m wondering if that rod got missed when torquing?
Ron
The interesting thing about this discussion is the simple fact that you aren’t logging actual knock. You are seeing the resultant retard the ecu applies to the timing after is sees the knock. Remember the knock has already happened. Retard is the result. And the retardant of course is the result of more than a few parameters in the tune you can change.
Back to the Hemis. In this setup, we can view the actual knock sensor volts in real time. Pretty interesting. You see the spike, then see the retard.
We run them 11:1 on pump fuel when boosted. No more than 7-8 psi if stock bottom end. The mighty Hemis are fragile! Ha!
We pretty much gave up on pump ****. Waste of time if serious about going fast with any sort of reliability
Back to the original story. Two bent rod bolts and the rod cap in the pan? I’m wondering if that rod got missed when torquing?
Ron
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Thread Starter
Joined: Dec 2009
Posts: 2,331
Likes: 29
From: Glennville, GA.
No im almost certain i torqued tht rod. I always double check all of them to be safe.
Im been thinkin on this lately. I think the block had a crack in tht cylinder, tht eventually busted and basicly bent/broke the rod etc.
Truck was having some issues were if i made 2 pulls kinda back to back it would get pretty hot. It would eventually cool right off when cruising. Never got hot at idle, in traffic etc. Just after 2 back to back hits.
This is why i think it might have had a hair line crack tht could have busted! Thoughts?
U can also see where the rod dug into the crank journal. This is what broke the cap/rod bolts. It took a hell of a hit. And for the rod to be twisted and wrinkled like it was, it does seem possible.
Im been thinkin on this lately. I think the block had a crack in tht cylinder, tht eventually busted and basicly bent/broke the rod etc.
Truck was having some issues were if i made 2 pulls kinda back to back it would get pretty hot. It would eventually cool right off when cruising. Never got hot at idle, in traffic etc. Just after 2 back to back hits.
This is why i think it might have had a hair line crack tht could have busted! Thoughts?
U can also see where the rod dug into the crank journal. This is what broke the cap/rod bolts. It took a hell of a hit. And for the rod to be twisted and wrinkled like it was, it does seem possible.