[Joshinator99]

Originally Posted by Kerry

Knock sensors should stop any damage unless they are tuned wrong. With in reason of course

Knock sensors aren’t saving a SBE LT1 on 93 at 11#… lol

[95 imp]

Originally Posted by Joshinator99

Knock sensors aren’t saving a SBE LT1 on 93 at 11#… lol

[95 imp]

Originally Posted by laynlo15

On my Manley forged motor we build after the stock Lt1 expired we opened the ring gap up to Manley's recommendations for a boosted engine. Expansion of the ring gap is an issue for the Lt1 when you want to make more boost then GM has it set up for.

Forged pistons expand much more than hypereutectic pistons.

[95 imp]

[KingLT1]

Originally Posted by Smokin19

Was thinking the same thing. Do you think a MM can helps in this regard?

Yep because it has the breather on top of the can. I already had a basic catch can, so I added the metco breather. If you haven't bought anything yet just get the MM setup.

Originally Posted by Kerry

Knock sensors should stop any damage unless they are tuned wrong. With in reason of course

Lol...if it was NA yes. Not on 11psi with 93 octane. By the time you see knock and let out chances are it's game over.

Originally Posted by Crazy Drywall Guy

Well after talking to my tuner today it appears I hit 11 psi at 6800 and he seen some detonation. I purchased the P1 procharger lightly used with 3.7 upper pulley . I called procharger direct before installing the unit and they said my setup was good for 8-9 psi and with headers would be closer to 8psi. Budget build ideas please!

. Remote tuning has a place and works well, but with these SBE LT1 you have to be paying attention. It's not something I would recommend for somebody that doesn't have a firm grasp on what they are doing. For starters you never go out and make a full balls pull after a tune revision. Take it up to 5k rpm let out, look over data...then 6k..etc.

The reason why the setup came with a 3.7 pulley is so it makes boost earlier in the rpm range. Typically P1 setups don't start to make much boost with 4" pullies until above 4500rpm and even then it's only 2-3psi and builds to 7-8 by 62-6400rpm. The previous owners car was likely only revving out to 6200rpm and making 8psi with the 3.7. I believe when Procharger rates pulleys on how much peak boost they makes, that claim is based around stock shift points or peak engine power made NA. Shifting the car clear out to 6800rpm is going to make another 2-3 psi as those P1 superchargers really start to ramp up above 6k rpm.

[Crazy Drywall Guy]

Any one care to see the logs I sent the tuner? See if this was something could have been prevented or just bad luck?����

[Kerry]

Originally Posted by Crazy Drywall Guy

Any one care to see the logs I sent the tuner? See if this was something could have been prevented or just bad luck?����

I would like to see ur log for sure. I will give u my email if u like.

A word about knock. You dont see knock you see knock retard. usually as in total knock retard. If u log all the cylinders u can see how much timing is pulled per cylinder. It may be 2 on one cylinder and none on the rest. Might see .5 pulled on all cylinders. The ecu is saveing the engine by pulling timing to where knock stops,( if sensors are set correctly).

Any car that has a procharger will need sensors adjusted period. I have seen knock retard a bunch of times on 13 14 pds no damage caint see it on the plugs and car still running strong at over 700 now I guessamate. In fact with good settings u can run right up to the edge of knock. My stock coop 2019 used to get up to 6 or 7 deg knock retard brand new no mods on shell 93. So thats what I think

[cjperformance]

Originally Posted by Crazy Drywall Guy

Any one care to see the logs I sent the tuner? See if this was something could have been prevented or just bad luck?����

Yes, I'm interested, mostly in spark and afr preceeding the event. For example, if it was .9 lambda at 25 degrees of timing instead of .8 and 13 degrees.

[LT1ornothing]

Originally Posted by Kerry

I would like to see ur log for sure. I will give u my email if u like.

A word about knock. You dont see knock you see knock retard. usually as in total knock retard. If u log all the cylinders u can see how much timing is pulled per cylinder. It may be 2 on one cylinder and none on the rest. Might see .5 pulled on all cylinders. The ecu is saveing the engine by pulling timing to where knock stops,( if sensors are set correctly).

Any car that has a procharger will need sensors adjusted period. I have seen knock retard a bunch of times on 13 14 pds no damage caint see it on the plugs and car still running strong at over 700 now I guessamate. In fact with good settings u can run right up to the edge of knock. My stock coop 2019 used to get up to 6 or 7 deg knock retard brand new no mods on shell 93. So thats what I think

Originally Posted by cjperformance

Yes, I'm interested, mostly in spark and afr preceeding the event. For example, if it was .9 lambda at 25 degrees of timing instead of .8 and 13 degrees.

I hope one of you guys gets a hold of log and can share your findings. I need to believe this was an octane starvation event.

[cjperformance]

eq commanded .812 ... actual eq... .87 was very lean... fuel pressure and such seemed spot on. Will look at more for root cause. Hard to say for sure, but I'd say the unexpected high boost and the lean afr was the cause... but why it went lean not sure.

That procharger tune I was initially running had me even leaner for part of the rpm range, but your pull was .85+ lambda from 4k to 6.8K rpm....

I think a .87 lamda is even worse than what my own was due to lack of PE at 1.0 lamba.

It was consistently lean through the same rpm range for the couple of pulls I see in the log.

If I see anything else I'll let you know. Had plenty of injector overhead, etc...

[cjperformance]

I'm a noob, but your setup is so similar to mine... what jumped out at me... The maf lbs/min for 11 psi in 55 degree ambient weather looks low at 76 lbs/min... so guessing the maf scaling might have been off. On my own setup, at 8-9 psi I see 78-80 lbs/min at similar rpm and ambient temps... so I would have *GUESSED* (because I dont really know) that lbs/min should be proportionately higher. Looking for more experienced input there... I dont have any context to know what airflow lbs/min should look like at 11 psi vs 8 or 9 psi.

[laynlo15]

Originally Posted by 95 imp

Forged pistons expand much more than hypereutectic pistons.

I don't recall saying anything about expansion of the piston. The ring gap needs to be opened according to the manufacturer for boosted motors. You could run the stock piston but open the ring gap for a boosted application as some do especially for the Lt4 engines.

[95 imp]

Originally Posted by laynlo15

I don't recall saying anything about expansion of the piston. The ring gap needs to be opened according to the manufacturer for boosted motors. You could run the stock piston but open the ring gap for a boosted application as some do especially for the Lt4 engines.

Right.

[Crazy Drywall Guy]

Looks like no major cylinder damage,can't even feel it. Bank 4 on driver's side is the only cylinder that fail leak down test.