need help with understanding knock sensor settings

[CADZLA]

Recently, while having tuning done on a dyno, the heads lifted and water was pushed. I am trying to determine what caused this to happen so I can avoid it from occurring again. Some guys have told me that detonation caused it, others said it was the 20 pounds of boost with stock head bolts, along with high IAT2s (210). After the heads lifted the plugs were checked and I was told no signs of detonation. I was also told the compression was ok. The tuner sent me only two of the logs (out of 5 or 6 dyno pulls). Supposedly one was when the heads lifted, the other was the preceding pull. I found some knock at around 5400RPM on one of the logs.
I heard that this tuner often reduces the knock sensitivity (this may be normal?) so I decided to compare the values of a stock tune vs. the current tune. This is what I found -

Knock sensor Threshold Init
Stock = 120.0195 for all cylinders
Tuner = 179.9805 for all cylinders

Burst Knock Retard vs. Cylair Delta
Stock = values ranging from 2 to 12 from 0.012 to 0.048
Tuner = All values set to 0

Knock Sensor Threshold Min
Stock = Voltage 50.0000 for all cylinders
Tuner = Voltage 150.0000 for all cylinders

Knock Fast Recovery Rate vs. Cylair Delta vs. RPM

Some values were changed (I'd have to scan as an attachment as too much to type)


BTW - I have a 09 CTS-V, auto, 11k miles, 2.9 whipple, mild cam, HX, full Stainless works exhaust.

I would greatly appreciate your comments, thoughts , concerns.

Thanks.

[CADZLA]

Attachment 36281

[BMWMD82]

I'm not going to be much help with the knock sensor settings, but that is a shit load of boost.

I'm not sure what type of gaskets those LSA engines come with, but I'm not all that suprised it lifted the heads. At those kind of boost levels, I think a lot of guys are looking at 6-bolt blocks and the like. I'd think you'd at least want some better gaskets and bolts or studs.

[IDRIVEAG8GT]

LS9 gaskets/ARP studs and you'll be good. 20 pounds is too much for stock hardware.

I have run over 23psi on the above with no problems yet.

[JSS06C6]

Concur! Not uncommon to increase the knock threshold, especially when more aggressive cam, head, intake and headers are in your build, but your setup is mild except the high boost pressures. Assuming you're running stock top end setup (oem heads/bolts/gaskets), you certainly need to move to Studs and LS9 gaskets. I set mine up with ARP studs to prep for boost when/if I go there. Should also do same for NO2 spray.

[decipha]

so what kind of torque was this jewel making?

[LT1Z]

Nothing out of the ordinary was done. Planning litigation I assume.

[CADZLA]

LS9 gaskets/ARP studs and you'll be good. 20 pounds is too much for stock hardware.

I have run over 23psi on the above with no problems yet.

Thanks.
LS9 Gaskets were installed along with ARP studs. However, I am going to run lower boost for a while (16-17), as I don't want any more problems.

[CADZLA]

Concur! Not uncommon to increase the knock threshold, especially when more aggressive cam, head, intake and headers are in your build, but your setup is mild except the high boost pressures. Assuming you're running stock top end setup (oem heads/bolts/gaskets), you certainly need to move to Studs and LS9 gaskets. I set mine up with ARP studs to prep for boost when/if I go there. Should also do same for NO2 spray.

Thank you for the info. I have learned that it is not uncommon to reduce the knock sensitivity especially if headers are installed.

[CADZLA]

so what kind of torque was this jewel making?

Far from a jewel BUT......
It was around 600/600 on a Mustang dyno (660? on a dynojet).
But that was with high IAT2s (210), as HX needed to be bled. I figure I lost decent power there. Other V2 owners with similar builds are around 700-740, pump gas, or so they say (LOL).

[aquickls1]

What does HX stand for?

[4evervette]

Hx = heat exchanger ..to the op ... Ur losing a lot of HP if u didn't bleed the HX system ..210 way to high ..n that might coz ur detention

[CADZLA]

Update - I went to local shop yesterday and they looked at the tune, They were SHOCKED at what they saw. Tuner had it at 20 degrees of timing!! So, he was pushing 20psi, 210 IATs, and 20 degrees of timing on STOCK head bolts and bottom end (except for cam).
Shop owner wants me to check 2 logs I was sent and let him know what AFR was. I can only imagine. They won't touch my car at this time in fear that something may bust as the bottom end may have been compromised. I found it interesting, though not surprising, that two other guys that used X Tuner while he was here recently visited the local shop I was at yesterday as they had issues (not as serious as mine though). Word has it tuner, while having good reputation in the tuning world, is fairly new to boosted applications. That's quite obvious now. I may be posting my tune and logs on here soon to get some opinions.

[CADZLA]

Nothing out of the ordinary was done. Planning litigation I assume.

Maybe ordinary with the reducing of knock sensors, But 20psi, 20 degrees timing, 210IATs, timing set to pull only 6 degrees at temps of 200 is a recipe for catastrophic disaster.

[Bill@HPTuners]

First and last warning, keep it civil guys. If nobody starts nothing there won't be nothing. If you guys have something personal against one another keep it off our forum as it will not be tolerated here.

[LT1Z]

Maybe ordinary with the reducing of knock sensors, But 20psi, 20 degrees timing, 210IATs, timing set to pull only 6 degrees at temps of 200 is a recipe for catastrophic disaster.

I was referring to the information given at the time of my post. Timing will be related to what octane will allow. Please stick to the facts. I am not the tuner in question here

[CADZLA]

First and last warning, keep it civil guys. If nobody starts nothing there won't be nothing. If you guys have something personal against one another keep it off our forum as it will not be tolerated here.

Thanks Bill. I am new member here, obviously. Just looking to get some advice, opinions, from, what I have heard, a good group of professionals.
Cheers.

[IDRIVEAG8GT]

OP, let me give you a comparison just so you can see where you're at. My truck, it's a 2007 Chevrolet Silverado crewcab. The powerplant is a 417" stroker LS3 4.065 bore/4.00 stroke. It uses a set of Cadillac CTS-V that have been worked by the good guys over at WCCH. They have a 78cc combustion chamber with a -9cc dished Diamond piston that brings the compression to right at 9.5:1 which is around 1/2 point higher than what you have. It has a decent cam and a 3.6Liter Kenne Bell supercharger. A 50 shot of nitrous, and methanol injection accompany it. At a mere 16psi it makes 894 RWHP with no nitrous, and that is going through a 4L80E, transfer-case and an 8 1/2ft long drive shaft. Timing bumbles around 23 degrees with meth and 17 or so off it, all on 93 octane. Off meth the IAT's are around 220 and it gets a few hits of knock retard up top, but has never hurt it. This is all on the same basic block you have. I built it all, in my shop with my own two hands.

Why do I say all this?

1. To let you know how much horsepower you should really make with the correct setup.

2. To show you that timing and knock have nothing to do with blowing the heads off your car.

3. To explain that what happened isn't the tuners fault because 20 degrees of timing didn't appear to knock any around peak horsepower, just a bit around peak torque.

(To make a supercharger car pull in the higher rpm's where the cam starts to fall flat, is just like a turbo car. You ramp the fuel out and timing in.)

4. Also to show that 15-20 pounds of boost is not what us LS guys call low.

5. Six degrees of timing retard even with high IAT's is more than enough to keep things safe in a high pressure environment.

6. Stock hardware was not EVER designed to hold that kind of pressure, and you should do a bit more research before trying to push something set up like this that far.

These motors aren't your foreign fancy pants crap that produce 700 horsepower at 40 psi. NO! 20 pounds of boost out of a big whipple will net your car at 800+RWHP with the proper supporting modifications.

Hell on my G8 I made 656RWHP at only 9 psi!

Just comparison numbers and facts from someone who has been doing this awhile.

[The Shop Inc]

OP, let me give you a comparison just so you can see where you're at. My truck, it's a 2007 Chevrolet Silverado crewcab. The powerplant is a 417" stroker LS3 4.065 bore/4.00 stroke. It uses a set of Cadillac CTS-V that have been worked by the good guys over at WCCH. They have a 78cc combustion chamber with a -9cc dished Diamond piston that brings the compression to right at 9.5:1 which is around 1/2 point higher than what you have. It has a decent cam and a 3.6Liter Kenne Bell supercharger. A 50 shot of nitrous, and methanol injection accompany it. At a mere 16psi it makes 894 RWHP with no nitrous, and that is going through a 4L80E, transfer-case and an 8 1/2ft long drive shaft. Timing bumbles around 23 degrees with meth and 17 or so off it, all on 93 octane. Off meth the IAT's are around 220 and it gets a few hits of knock retard up top, but has never hurt it. This is all on the same basic block you have. I built it all, in my shop with my own two hands.

Why do I say all this?

1. To let you know how much horsepower you should really make with the correct setup.

2. To show you that timing and knock have nothing to do with blowing the heads off your car.

3. To explain that what happened isn't the tuners fault because 20 degrees of timing didn't appear to knock any around peak horsepower, just a bit around peak torque.

(To make a supercharger car pull in the higher rpm's where the cam starts to fall flat, is just like a turbo car. You ramp the fuel out and timing in.)

4. Also to show that 15-20 pounds of boost is not what us LS guys call low.

5. Six degrees of timing retard even with high IAT's is more than enough to keep things safe in a high pressure environment.

6. Stock hardware was not EVER designed to hold that kind of pressure, and you should do a bit more research before trying to push something set up like this that far.

These motors aren't your foreign fancy pants crap that produce 700 horsepower at 40 psi. NO! 20 pounds of boost out of a big whipple will net your car at 800+RWHP with the proper supporting modifications.

Hell on my G8 I made 656RWHP at only 9 psi!

Just comparison numbers and facts from someone who has been doing this awhile.

Is your power with a mustang dyno? I only ask because They can show alot less. Im my testing I have seen 10-18% difference between DJ and Mustang with same car same day. Just wanted to clarify.
Either way your numbers are very impressive.

[98S10]

OP, let me give you a comparison just so you can see where you're at. My truck, it's a 2007 Chevrolet Silverado crewcab. The powerplant is a 417" stroker LS3 4.065 bore/4.00 stroke. It uses a set of Cadillac CTS-V that have been worked by the good guys over at WCCH. They have a 78cc combustion chamber with a -9cc dished Diamond piston that brings the compression to right at 9.5:1 which is around 1/2 point higher than what you have. It has a decent cam and a 3.6Liter Kenne Bell supercharger. A 50 shot of nitrous, and methanol injection accompany it. At a mere 16psi it makes 894 RWHP with no nitrous, and that is going through a 4L80E, transfer-case and an 8 1/2ft long drive shaft. Timing bumbles around 23 degrees with meth and 17 or so off it, all on 93 octane. Off meth the IAT's are around 220 and it gets a few hits of knock retard up top, but has never hurt it. This is all on the same basic block you have. I built it all, in my shop with my own two hands.

Why do I say all this? So with all that 2006 info you must surely have a mph run that corelates with 894 rwhp? Your not one of those internet guys that make 900 rwhp on a chassis dyno, didnt get it engine dynoed, and have no mph run correct? No offense meant just an honest question.

1. To let you know how much horsepower you should really make with the correct setup.

2. To show you that timing and knock have nothing to do with blowing the heads off your car.

3. To explain that what happened isn't the tuners fault because 20 degrees of timing didn't appear to knock any around peak horsepower, just a bit around peak torque.

(To make a supercharger car pull in the higher rpm's where the cam starts to fall flat, is just like a turbo car. You ramp the fuel out and timing in.)

4. Also to show that 15-20 pounds of boost is not what us LS guys call low.

5. Six degrees of timing retard even with high IAT's is more than enough to keep things safe in a high pressure environment.

6. Stock hardware was not EVER designed to hold that kind of pressure, and you should do a bit more research before trying to push something set up like this that far.

These motors aren't your foreign fancy pants crap that produce 700 horsepower at 40 psi. NO! 20 pounds of boost out of a big whipple will net your car at 800+RWHP with the proper supporting modifications.

Hell on my G8 I made 656RWHP at only 9 psi!

Just comparison numbers and facts from someone who has been doing this awhile.