LQ9 bent rods at 16psi/12*/11.5AFR
10-20-2014, 01:59 PM
#21
When does the meth come on? How much are you spraying and is it progressive. I can't see timing bending rods especially with the bearings looking good. Is your meth system still good? Pump make proper pressure, solenoids working properly if your using them. I'm very interested, I have the same engine/cpu combo ready to replace my 5.3.
10-20-2014, 02:19 PM
#22
When does the meth come on? How much are you spraying and is it progressive. I can't see timing bending rods especially with the bearings looking good. Is your meth system still good? Pump make proper pressure, solenoids working properly if your using them. I'm very interested, I have the same engine/cpu combo ready to replace my 5.3.
Good point though. For some reason the datalogger shows up to 40% of actual injection????? It ran too good for 40%. Unless the DL means 40% of the water/meth total capacity.
10-20-2014, 03:07 PM
#24
this is the timing table i have in the 403+s484 billet car that does 923 on pumpgas.
unsure what the issue is here, maybe high compression or just great power?
i didnt get to read the whole thread, i just had a request for a timing table haha have time to throw it in here quick for help
10-20-2014, 03:42 PM
#25
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I kind of have a hard time believing it bent them just from power. I am running 17psi on an LQ4 with the weaker rods and haven't had a problem yet. Same AF and peak timing. It's also in a heavier car with straight 91 pump gas.
Would peak torque still be at 4500 even though you aren't at full boost?
I guess the only other differences are that I have my rev limit set at 6300 and my timing is a little more conservative while building boost. Also smaller turbo I would assume, since I'm at full boost by 3500.
Would peak torque still be at 4500 even though you aren't at full boost?
I guess the only other differences are that I have my rev limit set at 6300 and my timing is a little more conservative while building boost. Also smaller turbo I would assume, since I'm at full boost by 3500.
Last edited by LSChevelle; 10-20-2014 at 04:03 PM.
10-20-2014, 05:56 PM
#26
Meth starts at 100kpa and progresses up to 10% of total fuel flow. I assume its working as the water/meth mixture is dropping in the tank.
Good point though. For some reason the datalogger shows up to 40% of actual injection????? It ran too good for 40%. Unless the DL means 40% of the water/meth total capacity.
Good point though. For some reason the datalogger shows up to 40% of actual injection????? It ran too good for 40%. Unless the DL means 40% of the water/meth total capacity.
10-20-2014, 06:20 PM
#27
Sounds like u found the do not cross point for your setup. I'd drop 5 deg. at peak torque and try again. As someone else mentioned verify timing sync. Find TDC with a piston stop. Mark crank, then when u press on balancer mark it as close as possible to mark on crank. I've seen some off as far as 5 degrees.
10-20-2014, 06:43 PM
#28
Agreed^^^^^. I would never run an engine without marking TDC during assembly. How the hell do you time it? You need to verify the timing an pull out a couple degrees. Too much timing with too much compression/boost and ignition cutoff on the limiter with fuel/water/meth still flowing is a recipe for disaster. I'd rather pull 2 degrees of timing out of it above 100kpa and not worry about the power loss. Figure the meth and fuel to cut out when you're on the limiter, but by all means, verify TDC and verify the timing.
10-20-2014, 06:59 PM
#29
Is verifying timing a requirement with the Holley EFI?
I would assume that the system gets the timing pretty dang accurate unless the reluctor wheel was installed incorrectly at the factory.
So question. If it's off, how do you correct it?
Also, I don't believe the factory balancer has any marks on it for timing. There is also no timing tab......
I would assume that the system gets the timing pretty dang accurate unless the reluctor wheel was installed incorrectly at the factory.
So question. If it's off, how do you correct it?
Also, I don't believe the factory balancer has any marks on it for timing. There is also no timing tab......
10-20-2014, 07:17 PM
#30
this is the timing table i have in the 403+s484 billet car that does 923 on pumpgas.
unsure what the issue is here, maybe high compression or just great power?
i didnt get to read the whole thread, i just had a request for a timing table haha have time to throw it in here quick for help
I can't see how an extra .5 of compression can cause an issue but again, I aint seeing any deto. Now I'm wondering if there was too much water/meth but you would need a sh!tload of the stuff to hydrolock it I would think.
10-20-2014, 07:20 PM
#31
Sounds like u found the do not cross point for your setup. I'd drop 5 deg. at peak torque and try again. As someone else mentioned verify timing sync. Find TDC with a piston stop. Mark crank, then when u press on balancer mark it as close as possible to mark on crank. I've seen some off as far as 5 degrees.
Agreed^^^^^. I would never run an engine without marking TDC during assembly. How the hell do you time it? You need to verify the timing an pull out a couple degrees. Too much timing with too much compression/boost and ignition cutoff on the limiter with fuel/water/meth still flowing is a recipe for disaster. I'd rather pull 2 degrees of timing out of it above 100kpa and not worry about the power loss. Figure the meth and fuel to cut out when you're on the limiter, but by all means, verify TDC and verify the timing.
10-20-2014, 08:48 PM
#34
Maybe it wasn't detonation but it was just a hair too much cylinder pressure because of a few degrees too much timing even at low boost? Maybe the old "don't pull timing until past 5psi" or whatever it is is always with a bigger cam that bleeds off a little pressure and allows that, but your tiny cam keeps the cylinder higher.
Hydrolocking it seems really unlikely and detonation seems impossible, stock pistons come apart way too easily for the rods to bend and the pistons to look perfect.
Hydrolocking it seems really unlikely and detonation seems impossible, stock pistons come apart way too easily for the rods to bend and the pistons to look perfect.
10-20-2014, 09:42 PM
#35
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Is verifying timing a requirement with the Holley EFI?
I would assume that the system gets the timing pretty dang accurate unless the reluctor wheel was installed incorrectly at the factory.
So question. If it's off, how do you correct it?
Also, I don't believe the factory balancer has any marks on it for timing. There is also no timing tab......
I would assume that the system gets the timing pretty dang accurate unless the reluctor wheel was installed incorrectly at the factory.
So question. If it's off, how do you correct it?
Also, I don't believe the factory balancer has any marks on it for timing. There is also no timing tab......
10-20-2014, 09:42 PM
#36
Is verifying timing a requirement with the Holley EFI?
I would assume that the system gets the timing pretty dang accurate unless the reluctor wheel was installed incorrectly at the factory.
So question. If it's off, how do you correct it?
Also, I don't believe the factory balancer has any marks on it for timing. There is also no timing tab......
I would assume that the system gets the timing pretty dang accurate unless the reluctor wheel was installed incorrectly at the factory.
So question. If it's off, how do you correct it?
Also, I don't believe the factory balancer has any marks on it for timing. There is also no timing tab......
Starts coming in at 100kpa and then ramps up. If up you mean where the map sensor is hooked-up to is right off the intake. If you mean the boost controller its hooked right to the turbo.
Maybe it wasn't detonation but it was just a hair too much cylinder pressure because of a few degrees too much timing even at low boost? Maybe the old "don't pull timing until past 5psi" or whatever it is is always with a bigger cam that bleeds off a little pressure and allows that, but your tiny cam keeps the cylinder higher.
Hydrolocking it seems really unlikely and detonation seems impossible, stock pistons come apart way too easily for the rods to bend and the pistons to look perfect.
Hydrolocking it seems really unlikely and detonation seems impossible, stock pistons come apart way too easily for the rods to bend and the pistons to look perfect.
10-20-2014, 09:51 PM
#37
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Run better fuel. I'm pushing 17 psi (backed it down from 20 due to inadequate fuel system) through an 02 LQ9 with 212 cam, 10.6:1 compression @ 5000 lbs. 14.5*. 1 part E85: 1 part 93. I think your tune is pretty good and probably not the culprit.
10-21-2014, 06:44 AM
#38
Timing looks a little aggressive around pk tq for that combo on shitty fuel. Could have just got screwed at the pump and getting 87 when you paid for premium. It happens more often than you think. One reason I don't push hard on pump gas. I've got a reliable 12 psi tune in my truck that I drive daily and once in awhile I get a bad tank of fuel and can hear it ping. I've also had tanks that will take 16psi. You never know what you are going to get out of these pumps.
10-21-2014, 08:43 AM
#39
Timing looks a little aggressive around pk tq for that combo on shitty fuel. Could have just got screwed at the pump and getting 87 when you paid for premium. It happens more often than you think. One reason I don't push hard on pump gas. I've got a reliable 12 psi tune in my truck that I drive daily and once in awhile I get a bad tank of fuel and can hear it ping. I've also had tanks that will take 16psi. You never know what you are going to get out of these pumps.
10-21-2014, 10:34 AM
#40
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You can get #1 on tdc, connect anything (like a coat hanger) off of a timing cover bolt or wherever, run it over the balancer and take a silver sharpie or something and mark the balancer directly beneath it. Unplug your injector harness and set cranking timing to 0 in the ecu, have someone turn the motor over while you hold a timing light on it. If it is off it won't show how much but will give you a ballpark idea. They sell tape you can wrap around the balancer if you wanted to but this is just a cheap easy check. The holley has an offset you can adjust, but you have to key off/key on for the changes to take effect.