Retard Timing to cure knock?

[unclesam099]

See this thread for some previous info: http://www.dsmtuners.com/forums/showthread.php?t=243232

Ok, so I ran a log with 100 octane gas and methanol and I'm STILL knocking. AFR is 11.x:1 and seeing 21-22deg of timing. I verified that all timing settings are correct.

On 93, I'm seeing knock even at 0* base timing.

Can I theoretically run base timing ATDC to get my timing down? I am at a loss now of what to do. I have seen other threads suggest running 1 more range colder plugs, I'm already running BPR7ES at .028" gap.

I will post up my log when I get a chance to it, there are other wierd things that I saw on there, like I'm seeing 106% IDC on 550cc injectors at only 18-19psi of boost.

 

[GVR4592]

We definitely need a log, if you have one with wideband data that would be even better. It sounds like you're just running out of injector though.

 

[unclesam099]

I am getting knock at 2800 - 3000rpm when the turbo is spooling. I don't think that the injector is at fault there, but I may indeed be running the base pressure a bit low for WOT runs. I can up it a bit later, but I'd like to get the original problem fixed (knocking when turbo is spooling at 3000rpm and 8psi).

 

[daren_p]

Thats not a common place for it to knock, are you sure its real knock?

 

[unclesam099]

Daren, it sure is real. I put in a few gallons of 100 octane and the problem disappeared.

Granted, I probably will get a new knock sensor (after I check for goo), but the 100 octane cured the problem of detonation from high timing. Or at least that is what I'm assuming.

It was a cinch to tune with the 100 in there. I was running 11.7:1 in a snap and the car was absolutely ripping.

 

[bfdahl]

barring that there is nothing wrong mechanicly with your car, you will not be able to pull out enough timming with your CAS to make much difference.

I had to upgrade my DSM chip to the newest one they had for pump gas timming with extended maps to get rid of the knock.

It was either that or DSM link!

PS: get bigger injectors!

 

[daren_p]

Daren, it sure is real. I put in a few gallons of 100 octane and the problem disappeared.

Granted, I probably will get a new knock sensor (after I check for goo), but the 100 octane cured the problem of detonation from high timing. Or at least that is what I'm assuming.

It was a cinch to tune with the 100 in there. I was running 11.7:1 in a snap and the car was absolutely ripping.

Oh okay, looks like there was a typo in the origional post, you said you put in the 100 octane & you are "STILL knocking". Knock sensor would defently be a good place to start.

 

[unclesam099]

daren, this is true that on the run last night, I got a large knock sum as I hit 6000rpm. Other runs that I made did not show knock. So random knocking on some runs and not on others probably means that I should check out the sensor, replace it (since it probably has never been replaced), or at least check the torque on it to make sure it is not overly tight.

I got a log of that run last night and I can post it up later tonight when I get home.

I had leaned away from the knock sensor before, but I have had knock when I was going up a hill or when starting out from a traffic light or just at random. I thought that phantom knock was all the time, just at random. This happens in specific situations, but now that I think of it, it is more often than not.

I had read somewhere before that the CAS could be rotated back, but I do know that I was running 0* base before and I did have the same problem, so it goes to show that the CAS can't be fixed like that.

It's a FWD car, otherwise I would get an EPROM ECU/DSMLink. But it's really not worth it for wrong-wheel drive and I'm saving up for a C5 Vette I just want a quick daily driver that can rip if I want it to, from this car.

 

[Generation1JeY]

So random knocking on some runs and not on others probably means that I should check out the sensor, replace it (since it probably has never been replaced), or at least check the torque on it to make sure it is not overly tight.

Hey, sorry i don't mean to thread jack, but i just rebuild my car and my knock sensor had major goo status so i replaced it, although i didn't torque it to a specific value. Would that have a big impact on its readings? Because now i'm having knock problems and i can't figure it out considering i'm on a nearly stock system running UNDER stock boost. I just have my bov line teed straight into the wastegate. So i'm getting right between 9-10PSI. I have a logger and pretty much everytime i do a WOT pull i will get knock whether its 2 or 8 or 11. It just seems erradic like it never really gets consistent readings.

Earlier when i had just finished my car i got 0 knock all the way to redline on 3rd gear pulls, but now sometimes it will knock and sometimes it wont.

I'm just wondering with stock fuel system, stock mas, stock everything except for UICP and exhaust and LOW boost settings what would cause me to get knock counts like this?

Also, is it regular when cruising on the freeway at like 70MPH in 5th to get a lot of knock if you just give it WOT in 5th? And when downshifting, right when you mash the gas will it get s knock spike?

 

[coltboostin]

I am getting knock at 2800 - 3000rpm when the turbo is spooling. I don't think that the injector is at fault there, but I may indeed be running the base pressure a bit low for WOT runs. I can up it a bit later, but I'd like to get the original problem fixed (knocking when turbo is spooling at 3000rpm and 8psi).

I would suggesat thickening the fuel there to stop the knock before it comes into play. This is usually how I tune my cars.

 

[unclesam099]

Generation1JeY, you shouldn't have knock at all if your car is tuned right Torque should be 17lb-ft I believe, so that's not very tight at all.

coltboostin, I've already tried running REALLY rich to the point that the car sputters and IDCs are too high if I richen it up, and it still knocks.

 

[Rice Over Wheat]

unclesam, do you always see around 22* timing on mid/hi throttle, or is this where you are aiming for? I'm having opposite problems trying to lower mine from 31*.

 

[unclesam099]

22* is what I see at WOT at higher RPMs. I'm not really shooting for anything, but just trying to rid the car of knock and tune for no/minimal knock. My timing curve looks to be pretty normal.

 

[Generation1JeY]

Generation1JeY, you shouldn't have knock at all if your car is tuned right Torque should be 17lb-ft I believe, so that's not very tight at all.

But if i'm completely stock what would be causing the knock then?

 

[unclesam099]

But if i'm completely stock what would be causing the knock then?

If you're stock with no upgrades at all, I'd look for a boost leak or checking your knock sensor to see if it's bad. There are articles about that in the tech section or if you search for it.

 

[unclesam099]

Looks like the knock sensor is leaking stuff like crazy. I was under the car tonight and saw it, so I think that'll be next weekend's project.

Can I drop the intake support bracket without having to worry about anything else? I'm going to get at it from under the car, it looks like it'll be much easier than going in thru the side.

Also, I think I'm going to be getting an M10 nozzle for the alcohol/water kit

Hopefully I can then weld up a J-pipe and get the FMIC on soon afterwards. And make the rest of my 3" exhaust. I love/hate this car!!!

 

[unclesam099]

Ok, knock sensor replaced but I'm still knocking.

I am at a loss for what might be wrong. I'm going to seafoam it tomorrow to see if I can clean everything out. This damn car is pissing me off so much.

 

[GVR4592]

You don't think the 106% IDC has anything to do with it?

 

[unclesam099]

It might.

But I have 550cc injectors. Theoretically, if I raise my fuel pressure, I will get more timing because of lower IDCs. Am I correct in this thought? I'm up for trying it, though. I was going to up it from 36 to 40 or 43.

 

[scottsee]

You don't think the 106% IDC has anything to do with it?

Where do you see that? I can't find a log..

I've had similar issues. Boost threshold Major knock, and compleatly out of the blue. My issue was caused by a combination of to small of Meth injector, inaccurate activation point on boost sensor, and just down right lean mixtures. If the car runs like a raped ape on 100/meth combo then your problem is in the AFR/Timing maps. Are you running a wideband that supports Lambda values of Meth? If not your wideband readings need to be caculated and are inaccurate..

I only saw one log from your other post. You mentioned a 10.0:1 wideband reading, but your log showed .86v on the o2. That is a HUGE discrepency. Aside from the wideband results, everything esle seems to point to over lean mixtures/to small of an injector..

NO FMIC?? Intake temps in the combustion chamber maybee effecting things??

 

[GVR4592]

See this thread for some previous info: http://www.dsmtuners.com/forums/showthread.php?t=243232

Ok, so I ran a log with 100 octane gas and methanol and I'm STILL knocking. AFR is 11.x:1 and seeing 21-22deg of timing. I verified that all timing settings are correct.

On 93, I'm seeing knock even at 0* base timing.

Can I theoretically run base timing ATDC to get my timing down? I am at a loss now of what to do. I have seen other threads suggest running 1 more range colder plugs, I'm already running BPR7ES at .028" gap.

I will post up my log when I get a chance to it, there are other wierd things that I saw on there, like I'm seeing 106% IDC on 550cc injectors at only 18-19psi of boost.

He said it in the first post.

 

[GVR4592]

It might.

But I have 550cc injectors. Theoretically, if I raise my fuel pressure, I will get more timing because of lower IDCs. Am I correct in this thought? I'm up for trying it, though. I was going to up it from 36 to 40 or 43.

Idc's don't directly affect timing advance. I looked at your other thread and in that log you were getting knock with IDC's in the 50% range, so that rules out my IDC guess.

Is it knocking even with the water injection? Have you checked cam timing? Sometimes if the belt skips a tooth it can cause some pretty significant knock. Oil in the combustion chamber can also cause a lot of knock, does the engine smoke from the exhaust at all?

 

[unclesam099]

It knocks even with the WI activated at 5psi. Timing belt was done ~2 yrs ago because the balance shaft belt snapped and took it out, and a few valves in the process. Head was rebuilt then. I haven't checked the timing but I probably should to be sure.

The car doesn't burn oil, it has decent pressure.

I thought of the FMIC issue, I have to get that on the car for sure. I should get an M10 nozzle now to see if 100% meth will help. Now it's a water/meth mix (more water than meth).

The wierd thing was that I didn't have these problems til I put the 550cc injectors on. The 450s were fine with running smurf piss, but had like 150% IDCs but only a small amount of knock.

 

[unclesam099]

Ok, so I just did the Seafoam treatment and I think that I have an exhaust leak between the head and the exhaust manifold and possibly some cracks in the manifold as well. That may explain the O2 discrepancy, but would that cause some of the knock problems?

The fuel pressure is now at 42psi w/o the vacuum source.

The UICP feels cool to the touch, and only a little warm up near the TB.

I'm really pissed that I can't solve this damn problem.

EDIT: Just went out and did some pulls. I added fuel to the area where I'm spooling and it helps a little. There is still some knock, adding fuel helps sometimes, but sometimes not. I'm not seeing 30+ counts anymore, more like 15 - 20 at most. WB is pegged at 10:1 tho, and I'm not really happy about that. I may try more fuel pressure, but I don't know if that will help much either.

 

[unclesam099]

Did a WOT run today with the wastegate actuator arm disconnected and didn't show any knock. So apparently this is real.

See post above, please give me some feedback. I added pressure but the car still thought it was running lean. What is the deal with that? Is that the manifold leaking?