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KR all over the place.

MillCityGTP

MillCityGTP

New member
A little frustrated right about now. On a 3.5" with a 3" DP w/ cat, Powerlog, ZZP rear Powerlog, 104's gapped a .055", 180 Themo, 4" Intake, and an Overkill tune, I'm seeing varying degrees of KR. A few instances:


-WOT pull with the car fully warmed up, not really heatsoaked, I'll see 4-6 degrees of KR.

-Climbing a hill, around 2500 rpms, as soon as the car hits 4th gear it will start and bounce around ranging between 0.5-3.5 degrees. This is when the car is still not making any boost yet.

-On the highway doing 65-70 mph, in 4th with the converter locked, if I give it a slight more throttle to accelerate it starts doing the same thing as above, kind of bouncing around between 0.5 degrees and 4 degees. Keep in mind the car still doesn't downshift, and I'm still not making boost. I floored it at one point on the highway after driving for 30-40 minutes and the KR spiked as high as 8.5 degrees.

I'm guessing I've got a factory knock box that's always going to require maximal mods to run any smaller of a pulley?
 


The kr you're seeing in 4th with converter locked is normal, high load/low rpm = kr. You can manually shift to 3, or just ignore it as this kr isnt as bad for your engine as it is at wot (cylinder pressures not as high). As far as your kr at wot, what do your 02's look like? How much timing? Can you post a scan in .csv we can look at? When you got the pcm, did you already have the pulley or was it added later?
 
I haven't looked at my 02's, I thought only a wideband would be accurate? I know it's cycling normally. The pulley, rear manifold, 104's, 180 themo, and tune were all installed at the same time. I looked at the aeroforce at WOT and it looked like it was at 10.5-11 degrees timing, so I'm guessing the Overkill PCM is looking for 18 degrees at WOT which is what it would be if there was no KR. I need to do a log on a pull with the Aeroforce and see what it's doing.
 
your best bet is to pick up a dhp powertuner and do some data logs. otherwise it will be difficult to determine the cause of all the kr. you could look for an hp tuner, but they cost more. you can use your narrowband o2 sensors to get an idea of how rich or lean its running, but the wideband is going to be more accurate. might be a good idea to pulley up to a 3.6 until you figure out what is causing the kr. with those mods you should be fine with a 3.5, but I would rather be safe than sorry.
 
NB isn't the greatest, but it's better than nothing. 920-960 is roughly where you want to be. When was the last time you changed your fuel filter? Injector cleaner? How many miles on the car, and do you have 93 octane, or is 91 only available to you?
 
I was contemplating getting a 3.6. I changed the fuel filter when all this stuff went on. Grabbed a ZZP filter when I ordered the rear manifold and puller. I have 93 octane and that's all I will run, I even avoid "no-name" gas stations just in case. I ran a bottle of fuel injector cleaner through it not too long ago.

Weird part is, I left work for a doc appointment yesterday. The car had been sitting all day. Once it reached operating temp, I really gave it hell on the highway, barely saw 2 degrees of KR the whole time. It's really strange, which is why I was thinking a lot of it had to do with it being false. Not willing to risk my motor on a hunch though.

The car has around 68k miles on it now.
 


off topic , but what do you think of that rear plog ? does it look like it'll flow better ? they don't give any specs for it or talk it up like they do on the front. it's kinda like , "well here's the rear" ...and that's it.
just got the front plog delivered today and considered getting the rear sometime later, but wanted to see what people had to say about it. there's no reviews so far.
 
It's possible it could be false, did you flip the swaybar when you did the DP? Trans dipstick tube not too close to anything? Is your lower motor mount in good condition? Could be possible you just got a bad batch of gas or something, if you weren't seeing any KR before this. I'd wait until you get another tank in there, from another good station and see what happens. Does the AF read 02's in mv?
 
The downpipe is not flipped, as for the trans dipstick I will take a look and see how the clearance there looks. The Aeroforce does read o2's in mV.

As for the rear manifold from ZZP, I installed it with the 3.5 and Overkill tune so I'm not sure on a "seat of the pants" difference in power. But prior to this if I got on the car hard off a stop and let off, the exhaust would pop a bit, with rear manifold, it no longer does this, so I believe it definitely flows better than the stock rear manifold.
 
you should be able to run a 3.4 let alone a 3.5 ...maybe it's something that pcm is doing..
 
check your fuel pump or could also be a clogged fuel filter mine was getting kr in higher gears i swapped pump and was fine after that
 


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