Feeeeeel the ft/lbs through your fingers
I just hand tightened it, clocking them correctly made no difference to me.
Feeeeeel the ft/lbs through your fingers
I just hand tightened it, clocking them correctly made no difference to me.
the force is not strong with me in that area lol.
most of my knock is in cyls 1&2 so it might not make much of a difference on mine either but id rather do it and know for sure everything is set up right.
2008 Sky RL
finally got the rear one clocked correct. i ended up taking off the tb to clean it so that made some room plus i also took off the top bolt of the intake manifold brace support and just loosened the bottom nut so i could swivel that brace out of the way enough to get to the rear sensor.
im hoping this plus some minor adjustments to my tune will get rid of some more knock.
2008 Sky RL
yeah shabby seems like it didnt do much for me neither unfortunately. back to tuning!
2008 Sky RL
My tuner is on its way from HP Tuners so as soon as I get it back I can monitor my knock. before I had tons of knock and discovered my KR sensors were all over the place so that has been corrected and will log as soon as my interface comes in. I hope I have better luck.
I've had persistent KR in certain mid load (40-50% ETC, 80-100% air load) ranges from 3-5*, even after pulling down the DALs and spark advance in those cells. Both my knock sensors were between 5 and 6 o'clock. They are now at 9 o'clock and once I get out to log, I'll post back.
2013 Cruze Eco - CAI, Catless DP, Catless MP, ZZP FMIC, Ported Intake Manifold, Mild tune (17psi), best 43.5mpg, 175ftlbs (pid)
2008 Solstice GXP - ZFR 6758, catless, AEM stage 1 water/methanol injection, Hahn Racecraft Intercooler, solo street race cat back, LE5 throttle body - 307whp on a dyno dynamics (stock turbo numbers), 100 octane EFR6758 numbers - 463whp/454wtq
It didn't do much for me unfortunately. I'm amazed how much a 3" cat back has affected my fuel trims though, certainly was unexpected.
2013 Cruze Eco - CAI, Catless DP, Catless MP, ZZP FMIC, Ported Intake Manifold, Mild tune (17psi), best 43.5mpg, 175ftlbs (pid)
2008 Solstice GXP - ZFR 6758, catless, AEM stage 1 water/methanol injection, Hahn Racecraft Intercooler, solo street race cat back, LE5 throttle body - 307whp on a dyno dynamics (stock turbo numbers), 100 octane EFR6758 numbers - 463whp/454wtq
So I found this is a file that I save random information that I find while surfing the interweb.
From the OEM world, I've worked with both. We've used "narrow-band" knock sensors that are tuned for a specific frequency range. The downside of these is that you're stuck with that particular frequency range and while it may work great at some RPM/load regions, it may have a piss-poor signal to noise ratio at others. (note -- cdvma's frequency is a good one for knock, but sometimes the signal to noise ratio is better at the resonance frequencies of the actual knock signal).
For some other packages, we use "wide-band" knock sensors which will read a broader frequency spectrum. Then use the ECU (actually, a specific chip on the ECU) to pull out a specific frequency spectrum, sometimes varying with RPM or load. These work more better but are a PITA to tune for.
Also note that a "good" knock system will always be adapting to the "background" non-knocking engine noise and look for a delta between the non-knocking signature and the current sensor output. I haven't seen much on the over the counter setups, but I don't trust them on this point.... They will, however, warn you of moderate-severe knock before the big parts of your engine vacate the block.
Does anyone know if we have narrow or wide band knock sensors?
GMTech you have any idea?
--Christian
LNF has a wideband in the O2 housing, and a narrow band in the downpipe, after the cats.
It seems that I'm in the minority on this board. I love all the instrumentation that this car provides from the factory, and I love that it almost always runs in a closed loop.
Originally Posted by Wangspeed
Wangspeed you are correct of the O2 sensors but I was referring to the knock sensors.
--Christian
Sorry, I failed reading comprehension, I guess.
we can't all be perfect
How vital is it that the kr sensors be torqued to a specific rating? I feel as if I could get to the rear one without removing anything, but I wouldn't be able to get a torque wrench in there I don't think. My front sensor is already clocked at 9 o'clock and I don't seem to get any false kr out of it.
i do not believe it as vital for these style knock sensors compared to what you would find on older fuel injected cars.
So the general consensus is 9:00 is the correct position, and some have lost false Kr while others have had no change... Also, on the LNF's, are they both under the intake manifold or is one under the intake manifold and the other on the rear side of the engine? Just thought I'd check since I'm going underneath the car today.. if I can see these, I'll clock them and see if it takes away some light load low rpm knock that I think must be false. Every now and then, 1 cylinder, usually 4, but sometimes 2 or 3 shows 2.99ยบ in a random cell or 2, sometimes at Wot but only sometimes... Just wish I could rid myself of any false crap cuz that'd make tuning the timing accurately so much easier.. as it is, it's just guesswork and hope for the best.
KR is really common with DI cars. There are reports of a good amount of KR on GM's new LTx motors in low RPM low and mid load situations.
Seems to be a common trend that can be minimized with stable fueling but not completely eliminated. You can also try hand smoothing your timing tables for smoother transitions to see if it helps.
I've found that keeping ST fueling in check (no huge swings) and smoother timing transitions have helped tremendously for the dreaded #4 random KR.
Others have hinted at messing with the injection timing to minimize random KR as well, though I've not tried that yet.
09 RY Cobalt SS Coupe - 19K miles - Bolt ons + 7163 ZFR, HP tuned on ethanol
Sold - 09 SRTC Cobalt SS Sedan
Totaled - 09 VR Cobalt SS Sedan
Sold - 09 RY Cobalt SS Sedan
I have some pretty smooth timing tables already.. haven't done another Maf cal since I cleaned n clocked my K&N to 11:30 but the trims are still pretty close.. a few cells are off but I don't like playing with that calibration lol.. it's so easy to throw it off :P My KR seems to wander everytime I open and close HpT though.. one time it'll be cyl 4 and next time it'll be cyl 2 or cyl 3.. very rarely is it cyl 1 but occasionally it'll be the main culprit as well... It HAS to be false KR.. so hard to tell though. Is there a way of seeing the difference between real and false on the chart display? It usually looks like an earthquake type of deal when it does it and only lasts a second or so.. maybe 2.. at any rate, it's short and annoying.
both knock sensors are under the manifold: one by the oil filter housing and the other under the fuel rail where the injector harness connector is.
2000 Ford Mustang - Top Sportsman
OK thx dude.. gonna Pm you a question or 2 CSSOB
Can anyone walk me through setting up the ability to monitor knock on all 4 cylinders for my 09 SS LNF?
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