Well I finally got HP tuners up and running and did some data logging before anything else. The first thing I noticed is that I get knock retard in areas I cant imagine would have any knock. On my first drive around I was getting full KR (6 degrees) at about 35% TPS and 2400 rpms. Which is when I am just barely accelerating. Then I also got full retard around 85 % TPS and 4500 rpm. But when I am full throttle the most I have seen is like .5 KR. I know that the MAP readings might mean more than the TPS but I dont know that file right in front of me to look at. I tried to figure out where I would need to cut timing but there is really no specific point where I should be cutting it at.
My only guess is that this is not true knock. That it may be some other factor causing the knock sensor to go off. I just dont know how to prove this. Of course running some higher octance fuel; however, I doubt that moving from 87 to 93 would get rid of 6 degrees KR. I have never heard an audible knock on this car before so I am leaning in the direction of somthing else but detonation causing the KR.
On a better note HP tuners is definatly worth the money. Once I get this KR issue figured out I can definatly see the amazing benifit it will have.
Run higher octane fuel, and if it DECREASES the KR then it's real, if no difference then there's the chance it's phantom knock. I'll agree that those are weird spots to see that much knock though, happy tuning.
15.3 @ 89.97mph, 14's on the way?
I will definatly run the higher octane fuel, I just have to wait for this last half tank to burn out. The only other thing that caught my eye was that these spots were usually at lower speeds, maybe more load or somthing. But also the IAT's jump up at lower speeds. But still for a relatively stock car I was just curious if others have had this issue.
i had same problem with kr in weird and random places
i turned my kr off altogether since it was pissing me off
I don't suggest doing the same however I do suspect its some form of false of phantom knock
DaFlyinSkwirl (PJ) wrote:i turned my kr off altogether since it was pissing me off
brave soul!
|Forged 8.9:1 Wiseco Pistons|Forged Eagle Rods|HPTuners|60trim|Tial Wastegate|
|Precision Intercooler|2.5" Exhaust|2.5" Charge Pipes|630CC Mototron Injectors|
|Stock: Fuel Pump, Transmission, Manifold, TB, Head, Head Gasket, Ignition, Suspension...|
indeed
my engine is not modified to the point of having the amount of knock I was seeing
I've heard that moving the knock sensor to an oil port somewhere on the engine desensitizes it to an extent, but it still keeps functionality
other than that the engine runs strong, had no hiccups with 4degrees ignition advance up high..
DaFlyinSkwirl (PJ) wrote:indeed
my engine is not modified to the point of having the amount of knock I was seeing
I've heard that moving the knock sensor to an oil port somewhere on the engine desensitizes it to an extent, but it still keeps functionality
other than that the engine runs strong, had no hiccups with 4degrees ignition advance up high..
But as the 4 degrees advance helped ur 1/4 mile times? And does the timing actually use those 4 extra degress of timing?
Nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
I moved mine from where my 2002 Eco was placed in the oil pan to the spot mext to the started in the block. where like 2004;s are place and LSJ Cobalt motors.
I still get knock however not much, but I am on 20+ psi and juice.
Best time:"""11.946""" @ 114.73 mph @17psi 1.83--60"
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Well I just put in some 93 octane and didnt really notice any difference in KR at all. I still hit full KR at a lot of spots. None of the spots were at full throttle. I actually logged a point where I was at about 25 % TPS and at about 25- 45 MPH and logged full KR the whole way. I just need to figure out what is going on. Has anyone figured out what is causing their phantom knock or is this just a performance killer that I need to live with?
Rollinredcavi wrote:Well I just put in some 93 octane and didnt really notice any difference in KR at all. I still hit full KR at a lot of spots. None of the spots were at full throttle. I actually logged a point where I was at about 25 % TPS and at about 25- 45 MPH and logged full KR the whole way. I just need to figure out what is going on. Has anyone figured out what is causing their phantom knock or is this just a performance killer that I need to live with?
What gear was this in, and what RPM? IF it was 5th at low RPM, it could still be legit KR, if not then it's time to start looking for potential causes of phantom knock, loose bolts, engine/tranny mounts, etc.
15.3 @ 89.97mph, 14's on the way?
This is a 3 speed auto tranny. It would definatly be in second gear at low rpm's. Around 2400-3000
i actually had a friend scan mine (using a different program than hptuners) and i saw 6 degrees at the top of 3rd... but i find it hard to believe i have knock with and intake, exhaust, and a pulley. i'm guessing it's something along the lines of my exhaust rattling or something.
keep in mind... generally (at least from what i've seen) phantom knock will kind of be all over the place. real knock tends to increase exponentially as the rpms increase.
There is no set reason why knock has to occur at wide open throttle. The greatest spark advance is found under high vacuum, high rpm conditions such as cruise. These are also the conditions where light knock is the least likely to do damage. To see if it goes away, locate the cells around where knock is occurring and remove 2-3 degrees timing. If you make a change in the indicated knock, it's real knock.
-->Slow
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But as the 4 degrees advance helped ur 1/4 mile times? And does the timing actually use those 4 extra degress of timing?
its hard to say
I put full exhaust on the car as well, and even tho i haven't beat a 14.91 yet, my trap speeds went from avg 90 mph to avg 92mph
there's a lot of variables as far as one run to the next with my setup.. not the best way to tune, but when I finally get the gauges I need I'll be able to see if its helping or hurting
i decided to blow money on cams and a balance shaft delete kit this week
I've heard that GM puts the ignition timing right on the edge, which would explain why I was getting so much KR since it can barely hold stock timing but it doesn't seem to have hurt
only track and dyno testing will tell when i'm ready
