Car is an 01 z24 auto. m45 with 2.7 pulley, r42lts plugs, header, sc tune, hpt, and 93 octane.
I have been doing some logging and I am seeing up to 6* of knock retard, usually at or close to WOT, and around 4500-5500 rpm. The thing that confuses me is that when I watch my IAT numbers it will go up pretty high in boost but then will shoot to -40. Is this because its getting so hot it runs out of "gauge" and goes to -40? The car runs great and has plenty of power I just want to figure these things out. This week I will be doing the 2.2 coil conversion and probably gapping the plugs a little wider, and getting some more logs. I plan on meth injection and more boost in spring, but for now wanna smooth out what its got.
Any ideas on this?
REplace your IAT sensor, and or check th wiring. -40 is the defaut if the sensor does not work, or no sensor reading.
FU Tuning
I kinda thought about replacing it but it works normally until the temp goes really high. I am just worried that the supercharger is putting THAT much heat into the engine that its out of the IATs range. The gauge in hpt goes up to 150 and it works, you can see that the peak needle went up to and stopped at 150. It also showing some KR at the same time the IATs go crazy.
I the IAT will read higher than 150. I have seen 180 (without meth). You can adjust the gauge on HPT to read higher. When it switches to -40 something is up with the sensor, or the wires. Make sure the wires are tight (meaning where they connect on the sensor that there is slack so when motor moves it does not pul on them. Ever had to re-wire the IAT for any reason?
FU Tuning
I havent messed with anything, but I bought the car with the charger on it. It was wrecked in the front, so one of the wires could have gotten messed up. I checked all that stuff when I fixed the front end, but I will look again. I guess I will adjust the gauge on hpt and see just how high it goes.
I havent logged any of the wideband yet, but I was wondering if I could see someones tune that has similar mods. I was wanting to smooth out some of the fuel and spark tables and wanted to see what others were set at. Car is running awesome, I just know theres always room for improvement.
I just did another log and changed the IAT max to 180. You can see it doesnt even peak near max and still hits -40. I guess I will be looking at the wiring and a new sensor possibly. Anybody have a part number for a new one? 6* of kr still bothers me guess I should get this temp thing figured out first though since they may be related
Keep this up and your next thread will be titled, "KABOOM/Ringlands are Broken" .... Get a wideband ASAP, and check the possible faulty wiring.
P&P Tuning
420.5whp / 359.8wtq
The KR does not concern me much because LD9"s are known for ghost knock. I have yet to find a LD9 that did not give off that kind of KR, and even pulling 10 degree's does not change anything.
FU Tuning
The car has been tuned with a wideband, I just haven't logged any with the wideband since I got the car. It has been charged for a long time and is very reliable. I am just trying to smooth all this stuff out. My guess is that the IAT or wiring got damaged in the crash now it has an intermittent problem with the reading like its not getting a signal temporarily. I suppose this could be affecting the fueling and spark and give me knock because of it. I didn't understand why the air charge temp would just all of a sudden drop to -40 and i get the kr right around the same time, so thats why I asked but afrs should still be fine regardless of these very infrequent "occurrences".
If you're IAT is really that high, something is wrong. Even if it's faulty wiring. At that temperature the knock is probably real. I would not drive it or put a larger pulley on until you get it figured out and get the meth injection hooked up.
If it was just the sporadic KR, I could see false knock, but when you maxing IAT I'd bet my bacon its real and dangerous.
The thing is that I dont think its really maxing the IAT out if you look at the last one I posted the peak needle is at around 110. Even if it is getting that hot it would still register up to 180 on the gauge. That run was yesterday and outside temp was probably around 35-40 degrees tops. There is no way the air was over 180 going into the engine, its not like it goes super hot then hits -40 it just jumps to it no matter where its reading at the time. Makes sense to be signal loss to me.
RedCavalac wrote:The thing is that I dont think its really maxing the IAT out if you look at the last one I posted the peak needle is at around 110. Even if it is getting that hot it would still register up to 180 on the gauge. That run was yesterday and outside temp was probably around 35-40 degrees tops. There is no way the air was over 180 going into the engine, its not like it goes super hot then hits -40 it just jumps to it no matter where its reading at the time. Makes sense to be signal loss to me.
Wanna put some money on that? Without Meth and with a smaller pulley, it can easily get to those temps or even above. While I agree with John's statement about the LD9 being known for false or "phantom" knock, I also agree with OldSkool's statement about the knock being real, especially after seeing the maxed out IAT in the first screenshot. Regardless if a WB was on it when it was tuned, there should be one on it at all times. There is no reason not to have one permanently installed with as cheap as they are now a days. As for your reading issue, I could also see it being a wiring issue or a faulty sensor.
P&P Tuning
420.5whp / 359.8wtq
Just replaced the sensor with a spare I had and went for a drive. No more weirdness there, peaked around 136 degrees at 6.5- 7ish psi. Seems pretty normal right?
The car has a wideband installed it just doesnt have a gauge so it gets wired to the interface. Im still getting the kr so I am hooking the wideband back up to the interface the log some of that next time I get a chance. I have only had the car on the road for a week or so and like I said I bought it wrecked so thats why Im messing with this stuff now.
I appreciate the concerns for the engines well being, and I am trying to get this all worked out. I am not some newb thats trying to just half@ss some boost, I was just really suprised by the erratic air temps and wondered if the kr could be because of it. I guess its not entirely though.
I have been reading up as much as I can about the causes of other peoples phantom knocks. I saw that someone was having an issue with there intake pipe being bolted to the power steering pump, which mine is. Also I have noticed my exhaust rubs a little, it is 2.25 inch, but was hung with metal cables with no rubber isolators.
I have a new megan racing exhaust to go on, since the car is parked for winter I am going to change those things and do some more logging in the spring. I noticed in my logs that the kr isnt under boost all the time and the 6* even happened at 20% tps at 3500 rpm. Sounds like a resonance/vibration issue at least for a few degrees of it. Since I put the new IAT in I havent seen over 140 temps and it seems to make power better through shifts under WOT.
My plans for next year are secret cams, meth, exhaust, OS crank pulley, cold air intake setup, and some new tuning. Any thoughts or suggestions?
Throw awayy the secret cam Idea and go with HO cams. Those hurt me bad in the 1/4 mile and dyno.
~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ
I have the secret cams already ( they didnt cost me anything), and they are better than the stock cams. Cant hurt me too much I dont think. Although I know where a quad is sitting at my local junkyard, next time I go I am gonna check numbers on it to see if it may be an HO. It is conveniently missing its IDI cover, but if it is I may just try to snag the whole motor.
my 3800SC pulls 10* at about 5500-6000 and my NA 3800 pulls 6* at 4000 in my GP
your 6 should be an issue at all
JBO since July 30, 2001
As foir ghost knock. I have been fighting it for a couple years not. N/A and supercharged. One thing I have not done that others have is trying to put thread tape on the threads of the knock sensor. I do want to try this.
FU Tuning
I am really anxious to try some new stuff to see if I can get the kr down a little. First I have to get my new drop ceiling done in the garage and then I need to make some progress on my v6 car. I've been pretty occupied with my wifes blazer lately, I just finished doing a heater core and intake gaskets. Hopefully now some of my "fun" stuff can get some attention.
I started driving the car again since I sold my truck.
Today I unbolted the intake from the power steering pump. It went from 6* kr EVERY time I drove at some point. To 3* max for the last few logs I've done. I am amazed at the result and cant wait to get the rattling exhaust fixed to see if that helps too. Bye bye ghost knock!!
the info you found was probably mine from a year or two ago. just had this thread pointed out to me now lol.
thats the type of mount i used. i think the female side that bolts to the power steering bump bolt was 6mm, but double check. the male side can be anything you want really, but i think mine was something different than 6mm. cost me about $15 CDN since its not exactly a common type of anti vibration mount.
I was thinking about an insulator like that, but I am most likely changing my intake setup. I am planning on doing a battery relocation and cold air straight across into the fenderwell.
I did some logging on the way to work today and WTF my iat did that stupid -40 thing again. I am going to re route the wiring for it to see if its just pulling on the connector when I floor it.
My sc idler pulley seems to have a little play in it, any idea where I can get a replacement? GM wants $200 for the idler/bracket and thats not gonna happen. lol
WHITECAVY wrote:Throw awayy the secret cam Idea and go with HO cams. Those hurt me bad in the 1/4 mile and dyno.
I don't think they hurt you that bad. I think a 13.0 in the 1/4 isn't too bad
I had 5 degrees of knock but mine was fixed my leaning it out. Now my car has 0 knock but who knows what will happen this year. My IAT was reading -40 as well but the wire was caught in the the tranny so we fixed that and it was fine.
