I just hooked up the commander finally to the apexi fc to monitor a few key systems and I noticed that my knock at wot was anywhere between 90 and 106. Is that normal for my mods or could there be something wrong? These are my mods:

*Pettit Racing 1.3L 13B-REW street ported engine w/3mm apex seals.

*99' J-spec non-sequential ceramic coat, ported and blueprinted twin turbos.

*Ported upper intake manifold.

*Ported lower intake manifold.

*Ported throttle body.

*Greddy front mount intercooler.

*Greddy elbow

*99' spec efini Y-pipe.

*NGK leading and trailing platnium plugs.

*10mm Magnacore spark plug wires.

*Upgraded Goodyear boost and vacuum hoses.

*Greddy Airnix dual intake system.

*Pettit Racing 3" stainless steel downpipe.

*3" High flow cat.

*HKS Carbon/Titanium Exhaust.

*Pettit Racing aluminum coolant AST.

*ACT extreme clutch.

*Pettit Racing 8.5lbs flywheel.

*Pettit Racing 60/40 short shifter.

*HKS Super SEQ BOV kit.

*Koyo radiator.

*RX7 Trix battery relocation kit.

*Blit Dual Turbo Timer w/harness

*AEM Wideband gauge uego kit

*Autometer boost gauge(still looking for the Defi D gauge)

*Apexi Power FC.

*Front strut bar.

*Greddy lightweight water pump and altenator pulleys.

I really dont know what Im actually suppose to be as far as my knock goes but my buddy basically has a stock motor and he says hes anywhere between 50 and 65. I just really need to know where I should be and if that normal for my setup? Thanks

 

It might be normal and probably is. My knock was about 50-75 and up to 150(!) when driving hard at the track. Then i changed my diff oil, and i have never seen any knock over 27 after that.

Its important that the knock stays consistant. As long as it does that there is no problem. It seems like the knock sensor picks up alot of sounds from the driveline.

 

If you have not been tuned that's probably why your knocking. I don't like seeing anything above 50 or so on my car but occasionally will see 120-180 because of drivetrain slack.

 

I'm tuned conservatively but I still have 80 knock.

 

Do you know your AFR's. If not I would suggest getting a WBO2 just in case there's an issue with something other than the tune ie fuel filter, pump, injectors. That being said if its knocking coming off full throttle then its probably drivetrain noise.

 

probably not related to your issue but my PFC never registered any knock reading until after upgraded to Bilstein HD S/S and HR springs.

10 - 42

 

I don't trust the PFC knock values, but I would be concerned with ammounts that high.

 

Tuned to 11.0 AFR, it's under boost. 14 peak torque timing.

 

I used to have max knock values up to 180 on my new reman. When observing it on the PFC it would occur only for a fraction of a second, particularly during the first hard acceleration, then, drop down to "normal". I could not figure it out what it was as I was running AFR ratios of 11:1.

Then, I changed my stock fuel pump for a Walbro and the knock dropped down to where it is about 40 max. This with the same AFRs after adjusting it for the higher pressure that the Walbro delivered.

Albert

 

I'm sorry, I don't mean to thread jack or anything but I just got an FD, it has a knock sensor (J&S) has a series of LCDs that go from 2.0 to 20.0 degrees and once in a while the lights really close to 2.0 (ie 4, 6 is the highest I've seen) how can I compare that to the "knock values" you guys are talking about like axr6 mentioned 180...?

The reason I'm wondering is every time that gauge lights up I damn near crap myself, put the car in neutral off the gas and coast, and never go past that RPM again...

I just want to know how I can conver the readings from my gauge to these numbers, and then how can I know whats safe?

Thanks in advance, and again, sorry if this takes the thread off topic, but I too want to know what is a safe knock level (if such a thing exists??)!

FYI the car has a PFS cat back, stock cat, greddy intake elbow, and an M2 ECU...

 

That actually sounds like a problem. Like i said before; if the knock is consistant - no problem. If you see spikes like this i would be worried. Dont know if 180 is a high value thought...

 

You can't look at peak values! You have to watch your knock reading during constant WOT. The knock sensor is just a microphone, a loose mounting, drivetrain noise or other noises can trigger high knock readings.

The knock sensor actually works very well...if you are consistently reading over 100 on constant WOT, I would definitely be looking for a problem.

 

Thanks for the info.

 

You should look at peak values. If you had a knocking problem every WOT you would need a new engine pretty fast.

 

If you have a datalogit you should actually log the data and take a look at where its occuring. Like I said my high knock values are because of drivetrain slack nothing is wrong with my map (damn crappy OE engine mounts). If I log my knock its always occuring off throttle after a run. Nothing to worry about. I do agree with Zebb, you should look at changing peak values. So if I'm seeing 20-30's and all the sudden I see a 50-60 reading in datalogit map watch then I would be looking at lowering my leading or opening my split timing in that cell and then smoothing timing around it.

 

Ahh, ok.

I dont have a datalogit but maybe i should buy one...

 

Not true at all. On many cars, you will see a high knock reading occur during shifting or going off-throttle. The only way to get a valid reading is to look at the knock value during a constant throttle opening. Period.

 

Yeah, we just said that, read previous posts.

Not true at all? So what you are saying is; If you have a peak of 150 you shouldent investigate? What if its not the driveline? Do not assume the driveline is making the knocking sound. You can check this by monitor rev(or boost?) and knock with the graph display. The last part was not for you Rynberg, i think you know this, hehe

"Period"? Why cant we discuss this?

 

is that datalogit really worth buying?


BTW when i had a stock motor non tunned my reading was 40 crusing & 130 WOT.

now after the tune my readings are 8 on wot. (we spended 3 hours tunning the car)

anything 50 or higher on the powerfc is not good. anything in the 100's meaning it isnt going to last!

 

Thats not true. I hit 97 today at 1300rpm while backing out of my driveway... just cruzing around town i get about 60-80. And WOT the entire time i've got 70s

I've had 4 FD's one 1/2 bridge, and some stockish ones. I found it just is different from car to car.