A Must Read For Budding Tuners, Or Those Interested In "knock"

[StealthX]

Hey Trent, can you list/work out the knock frequency for my QR25DE+T?

2.5L four, 9.5:1 CR, bore + stroke is 89x100mm respectively dunno what other info you need sorry...

[STATUS]

Hey Trent, can you list/work out the knock frequency for my QR25DE+T?

2.5L four, 9.5:1 CR, bore + stroke is 89x100mm respectively dunno what other info you need sorry...

6.4khz

[Drift Motorsport]

Thanks Trent. I think the Gizzmo will do me just fine and I should be able to have an ignition to knock compensation table dialed in the Motec.

Any tips / information regarding the mounting and location of the knock sensor? I know the JZ and RBs have threaded locations that you can use to tap in the factory and aftermarket but these are typically buried under the inlet manifold and are a real pain to get to!

[STATUS]

if you want one i can get it from ray direct ^^

best bet is on the block but you can go off the head too, just need a few runs to sort out the base noise of the engine.

[snozzle]

Good read.

Thanks for sharing good information!

Actually, while on topic i have a quick Question, are there any other engine components such as the rattle from twin plates, rattles from loose bolts, starter motors etc etc that a knock sensor can pick up as false knock? Have you found any common parts/things to bring up false knock ?

Reason behind the question is my gtr, everytime i start it up, power fc brings up a knock reading between 20-40 when i start it, hot or cold, clutch in or out but once its idling the knock reading is 1-2. Other cars dont seem to do this?

Edited November 23, 2010 by snozzle

[Drift Motorsport]

Hey Trent, I have sent you a PM regarding the purchase of a gizmo kmon. Please Check.

[unique1]

good topic Trent, i still havent worked out how to avoid static noise from pluging in my autronic cable to tune and the gizmo kmon cable at the same time on the same laptop as once the autronic is plugged in it just detects constant knocking and static noise. Have you had this drama before?

I tried tuning with this and lost patience and just kept the engine real safe as i didnt know if it was detecting knock or just engine noise alot of the time. I also run an egt sensor in each runner as a way to keep everything even.

[STATUS]

Good read.

Thanks for sharing good information!

Actually, while on topic i have a quick Question, are there any other engine components such as the rattle from twin plates, rattles from loose bolts, starter motors etc etc that a knock sensor can pick up as false knock? Have you found any common parts/things to bring up false knock ?

Reason behind the question is my gtr, everytime i start it up, power fc brings up a knock reading between 20-40 when i start it, hot or cold, clutch in or out but once its idling the knock reading is 1-2. Other cars dont seem to do this?

yup i have some clutches give high readings.. had some interesting issues with jb clutches were the knock levels on a car were getting higher and higher and it turned out the rivets for the clutch plates were not strong enough and both were rattling... found the source, so i called the other customer in and found the same thing.

The noise was discernible when using the head phones but not the pfc knock monitor.

[STATUS]

good topic Trent, i still havent worked out how to avoid static noise from pluging in my autronic cable to tune and the gizmo kmon cable at the same time on the same laptop as once the autronic is plugged in it just detects constant knocking and static noise. Have you had this drama before?

I tried tuning with this and lost patience and just kept the engine real safe as i didnt know if it was detecting knock or just engine noise alot of the time. I also run an egt sensor in each runner as a way to keep everything even.

get hold of a RF filtered USB cable, or try running a cig lighter usb powered cable.

[Rolls]

yup i have some clutches give high readings.. had some interesting issues with jb clutches were the knock levels on a car were getting higher and higher and it turned out the rivets for the clutch plates were not strong enough and both were rattling... found the source, so i called the other customer in and found the same thing.

The noise was discernible when using the head phones but not the pfc knock monitor.

With the extra noise from things like valve train and rattling clutches etc, I always though by using your bandpass filter centred at ~6.6khz or whatever value you are using it should pretty much drop all other noise? Or is the problem that these noises are broad spectrum and add noise in the 6.6khz range as well?

[STATUS]

With the extra noise from things like valve train and rattling clutches etc, I always though by using your bandpass filter centred at ~6.6khz or whatever value you are using it should pretty much drop all other noise? Or is the problem that these noises are broad spectrum and add noise in the 6.6khz range as well?

yeah you can filter out most other noises only issue is engines dont just die from det etc... so for me i like to hear a spectrum of noises not just the det frequency.

Unfortunately not all cars that come in are fresh so your average 120k import is actually more like 220k and you want to hear loss of oil pressure, or any other noise which may occur. Because the det cans are centred one one frequency they tend to "pop" over the top of the other noise.

One could easy turn all other noise off and miss something else more sinister.

[STATUS]

KNOCK BOX

[STATUS]

Anyone used the Knock Block from LINK?

[Drift Motorsport]

I borrowed a friends Gizzmo K-Mon and used it as a single channel for some tuning.

I am blown away as to how easy it is to tune ignition with a proper knock headphones setup!

I used one knock sensor and setup filtered left and non filtered right in my headphones and I picked up on a few points of knock.

Interesting note was that a well known tuner was able to pick up on the same knock, by ear, nearly at the same time as the knock sensor went off.

I find the K-Mon software to be a bit of BS in terms of recording / monitoring, but the headphones listening is absolutely vital.

I mounted the sensor on the engine mount, on the block, which is less than ideal, but I was still able to pick up knock.

I will move the sensor closer to the head once I find out where to put it lol. The 1JZ doesn't have any bolt blanks on the inlet side where I can tap into. I may try the inlet manifold with a bracket and see how it goes.

Interesting note is that when you hit limiter or a boost cut, the knock sensor crackles/goes off too.

[STATUS]

I borrowed a friends Gizzmo K-Mon and used it as a single channel for some tuning.

I am blown away as to how easy it is to tune ignition with a proper knock headphones setup!

I used one knock sensor and setup filtered left and non filtered right in my headphones and I picked up on a few points of knock.

Interesting note was that a well known tuner was able to pick up on the same knock, by ear, nearly at the same time as the knock sensor went off.

I find the K-Mon software to be a bit of BS in terms of recording / monitoring, but the headphones listening is absolutely vital.

I mounted the sensor on the engine mount, on the block, which is less than ideal, but I was still able to pick up knock.

I will move the sensor closer to the head once I find out where to put it lol. The 1JZ doesn't have any bolt blanks on the inlet side where I can tap into. I may try the inlet manifold with a bracket and see how it goes.

Interesting note is that when you hit limiter or a boost cut, the knock sensor crackles/goes off too.

should be able to pick it up way before you hear it with the k-mon or knock block. the software logging will show you well before you hear it. You need to log it run at a time so a maximum of 15 seconds to get the best resolution.

on the 1jz i use the spare spots on the head exhaust side front and raise the sensitivity on general tunes but on bigger setups i go to the block

[Drift Motorsport]

Hmm the kmon software doesn't show a trace or recording of what is happening - It could be a driver issue or my laptop.

Yep the engine hook mount on the head would be possible on the exhaust side, still less than ideal but certainly better than nothing.

I can certainly say that without a proper knock detection setup, you are tuning pretty blind, especially once that atmo gate opens - so hard to hear anything at times!

Thanks for the tips, I'll be doing another session soon to tune for 400rwkw at around 23psi on pump.

[STATUS]

Hmm the kmon software doesn't show a trace or recording of what is happening - It could be a driver issue or my laptop.

Yep the engine hook mount on the head would be possible on the exhaust side, still less than ideal but certainly better than nothing.

I can certainly say that without a proper knock detection setup, you are tuning pretty blind, especially once that atmo gate opens - so hard to hear anything at times!

Thanks for the tips, I'll be doing another session soon to tune for 400rwkw at around 23psi on pump.

yeah we just finished a car tonight which had a std 1.5jz (Knockbox)knock sensor on head set to super sensitive) in it and we were running 27psi through it... really want decent knock detection..... end result 520.7rwkw and smiles all round.

Feel free to drop past with the kmon ill run it up on my laptop to check it.

[Drift Motorsport]

Thanks for the invite I'll have to drop in some time and book in a power run once I've tuned it a bit better in the top end and see if she will crack 400 rwkw on pump gas on your dynapak setup.

I've got the 2 step working via a clutch switch so I'm looking at running it at calder feb 5th on low boost (17psi) and getting a benchmark and maybe doing some more tuning track side and see if I can take it to 20psi in the final runs once I get the start/launch right.

Hoping for 10s when it is sorted and a kick off the track ad I don't want to cage it as it is a street car

[battery]

hey trent i have this "false knock" issue im trying to sort out perhaps you have some ideas...

i have a rb25 with a power FC making 200kw, basically i get crazy knock readings and i'd really like to fix it so i can have a go at tuning the car.

on startup it will read 20-40 and i can be driving along in any gear around 3000-4000rpm not much load and it will shoot up to 80-100. On WOT it can hit 200.

I have had 2 different tuners check the car out and they reckon its fine, its been in this state of tune for over 20000ks with no issues.

I have a 5 puk exceedy clutch, oil cooler and relocation kit, other than than that its pretty standard. I have tried changed the knock sensors but there was no change.

whats the best way to eliminate this problem??

[paulr33]

use temp IGN adjust to back out -8 deg timing and floor it

if its does the same you can be pretty sure its not ignition related knock and some form of mechanical noise etc