RHD false knock

[v8hgt]

Has anyone else noticed false knock on RHD cars with tunes?
If you aren't sure take your car gently to 4000 rpm in third then floor it to 6000 rpm while logging the knock sensor. As standard with the Ford factory tune it will blip to +0.65 for half a second then back to zero as the revs climb. On a custom performance tune it will go instantly to +6 and stay there until you lift off at 6000rpm. The difference being the performance tune is noticeably more violent when you floor it. You really feel the extra power and the torque reaction.

I have a theory about what makes RHD cars more likely to exhibit false knock under hard driving and it stems from the Ford recall to secure the loom that was getting burned by the rhd header. If the loom was close enough to the header to catch fire on our cars but not an issue on LHD cars, then would it also be close enough to touch the header if the engine was rocking hard over on the engine mounts? I have just watched this video below and it shows a red car with the engine out. He shows an a/c line clip that can touch the right header of some lhd cars running long tubes. Could our rhd cars with their comprised standard header routing be effected by a very similar issue when they are given a bit more power? I'm going under my car this weeeknd to investigate this area specifically.

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[Manders Mustang]

Who tuned your car? a blip sounds like it's false, if it's holding steady that's constant... and bad!


Oh also, video aint there...

 

[Centurion07]

Gibbo had it and I think it was either something to with the exhaust or TB.

I'm sure he'll be along soon enough.

 

[Manders Mustang]

Gibbo had it and I think it was either something to with the exhaust or TB.

I'm sure he'll be along soon enough.

[MENTION=13598]Gibbo205[/MENTION] come on wizard.

 

[Centurion07]

He'll be on his way to Jockland so might be a while.

 

[Manders Mustang]

He'll be on his way to Jockland so might be a while.

Aye but i hear his car drives itself now :lol:

 

[Gibbo205]

Gibbo had it and I think it was either something to with the exhaust or TB.

I'm sure he'll be along soon enough.

The knock sensors in standard configuration are sensitive.

I have tried and tested extensively:
- Stock tune
- SCT/JDM/DS/FRPP canned tune
- Lund tune
- AED tune
- Palm Beach dyno tune


Blips from hard throttle inputs at high RPM or harsh shifting setting of the knock sensor is generally one of two things:
- Torque management system completely disabled, so the car hits too hard.
- Too much base or throttle tip in timing.

How do you know if your knock is real or false?

Real knock: The spark advance will reduce and keep reducing, the knock sensor will keeping going higher, once real knock begins it generally get worse due to the shockwaves developing and causing the piston to wobble to the point it eventually detonates, AKA BOOM! As such if your seeing knock, check you spark advance, if its around 20 but holding steady, this is false knock. If the spark advance is sub 15 and reducing, maybe negative its real knock. Or on the flip side if you making 30+ spark advance at WOT and it starts reducing, the tuner has demanded too much spark advance or you have crap fuel in the tank. You can also hear real knock or also known as pinging/pinking in UK.

False knock: Engines are noisy, the knock sensor has picked something up like exhaust banging, any metal on metal noise can potentially set off knock sensor. My RHD cat pipe flexi joint failed which was contributing but was not the main cause for me. But as such you see positive knock but if your timing is under 25 and it say just sits at 20 whilst showing +6, this is false knock, or if the spark advance climbs whilst showing positive knock, again false knock or the tuner has changed the way the KR sensor is working.

On Ford and canned tunes, I could maybe initiate false knock with a harsh gear change or a slam of the gas pedal beyond 4000rpm causing the car to whiplash but it would quickly go back to zero or negative. The canned tunes don't fully disable torque management so generally they are fine, but they can also be a little too aggressive on base timing at low RPM to get their claimed torque boost figures, sometimes that can cause a moment of real or false knock, particular if your on poorer fuel.

Lund is the most resistant to false knock, as I can't open their tune (encrypted) I do not know if they have dialled back the knock sensor somewhat (fine to do upto a limit) but also with Lund their fuel trims are spot on, if anything better than stock. They also give the KS a lot more control over adding in timing. As such Lund like to allow the KS to add in upto 10 degrees if the KS detects good enough fuel. This means a Lund tune base timing is a touch lower making them safer, but on the flip side allowing upto 10 degrees to be added back in does make them some of the most aggressive yet safest tunes. I often see 31-32 degrees on pump gas with Lund. The downsides is they can be a little responsive to partial throttle inputs compared to other tuners. TQ management is reduced a lot, so the car always does as you command but without absolutely breaking your neck or transmission.

Palm Beach, very similar to Lund in how they work and as such you rarely ever see false knock. This makes sense as the owner Ken Bjonnes is the ex head tuner from Lund, he setup by himself.

AED is different, more aggressive base and partial throttle timing, gives the KS less control and fully disables the TQ management system, this can cause issues for some but is fantastic for some others as it means maximum power is put to the rear tyre, particular good in drag racing. The downside is it can set off the knock sensor, giving false knock. The other advantages are precise but super smooth throttle and incredible partial throttle response. On my car this tune was causing my +6 when shifting the car fast which when your on a track day, country road blast you generally do.


Also I was running 350 TB which is noisier than the stock item, even the Lund tune would sometimes register knock upto around +3 on the 350 TB if hitting the throttle hard simply because its noisier, but the positive knock would quickly turn to negative and it happened rarely.


All other things aside being correct in a tune, spark advance degrees are worth:
FI around 10-15HP per degree, most SC cars will run 14-16 degrees for safety, essentially a canned one. A custom SC tune will dial this upto 18-20 degrees based on fuel, but in short 3 degrees on an FI tune could be a solid 40-50HP, it makes a big difference.
NA, each degree is worth a maximum of 5HP, more likely 3-4HP. Most canned tunes target upper RPM (4000-8000) at 26-27 irrelevant of fuel used. Whereas Lund, AED, PBD will see 29-31 degrees, this is why they generally make another 10-15HP at top-end over canned tunes.

So in my car my spark advance which would normally be 29-31 degrees was sitting at 18-20 when changing gear, in short I was losing around 50-60HP when it happened, I could also feel it, sometimes particular at Silverstone when I went from 3rd to 4th the car just went flat, as the knock sensor was sat at +6 throughout the open throttle position. Switching back to Lund solved the issue predominately, but the 350 TB could still set it off on odd occasion but at least the KS would realise and dial back in spark advance.


Of course spark advance is one of many tuning ingredients.

But in short false knock, load stock tune, if its gone, it is the tune, work with the tuner for a solution such as reduced based timing, slow the spark advance ramping or hand over more control to the KS logic.

Your better off asking in the US section though as many of the guys there really know their stuff, my understanding of logs and tuning is very basic, in short good enough to see if I have a real issue or some gremlin. In short if I got it wrong on any of the above don't shoot me!

 

[Gibbo205]

Still at home waiting for the yellow monster to fix his car.

 

[Manders Mustang]

Still at home waiting for the yellow monster to fix his car.

Fix... you mean mod it ;):lol:

 

[v8hgt]

Well it ain't that that's knocking!
However there are some bits of loom and pipework that are within mm's of the right cam cover held by a white plastic clip that would touch and vibrate on the cam cover under load. Can knock be caused by plastic on plastic or does it have to be metal on metal?

 

[Manders Mustang]

Well it ain't that that's knocking!
However there are some bits of loom and pipework that are within mm's of the right cam cover held by a white plastic clip that would touch and vibrate on the cam cover under load. Can knock be caused by plastic on plastic or does it have to be metal on metal?

It honestly sounds like it's the tune.... Have you added any more engine wise mods, if so tried with/without them?

 

[v8hgt]

FYI for anyone looking for an aftermarket tune. The standard knock sensor can be super sensitive and with more aggressive tunes it's easy to pick up false knock. More so it seems on our rhd cars. AED for one are now able to work around this and deliver no torque limiting and no false knock. As I understand it so are Lund. If you go with AED ask for this specific setup as it works really nicely. I can happily report that flooring it in first at tick over on p zeros with the clutch out now lays 11's like it should!

 

[stevnoof]

Couldn't figure out how to upload log. This is a 1/4mile run I was seeing +6 all the way through 4th gear spark advance was only 20 degrees. Does this look like false knock?

 

[v8hgt]

Couldn't figure out how to upload log. This is a 1/4mile run I was seeing +6 all the way through 4th gear spark advance was only 20 degrees. Does this look like false knock?

Email the log to Shaun at AED as I see you are running his tune. I had exactly the same in my original AED logs but in third. The new AED base tune will solve this problem so it won't back the advance off so much.

 

[Gibbo205]

Couldn't figure out how to upload log. This is a 1/4mile run I was seeing +6 all the way through 4th gear spark advance was only 20 degrees. Does this look like false knock?

100% false and as such your losing a good 50HP or so in 4th gear.

What was your ET/Terminal?

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