Here's a VERY good reason to instal a KnockLink, or similar...
13 May 2012 | 11:33 PM
#31
They are very old technology now, for the money, you can buy better, but if one comes along cheap enoguh, they are worth it, but new i think they were like £100, for £50 more you can buy alot better nowadays, but again,if 2nd hand for £40 or so, they are a good buy,if you can find them that is
where from for that money or am i just looking in wrong places
14 May 2012 | 12:03 AM
#34
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Yeah, sorry:
Knock, also known as det, or pinking, is caused by pre-ignition, that is when the mixture in the cylinder ignites BEFORE it should.
On a petrol engine, the explosion (ignition) in the cylinder should happen JUST BEFORE the piston reaches the TOP of it's upstroke. (TDC).
This will give it exactly the shove it needs to complete the most powerful downstroke.
Unfortunately, if the explosion occurs too far before the top, it has the effect of stopping the piston dead in it's tracks, or trying to, and the resultant forces are transmitted to the bearings on the crank and those at the big ends, where they cause the bearings to deteriorate, rather quickly
On a turbo car, det is more likely because of the extra fuel and air mixture in the upper cylinder, and the fact they they run hotter.
Subaru engines don't like knock. It MAY be because of the horizontally opposed format, but they seem to be LESS able to withstand bouts of knock than other performance engines. Maybe because the pistons are opposed, so any knock is acting against knock from the OTHER side, doubling the force? I don't know enough about it to say, but it would seem likely.
The knock link is an electronic gizmo that sits on your dash, or can, with patience, be built in, and responds to sounds coming from the engine via a knock sensor, bolted over one of the cylinders.
Once installed, it is adjusted so that it hears nothing when the engine is running normally. If it hears excess noise, it flashes up a warning via a row of LEDs, the more of them that light, the worse the knock
Where to buy I don't know now, they may still be available, they may have been superseded by a better type, (KS3), which is also dearer. You could Google "buy knocklink" or try ebay, or some of the tuning firms like API, Harvey Smith, AS Performance, Scoobyclinic, Scoobymania, Powerstation, etc.
They used to be around £100-£120, and are a doddle to fit.
HTH.
Knock, also known as det, or pinking, is caused by pre-ignition, that is when the mixture in the cylinder ignites BEFORE it should.
On a petrol engine, the explosion (ignition) in the cylinder should happen JUST BEFORE the piston reaches the TOP of it's upstroke. (TDC).
This will give it exactly the shove it needs to complete the most powerful downstroke.
Unfortunately, if the explosion occurs too far before the top, it has the effect of stopping the piston dead in it's tracks, or trying to, and the resultant forces are transmitted to the bearings on the crank and those at the big ends, where they cause the bearings to deteriorate, rather quickly
On a turbo car, det is more likely because of the extra fuel and air mixture in the upper cylinder, and the fact they they run hotter.
Subaru engines don't like knock. It MAY be because of the horizontally opposed format, but they seem to be LESS able to withstand bouts of knock than other performance engines. Maybe because the pistons are opposed, so any knock is acting against knock from the OTHER side, doubling the force? I don't know enough about it to say, but it would seem likely.
The knock link is an electronic gizmo that sits on your dash, or can, with patience, be built in, and responds to sounds coming from the engine via a knock sensor, bolted over one of the cylinders.
Once installed, it is adjusted so that it hears nothing when the engine is running normally. If it hears excess noise, it flashes up a warning via a row of LEDs, the more of them that light, the worse the knock
Where to buy I don't know now, they may still be available, they may have been superseded by a better type, (KS3), which is also dearer. You could Google "buy knocklink" or try ebay, or some of the tuning firms like API, Harvey Smith, AS Performance, Scoobyclinic, Scoobymania, Powerstation, etc.
They used to be around £100-£120, and are a doddle to fit.
HTH.
Thank you very much, most helpful
14 May 2012 | 10:57 AM
#36
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Joined: Mar 2000
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From: 5 beats 4 - RS3 Rulez!!!
It's all about putting things into perspective and suggesting this bit of kit is essential.... is well, not in perspective (I'll keep it polite!).
These devices are notorious for being "out of tune" to real DET. Most are not calibrated.... they need to be!
I had one fitted to my Spec C.... useful to stare at if you like that kind of thing, but in my case, fairly useless for anything else. My car was tuned well and had good knock strategy. I never had one problem with DET on that car, and you have to remember it was highly strung as well.
Needless to say I don't have one fitted to my current Scoob and don't intend to fit one either.
What am I saying then?
It's horses for courses and they are good devices, but in many ways I fail to see the need in most cases.
These devices are notorious for being "out of tune" to real DET. Most are not calibrated.... they need to be!
I had one fitted to my Spec C.... useful to stare at if you like that kind of thing, but in my case, fairly useless for anything else. My car was tuned well and had good knock strategy. I never had one problem with DET on that car, and you have to remember it was highly strung as well.
Needless to say I don't have one fitted to my current Scoob and don't intend to fit one either.
What am I saying then?
It's horses for courses and they are good devices, but in many ways I fail to see the need in most cases.
14 May 2012 | 11:23 AM
#38
Scooby Senior
Joined: Apr 2002
Posts: 14,230
Likes: 5
From: Harrogate
It's all about putting things into perspective and suggesting this bit of kit is essential.... is well, not in perspective (I'll keep it polite!).
These devices are notorious for being "out of tune" to real DET. Most are not calibrated.... they need to be!
I had one fitted to my Spec C.... useful to stare at if you like that kind of thing, but in my case, fairly useless for anything else. My car was tuned well and had good knock strategy. I never had one problem with DET on that car, and you have to remember it was highly strung as well.
Needless to say I don't have one fitted to my current Scoob and don't intend to fit one either.
What am I saying then?
It's horses for courses and they are good devices, but in many ways I fail to see the need in most cases.
These devices are notorious for being "out of tune" to real DET. Most are not calibrated.... they need to be!
I had one fitted to my Spec C.... useful to stare at if you like that kind of thing, but in my case, fairly useless for anything else. My car was tuned well and had good knock strategy. I never had one problem with DET on that car, and you have to remember it was highly strung as well.
Needless to say I don't have one fitted to my current Scoob and don't intend to fit one either.
What am I saying then?
It's horses for courses and they are good devices, but in many ways I fail to see the need in most cases.
14 May 2012 | 02:07 PM
#40
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From: The Terry Crews of moderation. P P P P P P POWER!!
It's all about putting things into perspective and suggesting this bit of kit is essential.... is well, not in perspective (I'll keep it polite!).
These devices are notorious for being "out of tune" to real DET. Most are not calibrated.... they need to be!
I had one fitted to my Spec C.... useful to stare at if you like that kind of thing, but in my case, fairly useless for anything else. My car was tuned well and had good knock strategy. I never had one problem with DET on that car, and you have to remember it was highly strung as well.
Needless to say I don't have one fitted to my current Scoob and don't intend to fit one either.
What am I saying then?
It's horses for courses and they are good devices, but in many ways I fail to see the need in most cases.
These devices are notorious for being "out of tune" to real DET. Most are not calibrated.... they need to be!
I had one fitted to my Spec C.... useful to stare at if you like that kind of thing, but in my case, fairly useless for anything else. My car was tuned well and had good knock strategy. I never had one problem with DET on that car, and you have to remember it was highly strung as well.
Needless to say I don't have one fitted to my current Scoob and don't intend to fit one either.
What am I saying then?
It's horses for courses and they are good devices, but in many ways I fail to see the need in most cases.
It's hardly fair to blame the device for not being calibrated properly! That's ignorance on the part of the user! I've had two now, one on my old classic and one on my Hawk.
Problems with knock are not just mapping issues. Both of my cars were tuned by "the Guru" for 99 octane fuel, as have many others on here. More often knock comes from a duff batch of fuel or a sensor on the way out.
If you have your car tuned to be contingent on the good stuff, then some form of knock monitoring over and above what is available on the std ECU is a VERY good idea IMO. It's so easy to get a batch of duff fuel or for a sensor to go on the fritz and the reality is -as you well know from seeing x amount of "my engine is dead" threads on here - sometimes the std ECU either doesn't react fast enough or can't pull things back sufficiently to save a meltdown.
If you have an ECU that gives you a visual/audible warning of DET (Simtek/Syvecs) then you don't need an additional knock detection device, but if you don't, then prudence indicates that you need one. Admittedly, the Knocklink is getting a bit long in the tooth now, so the KS3 might be the better bet.
Ns04
Last edited by New_scooby_04; 14 May 2012 at 02:10 PM.
14 May 2012 | 02:30 PM
#41
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Joined: Mar 2000
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From: 5 beats 4 - RS3 Rulez!!!
Ns04,
I didn't blame the device, I made a valid point about it's application installation - one which I doubt all appreciate.
As regards to rest..... by all means waste your money. A whole tuning industry relies on you to do just that!!!!!
I didn't blame the device, I made a valid point about it's application installation - one which I doubt all appreciate.
As regards to rest..... by all means waste your money. A whole tuning industry relies on you to do just that!!!!!
14 May 2012 | 04:30 PM
#43
Shaun, with respect, you are only seeing half the story.
Yes, you may run a decent ecu.
Yes Richard is a good mapper.
But without any warning device, what happens if you get an airleak from, say, a split pipe, that would cause the engine to lean out, and thus knock? Would you even know?
I did, and a few questions on here solved it. But without my KL I'd have been in the dark until the engine possibly went bang
And worse, what if you got a tank of poor fuel.......which would make the car knock? Would you have ANY idea? I did, and took the correct action: that tank was used off boost.
To write these devices off simply because SOME folk don't calibrate them and because YOU can't see the use for YOUR car is folly.
Yes, you may run a decent ecu.
Yes Richard is a good mapper.
But without any warning device, what happens if you get an airleak from, say, a split pipe, that would cause the engine to lean out, and thus knock? Would you even know?
I did, and a few questions on here solved it. But without my KL I'd have been in the dark until the engine possibly went bang
And worse, what if you got a tank of poor fuel.......which would make the car knock? Would you have ANY idea? I did, and took the correct action: that tank was used off boost.
To write these devices off simply because SOME folk don't calibrate them and because YOU can't see the use for YOUR car is folly.
14 May 2012 | 06:32 PM
#44
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From: The Terry Crews of moderation. P P P P P P POWER!!
Shaun, with respect, you are only seeing half the story.
Yes, you may run a decent ecu.
Yes Richard is a good mapper.
But without any warning device, what happens if you get an airleak from, say, a split pipe, that would cause the engine to lean out, and thus knock? Would you even know?
I did, and a few questions on here solved it. But without my KL I'd have been in the dark until the engine possibly went bang
And worse, what if you got a tank of poor fuel.......which would make the car knock? Would you have ANY idea? I did, and took the correct action: that tank was used off boost.
To write these devices off simply because SOME folk don't calibrate them and because YOU can't see the use for YOUR car is folly.
Yes, you may run a decent ecu.
Yes Richard is a good mapper.
But without any warning device, what happens if you get an airleak from, say, a split pipe, that would cause the engine to lean out, and thus knock? Would you even know?
I did, and a few questions on here solved it. But without my KL I'd have been in the dark until the engine possibly went bang
And worse, what if you got a tank of poor fuel.......which would make the car knock? Would you have ANY idea? I did, and took the correct action: that tank was used off boost.
To write these devices off simply because SOME folk don't calibrate them and because YOU can't see the use for YOUR car is folly.
We're wrong and someone gets a redundant KL = 100 quid down the loo for some pretty lights!
Anti kock detection folks are wrong and a KL would have warned someone that their car was knocking whilst they were driving hard on a duff batch of fuel or a dodgy sensor = thousands down the pan!
Mapping can be A1 but if the car's getting erroneous data, it's garbage in garbage (big ends) out!
14 May 2012 | 06:44 PM
#45
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Joined: Aug 2003
Posts: 437
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From: devon
Ive had what i suspect was a tank of 95 ron at a shell garage a few years ago ,my knocklink went off right away as i drove away on boost.
I wouldnt drive the car on boost without some kind of knock alert its just common sense.I use a ks3 atm witch can be calibrated.
I wouldnt drive the car on boost without some kind of knock alert its just common sense.I use a ks3 atm witch can be calibrated.
14 May 2012 | 07:57 PM
#46
Scooby Regular
Joined: Mar 2000
Posts: 8,617
Likes: 23
From: 5 beats 4 - RS3 Rulez!!!
Shaun, with respect, you are only seeing half the story.
Yes, you may run a decent ecu.
Yes Richard is a good mapper.
But without any warning device, what happens if you get an airleak from, say, a split pipe, that would cause the engine to lean out, and thus knock? Would you even know?
I did, and a few questions on here solved it. But without my KL I'd have been in the dark until the engine possibly went bang
And worse, what if you got a tank of poor fuel.......which would make the car knock? Would you have ANY idea? I did, and took the correct action: that tank was used off boost.
To write these devices off simply because SOME folk don't calibrate them and because YOU can't see the use for YOUR car is folly.
Yes, you may run a decent ecu.
Yes Richard is a good mapper.
But without any warning device, what happens if you get an airleak from, say, a split pipe, that would cause the engine to lean out, and thus knock? Would you even know?
I did, and a few questions on here solved it. But without my KL I'd have been in the dark until the engine possibly went bang
And worse, what if you got a tank of poor fuel.......which would make the car knock? Would you have ANY idea? I did, and took the correct action: that tank was used off boost.
To write these devices off simply because SOME folk don't calibrate them and because YOU can't see the use for YOUR car is folly.
) what I have already put. I'm not against any knock detection device, but since it's horses for courses, I would suggest in the majority of cases it shouldn't be needed whatsoever.Don't forget.... the ONLY reason I posted on this thread was because someone said these are "essential". That is ludicrus imo.
What's the chances of a split vac pipe on your FPR - assuming you know , or your servicer knows anything about proper maintenance? Extremely remote at best. If this happened (worse case scenario) at full hammer, the likely hood that your engine would not have any lasting issue is fairly remote anyhow - Knocklink or not - mute point in that specific scenario.
"Bad" fuel - who has ever experienced this and grenaded their engine as a consequence.... must be loads of people based on your reasoning?! Perhaps I've been the luckiest man on earth, never to experience this issue in all of my 24yrs of driving.
I've had performance cars (like 500bhp) that never even had any knock strategy and never had a problem.
Not all things are relative and context is the deal here.
Just to underline I don't think they are a bad device (FFS I owned one!!!), but the reasons given here for owning one are not worthy of buying one imo. Nothing you or anyone else says will enlighten me otherwise.
14 May 2012 | 11:43 PM
#49
It's interesting knowing that a few people who have filled up a at recent reconditioned Shell garages are mentioning poor fuelling.
Looking to get the AlcaTek display myself.
Steve
Looking to get the AlcaTek display myself.
Steve
15 May 2012 | 01:21 AM
#51
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From: The Terry Crews of moderation. P P P P P P POWER!!
Now you need to read what was said (slowly)
I said that in a tuned turbocharged car (i.e. one mapped above standard power to run on a certain grade of petrol) some means of visual/audible knock detection is essential. Some have an ECU that does it, which negates the need for an additional device.
No-one is saying they are needed in all applications.
If you've invested a lot of money in tuning your turbo car then it's only prudent to keep an eye out for knock, which can occur though no weakness in the mapping of the car or no fault of the driver. For some that will be done by an ECU for others, it's a KS3/Knock link.
At the end of the day, you get your advice from the experts, you pays your money you take your choice. Both David and Bob said a KL was a very good idea, so I went with it on both of my cars and both times it's flagged up a failing sensor/bad fuel.
Like I said, I'm wrong, 100 quids for pretty light show
You're wrong and the car encounters something that foxes the knock strategy, it's thousands for a rebuild!
I'm sorry, but I really don't see anything ridiculous about the above!
I said that in a tuned turbocharged car (i.e. one mapped above standard power to run on a certain grade of petrol) some means of visual/audible knock detection is essential. Some have an ECU that does it, which negates the need for an additional device.
No-one is saying they are needed in all applications.
If you've invested a lot of money in tuning your turbo car then it's only prudent to keep an eye out for knock, which can occur though no weakness in the mapping of the car or no fault of the driver. For some that will be done by an ECU for others, it's a KS3/Knock link.
At the end of the day, you get your advice from the experts, you pays your money you take your choice. Both David and Bob said a KL was a very good idea, so I went with it on both of my cars and both times it's flagged up a failing sensor/bad fuel.
Like I said, I'm wrong, 100 quids for pretty light show
You're wrong and the car encounters something that foxes the knock strategy, it's thousands for a rebuild!
I'm sorry, but I really don't see anything ridiculous about the above!
15 May 2012 | 01:34 PM
#52
Sorry Shaun, but dont agree with anything you've said.
Ok you've never experienced a bad batch of fuel, fair enough, but two others on THIS thread have. Without the likes of a KL they would not of known until it was 'maybe' too late.
Your comments are ludicrous, why wouldn't anybody want a device that can detect knock. And when you consider how cheap they are it makes your statements even more rediculous.
You said that the chances of a split pipe are remote, that is true but it can and does happen. I'd rather not take a chance so a KL is present in my car.
Ok you've never experienced a bad batch of fuel, fair enough, but two others on THIS thread have. Without the likes of a KL they would not of known until it was 'maybe' too late.
Your comments are ludicrous, why wouldn't anybody want a device that can detect knock. And when you consider how cheap they are it makes your statements even more rediculous.
You said that the chances of a split pipe are remote, that is true but it can and does happen. I'd rather not take a chance so a KL is present in my car.
15 May 2012 | 02:12 PM
#53
More to the point newage knock control on OEM ecu is very good so Knock link not really needed. The same cant be said for Classic Impreza's on std ECU, so Knock link etc may have some use.
15 May 2012 | 02:15 PM
#54
Scooby Regular
Joined: Mar 2000
Posts: 8,617
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From: 5 beats 4 - RS3 Rulez!!!
I said that in a tuned turbocharged car (i.e. one mapped above standard power to run on a certain grade of petrol) some means of visual/audible knock detection is essential. Some have an ECU that does it, which negates the need for an additional device.
No-one is saying they are needed in all applications.
If you've invested a lot of money in tuning your turbo car then it's only prudent to keep an eye out for knock, which can occur though no weakness in the mapping of the car or no fault of the driver. For some that will be done by an ECU for others, it's a KS3/Knock link.
At the end of the day, you get your advice from the experts, you pays your money you take your choice. Both David and Bob said a KL was a very good idea, so I went with it on both of my cars and both times it's flagged up a failing sensor/bad fuel.
Like I said, I'm wrong, 100 quids for pretty light show
You're wrong and the car encounters something that foxes the knock strategy, it's thousands for a rebuild!
I'm sorry, but I really don't see anything ridiculous about the above!
No-one is saying they are needed in all applications.
If you've invested a lot of money in tuning your turbo car then it's only prudent to keep an eye out for knock, which can occur though no weakness in the mapping of the car or no fault of the driver. For some that will be done by an ECU for others, it's a KS3/Knock link.
At the end of the day, you get your advice from the experts, you pays your money you take your choice. Both David and Bob said a KL was a very good idea, so I went with it on both of my cars and both times it's flagged up a failing sensor/bad fuel.
Like I said, I'm wrong, 100 quids for pretty light show
You're wrong and the car encounters something that foxes the knock strategy, it's thousands for a rebuild!
I'm sorry, but I really don't see anything ridiculous about the above!
I don't normally get this wound up, but your first statement is absolute bollocks! If you or anyone else thinks this is essential on a tuned turbocharged car, then you really need to get a reality check. I don't care whether that comes from you, Bob or David. In fact I have NEVER had the fitment of a knocklink or other det warning device recommended to me by any tuner.
I was driving mega bhp cars years ago that had ZERO knock strategy, let alone visual warnings. I along with many 1000's of people never had problems with managing DET.
I'm not saying you're WRONG for having a knocklink..... I am saying it is not essential. That is the WRONG bit, because it simply is not essential!
It's essential I breathe.... it's not essential I have a knocklink. You do appreciate context I assume!
MattyB1983,
Tell me how many people have grenaded their engines due to bad fuel, out of all the modified car owners. Then we can discuss what I mean about context!
I'm surprised how some of you lot leave your houses in the morning, with fear of getting mowed down by an asteroid from mars.
I really can't be arsed to keep this going, you're all sucking the life force out of me!
Perhaps I should start to sell Knocklinks.... according to you lot I'll be a millionaire in no time at all!
15 May 2012 | 02:17 PM
#55
15 May 2012 | 02:21 PM
#56
15 May 2012 | 03:28 PM
#57
15 May 2012 | 03:28 PM
#58
JohnD
15 May 2012 | 05:01 PM
#59
15 May 2012 | 07:50 PM
#60
Could you explain when this would happen? I'm not being funny but not sure how it would happen.