CP
Well-known member
Or is it a turbo-only thing? I was just wondering about tuning a non-turbo vehicle.
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Do NA cars knock?
- Thread starter CP
- Start date
gvr4ever
Well-known member
Any engine can knock. I think the knock sensor is a turbo engine part only though.
boostedinaz
Well-known member
Yes any engine can knock and as far as the DSM/GVR4 communtiy goes the N/A motors didn't have knock sensors.
Quote:
Any engine can knock. I think the knock sensor is a turbo engine part only though.
4g63 yes but overall no. My ls1 has a knock sensor
Any engine can knock. I think the knock sensor is a turbo engine part only though.
4g63 yes but overall no. My ls1 has a knock sensor
OldHairyBastard
Well-known member
A lot of N/A cars have knock sensors and most even have 2 knock sensors (V6 & V8's). The sensors help tune the engine timing better and alow for more timing and better engine managment all around.
gvr4ever
Well-known member
Quote:
Quote:
Any engine can knock. I think the knock sensor is a turbo engine part only though.
4g63 yes but overall no. My ls1 has a knock sensor
Well, the question was asked under general GVR-4 discussion, so I was talking about the NA 4G63.
Our 05 Corolla LE has a knock sensor too. Lots, if not all newer cars have them.
Quote:
Any engine can knock. I think the knock sensor is a turbo engine part only though.
4g63 yes but overall no. My ls1 has a knock sensor
Well, the question was asked under general GVR-4 discussion, so I was talking about the NA 4G63.
Our 05 Corolla LE has a knock sensor too. Lots, if not all newer cars have them.
roger roger
VR4coop
Well-known member
I believe it is called " Pinging " in NA cars, mainly older muscle cars, or high compressoin NA motors. It is kind of scary because you can actually hear it!!
OldHairyBastard
Well-known member
^^^Oh you hear it bad when it is hitting like a sledge hammer on the top of your piston. My 78 Camaro with a 383 Strocker and 14:1 compression would knock on 93 and you heard it bad if you tried to hit the gas hard. It sucked having to always run at least 100 octane because of the cost but that is when I was young and broke and the gas cost a lot less back then.
belize1334
Well-known member
Any engine can knock, but I believe that the ping is different.
You knock when the timing is too aggressive for the a/f and everything heats up and the mixture predetonates. This can happen even in N/A situations if the engine is running hot, the mix is lean, or the octane is low, and the timing hasn't been adjusted accordingly. The predetonation not only ruins any control you have with timing, but it also introduces a secondary flame front which, when it collides with the primary, causes crazy turbulence and extreme cylinder pressures.
Pinging, as I understand it, is a result of having pushed the timing to the point where all of the fuel has been combusted before the piston reaches TDC. Normally by that point the fuel would still be in the combustion process so temps and pressures are rising fast but the piston reaches TCD and heads back down before it gets too bad. If total combustion is reached before TDC then pressures go through the roof and the piston might as well be running into a wall. The head doesn't like it either and the pinging sound is (get ready for some speculation) probably the result of slack being taken out of the valve train and rod bearings due to the abnormally large forces acting on the system at that moment.
Or I could be completely wrong...but that's how I understand it.
You knock when the timing is too aggressive for the a/f and everything heats up and the mixture predetonates. This can happen even in N/A situations if the engine is running hot, the mix is lean, or the octane is low, and the timing hasn't been adjusted accordingly. The predetonation not only ruins any control you have with timing, but it also introduces a secondary flame front which, when it collides with the primary, causes crazy turbulence and extreme cylinder pressures.
Pinging, as I understand it, is a result of having pushed the timing to the point where all of the fuel has been combusted before the piston reaches TDC. Normally by that point the fuel would still be in the combustion process so temps and pressures are rising fast but the piston reaches TCD and heads back down before it gets too bad. If total combustion is reached before TDC then pressures go through the roof and the piston might as well be running into a wall. The head doesn't like it either and the pinging sound is (get ready for some speculation) probably the result of slack being taken out of the valve train and rod bearings due to the abnormally large forces acting on the system at that moment.
Or I could be completely wrong...but that's how I understand it.
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belize1334
Well-known member
Ok, so I was close, but a bit confused. I stand corrected.
FlyingEagle
Staff member
Alot of EDM engines ran higher compression and Mitsu compensated with knock sensors to keep those motors running happy under bad circumstances. Case in point, is that I believe alot of 1.6L high compression engines shipped to Europe in Colt's and the like. This goes as far back as the 1988-92 models with the uprated 16V motors. My two pennies.
my NA Galant Gti is pinging when I accelerate. The engine overheats too. Though not critical. Timing is set correctly. I use high octane fuel. The car's exhaust is smelly if that is any clue. My cooling system look to be ok mechanically but obviously isn't doing a good job.
Terry Posten
Well-known member
^^^^
That sounds like a plugged up cat.
That sounds like a plugged up cat.
Our Galants don't have cats.
DR1665
Well-known member
I wonder if the coolant temp sensor could be a culprit? If it's not telling the ECU the correct information, the mixtures could be all over the place. That could contribute to smell and operating temps. :shrug
Otherwise, back to the older topic, my 2GNT will knock at tip in on this weaksauce 91 octane we have in Phoenix. Especially when the AC is on and ambient temps are above 100* (which is a good three months straight here). I was hoping to get Megasquirt installed so I could pull some timing in the bottom end when it was hot outside (or rig up water injection on the NT), but then I got this good deal on the Galant...
Otherwise, back to the older topic, my 2GNT will knock at tip in on this weaksauce 91 octane we have in Phoenix. Especially when the AC is on and ambient temps are above 100* (which is a good three months straight here). I was hoping to get Megasquirt installed so I could pull some timing in the bottom end when it was hot outside (or rig up water injection on the NT), but then I got this good deal on the Galant...
atc250r
Staff member
If you think its a restriction in the exhaust system then remove the O2 sensor and drive it. If the problem goes away then you know the cause is downstream of the O2 sensor and in the exhaust.
John
John
Rausch
Well-known member
Quote:
my NA Galant Gti is pinging when I accelerate. The engine overheats too. Though not critical. Timing is set correctly. I use high octane fuel. The car's exhaust is smelly if that is any clue. My cooling system look to be ok mechanically but obviously isn't doing a good job.
what kind of smelly? running lean would cause this as well. perhaps a clog in a fuel line/filter, or a dirty injector if it is not exhaust related.
my NA Galant Gti is pinging when I accelerate. The engine overheats too. Though not critical. Timing is set correctly. I use high octane fuel. The car's exhaust is smelly if that is any clue. My cooling system look to be ok mechanically but obviously isn't doing a good job.
what kind of smelly? running lean would cause this as well. perhaps a clog in a fuel line/filter, or a dirty injector if it is not exhaust related.
