Discussion
All the knock triggers are adjustable. Mine are set to 55kpa.
Also in speed density mode with efilive custom OS you do have dual spark maps. I think Pomona used efilive so this may be the case. This is a big reason people use efilive as it retains the stock dual spark maps and scaling as per Paul/Wortec's comments. So it depends on what OS its running, stock or custom. Also with a supercharger the only way to map VE over 105kpa is with a custom os. So it makes sense if it is running one.
I dont know and only Pomona will be able to confirm. Paul maybe you would be interested in taking a look at efilive? Might be some good stuff in there for you
Also in speed density mode with efilive custom OS you do have dual spark maps. I think Pomona used efilive so this may be the case. This is a big reason people use efilive as it retains the stock dual spark maps and scaling as per Paul/Wortec's comments. So it depends on what OS its running, stock or custom. Also with a supercharger the only way to map VE over 105kpa is with a custom os. So it makes sense if it is running one.
I dont know and only Pomona will be able to confirm. Paul maybe you would be interested in taking a look at efilive? Might be some good stuff in there for you
V8HSV said :
"Greg, always worried about blowing the engine, without the knock sensors and a non maf set up resulted in a cracked cyclinder liner, with the new set up it only happens under full torque and about 450+ bhp, slightly ease off the throttle cures it and stick to 99 RON petrol."
Not being sensationalist, but if you are running 99 fuel and have had engine rebulid with supercharger, i would be very concerned if i heard or any knock or any was detected under load!!!!
>> Edited by caspy on Tuesday 13th December 19:21
"Greg, always worried about blowing the engine, without the knock sensors and a non maf set up resulted in a cracked cyclinder liner, with the new set up it only happens under full torque and about 450+ bhp, slightly ease off the throttle cures it and stick to 99 RON petrol."
Not being sensationalist, but if you are running 99 fuel and have had engine rebulid with supercharger, i would be very concerned if i heard or any knock or any was detected under load!!!!
>> Edited by caspy on Tuesday 13th December 19:21
OK well I'll go for the simple option then of sticking with high octane petrol and not worrying. Which I was doing anyway; I have always put 97+ in the Alpina and other performance cars. (Although bizarrely my 928GTS was noticeably quicker on normal unleaded but that's another story)
As Brian has driven the car for 27K miles without damaging anything it can't be that fragile!
As Brian has driven the car for 27K miles without damaging anything it can't be that fragile!
Thanks guys,especially Wortec 1 and V8HSV.I was beginning to wonder what I have been doing for the last 4 years.I would guess I have done maybe 30 dyno runs on Maha,Dyno Dynamics and Dyno-pack,track days, so I think that if detonation was a problem it would have shown its ugly head by now.If you drive with 545bhp under your foot why push the throttle hard at 1.8k in 6th!This car made 572bhp but I pulled out timing,changed injectors(again),VE cells to increase A/F ratio to give more fuelling for more peace of mind and relability as 27k miles has shown. For the enthusiasts my std 300kw GTS-R pulled at 6250rpm a spark in excess of 20 deg advance and showed anything up to 5 deg knock.This particular car only pulls max:10.5deg at6250rpm .EFI Live scans produce similar results on road and dyno .If anything better on road than dyno as clearer air,and load characteristics realistic.
I don't know what was in the tank when I collected the car and experienced the rattle, I didn't put it in. I haven't noticed the rattle with 97RON, I prefer Optimax so will use that when I can find it. I guess the way to look at it is: if putting 97 in made the rattle go away, then I can be even more confident with Optimax or 99RON... I just hope that no damage was done during that first drive when I was deliberately making it rattle in an effort to identify the source of the noise. Probably only did it 7 or 8 times, for about 2 or 3 seconds each time so fingers crossed.
Brian - I assume that all of your testing, dyno time etc was done on higher octane fuel? Hence you would not have seen any detonation that might be caused by SUL, or by fuel that had deteriorated in the tank whilst standing for a while...?
By the way, did you tend to use only Optimax, or 99RON, or 97RON or what?
"Beginning to wonder what I had been doing for 4 years" -
Anyone who knows your car is aware of how good a job you did, and I feel very fortunate to have been able to take the car over from you. And the reliability speaks for itself.
Neverthless I experienced something which is apparently very bad for an engine so it's only right for me to ask about it so I can avoid it happening again. This in no way indicates a criticism of your work. As we have said, you have presumably mapped the car for high octane fuel (correct?) which in my mind is a perfectly reasonable assumption to make on a car like this. I always use 97RON or higher anyway. In which case the problem goes away.
By the way, did you tend to use only Optimax, or 99RON, or 97RON or what?
"Beginning to wonder what I had been doing for 4 years" -
Anyone who knows your car is aware of how good a job you did, and I feel very fortunate to have been able to take the car over from you. And the reliability speaks for itself.
Neverthless I experienced something which is apparently very bad for an engine so it's only right for me to ask about it so I can avoid it happening again. This in no way indicates a criticism of your work. As we have said, you have presumably mapped the car for high octane fuel (correct?) which in my mind is a perfectly reasonable assumption to make on a car like this. I always use 97RON or higher anyway. In which case the problem goes away.
gregwatson said:
OK dumb question coming up:
When you say "5 degrees of knock" - does this mean you needed to retard the spark by 5 degrees to make it go away? How do you measure "degrees of knock" ?
There are many scan tools out there which you just plug in to the car to monitor engine functions.....
I am sure "Ringram" will give you info on EFI Live......
Yep anyone interested in scanners etc let me know. Good club prices.
There are over 280 different things you can log on the Monaro, but just on the spark side here is what you can see as well as being able to pull DTC codes and figure out why your Check engine light is on etc. Knock retard shows the amount of timing the engine management system has pulled due to the sensors detecting knock. These settings are configurable dependant on application.
You can go with a scanner only or step up to the programmer if you want to mess with such things. Sorry if this sounds like a sales speil, I just think its a great little tool.
EST - A/C Compensation Spark
EST - Base Spark
EST - Brake Torque Management Spark Retard
EST - Burst Knock Retard
EST - Cat Light-off Spark Retard
EST - Coolant Temperature Spark
EST - Cranking Spark
EST - EGR Spark
EST - Equivalence Ratio Spark
EST - Idle Spark
EST - Induction Air Temp Spark
EST - Run Spark
EST - Spark Smoothing
EST - Total Torque Control Spark Retard
EST - Traction Control Spark Retard
EST - Trans Torque Reduction Spark Retard
Retard Due to Knock
Rich (efilive)
There are over 280 different things you can log on the Monaro, but just on the spark side here is what you can see as well as being able to pull DTC codes and figure out why your Check engine light is on etc. Knock retard shows the amount of timing the engine management system has pulled due to the sensors detecting knock. These settings are configurable dependant on application.
You can go with a scanner only or step up to the programmer if you want to mess with such things. Sorry if this sounds like a sales speil, I just think its a great little tool.
EST - A/C Compensation Spark
EST - Base Spark
EST - Brake Torque Management Spark Retard
EST - Burst Knock Retard
EST - Cat Light-off Spark Retard
EST - Coolant Temperature Spark
EST - Cranking Spark
EST - EGR Spark
EST - Equivalence Ratio Spark
EST - Idle Spark
EST - Induction Air Temp Spark
EST - Run Spark
EST - Spark Smoothing
EST - Total Torque Control Spark Retard
EST - Traction Control Spark Retard
EST - Trans Torque Reduction Spark Retard
Retard Due to Knock
Rich (efilive)
There seems to be a lot of paranoia about fuels. If its pinking, and you are using SUL, something is wrong with the mapping.
Given it is pretty much the best fuel easily available ( well not always easy ) it would seem the most sensible fuel for the car to have been mapped on.
There's a lot of hype over Optimax, Ultimate, etc etc. I honestly doubt there's that much difference. I just use whichever I can easily get that doesnt cost a fortune. Which is basic SUL, BP Ultimate, and well thats it really over here.
Ive heard talk about Tesco's 99RON, but until Ive seen some back to back testing with other fuels I think I'll consider it as normal SUL with a big sales push.
Given it is pretty much the best fuel easily available ( well not always easy ) it would seem the most sensible fuel for the car to have been mapped on.
There's a lot of hype over Optimax, Ultimate, etc etc. I honestly doubt there's that much difference. I just use whichever I can easily get that doesnt cost a fortune. Which is basic SUL, BP Ultimate, and well thats it really over here.
Ive heard talk about Tesco's 99RON, but until Ive seen some back to back testing with other fuels I think I'll consider it as normal SUL with a big sales push.
In addition to Stevie's comments I can add that if it detonates, a piston will crack in nanoseconds and probably a liner will split as well. LSx parts are made well but only to do the basic job required. You would be surprised at how many people/firms have detonated these engines! If concerned do a compression check to test the cylinders. When you get bad detonation on an lsx it sounds like the lifters are rattling 
and afterwards the compression will be 20 odd psi down on the damaged cylinder/s. The damage is done in moments if the pinking becomes detonation.
Boosted.
and afterwards the compression will be 20 odd psi down on the damaged cylinder/s. The damage is done in moments if the pinking becomes detonation. Boosted.
To add to Greg's piece of mind, my 2004 CV8 Monaro has the same Starr s/charger (fitted by Linden and providing 10 PSi), with the base MAFless tune provided by Pomona. Only done 3,000 miles in it thus far, but its performance and driveability are excellent with no "pinking" issues on 97RON and higher.
Picking up a point from an earlier thread from Greg, it returns 26 mpg on a cruise, 22 mpg on most trips, limited around town to 17 and will drink fuel in a stationary jam.
Picking up a point from an earlier thread from Greg, it returns 26 mpg on a cruise, 22 mpg on most trips, limited around town to 17 and will drink fuel in a stationary jam.
So would that rattling definitely have been detonation, or could it have been something less damaging? I'm not sure if you can have "mild" detonation - presumably detonation is detonation....?
If the compression check is OK, am I in the clear? Presumably there could be some minor damage to the pistons, pitting etc which a compression check wouldn't show up?
>> Edited by gregwatson on Tuesday 13th December 23:07
If the compression check is OK, am I in the clear? Presumably there could be some minor damage to the pistons, pitting etc which a compression check wouldn't show up?
>> Edited by gregwatson on Tuesday 13th December 23:07
gregwatson said:
So would that rattling definitely have been detonation, or could it have been something less damaging? I'm not sure if you can have "mild" detonation - presumably detonation is detonation....?
If the compression check is OK, am I in the clear? Presumably there could be some minor damage to the pistons, pitting etc which a compression check wouldn't show up?
>> Edited by gregwatson on Tuesday 13th December 23:07
I had detonation in a Rover 5.0 at 1500 rpm in 5th gear on a tight corner, ie about 20 mph. Sounded like a man with a sledgehammer in the sump pan but because of the slow speed I just lifted off. No damage done at all
Get that at peak torque and you're probably knackered. Det is det but at slower speeds you can be lucky. Your rattling may not have been detonation at all, just pinking which is barely acceptable but a lot safer then det which comes next! If a compression test reveals the same cylinder pressures give or take a few psi then you're in the clear. Lfor over 200 psi per cylinder and 220 if on very low miles. Boosted.
Hmmm. Well, I guess I've either damaged it or I haven't. Higher octane should stop it happening again. I like to think that if significant damage had been caused, I'd notice something.
It wasn't a heavy hammering sound - I thought it was some sort of undertray or heat shield rattling because I've had that before in another car - a very light, tinny rattling sound. In terms of it happening at peak torque - remember that this car develops over 500 lb-ft by 2,300 rpm so there's a lot of torque pretty much everywhere.
It wasn't a heavy hammering sound - I thought it was some sort of undertray or heat shield rattling because I've had that before in another car - a very light, tinny rattling sound. In terms of it happening at peak torque - remember that this car develops over 500 lb-ft by 2,300 rpm so there's a lot of torque pretty much everywhere.
I've been reading this thread with intrigue...
As a complete mechanical nuffer (right pedal go faster, middle peddle???) I'd never heard of pinking b4! I always use normal unleaded in my C4B engined Coupe with std HSV programming & she goes well with no apparant rattles or probs. Is this thing just relavent to blown engines?
cheers, Julian"I just drive it"Horsley
As a complete mechanical nuffer (right pedal go faster, middle peddle???) I'd never heard of pinking b4! I always use normal unleaded in my C4B engined Coupe with std HSV programming & she goes well with no apparant rattles or probs. Is this thing just relavent to blown engines?
cheers, Julian"I just drive it"Horsley
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