Piston faliure 6.2 whipple 7psi

[AutoWiz]

I Like Toyota's implementation. to correct this gdi carbon buildup issue you need to spray something before the intake valve. so it can be constantly washing the intake valve while the motor is running. like the way it used to be. All the detergents in the world added to fuel won't help with this gdi issue. but it doesn't have to be fuel. you can just get a water injection kit. or 50/50 water and meth if you like and are boosted. Or just get a functional ram air and drive your stuff in the rain once in a while. for the heads/cam package install I like to run water through an iv drip into the intake and clean the inside of the motor before teardown. just to ensure a clean outcome. and that i'm not bolting a fresh combustion ceiling on top of a nasty floor. there is no reason to not do this. water is free. and how much better will the initial outcome be without any carbon buildup anywhere?

And carbon doesn't scratch cylinder walls guys. this statement suggests that you can get fuel to harden to the point of steel. honestly. more likely that cylinder got hot and was scratched by a ring. for that one cylinder with a scratch on it, over your lives how many carboned up pistons have you seen in a smooth bore? crosshatching gone maybe, but no scratches. if a motor could reach a point where carbon could hurt the cylinder bore, then at that point just the piston rings and piston sliding up and down would rapidly erode and destroy that cylinder.

[etm351]

What redline says makes sense, a direct injected motor does rely on injector timing to control cylinder pressure which is heat. In cummins and duramax that is everything injector timing and volume.

I can see where a leaner afr would be ok on a di engine with boost, i have only tuned a couple na di gm's i dont remember seeing an injector table anything like in the diesel tunes i thought it was odd but that was almost a year ago i haven't looked at another tune in a while. I do remember i had to add fuel and the truck made more midrange power runing richer topend horsepower was about the same.

I am a big on reading spark plugs on the dyno, and even at the truck, you can get into predetonation very quickly and it doesn't take much to hurt power.

[nkautz]

What redline says makes sense, a direct injected motor does rely on injector timing to control cylinder pressure which is heat. In cummins and duramax that is everything injector timing and volume.

I can see where a leaner afr would be ok on a di engine with boost, i have only tuned a couple na di gm's i dont remember seeing an injector table anything like in the diesel tunes i thought it was odd but that was almost a year ago i haven't looked at another tune in a while. I do remember i had to add fuel and the truck made more midrange power runing richer topend horsepower was about the same.

I am a big on reading spark plugs on the dyno, and even at the truck, you can get into predetonation very quickly and it doesn't take much to hurt power.

Tuning became a lot more enjoyable and less stressful when I learned how to read a spark plug ground strap. Especially when the knock sensors are unreliable. One time I had a plug showing a ton of heat on #4 cylinder only. Pulled the head , there were a few pit marks on the piston which were creating hot spots. If I hadn't caught it on the plug read, it would have been bye bye very soon.

[Redline MS]

Tuning became a lot more enjoyable and less stressful when I learned how to read a spark plug ground strap. Especially when the knock sensors are unreliable. One time I had a plug showing a ton of heat on #4 cylinder only. Pulled the head , there were a few pit marks on the piston which were creating hot spots. If I hadn't caught it on the plug read, it would have been bye bye very soon.

Nothing like being in the chamber to know whats going on! That's why 8 EGT probes will be interesting in watching how the injection timing is truly effecting fueling. Eight pressure transducers would be even better...


jarrah,

I think the meth is a plus in helping keep the intact tract clean for sure. What we need is a plate that bolts behind the throttle body that sprays a cleaner through the engine for periodic cleanings....... this issue is compounded by GM's on going issues with the crankcase...

[Eric@HPTuners]

This is key information for any tuner. All this "boosted cars need to be rich" crap is just dogma. It's all about maximum tolerable heat in combustion chamber without detonation. My car hit MBT at 20* (afr 11.5) and made 785rwhp. Not a peep from the knock sensors (working great), and spark plugs showed plenty of heat range left. Started leaning it out and making more and more power until I finally saw a small hint of KR at 13:1. Backed it off to 12.7:1 and made 856rwhp. 91 + meth. LS motor not DI.

Now , 5000 miles of abuse later , I have the engine apart, everything looks new. Putting another motor in with higher compression.

Just thought it was worth sharing

What wideband? Wideband accuracy plays a huge role here.

[nkautz]

What wideband? Wideband accuracy plays a huge role here.

PLX , LM-2 , and Dynojet. Running 14gph and 12gph meth nozzles. 100% , no water. I'll go through a gallon in 7 or 8 pulls.

[Nick@Newtech]

This is key information for any tuner. All this "boosted cars need to be rich" crap is just dogma. It's all about maximum tolerable heat in combustion chamber without detonation. My car hit MBT at 20* (afr 11.5) and made 785rwhp. Not a peep from the knock sensors (working great), and spark plugs showed plenty of heat range left. Started leaning it out and making more and more power until I finally saw a small hint of KR at 13:1. Backed it off to 12.7:1 and made 856rwhp. 91 + meth. LS motor not DI.

Now , 5000 miles of abuse later , I have the engine apart, everything looks new. Putting another motor in with higher compression.

Just thought it was worth sharing

hehe, luckily you have a really cool friend that lets you use his dyno a lot LOL

[nkautz]

hehe, luckily you have a really cool friend that lets you use his dyno a lot LOL

Goat-stroker

[Area47]

I Like Toyota's implementation. to correct this gdi carbon buildup issue you need to spray something before the intake valve. so it can be constantly washing the intake valve while the motor is running.

The split gdi port toyota engines only use the port injection setup under mid-high/ wot conditions. cruising around town and idle is all gdi setup. First tested on the IS-F engine and trickled down to the 3.5 2gr series.

[AutoWiz]

that's right only when there is higher amounts of airflow across the valvestem. Looking at spark plugs can be a lot of fun. but the idea of pulling usable data off of your eye-crometer across a spark plug that will directly apply to any tables or cells in your tune file is just wrong. and it would be nice for others to come out and agree with me here. reading spark plugs for tuning is a carb. trick. efi requires something a bit more specific and with more resolution. 2 degrees of knock retard will not show up on a spark plug but you can rest assured that your knock sensor will pick it up. and as for fueling, well, the narrowband o2 sensors, and not even the heated ones, the 1 wire o2 sensors back in the early 80's replaced looking at spark plugs and were much more accurate. today you waste time and add wear on the spark plug threads in your head for no reason. looking at a spark plug should be to check wear at sevice intervals. todays ecu are beyond what we can do with our eyes and hands. we need to understand how to use a computer to correctly scan another computer to tune it. It is for this exact reason that computer programmers make better efi tuners than mechanics.

I would like to postulate that a good tuner / tech could look at a data log and predict what a spark plug should look like better than he could pinpoint a cell that needed to be adjusted and by how much by putting his eyeball on a spark plug.

Really we don't even have to pull spark plugs to run a compression test: http://www.digitalcorvettes.com/foru...d.php?t=241761

[nkautz]

that's right only when there is higher amounts of airflow across the valvestem. Looking at spark plugs can be a lot of fun. but the idea of pulling usable data off of your eye-crometer across a spark plug that will directly apply to any tables or cells in your tune file is just wrong. and it would be nice for others to come out and agree with me here. reading spark plugs for tuning is a carb. trick. efi requires something a bit more specific and with more resolution. 2 degrees of knock retard will not show up on a spark plug but you can rest assured that your knock sensor will pick it up. and as for fueling, well, the narrowband o2 sensors, and not even the heated ones, the 1 wire o2 sensors back in the early 80's replaced looking at spark plugs and were much more accurate. today you waste time and add wear on the spark plug threads in your head for no reason. looking at a spark plug should be to check wear at sevice intervals. todays ecu are beyond what we can do with our eyes and hands. we need to understand how to use a computer to correctly scan another computer to tune it. It is for this exact reason that computer programmers make better efi tuners than mechanics.

Really we don't even have to pull spark plugs to run a compression test: http://www.digitalcorvettes.com/foru...d.php?t=241761

I think you've got it backwards , properly read spark plugs and putting a scope in the cylinder will always tell the real story. It's nice to have knock sensors giving a clean reading, but any tuner knows that with modified cars knock sensors often become totally unreliable with all the extra vibration. I love it when they are working, but you gotta be able to find max safe power with or without them. My background is 100% computer oriented but I have to say there is equal value in both the mechanical and technical sides of things.

[AutoWiz]

ok well I guess my entire statement does rely on correct sensor calibrations, lol. The right answer is to find a way to correct the knock sensor calibration. or at least to the point of it being usable. spark plugs do not show you time and spark plugs do not support histograms. spark plugs do not have digital readouts and there is no way of eyeballing a sparkplug and saying I was just running at 14.1 instead of 14.7. by the time there is evidence on the spark plug of detonation, you are already so far past the point where you could have safely corrected the issue if only you had been looking at datalogs and your knock sensor instead of your pulling your spark plug. it's ballpark data and we should be seeking pinpoint accuracy.

[Nick@Newtech]

For the Love of God people This is a DI motor, all AFR tuning Theories for regular port induction motors goes right out the window. DI motor do not like a Rich AFR. Now from the looks of the piston it had plenty of Fuel, and The timing IAT pull was not doing its job, PD blower a heat monsters, thus you really must pay attention to timing pull VS IAT Most tuners get Extremely frustrated and move that Window way over so it wont affect their Tuning process. In reality as a Pro tuner you need to tune for extreme conditions verify your tuning is doing its Job correctly via street logging. You want to give your customer a tune that will save itself from detonation under all circumstances. If your PD blower is hitting 150 degrees plus you need to work on thermal Efficiency big time. If i had to venture a guess this motor say 13 degrees of timing and no timing was being pulled at extremely High IAT values, also I would guess the IAT sensor itself was not calibrated correctly also. PD blowers like to use the older style IAT sensor relocated to the manifold, the Freq vs Temp Table is way off without calibration.

[nkautz]

ok well I guess my entire statement does rely on correct sensor calibrations, lol. The right answer is to find a way to correct the knock sensor calibration. or at least to the point of it being usable. spark plugs do not show you time and spark plugs do not support histograms. spark plugs do not have digital readouts and there is no way of eyeballing a sparkplug and saying I was just running at 14.1 instead of 14.7. by the time there is evidence on the spark plug of detonation, you are already so far past the point where you could have safely corrected the issue if only you had been looking at datalogs and your knock sensor instead of your pulling your spark plug. it's ballpark data and we should be seeking pinpoint accuracy.

Scenario: Customer pays to have their car towed to you from several hours away, you put the car on the dyno, strap it down , do a pull... you see a ton of false knock, unable to work around it. You do a quick inspection , no exhaust is rubbing anything , everything looks right. Most likely valvetrain noise / electrical issue or something else requiring significant diagnosis and correction to eliminate vibration. Do you take the car off the dyno , give it back to the customer and tell them sorry you can't help them? Or do you tune it anyways the old fashioned way so at least they have a good tune and they can sort out the vibration later if they choose?

I suggest looking a little deeper into spark plug reading , it won't give you a precise AFR but you can get very close. It WILL tell you exactly how much heat you have left to work with or if combustion is too hot. It's called reading the heat range on the ground strap and it's more precise than you think. You can see the difference from changing half a degree of spark advance.

[Nick@Newtech]

Scenario: Customer pays to have their car towed to you from several hours away, you put the car on the dyno, strap it down , do a pull... you see a ton of false knock, unable to work around it. You do a quick inspection , no exhaust is rubbing anything , everything looks right. Most likely valvetrain noise / electrical issue or something else requiring significant diagnosis and correction to eliminate vibration. Do you take the car off the dyno , give it back to the customer and tell them sorry you can't help them? Or do you tune it anyways the old fashioned way so at least they have a good tune and they can sort out the vibration later if they choose?

I suggest looking a little deeper into spark plug reading , it won't give you a precise AFR but you can get very close. It WILL tell you exactly how much heat you have left to work with or if combustion is too hot. It's called reading the heat range on the ground strap and it's more precise than you think. You can see the difference from changing half a degree of spark advance.

Right on the money, If you rely on Knock sensors 100% then you are naive. I have been tuning for 13 years and have several thousand tunes done under my belt, I know from Experience plug reading in high power boosted applications plug Reading is a MUST, if you are not doing this you are not being thorough. I tuned older fords for years, do you think they had knock sensors? NO. What if you tuned a car and knock sensors picked up nothing, next thing you know you have a broken ring land. This is where being on a dyno is also critical, if advancing timing does not pick up a significant amount of power you have gone past the "window" and your ground strap is now past the middle of the electrode and you are in the detonation zone or close to it. I love hearing people ssaying they have 100% faith in Knock sensors, it tells me just how green someone is.

[AutoWiz]

personally, and maybe I already make enough money in my life that I don't have to take jobs like that, but IF I goto tune a car, and upon initial pull and datalog I have a bunch of kr that I can not put my finger on or pinpoint then I might very well give the car back to the customer vs. being caught up in a pissing contest down the road when it comes apart. tuning the old fashioned way does not translate well to efi. and you sound like the guys throwing out what if rape scenarios to justify planned parenthood. sometimes to be a good tuner, you gotta know what to tune and what to avoid. especially if you catch that at the beginning of the job before you have any time into it.

[AutoWiz]

let me spit a scenario back at you. so you pull your plug and see that there is evidence of detonation. or evidence of rich running or lean at higher rpms. ok. so now what do you do? attempt surgery with a baseball bat? just grab large sections of a map and make sweeping changes? sure that is so much better than finding the specific cells that are giving you trouble. if we want to argue to verify I mean we can waste time however we like, but in reality, the engines sensors have much better resolution than our human bodies are capable of. one more time, the right answer is to fix sensor calibrations so the right data can be logged to tune with. when you feel like you want to use your data out of your head to tune with, the end result is going to be less. each and every time. because your brain is not capable of fetching specific data for specific cells on it's own. it takes an ecu to scan and read an ecu.

is that spark plug gonna show you at what coolant temp or intake air temp the detonation was occurring? is that plug going to show you that is was running rich because of pe? or cot? is that spark plug going to show you at what rpm you were detonating? absolutely not. for you a spark plug seems to be a good place to scratch your head

[Higgs Boson]

let me spit a scenario back at you. so you pull your plug and see that there is evidence of detonation. or evidence of rich running or lean at higher rpms. ok. so now what do you do? attempt surgery with a baseball bat? just grab large sections of a map and make sweeping changes? sure that is so much better than finding the specific cells that are giving you trouble. if we want to argue to verify I mean we can waste time however we like, but in reality, the engines sensors have much better resolution than our human bodies are capable of. one more time, the right answer is to fix sensor calibrations so the right data can be logged to tune with. when you feel like you want to use your data out of your head to tune with, the end result is going to be less. each and every time. because your brain is not capable of fetching specific data for specific cells on it's own. it takes an ecu to scan and read an ecu.

is that spark plug gonna show you at what coolant temp or intake air temp the detonation was occurring? is that plug going to show you that is was running rich because of pe? or cot? is that spark plug going to show you at what rpm you were detonating? absolutely not. for you a spark plug seems to be a good place to scratch your head

I don't think anyone is insinuating to power down the old laptop and tune by smell here.....after all, this is the HPTuners forum, a laptop based tuning system.

You are being a bit myopic, don't you think? If you can supplement your findings on the computer with real world, time proven physical indicators, it is nothing short of better. I bet you fly your plane and never look out the window either. After all, the altimeter tells you that you took off at some point, right?

[Nick@Newtech]

personally, and maybe I already make enough money in my life that I don't have to take jobs like that, but IF I goto tune a car, and upon initial pull and datalog I have a bunch of kr that I can not put my finger on or pinpoint then I might very well give the car back to the customer vs. being caught up in a pissing contest down the road when it comes apart. tuning the old fashioned way does not translate well to efi. and you sound like the guys throwing out what if rape scenarios to justify planned parenthood. sometimes to be a good tuner, you gotta know what to tune and what to avoid. especially if you catch that at the beginning of the job before you have any time into it.

There are some cars that come in that are in very poor mechanical shape and you simply just have to fix those problems before the car is ready to be fully tuned. This comes down to communication with your customer. Now when a car seems mechanically very sound but has KR for absolutely no apparent explanation, this also comes down to communication with your customer. Before I choose my approach I assess how technically inclined they are before I begin to explain what is happening. I am not saying to tune the old fashioned way, I am saying that on top of using cutting edge technology, verify and backup what you are seeing with your instruments with plug reading, verify your equipment is accurate. it is not a replacement but yet another tool in your bag of tuning knowledge, to get the job done right. I was a network engineer before I started tuning cars professionally, people genuinely needed my help it is a path that chose me I guess. Never stop learning or you will become obsolete.

[Nick@Newtech]

I don't think anyone is insinuating to power down the old laptop and tune by smell here.....after all, this is the HPTuners forum, a laptop based tuning system.

You are being a bit myopic, don't you think? If you can supplement your findings on the computer with real world, time proven physical indicators, it is nothing short of better. I bet you fly your plane and never look out the window either. After all, the altimeter tells you that you took off at some point, right?

precisely, you got it.