Cause of the #8:

[kevinp]

I highly doubt it's any one thing at fault here. It sounds like a combination of a less than ideal piston design and a small tuning window.

It seems like a lot of these newer engines these days are pushed further and further straight from the factory, leaving not a ton of room for the aftermarket, which the tuner crowd isn't used to. In this case, we are talking about a 5L engine with high compression that makes 400hp on 87 octane. That is a pretty damn good specific output for a mass produced engine.


The OEM's have very strict durability, performance, mileage, emissions and cost requirements that they have to achieve. I think we just need to come to grips that the days of tuning lots of extra power is gone.

Yes they are pushed further and the calibrations are very complex on these, not only can the knock sensors take away timing, but they can add timing as well so they are an active part of the spark scheme - not just a safety device. They also have piston protection tables, cold piston knock spark tables, individual cylinder spark adders and I really dont think anyone knows exactly how all the spark tables interact except the people that wrote the code. Who is to say that by just simple rewriting the PCM with an aftermarket tuner it doesnt screw up one individual spark or fuel table?

I dont blame the tuners, they are just giving people what they are asking for - more power for little money and labor. No one is holding a gun to anyone's head to put a tune in, and I believe there are plenty of disclaimers. How can anyone possibly check every facet of a tune on a dyno only, it would take thousands of miles of logging to see whats going on. Unfortunately these arent video games, if you blow it up you cant just start a new game and expect Ford to bankroll it.

 

[Shaun@AED]

From what I have seen, it's not ring butting. There might be some of that going on, but ring butting does not cause pistons to melt. Ring butting pops ring lands.

93Pony I have some headers, catback and some other things to install and a new tune as well. I told the customer I was going to throw new plugs in and check the tune before and after. I really want to see #8, see if the ground strap looks like the earlier pics.

Please keep us informed on what you find with the plugs.

 

[CPRsm]

Rings butting will start flaking the moly off, detonation can cause the moly to flake off as well, so unless the ring ends are shiny I'm not buying that. Easy enough to see. Sure ist possible but usually rings will just grind themselves to fit and wreck the face well before grabbing a cylinder hard enough to break a piston.

Agreed. Just the sealing edge of a piston is a dead give away to butting. I have not had a chance to hold one in my hand to see. Only pics.

Are you implying that there is a problem in the pics I posted? I'm trying to understand the finer details of "reading plugs"...

I was agreeing with 93Pony, the heat in the cyl looked a little hot for me as well. The burning on the ground strap will tell you how much heat is in the cyl. Anytime you heat something up, the edges will get hot faster because they are the most exposed. The base of the ground strap is connected to the plug, which help dissipate heat. The other end where the spark jumps has nothing to help with the heat, so it will start burning off the plating there first and work it's way down the strap towards the plug itself. Remember this.
Detonation is a combination of time and heat. You can get a away with more heat, if in short blasts. He he much be lower if you are going to be on the throttle longer. This is why a Texas mile tune is different than 1/8 racing. You can be MUCH more aggressive with that tune because it only last for a few seconds. The Texas mile is longer, so more heat will build up in the cyl. Not to mention the MUCH higher load on the engine due to aerodynamics. You take a 1/8 tune, throw 3:00 gears in the car and head to Texas, kiss your engine good bye.
So when gauging the timing in an engine, you can tell by looking at the strap. As you engine is loaded and you're WOT, the plating starts to burn off the ground strap. Longer you are on it, farther down the strap the plating will burn. If you run the same distance every time, say 1/4 mile, the time won't WOT won't change. Now you just need to know how much heat to put in the cyl. Since your plating is completely gone, it's hard to explain it. Get your self a new set of plugs. Go go do a 4th gear pull and pull over. Compare that plug to #8 you showed here and you should see the plating is not completely gone, and get a better understanding of what I mean.


Should be a few days 93Pony, but I will.

 

[RSKtakR]

double post

 

[RSKtakR]

I have run E85 for over 3000 miles in my daily driver 5.0.. I have a tune from a shop in Texas.. Powerwise this car feels INSANELY different then 91. Now I jsut run a stock tune most of the time, and when I know its a weekend that I am planning on going out and "playing" i load up the E85 tune and run all the 91 out (when the car tells me I have less then 20 miles left of the 91oct). However after hearing of this #8 issue, and hearing from some other shop that these cars cant run E85 on the stock fuel system because they run out of injector (even though I have heard from numerous tuners, shops etc) that the stock fuel system will support 600hp. I plan on doing some data logging while on the E85 w/ the SCT live link logging. I called the guy that wrote my tune to make sure the knock sensors weren't messed with. Im fillling up w/ the E85 today and hopefully logging it tonight and tomorrow when its not 100+ degrees out. I have a 100% STOCK fuel system, the only change is the tune for the E85. I think my only worry with the E85 is if the stock fuel filter will be able to survive and if so how long? After reading this thread I am for sure going to look into that Kinsler racing filter right after I post this. Im also half tempted to buy a water/meth injection kit to cool down the intake charge for the 91 and the E85 more just to try and steer clear of to much heat in #8.. not so much to try and make more power, just the cooler air temps etc.......

BTW VERY informative thread!!! :beer:

.

 

[DIB5.0]

Great couple of posts by members over at S197

I dont think its a weakness at all. Heres my opinion on the matter


Stock ford tune is MAXED at ignition timing as it is.
Ignition timing increases heat.
This is most likely why they have piston squirters.
Aftermarket N/A tunes increase ignition timing to gain more power as its simpler than figuring out the TiVCT and "cheaper"
#8 is the hottest cylinder and the more timing it gets, the hotter it gets, thus causing the failure
The reason the S/C cars dont see this problem is the timing is backed way down

IMO aftermarket tunes should only be adjusting throttle response, and maybe some tweaks to the A/F ratios but NEVER modifying ignition timing.


There's a difference between taking advantage of, and taking it over the edge. Install an intake and add a little timing, but pay attention to the knock. You'll still see gains, but it'll be safe. Add more timing, and yes the gains will be higher, but so will the risk of failure.

As for why the failures are hit and miss, I think it's because of a combination of things. On good clean straight 93 octane, an average temperature and normal driving conditions the aftermarket tunes are likely absolutely fine. Those are 3 variables though. One of them changing probably isn't a big deal. The knock sensors will do their job and keep it safe. But if all 3 go extreme (bad gas, hot day, and heavy throttle), then that's where the "recipe for disaster" comes into play.

It's just like a plane crash. Planes don't crash because of one single thing. They crash because a combination of things, or a series of events that leads up to the crash.

 

[Chris_Red_V8]

Not that it matters much, but I can verify all of his table information

Second, E85 is great and will let you get max power

Third, i would say you can run advanced timing on 93 but not much more than stock

Datalog and verify

Finally, the old way of copying mbt to bkt, command .87 lambda, reduce knock retard and increase advance is what is blowing these engines.

I saw a dyno from a well known shop it knocked 11 times during the run. Knock is detected then timing retarded so 11 timesduring the run his pistons were hammered.

My guess is #8 is the first to knock. The ecu detects it and retards so most of the other cylinders ate protected

Also a leaner afr really does not pick up pwr. Torque does improve slightly.


Sent from my iPhone on an overpriced data plan

I'm guessing you're talking about my car? Until this stuff all gets sorted out, I'm staying the hell out of the right pedal.

 

[ubeenbit]

I'm guessing you're talking about my car? Until this stuff all gets sorted out, I'm staying the hell out of the right pedal.

I guess. Names change. Get the prp like you suggested. I can send you my tune as a value file for you to compare and look at.


Sent from my iPhone on an overpriced data plan

 

[Shaun@AED]

FYI, increasing throttle response the way some tuners are doing it creates other issues.
3/4 throttle surge is what the driver feels.
The computer is seeing TQ calculation errors and trying to correct engine TQ thru the throttle blade.
This wasn't a problem on older DBW stangs, but due to the widebands, A/F can be precicely controlled at P/T high load, so Ford can now close the TB to control TQ production more accurately.

It's important to minimize TQ error, not simply set the maximum error to some crazy value like 50,000.

 

[phack]

For what its worth, I was told by Fred Cook of Evolution that they do NOT recommend their 93 Aggressive tune with anything other than race gas. The difference between the Aggressive tune and the normal 93 tune is 2 degrees as per Fred.

 

[DIB5.0]

Remember not to long ago there was a guy from Evo in a post saying you should only run the aggressive tune at the track and after cool downs. Everyone got on his shit for that.
If you talk to Lund though he says the aggressive tune is fine to run everyday.

 

[1HUBCAP]

Remember not to long ago there was a guy from Evo in a post saying you should only run the aggressive tune at the track and after cool downs. Everyone got on his shit for that.
If you talk to Lund though he says the aggressive tune is fine to run everyday.

Talked to Jon last night,and thats what he said. Tunes after 5/10/11 are updated with stock knock sensor settings. I am pretty sure i will be going with a roush tvs soon though,sounds safer!:rockon: What is your opinion on installation kevin p ?

 

[layzie]

Good post and all but I would like for you to divert all of your attention away from the GT's #8 cyl. Trust me when I say that there are more important issues than the 2011 GT's #8 cylinder.. so lets focus on the right information here...


Now, we all know that the Terminators #7 cylinder is way more important than the 2011 GT's #8 cylinder so if we could all get back on track here that would be much appreciated.

Respectfully,
Layzie

 

[kevinp]

Talked to Jon last night,and thats what he said. Tunes after 5/10/11 are updated with stock knock sensor settings. I am pretty sure i will be going with a roush tvs soon though,sounds safer!:rockon: What is your opinion on installation kevin p ?

Simple enough if you have the tools and some experience. Good instructions and OE fit/finish.

It is kind of funny that bolting a blower on is the 'safe' thing to do lol. I have no illusions, I am stressing this thing pretty good with a PD blower and I know full well it can let go at anytime. Even if it loses a piston and trashes the block a decent short block isnt too bad, if I wasnt lazy and it wasnt hot as hell I would just do rods and pistons now so I can play hard in the fall. But then the trans will die lol.

 

[SILV03MustangGT]

dunno if you guys have seen this or not

IMPORTANT: 2011+ Mustang Air/Fuel Ratio Safety & Accuracy - Ford Mustang Forums

 

[Mika]

Silv03MustangGT, thanks for the link. More info is great.



Mika

 

[Ray Lucca]

My question is how do we really know how much Ethanol is in fact in our gas?? Out here in S. Ca. , 91 Octane is the top 'Premium' available.....

 

[SILV03MustangGT]

thats the thing we dont really know. here it says may contain up to 10% ethanol. i read somewhere (bobistheoilguy.com IIRC) that the gov't regs say it must contain a minimum of 5% no more than 10% and that most average 7%

 

[acrbill]

Maybe performance tunes are flushing out an issue that may take months or years to appear in a stock application??

Why are there issues with one cylinder across the board?
If it is a matter of too much timing then a stock car is one bad tank of gas away from hurting #8.

The fact that Ford issued a TSB for aftermarket tuning means the issue is bigger than most realize.

If I popped #8 the last thing I am doing is posting about it on the internet because God knows who is watching.

Here is my reality.

The day that Ford put that TSB out and included clutch issues is the day they lost me as a future customer. My clutch was ****ed when the car was stock and even after "fixing" it the clutch is still having issues. This is obviously a factory issue they are trying to get out of paying for.

I should have bought a Vette and all its pushrod goodness. LOL

 

[ViciousJay]

Maybe performance tunes are flushing out an issue that may take months or years to appear in a stock application??

Why are there issues with one cylinder across the board?
If it is a matter of too much timing then a stock car is one bad tank of gas away from hurting #8.

The fact that Ford issued a TSB for aftermarket tuning means the issue is bigger than most realize.

If I popped #8 the last thing I am doing is posting about it on the internet because God knows who is watching.

Here is my reality.

The day that Ford put that TSB out and included clutch issues is the day they lost me as a future customer. My clutch was ****ed when the car was stock and even after "fixing" it the clutch is still having issues. This is obviously a factory issue they are trying to get out of paying for.

I should have bought a Vette and all its pushrod goodness. LOL

i should have just gone with the camaro