GT Redline

[DivineStrike]

My fuel cuts off at around 6800... Not once has it gotten anywhere near 7k. I think maybe those stats are backwards. 6750 fuel cutoff with a 7k redline for an overrev indication.

Jimmy, the 6500 is more of a soft "redline" meaning the engine isn't making much more usable power beyond that. More or less a recommendation to shift. It is the ideal shift point for a Stock coyote.

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[Rob00GT]

According to the Ford specs, the 5.0 on 93 octane fuel makes it's maximum 435 horsepower at 6500 RPM. So rev away!

 

[R1V3R5]

I have that light grey section on my V6. Also your check engine light is on.

LOL. Not my car. Thanks though. :cheers:

 

[DivineStrike]

No, doesn't make sense for the fuel to cut off at 6750 and the engine red lines at 7,000. The cut off is to save the engine IF you tend to go past redline. It's but a fraction of a second in time.

Peak hp is at 6500....but, that too is SHIFT TIME!...too bad peak hp is at an RPM point so close to redline. So, shifting should be based around where peak torque is. Redline shifting is just wasting engine torque, fuel, etc, etc.

Again, these are Fords own tech. info. I'm just passing on their own stats. Argue with them if you'd like.

Redline: 6750
Cutoff: 7,000

If fuel cuts off at 6750 the engine wouldn't make it to 7,000. It falls off right now. I know, been there with past engines.

I'm sure some computers could be off just a "hair" 100 rpm's or 200 is not much when you're up that high.

No, what you are saying doesn't make sense. An engine redline in most cars is a point where you don't want to exceed ever. Why would the fuel cutoff be after the point of potential damage? Preventative measures are the best solution. Most cars have the fuel cutoff before redline.

And your last point is exactly why I'm suggesting the stats are backwards. My car won't make it even close to 7k. Redline is only important to the manufacturer for troubleshooting reasons. If there is a problem with your car they will run a diagnostic to see if it was overreved. An overrev before reaching the fuel cutoff would be a nuisance indication and not helpful for troubleshooting. Most overrevs are due to a mis shift and mechanical. I am sure there are some cases where the fuel cutoff fails and the driver isn't paying attention and overrevs the car; but those are probably pretty rare.

 

[DivineStrike]

I'm not saying it will blow up at all. I am just telling you what the car actually does. There are not two redlines on an engine. There is one. And of course there is a margin for error. That is why it's only a troubleshooting indication. Most people confuse redline for rev limiter ie the fuel cutoff. And yes margin or not it is what the engine builders don't want the engine to exceed. Hence why normally the fuel shutoff is before the engines redline. I'm not arguing with the engineers or you...just stating the information could have been misprinted

 

[foghat]

No, what you are saying doesn't make sense. An engine redline in most cars is a point where you don't want to exceed ever. Why would the fuel cutoff be after the point of potential damage? Preventative measures are the best solution. Most cars have the fuel cutoff before redline.

And your last point is exactly why I'm suggesting the stats are backwards. My car won't make it even close to 7k. Redline is only important to the manufacturer for troubleshooting reasons. If there is a problem with your car they will run a diagnostic to see if it was overreved. An overrev before reaching the fuel cutoff would be a nuisance indication and not helpful for troubleshooting. Most overrevs are due to a mis shift and mechanical. I am sure there are some cases where the fuel cutoff fails and the driver isn't paying attention and overrevs the car; but those are probably pretty rare.

Fuel cut-off (or rev limiters) occur after redline. I look at the redline as the point you should not exceed and the cut-off as the point you cannot exceed.

As to why you can't hit 7000rpm, dunno. I need to pay closer attention to where I cut off at - has only happened once to me.

 

[foghat]

I'm not saying it will blow up at all. I am just telling you what the car actually does. There are not two redlines on an engine. There is one. And of course there is a margin for error. That is why it's only a troubleshooting indication. Most people confuse redline for rev limiter ie the fuel cutoff. And yes margin or not it is what the engine builders don't want the engine to exceed. Hence why normally the fuel shutoff is before the engines redline. I'm not arguing with the engineers or you...just stating the information could have been misprinted

Fuel cut-off/rev limiter usually occurs after the start of redline. Sometimes right at redline.

 

[Stevefreestyle]

Again, these are Fords own tech. info. I'm just passing on their own stats. Argue with them if you'd like.
[/B]
The redline is where the mfg. wants the engine to stop revving. IF you tend to go JUST PAST that the fuel shuts off.

Now...find a Ford engine engineer and deal with him. I gave their stats.

So, think about it. Ford gave a red line that is truly just below THE actual red line at 7000..that's why fuel is shut off then.

For us...the red line is 6750....for the engine itself it's 7000 and that's it...no more fuel. Truth be known it will actually rev past that a little and survive. They build in a "safety margin" and stop the engine at 7000.

Engine builders DO NOT work without "margins." They don't let them be pushed RIGHT TO THE "blow up limit." 7000 is NOT the "blow up" point.

It's THE limit they want this engine to stop revving. Period. It will do a little more. Prolonged high rpm running...that's another issue too.

Same with diesels and turbines. I taught the GE turbo fan engines on a DC-10 jumbo jet. Trust me...there are margins...on all engines.

Truly...if you think the engine would "blow up" at 7,050 rpm..well you're wrong. Again...the engines have built in "margins" and that is what I'm trying to explain. You can believe me...someone who taught engines of all kinds...gas, diesel, turbine....or not. I have no reason to mislead you or anyone else.

Unfortunately you did not give your source - therefore your claim of information legitimacy is not sustainable or verifiable - ie totally irrelevant.

 

[Stevefreestyle]

Ford Motor Co. on the '15 Mustang GT engine. I said I got it from Ford. Believe it or do what you want.
Trying to help here. I know my #'s and engines. Spent too many yrs teaching with doing tons of research, know what I'm talking about before class. Human and make mistakes...we are all fallible. Not here.

What have you offered to "challenge" my info? YOU are irrelevant to me and us. Your info. would need to be better than Ford's own tech specs!!
Good luck with that!

No need to be offended, you obviously have no concept of what i was talking about - in substantiating a statement which claims definitive truth or fact with a supporting reference source - for verification. It is standard practice and a basic requirement for any educated person!

 

[Sasuketr]

GT PP owners i think we are in for a TSB or some type of calibration due to the speedometer and accelerometer not being accurate. The fuel cut off is indeed 6750 and that might be the reason a GT PP can't make it to 60mph on second gear! Whats really going on here? Maybe the engine is actually reving up to 7000 rpm but accelerometer is not catching up and showing 6750!

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