Rev Limiter Question

[TomcatDriver]

In over 40 yrs and millions of miles of driving (all kinds of sticks to autos) I've hit redline or a rev limiter maybe 6 times. I've never seen a forum like this one where folks think hitting redline is a cool thing (hey cool the display goes Red--really, I wanna try that...or they admit to how many times they hit redline as if it was a badge of honor instead of the badge of stupidity that it is)....not saying the OP said that and one time mistakes do happen (hell I've done it about 6 times but over 40 years on a manual) but the number of threads and posts therein is staggering on this topic.

Go on an import forum, or better yet, watch some Youtube videos of "tuners" or "ricers", take your pick. Not only is there an entire subclass of automotive enthusiast that revels in bouncing off the rev limiter, they even install adjustable rev limiters for the explicit purpose of bouncing off so they can get that popping backfire...on purpose. Yea, I don't get it, but I would not rate this forum as a place where people actively enjoy bouncing the rev limiter.

Sponsored

 

[TheReaper]

Go on an import forum, or better yet, watch some Youtube videos of "tuners" or "ricers", take your pick. Not only is there an entire subclass of automotive enthusiast that revels in bouncing off the rev limiter, they even install adjustable rev limiters for the explicit purpose of bouncing off so they can get that popping backfire...on purpose. Yea, I don't get it, but I would not rate this forum as a place where people actively enjoy bouncing the rev limiter.

I'm sure he's never heard of a WOT box in his 40 years of driving.

 

[Sig556]

I love this back and forth of misinformation.
The tach in your car is a TOOL it shows you the actual safe operating RPM.( Revolutions Per Minute) of your engine. Constantly Exceeding the RPM (REDLINE) puts you at the cusp of disaster. which MAY cause valve float, broken springs, spun bearings. You get the picture. Every time you exceed REDLINE you roll the dice. Yes I agree with others you should be fine and hitting Redline once in a while should not hurt your engine. Then again you never know . Stay safe and keep the revs under Redline. Why do you think a Redline is built into your dash? HINT ! It's not for show.

 

[Eritas]

I love this back and forth of misinformation.
The tach in your car is a TOOL it shows you the actual safe operating RPM.( Revolutions Per Minute) of your engine. Constantly Exceeding the RPM (REDLINE) puts you at the cusp of disaster. which MAY cause valve float, broken springs, spun bearings. You get the picture. Every time you exceed REDLINE you roll the dice. Yes I agree with others you should be fine and hitting Redline once in a while should not hurt your engine. Then again you never know . Stay safe and keep the revs under Redline. Why do you think a Redline is built into your dash? HINT ! It's not for show.

Are you calling "redline" when the tach goes red at ~6,500rpm?

"Redline" and the "Rev Limiter" are usually synonyms. You can dig into it deeper and talk about "soft" and "hard-cut" limiters. At the end of the day, bouncing off of these 'rev limiters' isn't going to make your engine last longer, but it is not causing damage to your engine -because their function is to prevent damage before reaching an RPM that can cause damage. Now bouncing off the limiter when doing a burnout for minutes on end like an idiot is probably not good for your engine, but you're unlikely to drop a valve or break a valve spring from it.

As others have said, Ford offers warrantied 'tunes' that raise the factory rev limit from 6,800rpm to 7,500rpm. The stock valvetrain can handle 8,000rpm without issue.

 

[Sig556]

NO! My second sentence "When you exceed Redline"

 

[Eritas]

How do you "exceed redline"?

 

[DickR]

How do you "exceed redline"?

In current Mustangs and probably many other current cars with oem rev limiters there are two ways to "exceed redline".

1) With a manual transmission downshift to a gear which is too low for the road speed. Typically this happens when attempting to shift to say 3rd gear and getting 1st instead. The rev limiter cannot prevent this kind of overrev. Ditto if attempting to downshift to 4th at high speed and getting 2nd instead. These kinds of shifts are sometimes called "money shifts" because if the revs are high enough you get to buy a new engine and/or if on a race track lock up the rear tires and crash. :-(

2) Install a tune which raises or eliminates the oem rev limiter setting. Ford even sells a tune which raises the rev limit to 7500 for the 5.0 (as I recall).

 

[thehunterooo]

Might want to trade it in before the engine blows :lol:

I know a lot of the forum won't go past 3k rpm because that is the rule of daily driving a car but I go past 7k everyday.

 

[WildHorse]

Redline and Rev limiter are two completely different things. Just sayin..

 

[FIVE_LITER]

 

[Sig556]

How do you "exceed redline"?

STAY IN IT!

 

[millhouse]

Hitting the fuel cutoff during acceleration will not damage the engine or hurt your warrant. No fuel = no combustion. This is an industry standard and is the safest hard rev limiter.

 

[CEHollier]

:cheers:

 

[Grintch]

You're misinformed...

Also Redline and rev limiter are different. Shifting at the Redline is the optimal shift point for maximum performance (generally speaking). If you've only done this 6 times...you're missing out.

The redline is often not the optimum shift point (which is almost always different for different gears) . It's more a maximum recommended rpm. While the rev limit is the maximum allowed (it does not protect against downshifting too early or too far, so it's not complete protection from stupidity).

But yeah, sporty cars should see the occasional run to redline (or close to it). And hitting the rev limit once in a while is not something to worry about.

 

[Trackaholic]

In the Mustang GT, the optimal shift point is at redline (which also happens to be approximately the fuel cutoff/rev limiter). In the EB, you'd shift earlier (I've done the calcs, but forget exactly what the number is, and for that car it does depend on gearing somewhat).

Running up to the rev limiter and bouncing off it momentarily should not cause any issues. The designers know this will happen and set those values in order to preserve some safety factor against damage.

Missing a shift and forcing the engine far beyond the rev limiter can definitely be a problem, and should be avoided.

If you have an automatic, it will prevent you from downshifting to a gear that would force the engine past the rev limiter. Basically if the automatic lets you do it, you should be fine.

Just don't try to put the car in park while it is still moving.

-T

Sponsored