Rev Limiter Question?

2012 SVT...
When I do a hard pull, if I hit the rev limiter, instead of stopping at 6K and holding, it seems like the engine loses power..I can feel the car hesitating and almost cutting out. This does not seem normal to me, as I'd expect to hit the set limit and stay there as long as I was on the gas.

Thanks

pwnyryd said:

2012 SVT...
When I do a hard pull, if I hit the rev limiter, instead of stopping at 6K and holding, it seems like the engine loses power..I can feel the car hesitating and almost cutting out. This does not seem normal to me, as I'd expect to hit the set limit and stay there as long as I was on the gas.

Thanks

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That's normal....your motor won't just hold there right at 6K for as long as you're in the gas. It kills power by cutting spark. That said, you really want to avoid bouncing off the rev limiter. It's very rough on your timing components, and if you pop something there it's going to cost you.

pwnyryd said:

I'd expect to hit the set limit and stay there as long as I was on the gas.

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You really don't want to be doing this. You will become a new member of the "Blown Motor Club" in short order bouncing it off the limiter. It's a good way to break timing components or break the oil pump gears. Either will take other components with it, neither of which will be a cheap repair.

Thanks for the info, guys. This seems like (to my ignorant mind) a bad way to protect the engine; is there any reason it was implemented this way? As opposed to what seems the "normal" way, where the car's computer limits throttle?

There are rpm based and speed based limiters on the car. Your stock rpm based limiter is 6250. It cuts fuel and spark at that point to keep you from overreving the car. We generally up that a tick to 6500, which is a safe place to be as long as you are running good fuel.

That said, these limiters are not designed to act as 2-steps at low range nor a brick wall at the high end. They are solely to protect the engine.

These cars do not like to rev high. Keep your rpms below the limiter and it'll be happy. Bounce off the limiter and you'll hurt stuff (timing assembly first and foremost).

So...the question would be what it is that you're wanting to accomplish by hammering it on a limiter.

Let me know and I may have some safer suggestions.

bj

No, I'm only curious about what our engines did when we hit that limit, and why. I guess I need to be extra aware of the RPM during pulls, that's all. Thanks!

You can set your SVT light as a shift light. If youre on the stock tune, set your light RPM to 6000. By the time you react youll be out of the gas and into the shift right at the limiter.

My redline is at 6500 and i have my shift light set to 6300.

Getting to that limit during a drag run where your at the speed but only for a moment is fine. Driving on the street at redline for extended amounts is a big no no

I have a shift light, the svt is really hard to see at the track, my shift light will blind you, just what I need to get my attention.

I've never been able to see the SVT shift light or hear the beep....it's been totally useless for me.

Really... its yelled at me quite a few times on the street

lexustech48 said:

Really... its yelled at me quite a few times on the street

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For real man. If it's daylight hours the light just doesn't get bright enough for me to really notice it. And I've never even heard the beep. Is it even a beep lol? Maybe my exhaust setup is too loud, but I hear nothing at WOT when I hit the appropriate set point.

I had an M3 a few years back with the shift lights on the steering wheel. I loved that damn thing. Wish we had something like that.

I thought my VMP tune was the cause of this weird rev limiter issue. When I hit my rev limiter it kills power for 500 ft or more. If I shift to another gear and rpm are down to 4500 or so and hold it wot it will not pull or show any boost and slowly the car will keep applying power even though I'm wot, this can take 5-10 seconds to give full power back. If I'm in a race or at the drag strip its over. It looks like I put my tail between my legs and limped back in shame.
BTW this usually happens when in 1st spins and revs up quick sometimes second.
Anybody else have this type of rev limiter issue?

Lol. I call it driving mrs.daisy when that happens at the track lol! I don’t do that anymore .

Are you in sport mode for Advancetrac? Or is it completely disabled by holding the button for 10 seconds?

I've just ran into the same questions myself...

Everything I've heard is that these things can safely rev up to 7000 and that bouncing off the stock limiter is not a good thing... I've talked to 2x very respected Tuners and they both up'd the RPM limit to 7000 to help avoid bouncing off of it...

On top of that I just hooked up a Sniper Shift Light to help out... The SVT light didn't do sh*t for me...

This thing is easy to adjust to whatever setting and the light is a lot more noticeable. I have all the light going off at 5500 for every gear right now but adjust when racing or whatever.

Titan 5.0 said:

I've just ran into the same questions myself...

Everything I've heard is that these things can safely rev up to 7000 and that bouncing off the stock limiter is not a good thing... I've talked to 2x very respected Tuners and they both up'd the RPM limit to 7000 to help avoid bouncing off of it...

On top of that I just hooked up a Sniper Shift Light to help out... The SVT light didn't do sh*t for me...

This thing is easy to adjust to whatever setting and the light is a lot more noticeable. I have all the light going off at 5500 for every gear right now but adjust when racing or whatever.

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Tuners will raise the rev limit because they don't want you bouncing off the limiter....as stated, that's really hard on your timing components and OPGs.

I wouldn't say that it's safe to continuously rev a stock motor to 7K RPMs, though. I would definitely not do that, you're going to break something....and it's going to be something that takes out other stuff with it. Ask @biminiLX about that. He broke his OPGs revving to 7K on a 13, where that actually is allowed in the stock tune. Factor in your RPMs flaring during the shift and revving a stock motor that high is just asking for trouble.

Yes, in my example I had a Lund tune which ups the rev limit and I was datalogging for a race, so I was trying to shift about 6800 w/o a shift light.
The problem when you do very fast speed shifts or power shifts is that the momentum of the engine will cause a shift over rev 'shift flair'.
I kicked the clutch about 6800 and the shift flair engine speed went to almost 7300rpm and no more oil pump gears.
The '07-12 cars don't need to rev high as BJ mentioned.
The '13-14s do have GT cams and peak higher and do run faster with higher shift points BUT, be prepared as above.
I would recommend setting your shift light 300-400rpm lower than your intended shift rpm and then datalog to see.
-J

On a 5.4, 7,000 is not really a safe limit, but I sort of see your point. The 5.8 limiter was set higher at 7,000 rpm, but they also reduced weight on the top end of the rod, used a different piston configuration and a have little more cam as bimini mentioned to make power above 6,200 rpm. You're better off leaving it at 6,500 and shifting accordingly. If you're going to hit the rev limiter, you'd be better off hitting it at 6,500 rpm than 7,000. The thing is, if you hit it, LIFT! Don't stay in it.

Totally agree with the last few posts... with the limits being raised to 7000 by tuners it basically means we need to manage the RPMs we go to on our own, the reason I got a shift light.

If I go above 6500 it's unintentional and probably due to shift flaring.

Very informative thread. I've power shifted 66-6800rpm and when datalogging realized my revs would tap as high as 7300-7400. I called FRPP Tech with a worried tone . They said not to worry about it as it's not under load after shift point and it's only for an instant. Lund did not feel it was a concern but not as a regular routine. I asked about lowering the rev limiter but was told this would be worse for reasons above. Time to start moving at 62-6300rom.