Rev limiter proper operation

[Bexar80]

I had never hit the rev limiter so the other day I thought I would give it a go. I ran it up in 3rd gear and all of a sudden it felt like the car just cut off power and at 120mph it was unnerving. I was expecting a bouncing tac type operation. What is the correct operation for my 2000 gts?

 

[Tagoo]

Nope, no bouncing. Spark is cut very abruptly.

 

[Steve-Indy]

Engaging said rev limiter in a low gear can not only be unnerving, but can cause a spin...especially if road surface cold or damp, tires worn or cold.

 

[V10SpeedLuvr]

Hitting the limiter on purpose. You're braver than me!

 

[Tom F&L GoR]

I did it the first time at an autocross and thought I broke something expensive. Now I have a light mounted on the steering column that lights up at (adjustable) about 5200 RPM. For a Gen 1, that's past the power peak and there's still "safe" RPM to go, but a good place to shift. And avoid the limiter.

 

[V10SpeedLuvr]

I did it the first time at an autocross and thought I broke something expensive. Now I have a light mounted on the steering column that lights up at (adjustable) about 5200 RPM. For a Gen 1, that's past the power peak and there's still "safe" RPM to go, but a good place to shift. And avoid the limiter.

Thats exactly the RPM my shiftlight is set to as well.

 

[jmasin]

LOL

Never hit in the Viper yet but in my other car when I hit the rev limiter it sounds like pieces of the engine are going to start flying out at any instant LOL... it is an awful sound/feeling.

 

[plumcrazy]

its a great way to bend a pushrod or worse

 

[AZTVR]

I had never hit the rev limiter so the other day I thought I would give it a go. I ran it up in 3rd gear and all of a sudden it felt like the car just cut off power and at 120mph it was unnerving.

So, what RPM does a Gen2 cut out at ?

 

[Zentenk]

I hit it once, stayed in gear around a turn and accelerated out of it. Thought I had more RPMs to go but I guessed wrong... felt like my car shut down and hit an invisible wall.

I have hit my rev-limiter on my LS1 and it was not good, car would not run properly right after and I had to stop and shut it off for awhile. Ran fine after start-up. I did have a shift light on my TA but it was yellow and hard to notice during the day.

 

[Paul Hawker]

Later model Vipers have a red "approaching rev limit" light on the dash. It is the same light that turns yellow to encourage an upshift.

SRT's will bounce off rev limiter. It was exhibited the most on the "Ring" record run with the driver bumping up against the rev limiter instead of shifting into the next highest gear.

 

[Zentenk]

Later model Vipers have a red "approaching rev limit" light on the dash. It is the same light that turns yellow to encourage an upshift.

SRT's will bounce off rev limiter. It was exhibited the most on the "Ring" record run with the driver bumping up against the rev limiter instead of shifting into the next highest gear.

Oh yeah, the only other time I hear rev limiters hit that often is at a Honda car meet.

 

[J&R3xV10]

I have hit the rev limiter on both my vipers but I never got the unnerving feeling at all, just shifted and kept going. I hit the rev limiter several times when I first got the 08 because my foot would keep the gas pedal down when I hit the cluth and brake hard like on an autocross but I got used to the pedals and don't have that issue anymore. If I remember correctly at one of the first SRT events that had the 08s the instructors told everyone that they would hit the rev limiter when doing a "box stop" during one of the autocross runs and just about everyone did.

 

[Ratical2]

I hit it once during hard acceleration getting onto a freeway. Once was enough...

 

[plumcrazy]

6200 rpms on gen1/2

 

[redrichard]

Hit the rev limiter, SHIFT GEARS ![media]http://forums.viperclub.org/images/smilies/drive.gif[/media]

 

[slysnake]

SRT's will bounce off rev limiter

Will they? The one time I hit the rev limiter it acted just like described. Car dropped power and scared the crap out of me. I don't think its a good idea to do it on purpose, thats for sure.

 

[Konza800]

At the strip if I get a good launch I will hit the rev limiter in third gear just before the finish. The engine just cuts out until I lift so I just coast through the traps. Not good for MPH.

On the other hand, I have hit the rev limiter while doing a burn out and if I remember correctly it bounced in that situation.

 

[Bexar80]

I did it the first time at an autocross and thought I broke something expensive.

That was also one reason for me to try out the limiter. I have my first autocross coming up and I've heard to watch hitting the limiter on those types of courses. I had never worried about hitting it on a road track.

its a great way to bend a pushrod or worse

No disrespect but is not the purpose of the limiter to prevent that type of damage?

At the strip if I get a good launch I will hit the rev limiter in third gear just before the finish. The engine just cuts out until I lift so I just coast through the traps. Not good for MPH.

I had heard that a lot of genII cars "bounce" off the limiter in 3rd on the 1/4" mile as mentioned. Obviously these cars will not "bounce" and it is not really a good technique.

I hit it once during hard acceleration getting onto a freeway. Once was enough...

Ditto, once is enough.

Thanks everyone for the input

 

[DarcShadow]

I have an 01 and it "bounces". I've hit the limit a few times at both a road track and an 1/8 mile track.

 

[Russ M]

Lots of speculation and BS in this thread.

1) Rev limiters are designed to save motors not damage them, hitting a rev limiter is usually very safe especially if its the hard cut like the viper has.

2) You will NOT bend a push rod hitting the rev limiter, unless you do it by down shifting and over revving which the limiter can not prevent.

3) It is normal and safe for a good hard cut, it is by far the safest way to limit RPM, but not the only way.

4) Soft cut rev limiters are great for racing applications, launch control or anti lag. They are generally only available when you switch to an aftermarket ECU like an AEM.

The way they work is you set a rev limit lets say 6k rpm, you also have to set a range value say 200rpm. This means that once your car hits 6k it wont shut off the limiter until your rpm drops to 5800rpm or lower.
Now this is where you can get your self into trouble if you don't know what you are doing. If lets say you set the value to 50rpm then your motor will be back on power at 5950rpm, and some people set it up to be much tighter than that and it will damage parts due to all sort of reason. The better built the motor the tighter you can go on these settings, but there is always a limit.

Hope this helps.

 

[ViperTony]

FWIW, I've installed the modifry shift beeper and did what Russ discussed which was setting 200RPM increments as I approach my desired upper limit RPM, say 5,800. So say starting at 5,000RPM I begin hear a series of increasingly louder and faster beeps letting me know I'm approaching my set RPM limit. There's a How To in the illustrated's section for this. Worked great until I did some engine work, not I can't hear the beeps anymore and I have the speaker mounting behind my right ear.

 

[Toma]

Will they? The one time I hit the rev limiter it acted just like described. Car dropped power and scared the crap out of me. I don't think its a good idea to do it on purpose, thats for sure.

Yeah, they just "cut" suddenly. raised my to 6450. Made the car quite a bit faster in the quarter mile cause of the shift recovery rpm was a tad higher.

Mopar ECU raises it to 6400.

 

[PDCjonny]

So the Gen 4's don't shut down when the rev limiter is hit as evidenced by the ACR run at the 'Ring?
He bounced off it repeatedly with no power loss.

 

[plumcrazy]

a couple of guys have bent pushrods by hitting the limiter, one of them is a good friend. talk to greg good and he will tell you the limitations of these engines and high rpms, they dont mix well. tator knows of a few bent pushrods from this as well IIRC.

 

[VIPER GTSR 91]

Not to mention going as far as the rev limiter is waisting rpm as the max HP and torque are reached well before. In my old race car I used a shift light on the column which flashed brightly and had a chip for the perfect max power shift RPM point.

 

[georgethedog]

I never hit the rev limiter in either my Gen 1 or 2. However, I hit the thing every once in a while in my Gen 3 and I think it is because I was used to the Gen 1 & 2 gearing and the Gen 3 has 3.33 gears and I am not quite used to it yet. I light/noise would help. I am going to look in the How-to section...

Driving my wife's SRT-8 Challenger I hit it easy because that engine revs so much quicker it seems than the V-10 and I think the rear-end gears are quite different (I'd have to look again for the exact numbers).

 

[ViperTony]

I never hit the rev limiter in either my Gen 1 or 2. However, I hit the thing every once in a while in my Gen 3 and I think it is because I was used to the Gen 1 & 2 gearing and the Gen 3 has 3.33 gears and I am not quite used to it yet. I light/noise would help. I am going to look in the How-to section...

Driving my wife's SRT-8 Challenger I hit it easy because that engine revs so much quicker it seems than the V-10 and I think the rear-end gears are quite different (I'd have to look again for the exact numbers).

Pics are missing for this mod in the illustrated section, I'll update it with my install pictures. It's very easy to do. The product can found here: Modifry's Redline Shift Beeper Shift lights are also an option but I prefer the sound indicator. I agree with others that hitting the rev limiter shouldn't be a goal.

 

[georgethedog]

Pics are missing for this mod in the illustrated section, I'll update it with my install pictures. It's very easy to do. The product can found here: Modifry's Redline Shift Beeper Shift lights are also an option but I prefer the sound indicator. I agree with others that hitting the rev limiter shouldn't be a goal.

Thanks Tony. Man, it freaked me out when I did it. I thought I broke the freakin' car.

 

[ViperTony]

Thanks Tony. Man, it freaked me out when I did it. I thought I broke the freakin' car.

You and me both!