How bad is it when you accidently take a gear to it's limit for a second. Obviously you wouldn't do this on purpose, but it could happen now and then when your racing , so how bad is it, and what are you straining?

 

hi, im new to this stuff...and asked my tuner pretty much the same thing....his response: no worries...you'll hit the rev. limiter and the system will cut out...i personally have never done it...but on the dyno it sounded hairy....i asked WTF was that in a paniced voice...they laughed and explained...
sorry...not much help...

 

Hey, man that helps, I've done it twice :o , glad to know I'm not breaking $hit.

 

iv bounced off the rev limter a couple times it dosnt do to much beside sound nasty - some guys raise there limiters to rev even higher so its not to bad on the engien but i did hear if you do it alot it might bend one of yoru push rods soo i donno

 

I've hit the rev limiter a few times, not on purpose. The limiter is there to prevent problems and so far I've had none.

 

My HUD displayed 103 the other night just as I hit the limiter for that gear. 03' unmodded Z06..no ill effects that I can tell...I love to hear that engine wind up tight...

 

That's what the rev limiter is supposed to do, it protects the engine from acceleration over rev events. Without it, one could fly right through 6500 and not realize it until it's too late. BTW, the rev limitation is based upon engine RPM not what gear you are in. Also, the rev limiter works by shutting off the fuel flow, thus shutting down the engine. As soon as the RPM falls back below the limiter setting, the fuel will kick in again, and the engine RPM will shoot up again, this is the driver's notice to reel in his right foot a bit.

Aren't these cars great!

zo6vettepilot

 

You will hear all sorts of stuff about where your Rev limiter should be.. those who don't own your car 7000... after you ben valves and you take it in "6500?!?!?!"

 

These cars are Great!

 

Yep what they said. Now if you DOWNSHIFT into a gear and that results in an overrev all bets are off, but if you accelerate to the limiter you're fine.

When you hit the limiter it will sound like your engine is falling apart though

 

I have at one point or another bounced off the limiter in every gear except for 6th. Everything is fine. These motors are made to rev higher the General is just being safe and in stock form you will loose power over the current limiter, in a non Z06 C5.

Raftracer (Danny Popp has the limiter on his Z06 bolt on only car set at 7200. and has just a bit of success with it )

 

Top end: Usually the limiting factor is your valve springs. For streetability, you will have fairly mild spring compared to say a NEXTEL Cup car. Your not turning 9500 RPM either. If the valve spring cannot keep up with the RPMs, it will cause the valve to "float". This is the problem. If you raise RPMs past the "float" RPM of that valve spring, the piston meets the valve. Not good. Also at high RPMs, the valve train will move around some. You try jumping up and down at half the engine RPM and see if you staying in the same spot. The roller-rocker enines are a ton better than the conventional GEN I V-8 355 I have in my 1/2 ton '84 Chevy. So, like the previous posts have said, you will probably have to turn it pretty hard to make some damage as long as there arent' any manufacturing defects in the engine on the way up through 6500.

Bottom end: I have been taught that metal fatigue is much less a factor when you get high torgue gradually versus a lower torque rapidly. Take a standard NO. 2 pencil. If you just try to bend it slowly for a while it will take the stress. If you gronk on it, SNAP. This is what happens to the crank or connecting rods. The crank bearing sleeves are clam shells put into the bearing seat. If for any reason, the bearing gets spun, you will lose oiling to that bearing. Mass amouts of heat is generated, then the con rod or crank breaks under the pressure from the rolling mass and the bearing seizure where you spun the bearing.

These are just a couple of scenarios that I see in my head as I am grabbing 4th at 6500 RPM. if you use good oil and common sense, then you should be fine.

 

You MANIAC you!

 

You mean the rev limiter is not supposed to be used as a shift point???

 

Correct me if I'm wrong but hitting your rev limiter with a power adder (boost, Nitrous) will lean the fuel and cause severe damage? I believe alot of nitrous guys shut their nitrous window a few hunderd RPM's before the rev-limiter to prevent this?

 

So the rev limiter won't stop the engine from over-revving if you downshift into a gear that pushes the engine over?

 

That's correct. The any rev limiter only protects the engine from a heavy foot during acceleration. Downshifting, the drivetrain "drives" the engine therefore nothing will prevent an over rev event except immediate application of the clutch to disengage the engine from the drivetrain. Even then, it may happen so fast that damage may still occur.

zo6vettepilot

 

*smacks forehead*

I should have known that ... all the fancy electronics won't stop the actual mechanical over drive ...

Thanks ...

 

Dont laugh...many times I have shifted only when I hit the limiter (and mine is raised to 6900rpm) Gotta invest in a shift light

Seriously... a good street setup like mine (Manley valves, 918 springs, Ti retainers and hardened pushrods) would probably fail somewhere >7500rpm