baptistsan

How much damage could/would be done by bouncing off the rev limiter a few times?

BenHampton

None I would hope - thats the point AFAIC as its stops you before you DO any damage

I use it all the time (except when cold obviously)

Kobe

I guess it's not a great idea..

but this is what I read on the tech forum..apparently this is a Honda guy writing:

I have data to show that the S2000 engine will live at redline. The problem is that any more than 9,000 RPM will allow the valves to "float". This means that the cam is turning so fast that the rockers can't stay in contact with the cam lob. As this happens the rocker doesn't push on the valve stem constantly. If the rockers are floating then the valve spring is going to slam the valve closed as hard as it can since the contour of the cam lobe isn't gently closing the valve. (9,000 crank revs per minute is 150 per second/2 or 75 valve slamming per second). With the valve spring at full force closing the valve the only thing stopping the valve is the valve seat but the spring is still working (pushing the retainer up) and the only thing stopping the retainer is the keeper and the valve. Thus the retainer starts to split when the valve isn't controlled by the cam.

When the engine goes more than 10,700 RPM the valves stay open long enough to get slapped by the piston. That is when you see the valve bend and then break off. If the valve only is bent a little it may bend back each time the valve spring is pulling on it and it may close properly and not cause a misfire code. Eventually it will fail and cause extensive damage. That is why someone can say "I was driving slow down a city street and it just failed". That is usually a true statement.

HTH,

woodwork

baptistsan

So if its only happened the once its unlikely to have done any damage?

SiDHEaD

Oops i use it as a marker to change gear when hooning it.. I guess I shouldn't always believe what i've read on here

s2uk

which limiter did you get to ? cold start off 6000 or the full on 9000?

I have only hit the 6000 limiter once didn't realise car was not warmed up and booted it, the full on one I have a few times without wanting to, was always told by honda not to do it to often.

S2KPDQ

Absolutely nothing wrong with hitting the limiter. That is what it is there for...be assured that there will be plenty of safety margin.

The only consequence of hitting the limiter is that you will be slower - best to change on the third red flash and keep the acceleration going

Andy

tim_d

Depends on the circumstances the limiter was hit under..

If you hit the limiter through acellerating all the way up through a gear until it cuts in, that's fine, it's what it's there for. The limiter will protect the engine and do it no harm.

However, if you hit the limiter by changing down a gear to soon, ie 5th to 2nd instead of 4th, and the roadspeed is higher than the 9k revlimit would allow - that's not fine. Although the limiter will cut in and try to help, the road speed will drive the engine above it's operating limit - this can cause damage.

HTH.

S2KPDQ

baptistsan

Booted it on a slip road in second, watching traffic already on the motorway, not paying any attention to the rev counter and then had a loss of power a couple of times, this happened for a couple of seconds before my slow arsed brain figured it out and I changed up to third.

My fault entirely, as I usually change up just before redline, but missed it this time.

Car was fully warmed up but was a little concerned as to whether I could have hurt anything. Just me being paranoid I guess.

Cheers all.