rev limiter

[sixx]

Still waiting to take delivery , but had a quick question about redlines. The Tacho has no readline, so what can I push it too? Is it 6k or further. Additionally is there any rev limiter that stops me sending the pistons out of the block?

[williamball]

There's a change-up light in the bottom of the rev counter rather than a red line. Never explored the higher reaches to see if there's actually a limiter.

WB

[jeremyc]

For the standard 4,5 max power is at 6750rpm and changge up light/buzzer triggers at about 7000rpm.

I've never found out where the limiter cuts in....

[craigw]

plenty of time for that...

[minicooperturbo]

On mine (4.5), the light and buzzer comes on after 7K (around 7,200), but I have seen 7,500 (too busy steering the car to worry about changing gear).

[Byff]

I tripped the limiter, ahem twice, in first and second when I raced a scooby. The bugger got the better of me on the start but I soon caught him

Didn't notice what the revs were - I was a bit busy

[Big Al.]

Byff said: I tripped the limiter, ahem twice, in first and second when I raced a scooby. The bugger got the better of me on the start but I soon caught him

Didn't notice what the revs were - I was a bit busy

Don't tell us, eating a burger and answering the mobile as well.

[dannylt]

Agree, buzzer at 7200. I believe the limiter is at 7500, but given the power drops off, why would you go that high?

[beemer]

sure I read somewhere on here a few weeks ago that there was no rev limiter on a Cerbie - might be wrong though?

Only had mine a week so haven't explored revs above about 6500 - might be being paranoid but worried that the shift light might not be working!!

are they pretty reliable?

sean

[dannylt]

There's definitely a limiter, don't worry. It's worth using the revs to 7000 because of the wide gearing when you're going for maximum thrust.

If the engine is going to break, then the diffeence between using 6.5 and 7.0 isn't going to make any odds. And it's a waste if you don't use it properly anyway!

[beemer]

thanks danny - very reassuring!

another quick question from a (probably) paranoid new owner.

Have been driving my Cerb in to London for work a few times - temp fluctuates between 90 and 100 in traffic. Couple of times when at c.100 the MIL light has flashed briefly - do I need to worry about this?

thanks

Sean

[stickshaker4185]

Revving the life out of these big engines isn't always going to achieve the desired results. Acceleration is all about using the engine's torque to overcome the vehicle's inertia. The G telemetry I collected from acceleration runs(standard 4.2)has shown that the best results are achieved when changing at about 6200rpm. The only benefit from changing up at a higher rpm is to put the engine closer to its ideal torque/rpm for the next gear, while sacrificing acceleration in the current gear.

[gazzab]

Beemer - get it checked by someone with the software. They can check what the warning message is ie which of the sensors is complaining. They can also see what the causes is sometimes.
If you have got cats then you are risking damaging them if the mil light is detecting a misfire.

[dannylt]

stickshaker4185 said: Revving the life out of these big engines isn't always going to achieve the desired results. Acceleration is all about using the engine's torque to overcome the vehicle's inertia. The G telemetry I collected from acceleration runs(standard 4.2)has shown that the best results are achieved when changing at about 6200rpm. The only benefit from changing up at a higher rpm is to put the engine closer to its ideal torque/rpm for the next gear, while sacrificing acceleration in the current gear.

Your 4.2 must have a very low torque peak. Mine is 5000, so changing at power peak (7000) drops the revs to around 5000, i.e. the torque peak and so gives ideal acceleration. If your torque peak and power peaks were lower, say 4200 and 6200 that would be ideal for yours.

And it's just not vehicle intertia- there's significant aerodynamic drag and friction.