Why the redline?

[br d]

Why do cars have the redline on the rev counter?
The computer kicks in and stops my car revving at 8500, so why does my rev counter go up to 10,000 in the red!
What's the point? Is it saying "Don't f*ck with my top end mate!"
The dial might as well just stop at 85,000.
If it's going to hurt the engine then why offer the choice?

[eldar]

Same reason the speedo reads 30mph faster than the car will do. Marketing and standard parts bin.

[moleamol]

What if the limiter died and you were inadvertently revving to nearly 10,000rpm all the time?

[mccarn]

moleamol said:

What if the limiter died and you were inadvertently revving to nearly 10,000rpm all the time?

You'd use a fair bit of fuel

[LMC]

eldar said:

Same reason the speedo reads 30mph faster than the car will do. Marketing and standard parts bin.

Good point !

I drive a Focus 1.8L diesel estate at work at the speedo top end is 140 !!!

In nice cars, like mine, the speedo goes up to the max speed and the rev limiter bounces the needle off the end of the gauge

[Nobody You Know]

To tell you if you're down shifting to early?

[odyssey2200]

So that when you change down from 5th and accidently get 2nd you can guage the size of the repair bill by how far into the red the needle goes

[eldar]

moleamol said:

What if the limiter died and you were inadvertently revving to nearly 10,000rpm all the time?

The reserve rev limiter (the crankshaft) would then remind you by making a funny noise

[odyssey2200]

I once had a VTEC Civic the would rev to 11K

started to use a bit of oil though!

[andy-xr]

Rev limits can be changed though

[gib6933]

eldar said:

moleamol said:

What if the limiter died and you were inadvertently revving to nearly 10,000rpm all the time?

The reserve rev limiter (the crankshaft) would then remind you by making a funny noise

And a con rod finding a new direction to travel.

If you are lucky you get a nice paper weight as a reminder that a lotus twin cam doesn't like to see the wrong side of fifty thousand rpm

[Huff]

I've got a bit of 1973 VW Beetle piston that says a very similar thing about 5000rpm...

[The Black Flash]

gib6933 said:

eldar said:

moleamol said:

What if the limiter died and you were inadvertently revving to nearly 10,000rpm all the time?

The reserve rev limiter (the crankshaft) would then remind you by making a funny noise

And a con rod finding a new direction to travel.

If you are lucky you get a nice paper weight as a reminder that a lotus twin cam doesn't like to see the wrong side of fifty thousand rpm

Grusome!

[Alfanatic]

gib6933 said:

eldar said:

moleamol said:

What if the limiter died and you were inadvertently revving to nearly 10,000rpm all the time?

The reserve rev limiter (the crankshaft) would then remind you by making a funny noise

And a con rod finding a new direction to travel.

If you are lucky you get a nice paper weight as a reminder that a lotus twin cam doesn't like to see the wrong side of fifty thousand rpm

I've gotta know how you persuaded it to spin to the wild side of 50k (and how you figured out it did so)

[Heathwood]

I seem to recall that my wife's '03 Fiesta Zetec didn't have a redline. Revcounter just ended (at 7k I think) although it wouldn't rev that high anyway as the ECU / intake or whatever wouldn't allow it.

[gib6933]

Alfanatic said:

gib6933 said:

eldar said:

moleamol said:

What if the limiter died and you were inadvertently revving to nearly 10,000rpm all the time?

The reserve rev limiter (the crankshaft) would then remind you by making a funny noise

And a con rod finding a new direction to travel.

If you are lucky you get a nice paper weight as a reminder that a lotus twin cam doesn't like to see the wrong side of fifty thousand rpm

I've gotta know how you persuaded it to spin to the wild side of 50k (and how you figured out it did so)

I was overemphasising a bit sorry, so you could imagine what it was like.
It was more likely to be around the 12-13k mark.
Stupid mk9 box

[Zad]

ECUs don't tend to just cut out at the red line, they cut the power to 1 spark plug, then 2 etc (depending on engine type). Chances are on expensive cars that they log and "excursions" over the red line though.

[tomTVR]

LMC said:

eldar said:

Same reason the speedo reads 30mph faster than the car will do. Marketing and standard parts bin.

Good point !

I drive a Focus 1.8L diesel estate at work at the speedo top end is 140 !!!

In nice cars, like mine, the speedo goes up to the max speed and the rev limiter bounces the needle off the end of the gauge

My mates 90bhp 1.4 meganne has a 150mph speedo!