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MG MGF Technical - Rev limiter

I regularly rev my year 2000 1.8 vvc to 6500. At what revs does the limiter cut in.
Thanks Chris
Chris

7200, I believe. I've only hit it twice! :)
Tim Jenner

Tim, Many thanks. Ill give it a go Thursday.
Cheers Chris
Chris Jones

Doesn't the red line on the rev counter indicate approximately where the limiter should cut in. I believe it is different for MPi and VVC.
Chris Catchpole

>7200, I believe. I've only hit it twice! :)

Me too. I've got more sensitive with top rev's since I've seen the opened engine of a damaged engine recently (Gotta pic anywhere)

The owner had taken the car to a dealer and moaned about noisy engine.
They took the head off and *surprise, surprise*, clear visible halfmoon shape marks of valve circumferences on all the pistons. (valves bent of course)

Interview with the owner, male btw !!:
"I've done nothing, but normal driving"
"OK, once I missed the right gear and put in a lower (3rd) instead of the 5th..."
;)

No joke. He obviously mixed up the valve timing with heavy over reving. I think the speed limiter had no chance.
;)
Dieter K.

Not a great deal of point revving the engine to that kind of speed anyway: power is all over on the 1.8MPi by 5500rpm anyway :o(

Now if you had some head porting and some naughty cams, the story would be rather different! ;o)
Rob Bell

>>power is all over on the 1.8MPi by 5500rpm anyway <<

Chris started by saying he had a VVC.
JohnP

Dieter - completely off topic, but I've been trying to reply to your email about the EPC for ages now but it keeps getting bounced back. Have you got that sorted now or do you have another email address?

Tim
Tim Jenner

D'oh! So he did John - skim read past the lower case initials...

Isn't the VVC red lined at 7250? In which case the rev limiter will probably cut in at around 7400-7500?
Rob Bell

so you can change

>power is all over on the 1.8MPi by 5500rpm anyway
to power is just getting peachy by 5500rpm
Will Munns

LOL indeed!

Mind you, even the VVC's torque peaks before 6750 and starts to fall away - so challenging the rev limiter doesn't make all that much sense ;o)
Rob Bell

Difference between hitting 6750 revs (optimum torque) and 7200 is around 3 nanoseconds (plus, if you're in a critical overtaking manoeuvre, changing gear can waste time), so have hit rev limiter numerous time. Only problem is engine can suddenly be starved of fuel - I believe this a known "feature" requiring a stiffer fuel pipe or some such, but I've never bothered doing anything about it.

Will is right - VVC begs to be revved - main reason for getting a VVC over an MPi is overtaking capability in 2nd or 3rd.
Paul Daykin

Agreed - I've never actually tried to hit the rev limiter, it just doesn't take much time or effort to get there! :)
Tim Jenner

I agree with Tim - no effort needed beyond taking the car for a drive.
JohnP


>red lined at 7250? In which case the rev limiter will probably cut in at around 7400-7500.

well... no, it cuts in at 7250.

Actually, I seem to have noticed on my VVC that if I accelerate from standstill through the gears to the limiter, it will cut in around 7350 in first, 7200 in second, 7,000 in 3rd and like 6900 in 4th. As if it "adapted" to the increased stress on the engine. Not that I do it very often, mind you.
Anthony Braham

That's interesting Anthony - I don't know why your car should do that - afterall, MEMS won't know what gear your in (unless it is an engine load thing?)

Anyone else got similar experiences with their VVC?
Rob Bell

The new MEMS takes an road speed feed as well, but I don't know what it's used for (data logging?)
Will Munns

This thread was discussed between 11/02/2004 and 17/02/2004

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