Optimum revs to change gear..discuss

[PeteIreland]

I drive a 1.2 SX and find that I really have to keep the engine singing to get anything out of it. Now I realise that its only a small engine and that it will never out perform bigger engined cars but is there an optimum range where you should change gear with out toasting the engine..I usually change around 4000rpm.

 

[Tom]

change gear just after peak power, ie about 5700ish.

An ideal gearbox will drop the engine revs from peak power to peak torque.

 

[thomas]

Hell no, you're doing it all wrong!

Those 1.2 twin cam engines are tough little buggers and their design encourages high revving. You could give it at least 5000-5500rpm before changing and not hurt its lifespan i'm sure.

Key for me is to change gear at the point that when you engage the next gear you are roughly at the engines point of max torque which i guess is around 4000rpm.

If you rev only to 4000rpm before changing up you are only starting to hit the point where your car will accelerate fastest. Let her go to 6K

 

[thomas]

Beaten to it by Tom

 

[J]

Was just curious - what is the optimum rev for gear change on a 1.8 HLX?

 

[Nikshaw]

Are you all bonkers or am I just a model T ford driver incarnate!!??

I'm still adjusting to the high revs my HGT likes before changing up a gear. By high revs i mean I used to change gear at 1500 and now I wait till perhaps 2500 (cos you can actually sense that the car dosn't like at all you changing gear at revs any lower than this!).

I got the 2.0 Bravo for more power for better handling and brakes really, as well as better economy on the motoway with higher top end (might have been diluding myself a bit there me thinks!). I hadn't even considered throttling it up to 4K or more, in any car I'd driven until I got my HGT and my brother asked me what it could do in 3rd; since I hadn't the foggiest, I drove onto the ring road and opened her up.

I think I was nearly hysterical when the car reached 80 mph, before I finally notched it into 4th. I am gradually getting used to letting the revs reach 4 or even 5K (since my exhuast dosn't like revs lower than 3.5K either).

Surely though, our fuel economies must drop through the floor when running the motors like this, even if the car itself does likes to be run this way You'll all no doubt roll your eyes and shake your heads at this point and question why on earth I bought a HGT instead of a morris minor

Suppose actually, I could do a standing start, ..actually test how quick I can get from 0 to 60mph compared to what the book says. What an idea!! (am i a little unusual for having never actually attempted this in a car before!??) Maybe this is a part of adolecence i missed, and my having bought an HGT had kick started puberty again 10 years late!!??

ps. I aint that old, since I was born in 75.

 

[Ian]

Is that 1875?

 

[Anonymous]

jeez,

I try not to let my hgt drop below 4k as the power drop off is famously huge, and tend to change up at 6-6.5 so that i'm at 4k in the next gear.
the car sounds like it enjoys it too

If ever you hear thunka-thunka-thunka from your front wheel, pull over; you may well find you have only two wheel nuts left and both of those are probably loose! Not that that has ever happened to me, honest!

 

[Tom]

Its not like its gonna hurt your engine Bouncing it off the rev limiter when its cold will but you've gotta be a prize mong to drive like that.

 

[Anonymous]

What's wrong with bouncing it off the limiter when its cold?

Daz

 

[Tom]

Cold & thick oil, not as good at lubrication as hot oil

 

[Anonymous]

But i thought that was what the limiter was for?

Daz

 

[Tom]

The limiter stops it destroying itself. Revving the nuts off it when its cold will just wear it alot faster.

 

[Anonymous]

But when cold my limiter cuts in at lower revs...(around 5k)

Daz

 

[Tom]

Not on all cars

 

[Conrad]

Hmm, love what you are all saying, but my g/f demands that I drive like a dweeb! Any advice on dealing with that because I am sick of changing up at 2k just to avoid her rictus of terror (she used to drive a 1.1 'C' reg micra). All I want is an incontravertable arguement as to why I should send my 115 HLX above 4k at least before bothering to change up.

Techno babble is seriously appreciated

Conrad (probably the slowest bloke on the forum)




"Carlsberg don't make a slow driver, but if they did..."

 

[J]

Whats the optimum time to change gear in a 1.8 HLX, find myself doing it about 4-5K that bout right?

 

[marko]

Mines a 1.6 and I do my best to use the full range of the engine once warm. There is little point in having a peak power range that isn't used. The car runs most ecomomically at around 50-60 mph so it's best to get there as fast as possible. I rarely thrape it to the red in 1st since my GB complains when I select 2nd gear after revving high, all the way up to 5700 in second if conditions permit, same in 3rd until you hit the speed limit, then 3rd to 5th to settle the speed. Hey presto - efficient, fun and safe driving.
Get your G/F a push bike and see if it will go over 1000 rpm.

 

[smithers]

glad to hear i'm not the only one that revs their bravo hard. I think it must be the italian personality of the engine, cos i've driven other cars and you have to really put your foot down, whereas the bravo's revs climb constantly. You're either accelerating or slowing down, there's no in between till you get over 60mph.

 

[PeteIreland]

Now I am really confused...should I only change gear above 5000rpm..or does it depend on the engine size?