any miles?

[jug]

So you're not hitting the limiter then....Unless you're telling me you can here the change in sound and react quicker than one revolution of the engine....

i change at the same rpm as the limiter, so i'm changing "on the limiter". "hitting the limiter" is when you allow the revs to bounce off it while still in gear, and technically i'm not hitting it until i'm out of gear. i do still hit the limiter after the clutch is pressed because i dont lift off the accelerator until after i hit the clutch; this is done to reduce the rpm drop during gear change and to make sure you get a clean disengagement (no lurch forward like you get when you take foot off accelerator before pressing clutch). instead, this technique makes the car lunge forward when you get into the next gear, a good sign that you've done it right.

obviously this style causes more wear to the engine and gearbox etc etc, but i dont really care if they all die at 250k instead of 500k, either way the car will have been scrapped and recycled long before that ever happens so it is of no consequence. the only issue to worry about is clutch wear, but replacing your clutch every 100k isnt a big deal, and an average woman driver playing the clutch too much causes far more wear than aggresive boyracer gearchanges.

 

[Chas Uno]

acceleration.

when you change gear your rpm drops. you want the rev range you use (from drop to change) to have the best average bhp and lb/ft figures. you can use curve printouts to determine what your best possible range is, but on most cars you need to change on the limiter to achieve highest possible average bhp and lb/ft.

It also depends on the power and torque curves of the car concerned. Most cars actually experience a torque decrease near maximum revs, and most have a power decrease too. The secret is to change up a gear so that the revs fall to the point where the torque curve peaks and remains flat for the next 1 - 2000 revs. That's the way to get best acceleration and I reckon on most average cars changing up at the rev limit is NOT the best place to do it. 8v Puntos for instance are designed for torque and economy and to keep in the torque band you're often best off changing up at approx. 5000 - 5500 rpm. Exceptions may be cars with V-tec type of engines or rotary Wankel engines as these can often rev much higher than their red lines whilst still increasing power. However the engines may not be designed to sustain constant over-revving and engine longevity is likely to suffer.

 

[ChrisUK]

legally they cant void a warranty for that unless it is covered in the warranty terms and conditions. hitting the rev limiter does not constitute misuse so there would need to be a term specific to the rev limiter. you get all kinds of excuses from warranty honorers, if you accept those excuses then you've lost. the Ts&Cs are legally binding both ways so you should fight back and use their own terms agaisnt them.

i hit the limiter 160 times a week easily. i must have hit it at least 10 times on the way to work this morning, actually at least 20 times now i think about it (probably more tbh). most of my gearchanges are at the limiter, unless traffic/road conditions do not allow it. its what the limiter is there for.

Stephan has it slightly wrong there... It wasn't limiter it was 'overrev' as in the engine was forced to rev higher than limiter due to early downshifting. Obviously someone slamming it in 2nd at 65mph :devil:

 

[StevenRB45]

Stephan has it slightly wrong there... It wasn't limiter it was 'overrev' as in the engine was forced to rev higher than limiter due to early downshifting. Obviously someone slamming it in 2nd at 65mph :devil:

I tried to find it again but can't would have liked to refresh memory as it was about 4am and I was p**sed at the time

 

[ChrisUK]

I tried to find it again but can't would have liked to refresh memory as it was about 4am and I was p**sed at the time

was a funny thread. Couldn't believe someone bought an ex rental

 

[StevenRB45]

I was sitting with a female friends dad at one point making small talk and as I'd just got new car he was like ah mate you shouldn't have gone to a dealer what I do is buy an Exhire car. They use them up to 10k then park them in a field till they are 1 year old and sell them at much reduced prices and theres loads to choose from.

So if thats accurate...which tbf its a bit of a bloke in the pub told me story for my liking. Car is probably used very hard for 6-8 months, stands in storage for 6 months and then some poor sod buys it either direct or more probably from Carcraft or a similar organisation...:bang:

 

[jug]

It also depends on the power and torque curves of the car concerned. Most cars actually experience a torque decrease near maximum revs, and most have a power decrease too. The secret is to change up a gear so that the revs fall to the point where the torque curve peaks and remains flat for the next 1 - 2000 revs. That's the way to get best acceleration and I reckon on most average cars changing up at the rev limit is NOT the best place to do it.

i agree with this 100% in theory, but i always test different techniques to see which gets the best acceleration.

when i recently got my astra i did tests changing at 5000rpm, 5500rpm, 6000rpm and 6500rpm on a straight where you start from a junction (hutton henry turnoff on A19 southbound) and then do a 1st 2nd 3rd drag along a flatish road up to a small hill. i use the top of the hill as a checkpoint to see which change rpm gets the highest speed by the checkpoint. changing on the limiter gave me the highest speed at the top of the hill. the same is true for my alfa. my girlfriend's mk2 punto sporting gets almost exactly the same speed using a variety of rpm's (i dont understand why tbh).

but i agree some cars will have curve peaks that are more shifted to the left in relation to the limiter, and then it will definately be quicker changing before the limiter. as i originally said- the aim is to maintain the highest average bhp and lb/ft at all times. your curves will show what rpm is your optimum range, but real world tests are more important than the theory and its easy to find out for yourself what difference it makes to your acceleration- all you need is a road.

 

[jug]

Stephan has it slightly wrong there... It wasn't limiter it was 'overrev' as in the engine was forced to rev higher than limiter due to early downshifting. Obviously someone slamming it in 2nd at 65mph :devil:

well that is naughty and should void a warranty.

i got 2nd instead of 4th in my orion at 100mph and it made the timing belt slip, bending all but 2 valves. happy days, well not really but it was almost worth it because i got to witness engine braking unlike anything i've ever witnessed before or since. i must have gone from 100 to 20 in less than 2 seconds.

 

[ChrisUK]

well that is naughty and should void a warranty.

i got 2nd instead of 4th in my orion at 100mph and it made the timing belt slip, bending all but 2 valves. happy days, well not really but it was almost worth it because i got to witness engine braking unlike anything i've ever witnessed before or since. i must have gone from 100 to 20 in less than 2 seconds.

ouch