[blaze6]

i've had an exedy clutch/flywheel fitted. is it normal for the car to lose torque lower down in the rev range from 1500-4000?

i've noticed as at the end of my road i turn out onto the A3 and there's a stretch not too dar ahead where there are speed cameras and i always confidently reach 60 before hitting the speed cameras with the revs below 4000. now i have to raise the revs in order to do the same thing.
is this normal?

[V 5ARY]

you may have lost some torque but your car will be a lot faster at spinning up! you may need your rev limiter raising to 7500..

[NeuroBeaker]

Strange... I'd be interested to know the technical explanation behind this, as I've always thought lightened flywheels were the way to go to get torque.

[batou]

Everyone whos been in mine since I had the lfw fitted says they can feel it pull better even before I've past 3,000rpm... not sure on the exedy combo but doesn't feel like I've lost torque at all with the Clutch-masters set up.

They don't alter power or torque Beaker, they just make the engine spin up quick making it feel more responsive. Uprated clutches have better torque holding meaning it can cope with more ft/lbs before say a stock one would slip (my worn stock one started slipping right after the manifold went on).

[blaze6]

Quote: Originally Posted by NeuroBeaker (original)

Strange... I'd be interested to know the technical explanation behind this, as I've always thought lightened flywheels were the way to go to get torque.

that's what i thought! i had a belt change at the same time as the new clutch being fitted, i'm wondering if my belt's slipping. i'm going to book into 1320 autos prob in august and get the car dyno'd and see what's going on. it might just be my driving skills!

[robbo mcs]

Quote: Originally Posted by sayanthan (original)

i've had an exedy clutch/flywheel fitted. is it normal for the car to lose torque lower down in the rev range from 1500-4000?

i've noticed as at the end of my road i turn out onto the A3 and there's a stretch not too dar ahead where there are speed cameras and i always confidently reach 60 before hitting the speed cameras with the revs below 4000. now i have to raise the revs in order to do the same thing.
is this normal?

Hi,

With a lightened flywheel the car builds revs quicker, but obviously it loses revs more quickly as well. This is obvious from the laws of physics , but is not realised by many people.

What this means is that you have to do lightening fast shifts, or even flat shifts on the upshifts. If you do a normal "lazy" gear shift the car loses revs and bogs down in the next gear. I suspect this is what is happening

Cheers

Robbo

[Ant FR]

Quote: Originally Posted by robbo mcs (original)

Hi,

With a lightened flywheel the car builds revs quicker, but obviously it loses revs more quickly as well. This is obvious from the laws of physics , but is not realised by many people.

What this means is that you have to do lightening fast shifts, or even flat shifts on the upshifts. If you do a normal "lazy" gear shift the car loses revs and bogs down in the next gear. I suspect this is what is happening

Cheers

Robbo

sounds about right, so what you are saying is unless its for race use, then lightened flywheel is just not worth iton the public roads and everyday driving

[Bhozar]

Quote: Originally Posted by robbo mcs (original)

Hi,

With a lightened flywheel the car builds revs quicker, but obviously it loses revs more quickly as well. This is obvious from the laws of physics , but is not realised by many people.

What this means is that you have to do lightening fast shifts, or even flat shifts on the upshifts. If you do a normal "lazy" gear shift the car loses revs and bogs down in the next gear. I suspect this is what is happening

Cheers

Robbo

Thanks Robbo. That will explain why I dont have a clue what they were talking about. I always do fast shifts, so never noticed.

[blaze6]

Quote: Originally Posted by robbo mcs (original)

Hi,

With a lightened flywheel the car builds revs quicker, but obviously it loses revs more quickly as well. This is obvious from the laws of physics , but is not realised by many people.

What this means is that you have to do lightening fast shifts, or even flat shifts on the upshifts. If you do a normal "lazy" gear shift the car loses revs and bogs down in the next gear. I suspect this is what is happening

Cheers

Robbo

thanks, that makes sense, - "flat shifts on the up shifts"? - what does this mean?

[batou]

Quote: Originally Posted by Bhozar (original)

Thanks Robbo. That will explain why I dont have a clue what they were talking about. I always do fast shifts, so never noticed.

Ditto, if your cruising then I might understand (that said if it plant it at 2k it will pull hard) as between gears the revs drop quick if your nursing the box too much ... if you keep up with the flywheel and the clutch can cope the changes are rapid both up and down.

[robbo mcs]

Quote: Originally Posted by sayanthan (original)

thanks, that makes sense, - "flat shifts on the up shifts"? - what does this mean?

Hi,

Changing up a gear keeping the accelerator flat to the floor ie you don't lift the power and rely on the rev limiter for the instant it is in neutral between gears. You need to change gears very quickly. Usually this is also combined with the technique of not using the clutch at all on upshifts.

For example, you are going flat out in 3rd. As the car approaches the rev limiter you keep the accelerator planted to the floor, don't touch the clutch, and very quickly slam the gearshift into 4th, keeping the accelerator planted the whole time.

Don't try it in your mini it is really a technique only for race cars Not very sympathetic to your cars mechanical components

Cheers

Robbo

[Bhozar]

Quote: Originally Posted by robbo mcs (original)

Don't try it in your mini it is really a technique only for race cars and hire cars Not very sympathetic to your cars mechanical components

Cheers

Robbo

Fixed that for you.

[blaze6]

this brings me back to the point of a lightened fly wheel:-

1. whether you're getting more torque higher or lower in the rev range, is the amount of torque any different? ie: does a flywheel increase the maximum torque available to you, or is it a case of shifting the torque up the rev range. in other words, is there a performance gain? - i assume there is otherwise why have it?

2. what are the advantages of having torque further up rather than lower down the rev range? i understand that the engine spins up more easily, but in terms of speed, acceleration, what are the differences? as this is going to happen anyway lower down the rev range.

i've changed my driving style and now i am fast as i was before, (not that i'm a particularly good driver) but i wouldn't say considerably faster. the car feels "more comfortable at high revs" than before for want of a better word. not sure if this is healthy for the engine!

i'm going to get the car dyno'd on thursday at 1320 autos and get them to check the car over check there are no other issues, sadly i've got no previous dyno data to compare to.

has anyone dyno'd their car before and after fitting a flywheel?

[jhiggs26]

Quote: Originally Posted by robbo mcs (original)

Hi,

Changing up a gear keeping the accelerator flat to the floor ie you don't lift the power and rely on the rev limiter for the instant it is in neutral between gears. You need to change gears very quickly. Usually this is also combined with the technique of not using the clutch at all on upshifts.

For example, you are going flat out in 3rd. As the car approaches the rev limiter you keep the accelerator planted to the floor, don't touch the clutch, and very quickly slam the gearshift into 4th, keeping the accelerator planted the whole time.

Don't try it in your mini it is really a technique only for race cars Not very sympathetic to your cars mechanical components

Cheers

Robbo

Yep that's what dog engagement boxes are good for Robbo! We've got synchros so use em.

Jeremy

[blaze6]

Quote: Originally Posted by jhiggs26 (original)

Yep that's what dog engagement boxes are good for Robbo! We've got synchros so use em.

Jeremy

can the gearbox take it? not using the clutch at all on upshifts at the rev limit?

[Lucky Dave]

What are the effects of a non dual mass flywheel on the crank and oil pump? I would of thought this would do more damage than a non dampened crank pulley?

[batou]

Quote: Originally Posted by Lucky Dave (original)

What are the effects of a non dual mass flywheel on the crank and oil pump? I would of thought this would do more damage than a non dampened crank pulley?

I wasn't aware of this until recently, I've always been anti crank pulley so may have to check out my oil pump earlier than expected!

I guess by still having the stock damper less is getting through though right? Does it not just mean the crank damper has more to dampen?

[BGB]

Quote: Originally Posted by Lucky Dave (original)

What are the effects of a non dual mass flywheel on the crank and oil pump? I would of thought this would do more damage than a non dampened crank pulley?

i wouldnt have thought so being at the other end of the crank

[Lohen]

Quote: Originally Posted by Lucky Dave (original)

What are the effects of a non dual mass flywheel on the crank and oil pump? I would of thought this would do more damage than a non dampened crank pulley?

Hi,

Sadly none of us will know until someone breaks theirs (or hopefully NOT ). Here is a "brief" (who am i kidding- brief ) explanation:

1. The crank pulley (harmonic damper & etc.) - no matter what you want to call it, it is supposed to take out the "flex/vibration" created by the combustion in the cylinder. It is highly tuned to the standard set up (standard crank, flywheel & clutch cover), in particular the weight. However the construction material of the crank (& the crank pulley itself) will also have an effect.

2. Altering anything in the set up - WILL deviate from the original design. Hence changing the crank, flywheel, clutch cover, will change the frequency at which the crank will vibrate. (because adding or removing the weight will have an effect, because moving the weight in/out will have an effect, because changing the material from which the crank is made will have an effect).

3. Hence - once you have modified anything in the set up the harmonic damper is no longer functioning properly. END OF STORY

4. Depending on what you have done you might be not too far away and hence the damper might be working to some effect, but unless you go and test the set up and calculate where the resonant frequency of your current set up is then you will never know.

On the other hand you might be very far away... we just won't know until someone pulls the whole thing apart and scientifically investigates the matter.... and that costs a LOT of money...

Andrey

[blaze6]

Quote: Originally Posted by Lohen (original)

Hi,

Sadly none of us will know until someone breaks theirs (or hopefully NOT ). Here is a "brief" (who am i kidding- brief ) explanation:

1. The crank pulley (harmonic damper & etc.) - no matter what you want to call it, it is supposed to take out the "flex/vibration" created by the combustion in the cylinder. It is highly tuned to the standard set up (standard crank, flywheel & clutch cover), in particular the weight. However the construction material of the crank (& the crank pulley itself) will also have an effect.

2. Altering anything in the set up - WILL deviate from the original design. Hence changing the crank, flywheel, clutch cover, will change the frequency at which the crank will vibrate. (because adding or removing the weight will have an effect, because moving the weight in/out will have an effect, because changing the material from which the crank is made will have an effect).

3. Hence - once you have modified anything in the set up the harmonic damper is no longer functioning properly. END OF STORY

4. Depending on what you have done you might be not too far away and hence the damper might be working to some effect, but unless you go and test the set up and calculate where the resonant frequency of your current set up is then you will never know.

On the other hand you might be very far away... we just won't know until someone pulls the whole thing apart and scientifically investigates the matter.... and that costs a LOT of money...

Andrey

oh well,
in that case i may as well get a lightened crank pulley fitted too & raise the rev limiter to 9000.....