Flywheels

[jon]

Random thought for the week...

 

In theory, as long as you had a trick enough ECU, could you remove the mass of my flywheel to allow for freer reving?

 

I realise there are a few usability and economy downsides to doing this but for a car that wasn't a daily drive these would can largely be ignored...

[TDIPLC]

Random thought for the week...

 

In theory, as long as you had a trick enough ECU, could you remove the mass of my flywheel to allow for freer reving?

 

I realise there are a few usability and economy downsides to doing this but for a car that wasn't a daily drive these would can largely be ignored...

 

Certainly, a lower mass flywheel will enable the engine to respond faster to inputs. The net effect will be faster engine acceleration and deceleration. The potential downside could be an overly sensive engine that becomes more difficult to drive in traffic.

 

Personally I would choose a well developed flywheel such as Toda Racing which works very well

[jon]

I'm just thinking out loud. I've got to get the gearbox off the track car at some point to fit a 1.5 kaaz diff, thought I'd make a flywheel mod too. Not for performance per se, more just to see if it can be done.

 

Driveabilty isn't a concern.

[TDIPLC]

I'm just thinking out loud. I've got to get the gearbox off the track car at some point to fit a 1.5 kaaz diff, thought I'd make a flywheel mod too. Not for performance per se, more just to see if it can be done.

 

Driveabilty isn't a concern.

 

The Toda flywheel is certainly worthy of your consideration. It's very strong too

[jon]

I'm fairly sure my car already has what people would call a lightened flywheel, so unless the toda unit is made out of a combination of tin foil and butter it probably won't do what I want it to

[Sam@TDi]

The Toda Racing flywheel for the 3S-GTE is 0.46 of the inertia of the standard, weighing in at just 4.5kg

 

Ultimately it's worth remembering that engines have flywheels for a reason and reducing the flywheels effect more than is necessary can be counter productive. What problem are you trying to solve? or what characteristic are you trying to improve?

[jon]

I guess this is more a learning thread than anything else. What problems would there be with an extremely light flywheel?

 

As you've probably already guessed, this has been spurred on by hearing a friends Gallardo blipping, the speed at which it jumps up and down the rev range is fantastic. I'm not discussing replicating it on a 3SGTE for any reason other than "can it be done, and what are the drawbacks."

[Sam@TDi]

Ok cool, well the rev up on your engine will never be as sharp as the Gallardo for a number of reasons.

 

Static compression ratio is much lower on the 3s-gte and the engine relies on elevated intake manifold pressures to recover from and over come this deficit, but being a turbocharged set-up it's unlikely you'll make any meaningful manifold pressure whilst quickly revving the car. Turbo cars traditionally are fitted with heavier flywheels than their N/A counterparts because of the lack of low engine speed torque

 

The Gallardo engine is physically a much larger unit and so will be simply able to apply more torque to the crankshaft at low engine speed.

 

Because the Gallardo engine has 10cylinders each firing once per cycle the supply of torque to the crankshaft is far smoother and more continuous than a 4 cylinder engine, this reduces the need for a flywheel with much inertia which in effect enables the engine to maintain a low speed idle with a light flywheel

 

If you use an overly light flywheel on your 3s-gte the idle will need to be high in order to be stable and the low speed operation whilst drive is engaged will feel quite week, and then as more throttle is applied the corresponding torque rise might feel more abrupt or "jerky"

 

hope that helps

[jon]

Thanks Sam, pretty much what I was assuming but as always, you can put it extremely gracefully

 

Have a good weekend mate