will a stock flywheel help with torque? ??

[slider4life]

Hi guys probably a stupid question. But i had my car tuned recently goes great had 138rwhp and 160nm torque. But when i skid it it still seems to die so im putting it down to the low torque figure.
My last ae86 made 128rwhp but 280nm torque and it skidded like a champion.
My question is i currently have a light weight fidanza flywheel, if i change this to a heaver stock one will it make enough diffrence and help with tourque?????
Thanks guys.

[Jimmee1990]

Won't help with torque at all, will just help to keep the momentum up.

[slider4life]

And will this help with drifting to keep the revs up mid corner??? Or would it be a waste of time doing this??

[Konakid]

waste of time. Look at your suspension setup and tyre choice? What is different?

[slider4life]

I have bc gold coilovers, cusco sway bars, 40mm rcas, xt130 lcas . Tyres bridgeston re002 all round but im about too swap them out for some shitters on the rear for less grip. Alignment -2.5 camber, 0 toe cant remeber the castor.

[Jip86]

triangles with 50+ psi is what you need on the rear.

[Matt]

http://www.superstreetonline.com/how-to/transmission-drivetrain/impp-1005-lightweight-flywheels-fact-or-fiction/

what at it says here is no it doesn't decrease torque, but more torque would be required to turn the tyres. What diff ratio are u running?

[Hen may possibly be a nut]

Concur with the above, you will not lose torque with a light flywheel. The only time they are a problem when drifting is when clutch kicking. Since there isn't as much weight (or more accurately moment of inertia) in the light flywheel it doesn't have as much of an effect when you drop the clutch again.

Also I am very skeptical of torque figures form dynos. Unless you have tyre diameter, gear ratio and diff ratio correct you get crazy figures. Essentially all NA petrol motors make 100NM per litre. Therefore the 160Nm you quote for your current 4AGE sounds reasonable. Unless your last motor was SC or turbo then the 280Nm is purely fictional.

It may be your new motor, which seems to make good power, only has top end, meaning it's a pig and feels slower through most of the range.

[bunki86]

Revs wont drop as fast with a heavier flywheel.

[Hen may possibly be a nut]

^^ While this is correct, if you are concerned about revs dropping while you are foot flat and drifting, than a light or heavy flywheel makes SFA difference. Then it comes down to power vs. grip.

Where you will notice revs dropping faster with a lighter flywheel is when changing gears, double clutching (as opposed to granny shifting of course), turning your engine off, etc. I honestly see know downsides to a light flywheel at all, other than the old clutch kick issue, and the increased likelihood of stalling it when taking off and looking like a gumby.

[Frak]

Also I am very skeptical of torque figures form dynos. Unless you have tyre diameter, gear ratio and diff ratio correct you get crazy figures. Essentially all NA petrol motors make 100NM per litre. Therefore the 160Nm you quote for your current 4AGE sounds reasonable. Unless your last motor was SC or turbo then the 280Nm is purely fictional.

.

Why are you sceptical of torque figures from dyno's? They are accurate if you understand what's going on. I operate an engine and chassis dyno on a daily basis. What many don't understand with the chassis dyno, is the torque figure you get will be at the wheels unless the dyno has the facility to work out derived torque(basically torque at engine ignoring gearing).

If an engine is say putting out 100NM and the car has a 1st gear of 3:1 and a diff ratio of 4:1, then the torque TO the wheels(not at the wheels will explain in a second) would be 1200NM, this is where some guys get confused as they think this is what the engine is putting out, it's not.

Now lets say the same engine is now in 4th gear 1:1 then the torque to the wheels is 400NM, a gear box multiplies torque but NOT power.

So they are actually not crazy figures but legit figure.

Now some dyno's will get the kw figure, back work it using an rpm input and give derived torque, which is much closer to engine figure and will not alter regardless of what gear the run is done in.

Now another thing I hear is, do it in this gear or that gear. Now all things being equal, no wheel spin etc etc, regardless of what gear you do it in the power will be the same BUT the torque at the wheels will be different, lower gear, higher torque(because of gear ratio) and higher gear, lower torque BUT the power figure will be the SAME.

The reason is, 1st gear has high torque but low speed, 4th gear has lower torque BUT higher speed, this is basically the relationship, torque and speed.

Now this torque to the wheel figure of for example 1200NM will actually be lower torque AT the wheels as the tyre diam is usually larger than the roller diam so that 'gear ratio' will reduce torque......just like an overdrive gear, so using above engine example a gear box with 0.85 ratio would now have 85NM coming out of gear box and still using that 4:1 diff ratio would now be 340NM. So going from 4th gear to 5th gear would drop the torque from 400NM to 340NM, but remember we had 1200NM in 1st gear.....but lower road speed ;)

So Torque figures on a chassis dyno are legit but you cannot compare torque at the wheels with torque at the engine......derived comes close and is much more accurate but will still be lower than actual engine torque figure but much more realistic..


Now flywheels are a storage device nothing more, nothing less, they do not add torque they do not take it away, what they are designed to do is store energy to keep the engine spinning over smoothly until the next torque pulse. If you have a small capacity engine with a heavy flywheel it will probably operate smoothly at low rpm, now fit the same engine with a very light flywheel, the engine still makes the same torque BUT now at lower rpm it may not have enough inertia to keep the engine turning over smoothly to the next torque pulse so torque fluctuations affect how smooth the engine is. You may find after fitting a light flywheel that the engine is not as smooth at low rpm OR it may not even like operating at lower rpm and you may have to go down one gear to increase the rpm, in fact what you have done is increase the number of torque pulses in that given time frame. Of course all the other benefits quicker revving etc I'm not going into as it's been well documented.

Also I find amusing sometimes when people say things like 'that engine's shit has no torque, or not the torque of a bigger engine', for example, lets say we have 2 engines, one engine (engine A) has 210NM at peak revs to 6500rpm, the other makes engine(engine B) 170NM peak BUT revs to 8500rpm. Now lets say in 4th gear we want both to max out at 200km/h, (using 195/50/15 tyre) engine A would need a 3.5 diff ratio and engine B a 4.3 diff ratio, so engine A would have 735NM TO(not at) the wheels and engine B 730NM, very similar, so you can see what gearing can do to an engine with less torque and we still get the same speed.

[Hen may possibly be a nut]

I agree entirely with your long post Mr Frak. My point was that many people don't know what is going on and will quote at the wheels torque figures from dynos, thinking it relates to the engine. You often see totally unrealistic numbers being spouted, hence my distrust of quoted torque figures.

[slider4life]

4.3 ratio car revs at 4000rpm a 110klmh


http://www.superstreetonline.com/how-to/transmission-drivetrain/impp-1005-lightweight-flywheels-fact-or-fiction/

what at it says here is no it doesn't decrease torque, but more torque would be required to turn the tyres. What diff ratio are u running?