improving power to torque ratio.

[Oedipus Rex]

I\'m not too happy with my power to torque ratio. I\'m running about 350 at the fly, maybe a bit higher, but my torque peaks around 240-250lbs. Is there any way to increase the power to torque ratio on a car?

[MikeLMR]

Power and torque are directly linked, power is calculated from the Torque multiplied by the angular velocity in Radians per second.

It all stems back to basic physics with workdone being a function of  force, distance and time.

so its the same steps you will take to raise the hp in that section of the curve that will net you more torque low down.

so unless you are god and able to change the laws of physics you can\'t change the torque to power ratio

[Oedipus Rex]

Originally posted by MikeLMR
Power and torque are directly linked, power is calculated from the Torque multiplied by the angular velocity in Radians per second.

It all stems back to basic physics with workdone being a function of  force, distance and time.

so its the same steps you will take to raise the hp in that section of the curve that will net you more torque low down.

so unless you are god and able to change the laws of physics you can\'t change the torque to power ratio

yeah I realise this but you will see two cars (two FD\'s even) with the same power output but totally different torque outputs.

What I want to know is why?

[MikeLMR]

suppose its all down to how well the turbocharger and engine work together. Also a ported engine will make more power off boost and will also spool a turbo  quicker vs an unported engine etc. etc. it really is very difficult to put an exact reason on it.

[Oedipus Rex]

Originally posted by MikeLMR
suppose its all down to how well the turbocharger and engine work together. Also a ported engine will make more power off boost and will also spool a turbo  quicker vs an unported engine etc. etc. it really is very difficult to put an exact reason on it.

OK so at that point I have to conclude that I can increase my torque without increasing my top end power output. For instance If I can get my turbo up to pressure quicker I will see an increase in torque but probably not in the top end of my power, as at the top torque tails off bu power continues to rise.. So how about porting the wastegate?

[MikeLMR]

the wastegate should not be open until you hit your boost limit. So porting it will make no difference at all as it is only there to control the boost by bypassing the turbine.

Theres far too many variables to give a concise answer ... you may get more low down torque with a better map ? who knows ?

[MikeLMR]

also the torque peaking and then falling off towards the red line is normal, I think its all to do with getting the mixture in and out in an ever decreasing amount of time (I *think*) + even on a turbocharged engine it will have a peak where the inlet and exhaust harmonics work best to fill the chambers. The reason you still make power while the torque drops is because your engine is delivering less force but in a much shorter space of time so the power rises as long as the torqe doesn\'t drop faster than the rpm\'s rise.

I\'m sure lots of other factors affect it too. I\'m a little out of my depth when it comes to this stuff ...

[Warthog]

What "out of your depth" that was great to read, thank you:)
Now why do you loose torque when you fit a lightened fly wheel but make revs faster?:wave

[MikeLMR]

you don\'t loose torque you loose momentum on the engine side of the drivetrain which makes engaging the clutch more interesting as the engine will decelerate quicker if you don\'t get it right.

I am definetly out of my depth I can remember some of the facts but tend to fill in the blanks using common sense ... works some of the time ... but not always :o

I like things that you can take back to first principals and work out that way. its suprising what you can make sense of if you think of it that way.

[Warthog]

Now you have lost meeeeeeeeeeeeeeeeeeeeeee:confused:

[MikeLMR]

its difficult to explain but the flywheel does not consume energy (we are talking text book theory world here ... don\'t want to get really complicated!) it just stores it. The lighter the flywheel the less \'capacity\' it has for storing that energy.

so the reason an engine accelerates quicker with a light flywheel is the flywheel is storing less energy so the engine will have more energy to accelerate other things and itself.

[Warthog]

Well that hit the spot. You do have a way with words, very good, thank you. Do you teach or is it a natural gift.:burnout :3gears-lh :3gears-lh :3gears-rh

[Oedipus Rex]

Originally posted by MikeLMR
also the torque peaking and then falling off towards the red line is normal,

Yeah I realise that, that was kinda my point.

The fact that BHP keeps increasing, to the redline but torque falls, surely means I should be able to get an increase in torque by increasing the speed in which the power is delivered, but not necessarily increase the actual top end power of the car. Therefore giving me more torque but not more power.

[MikeLMR]

Well that hit the spot. You do have a way with words, very good, thank you. Do you teach or is it a natural gift

LoL no
 I am more likely to be the one being taught than teaching ... just signed up for an engineering degree (or will have once I fill out the forms)

[MikeLMR]

Originally posted by Oedipus Rex
Yeah I realise that, that was kinda my point.

The fact that BHP keeps increasing, to the redline but torque falls, surely means I should be able to get an increase in torque by increasing the speed in which the power is delivered, but not necessarily increase the actual top end power of the car. Therefore giving me more torque but not more power.

yes if you improve the efficiency lower down but not at the redline you can change the low down torque and power but not alter the peak. so it is possible.