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f4r torque ceiling
- Thread starter MarkM
- Start date
Torque is related to power? There is no ceiling....
The extra power you get from say 195bhp to 225bhp will generally be made with some pretty major mods and the power most likely comes in 1K further up the rev range. Since torque relates to power and engine speed, this is why it appears not to increase as much.
There are some very good sites that explain everything to do with this, I'm sure someone will remember them.....
The extra power you get from say 195bhp to 225bhp will generally be made with some pretty major mods and the power most likely comes in 1K further up the rev range. Since torque relates to power and engine speed, this is why it appears not to increase as much.
There are some very good sites that explain everything to do with this, I'm sure someone will remember them.....
Tom_16v said:
Yes I know what you mean bhp is based on engine speed in some way (not sure how though)
I am talking about peak torque really. A good example of this is my car vs. yozzas
torque
yozza = 175@5600, mine= 177@5500
power
yozza = 225@7150, mine 205@6500
Yozzas engine maintains better torque then mine at higher revs which is why he gets bigger bhp, I assume. But both engines have similar peak torque. I have not seen a bigger peak torque figure then 183 (rmcardel). Which is my question really is the engine at its limit for peak torque and all you can really push is the bhp figure.
Apparently:
Ben's AWT Cat Cams produce around about 180 ft/lb +/- 5 ft/lb from what I have seen / been told.
The ones that we have used - Shrick Vs 2 - 170 - 175 ft/lb
If you went to solid lifters you should be able to get even more power & torque, but you have to use the Super 1600 lifters which cost £2600 for a set (thats what I was quoted anyhow)
I would say with the standard lifters your maximum would be 190 ft/lb but with even wilder cams than the ones that Ben has had made up.
I don't know what torque the pipers produce after their re-workings.
/y0z
Ben's AWT Cat Cams produce around about 180 ft/lb +/- 5 ft/lb from what I have seen / been told.
The ones that we have used - Shrick Vs 2 - 170 - 175 ft/lb
If you went to solid lifters you should be able to get even more power & torque, but you have to use the Super 1600 lifters which cost £2600 for a set (thats what I was quoted anyhow)
I would say with the standard lifters your maximum would be 190 ft/lb but with even wilder cams than the ones that Ben has had made up.
I don't know what torque the pipers produce after their re-workings.
/y0z
Novidem makes a supercharger kit for the Clio.
Fitted for 7500 euros.
http://www.novidem.ch/
242 bhp / 173 lbs
http://perso.wanadoo.fr/olin/IMAGES/novidem.jpg
Peak torque is not very impressive. I don't have any curve for this.
Fitted for 7500 euros.
http://www.novidem.ch/
242 bhp / 173 lbs
http://perso.wanadoo.fr/olin/IMAGES/novidem.jpg
Peak torque is not very impressive. I don't have any curve for this.
Time for a rant guys, i've had a really bad day with everybody i know seemingly talking some other language to me, dont ask me why......but i have spent the day confused as hell asto why today seems to be so out of whack. Not this thread per say, but the off tangent nature just prompted me.
Torque is the straight forward torsional force applied to a point at the suggested distance from the centre. So, 1lb.ft torque would be the same as hanging 1lb weight from a 1 foot stick.
Torque in an engine isnt capped, it is the result of the force implied from the burn on the piston, through the mechanical leverage of the conrod onto the crank. So, if you change any factors you will change the torque.
You can alter the force on the piston by changing the amount of pressure within the cylinder, as it isnt the burn which generates the force, but the resultant rise in pressure after it. So, in laymans, if you make the pressure higher by increasing the amount of air and fuel you can fit in the cylinder at any single rpm point, then you will increase torque. Turbos do this artificially, which is why they can make more torque (thus power) at the same rpm levels with the same capacity cylinders.
However, the amount of air you can squeeze in, reffered to as volumetric efficiency, is affected by the efficiency of the engine system itself. And this is what 'tuning' or modifying an engine is all about. We are only trying to increase the VE. We use camshafts that hold the valves open longer, we design induction systems which provide less restriction, more efficient cylinder heads, exhaust systems etc.
But each time we modify one area and increase torque, it will result in a decrease in torque at another point (once we go over a certain level from std). This is because we are trying to increase bhp, and to do that we have to increase the efficiency of the engine at higher rpm's, or rather its ability to hold VE at higher rpm's, but this will decrease efficiency at lower rpm's primarily due to the camshafts design having increased overlap between inlet and exhaust valves, which allows the fresh charge to blow straight through the cylinder.
Ok, this is going absolutely nowhere and i'm makiing zero sense.
In total rant form.
bhp = workdone = force*distance = torque. Increase torque you increase VE. Increase VE = increased system efficiency = increased valve off seat time = longer duration higer lift cams = use of natural phenomenons like inertial ramming from high velocity intake flow, pulse tuning from induction and exhaust lengths = loss of lower rpm efficiency = then torque can be affected by igniton timing factors, which then depend of r/s ratios as to where you want peak pressure to occur after TDC, which then depends on how fact you can get the burn to happen, which depends on det sensitivity, which depends on piston and chamber design, which depends on how well you can manipulate an engines design characteristics. Then going back to rod/stroke ratio you can affect the amount of torque you get from exactly the same burn time and force. Then you have static and dynamic CR's come into affect, which then depends on what engine system your running.
basically you have asked a never ending question........you've asked how to tune an engine.
Torque isnt capped, it all depends on how much you can afford to change within the engine. The limit its currently 'at' is only because nobody has spent more to actually change anything within the engine subtantially and made use of those changes.
What you want to be looking at is area under the graph, peak bhp and even torque numbers mean zilch.
People have written books on the question you asked lol and still not answered it all.......infact, the question will never be answered in full, by anyone!
Torque is the straight forward torsional force applied to a point at the suggested distance from the centre. So, 1lb.ft torque would be the same as hanging 1lb weight from a 1 foot stick.
Torque in an engine isnt capped, it is the result of the force implied from the burn on the piston, through the mechanical leverage of the conrod onto the crank. So, if you change any factors you will change the torque.
You can alter the force on the piston by changing the amount of pressure within the cylinder, as it isnt the burn which generates the force, but the resultant rise in pressure after it. So, in laymans, if you make the pressure higher by increasing the amount of air and fuel you can fit in the cylinder at any single rpm point, then you will increase torque. Turbos do this artificially, which is why they can make more torque (thus power) at the same rpm levels with the same capacity cylinders.
However, the amount of air you can squeeze in, reffered to as volumetric efficiency, is affected by the efficiency of the engine system itself. And this is what 'tuning' or modifying an engine is all about. We are only trying to increase the VE. We use camshafts that hold the valves open longer, we design induction systems which provide less restriction, more efficient cylinder heads, exhaust systems etc.
But each time we modify one area and increase torque, it will result in a decrease in torque at another point (once we go over a certain level from std). This is because we are trying to increase bhp, and to do that we have to increase the efficiency of the engine at higher rpm's, or rather its ability to hold VE at higher rpm's, but this will decrease efficiency at lower rpm's primarily due to the camshafts design having increased overlap between inlet and exhaust valves, which allows the fresh charge to blow straight through the cylinder.
Ok, this is going absolutely nowhere and i'm makiing zero sense.
In total rant form.
bhp = workdone = force*distance = torque. Increase torque you increase VE. Increase VE = increased system efficiency = increased valve off seat time = longer duration higer lift cams = use of natural phenomenons like inertial ramming from high velocity intake flow, pulse tuning from induction and exhaust lengths = loss of lower rpm efficiency = then torque can be affected by igniton timing factors, which then depend of r/s ratios as to where you want peak pressure to occur after TDC, which then depends on how fact you can get the burn to happen, which depends on det sensitivity, which depends on piston and chamber design, which depends on how well you can manipulate an engines design characteristics. Then going back to rod/stroke ratio you can affect the amount of torque you get from exactly the same burn time and force. Then you have static and dynamic CR's come into affect, which then depends on what engine system your running.
basically you have asked a never ending question........you've asked how to tune an engine.
Torque isnt capped, it all depends on how much you can afford to change within the engine. The limit its currently 'at' is only because nobody has spent more to actually change anything within the engine subtantially and made use of those changes.
What you want to be looking at is area under the graph, peak bhp and even torque numbers mean zilch.
People have written books on the question you asked lol and still not answered it all.......infact, the question will never be answered in full, by anyone!
For any given displacement torque depends on how efficiently an engine can inhale air, how efficiently it can burn it, and how little of the resultant force it wastes.
Power is simply torque times revs.
So you can get more power by optimising your engine to produce power at a higher revs. That's what a hot cam or a different exhaust manifold does.
But to produce more torque you have to improve your engines inherent efficiency. That's a lot harder. You can do it by upping the compression ratio. But that's limited by the octane rating of the fuel. And modern engines like the F4R already have incredibly high compression ratios with knocking managed by the engine computer. You can't change the basic geometry of the engine or the frictional losses. You could look at all the factors that determine how much air it can inhale and optimise them all at some specific number of rpms. But that just means that where all the varies peaks occured at different speeds and gave various boosts to the torque peak at various points, now everything comes together at one point but torque is lower everywhere else.
The 182's 4-2-1 exhaust was a way to get boosts at two different speeds. You could do something like that on the intake side.
Most people don't realise that the size and length of the snorkel - the intake to the air filter - on the intake side is important. They open it up and that gets them a higher peak power figure, but they loose mid-range torque.
Power is simply torque times revs.
So you can get more power by optimising your engine to produce power at a higher revs. That's what a hot cam or a different exhaust manifold does.
But to produce more torque you have to improve your engines inherent efficiency. That's a lot harder. You can do it by upping the compression ratio. But that's limited by the octane rating of the fuel. And modern engines like the F4R already have incredibly high compression ratios with knocking managed by the engine computer. You can't change the basic geometry of the engine or the frictional losses. You could look at all the factors that determine how much air it can inhale and optimise them all at some specific number of rpms. But that just means that where all the varies peaks occured at different speeds and gave various boosts to the torque peak at various points, now everything comes together at one point but torque is lower everywhere else.
The 182's 4-2-1 exhaust was a way to get boosts at two different speeds. You could do something like that on the intake side.
Most people don't realise that the size and length of the snorkel - the intake to the air filter - on the intake side is important. They open it up and that gets them a higher peak power figure, but they loose mid-range torque.
Most people don't realise that the size and length of the snorkel - the intake to the air filter - on the intake side is important. They open it up and that gets them a higher peak power figure, but they loose mid-range torque.[/QUOTE]
cant agree more.... changing this can make large differences
cant agree more.... changing this can make large differences
I love it when he talks technical :evil: lol
Audi A6 (S3 on order)
Just wait and see how much you want the new custom manifold !! 
oh and the exhaust system.
If I swap my inlet cam AGAIN ... you can have the one thats in it, then you just need to order an exhaust cam. Might need an omex to idle though lol
oh and the exhaust system.
If I swap my inlet cam AGAIN ... you can have the one thats in it, then you just need to order an exhaust cam. Might need an omex to idle though
lolGary G said:haha very true.....his inlet manifolds are in hooooge demand and i really want his cams
BenR=Genious?! Takes one to know one hahaha
Audi TT 225
GordonD said:
Can you elaborate on this? Im interested...
What are the factors that effect performance? i.e. would a long pipe be better than a short etc etc.
A typical set up would be throttle body, hose, filter, cold air feed. How does the hose length between the throttle body and filter, and filter to fresh air effect performance?
Its all about the total length from the back of the valve to the face of the crossectional opening to atmosphere. Sound a pressure waves (pulses refered to in pulse tuning) originate from the back of the valve upon opening/closing, travel at the speed of sound up the inlet tract and out to atmosphere, where it is refracted and a negative sign travels back down till it gets to the valve again. The length and design of the whole induction sustem will effect the time it takes and at what rpm point it will correspond with the valve opening again, where the negative wave provides a positive pulse to naturally 'supercharge' that one valve timing event.
Its easier to play with on ITB setups as each cylinder does not interact with the other and you do not have a plenham to deal with, or single ITB and inlet filter arrangement. Multi order pulse tuning is incredibly complex.
So, when you alter the lenth you will move the peaks and trough in the torque band around, but there will always be one point that gains and one that looses out.
yea yea, holiday............
Its easier to play with on ITB setups as each cylinder does not interact with the other and you do not have a plenham to deal with, or single ITB and inlet filter arrangement. Multi order pulse tuning is incredibly complex.
So, when you alter the lenth you will move the peaks and trough in the torque band around, but there will always be one point that gains and one that looses out.
yea yea, holiday............
Audi TT 225
Cool. Reason I asked was to compare the pipercross viper and the k&n typhoon for example.
One uses a sealed filter close to the TB and the other has a large metal pipe that moves the filter down behind the bumper.
But I know you'll just say they'll both make you gain and loose some where in the rev range lol.
One uses a sealed filter close to the TB and the other has a large metal pipe that moves the filter down behind the bumper.
But I know you'll just say they'll both make you gain and loose some where in the rev range lol.
Christopher
ClioSport Club Member
Z4M
Andy GDI said:
fpmsl!!
