- The U.S
O wow I never thought the mustang was a 5 gear. I thought it was just stuck. Like the viper concept, it cant touch gear 6 even if it depended on its life.
The HP is not just representative of the torque but also the engine speed, when the torque falls the HP still rises because of the engine speed (rpm) HP IS torque x RPM / 5252, so the more RPM the more HP as well as the more torque at a given RPM the more HP. SO as you will notice looking at power grafs is that even after the torque begines to fall, the hp still rises well after becase of the incresing engine speed.
Unfortunatly your statement is verry wrong
Car 1 and car 2 will make EXACTLY the same amount of hp. Becase they make the same amount of torque at the same engine speed, increase the engine speed and still the same amount of torque is being increased at the same rate.
500hp at 5500rpm means that the car has aproximatly 477 ft-lb at 7000 rpm. BOTH cars will make the same power and that would be 635hp. WHY? because they are using the same amount of torque at the same engine speed.
Large displacement turbo deisel trucks dont get the engine up to the same speed. The larger the piston, the stronger the stress on the rotating assembly (larger heavier pistongs generate more stress, because of the greater mass) the engine speed is not as high as lower displacement engines (9000rpm in some honda 4 bangers) So the Big Deisels will usually rev to low peek rpm's, reaching peek torque and not streatching it too far. That's why they make HUGE torque but low Hp. They get that torque from high displacement and with the turbo pumping serious boost (deisel uses compression to ignight the fuel instead of spark plugs) hp is simply a representation of the cars power (torque) put to use with engine speed. Truck are work horses, and need large torque to move heavy loads, but they are not for driving fast etc, and dont need high HP.
V8's in Cars also dont rev as high as some 4 bangers (remember 9000rpm 4 bangers)
For example, the Mustang GT's V8 doesnt even get close to 7000rpm, it only hits 5750rpm, thats more like a V8. Its larger displacement makes 319 ft-lb of torque peeking at 4500 rpm, however the hp still climes until the peak of 5750 rpm (because of the increasing engie speed) IF the Stang could keep the engine speed rising to 7000 rpm it would make 425hp instead of 295hp
Please you are arguing with the wrong person I am very aware that HP is a product of torque and RPM. After torque has fallen off bhp does not always continue to rise, as this is still very dependent on how sharply the torque falls away as revs continue to rise. I have a catalogue of BHP graphs where you will find many instances where also at some point power will tail off.
Wrong wrong wrong.
A 500 bhp car producing it's peak BHP @ 5500rpm does indeed make 477 ft/lb of torque @ 5500rpm.
I never for one second said that both engines also make 625bhp at 7000rpm in which case yes both would be making 477t/lb also.
I clearly stated that both imaginary engines produced 500 (peak) bhp @ 5500rpm. both engines continued to rev after making peak power both with different results. engine 1 produced 350bhp @ 7000rpm while engine 2 produced 450bhp @ 7000rpm.
Dude Do some of the math
Engine 1 := 500bhp @ 5500rpm and 477ft/lb @ 5500rpm - and 350bhp @ 7000rpm would be producing 262ft/lb at 7000rpm.
Engine 2:= 500bhp @ 5500rpm and 477ft/lb @ 5500rpm - and 450bhp @7000rpm would be producing 337 ft/lb @ 7000rpm.
In my original post I did not want to get too technical, but still my original example of a power/torque curve is mathamatically correct as you can work out BHP from torque and torque from Power
(Torque x Engine speed) / 5,252 = Horsepower
(Power / Engine speed) x 5,252 = Torque
You are getting confused, you simply can't take the peak torque figure of an engine and use this figure wherever you like in the rev range.
Because an engine has 500bhp @ 5500rpm and 477ft/lb @ 5500rpm does not mean if we could magically make it rev to 7000rpm it would make 635bhp. It would only make 635 bhp at 7000rpm if the motor produced 477ft/lb at 7000rpm but my imaginary engines did not produce this torque figure @ 7000rpm! The engines in my example made 262 ft/lb and 350bhp @ 7000rpm and 337ft/lb and 450bhp @ 7000rpm and both still had 500bhp @ 5500rpm.
You also forgot to mention the bore and stroke which is quite important. Slow reving engines with big pistons often have a long stroke giving better leverage and thus more torque for every given stroke. Longer stroking pistons travel a greater distance in any one stroke of the engine vs a piston of the same size with a shorter stroke. Having a big piston does not always limit how fast it can spin. My motorcycle pistons are 500cc each, not exactly small but my motor can still spin @ 10750rpm. The reason for this is that the pistons travel a very short stroke as the motor is a 'short stoke motor'.
Wrong again, if the stang could produce 319ft/lb @ 7000rpm then it would have 425bhp @ 7000rpm.
IF the Stang could keep the engine speed rising to 7000 rpm it would make 425hp instead of 295hp...
Simply being able to rev to a certain rpm does not magically procude power. You first need to be able to produce torque @ any specific rpm before you can have BHP. The Stang would need to simply continue making torque as it revs to 7000rpm.
So if he called them 2 hypothetical engines it would be ok?
PLEASE somebody show me an American V8 that makes 477ft-lb @ 5500rpm then keeps reving to 7000rpm.
The LS7 is a 7,011 cc (7.011 L; 427.8 cu in) engine, based on the Gen IV architecture. The block is changed, with sleeved pistons and a larger 4.125 in (104.8 mm) bore and longer 4.00 in (101.6 mm) stroke than the LS2. The small-block's 4.4 in (111.8 mm) bore spacing is retained, requiring pressed-in cylinder liners. The crankshaft and main bearing caps are forged steel for durability, the connecting rods are forged titanium, and the pistons are hypereutectic. The two-valve arrangement is retained, though the titanium intake valves by Del West have grown to 2.20 in (55.9 mm) and sodium-filled exhaust valves are up to 1.61 in (40.9 mm).
Peak output is 505 hp (377 kW) at 6300 rpm and 470 lb·ft (640 N·m) at 4800 rpm with a 7000 rpm redline During GM's reliability testing of this engine in its prototype phase, the LS7 was remarked to have been repeatedly tested to be 8000 rpm capable, although power was not made at that rpm level, due to the constraints of the camshaft's profile and the intake manifold ability to flow required air at that engine speed.
If you can show me ONE we can keep this up, but you cant because it doesnt exist, let along a second engine having all the same but making 100hp difference @ 7000rpm for no aparent reasonreason.
THanks, this is great
So its only 470 and not 477 and it comes 700rpm earlier. But its pretty damn close. I am sure some good ol'boys could get it to 477 at 5500.
The LS9 engine (in the Corvette ZR1 that is in the game) has the torque, but I think it only goes to 6500 rpm.
Just to keep this going a little longer...
How about 2 engines that both make 200hp at 5250 rpm. The first engine is tuned to just barely make it to 7000 rpm and is way down on hp by then. The second engine is a high revving engine that is still making better power at 7000 rpm. In this case two engines could have the large difference in power at 7000 rpm. These two engines would most likely not have the same peak power and it would not occur at the same rpm.
Here is where I have a problem (no biggie)
If they both make the same torque at the same RPM, then its safe to assume that they are identical, inorder for one of the 2 to have a different tune, YET still make the same tq at the same rpm, then there is aditional tech that allows it to do so, I would assume there is a variable valve timing system on the engine that allows the engine to make the extra power (pertinant detail) Even still the gap wouldnt be 100hp over a 1500rpm gap.
For example the Integra LS engine vs the same engine using V-tec. The second cam profile of the v-tec cams would alow a increase of air flow that the normal LS doesnt have giving it the ability to keep making power after the non V-tec engine has crapped out.
I was thinking of 2 very different engines. Like a big American V8 vs. a racing engine. Lets say a small block chevy vs. a F1 engine. Both could make the same torque at the same rpm, but the peak torque would be different, and at different rpm and the rev range would be different. At 7000 rpm they could have a huge difference in horsepower.
But we can go both directions and compare 2 similar engines & 2 very different engines.
however lets use 2 engines that are in GTPSP
What I don't like about using an F1 engine, is that its built to last one race and one race only. In a perfect world, the F1 engine would blow right after crossing the finish line, meaning they extracted every bit of performance out of the engine inside the regulations, limit of the engine, & duration of the race. While engines in street cars are built to last a lil longer.
They are only allowed 8 engines all season, so its 2.375 races per engine. And those engines have to be used for practice and qualifying too.
But I see your point.
(this is a good reason why a lot of these cars are limited productions) Its about prestige, and an adaptation of the old saying from NASCAR "Race on Sunday, Sell on Monday".
Oops. You've kind of shot yourself in the foot there. First of all, I don't know how much gold there is in the engine bay of a McLaren (not McLauren) F1. But if various sources on the internet are to be believed, there are 25 grammes. The cost of this gold in 1992, the year the F1 was released? Somewhere in the region of $300. Hardly a huge chunk of the almost $1 million price tag.
Secondly, the gold wasn't there to 'dissipate the heat', it was there to reflect the heat away from the expensive carbon fibre bodywork.
If you're going to ridicule other people's information, it's probably best to get your own house in order first. Glass houses and all that...
Wow, such a shining wit. Look up 'spoonerism' while you're using an online dictionary for those words you find difficult.
Come on guys, I don't think anyone (including yourselves) enjoys this argument very much. Let's try to get the thread back on track ok?
Interesting stuff about the overdrive gearing, seems I had some misconceptions about those.
How about Show me 2 REAL engines that, have the same amount of torque, reach the peek torque level at the same rpm, on top of rev'ing to the same max, but produce 100hp difference.
As I suspected. I never thought dodge would do it too.