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Oo name calling on the internet. Glad you are mad. Too bad you are still wrong.
You can turn anyone of these engines to 7k rpm and make the same power. The RPM is useful for top speed. Here is an example for you
Tuned this car friday, 2.5L Engine
It spins almost 8000rpm. But look at the MPH: 160MPH. When will he ever use 160mph on the street? Engine will be limiting the RPM to 6500rpm, perhaps 6300rpm for street use, because going over 135MPH on general highway is kind of wreckless IMO.
But you would have him spin to 7500 rpm 160MPH with his daily driver every day in traffic to avoid being an idiot? who is the idiot.
Triggered much? The car has more than one gear ya know. Limiting that motor in the 6000 range is beyond retarded. Build a motor that's done by 6000 if that's where you want to run it. What a waste.
I was hoping you would say that.
This car only has 2 gears, its a powerglide.
In first gear so long as the shift occurs into peak power for 2nd gear it doesn't make any difference what the RPM is even in a racing environment.
It doesn't make sense to spin the engine RPM any higher than needed to generate a peak power shift. Waste of stress.
For other cars, lets say have 5 or 6 gears. Things happening too quickly in first and second gear to build the kind of boost pressure and power needed to attain these figures. The only thing protecting the rod cap with this kind of output:displacement is the exhaust gas pressure, if this engine ran 7k rpm with a 5 or 6 speed transmission in 1st or 2nd gear it would be damaged. The internal forces are too high to be reliable without a linear, smooth onset of power through a gear, and 1st and 2nd gears of such manual 5 or 6 speed transmission are too short to give the kind of smooth onset of torque application necessary to maintain reliability. If an engine was going to spin 7k in such a gear ratio with a short duration it would need very light internal parts to reduce stress, and then it would be like a corvette engine and fragile at significantly higher outputs due to low internal weight by design. There is a give and take with components. Truck engines like 2002 LM7 and 2005 L33 can handle 800 to 1200rwhp because they are using heavy robust internals designed for large stress loading, but these make insane high internal forces at high RPM unsuitable for such high operating speeds, but capable of high power output with reduced RPM say 6000rpm 6500rm, even 7,000rpm is potential if the onset of torque is smooth applied and using a turbine to generate protective exhaust gas pressure for the OEM rod caps. I won't waste my time anymore it is clear you have anchored psychology in this. But others can use this information I am sure.
The bottom line is there is no excuse, rhyme or reason to spin such high RPM for any amount of power if we can make the same power at reduced RPM more reliably in a non-racing environment. Power is power, at 5k 7k the same power is the same acceleration, just reduced engine stress at 5k and enhanced longevity with low RPM. Available to people that know how to get the power and reliability they desire.
The force of inertia is a function of mass times acceleration, and the magnitude of these forces increases as the square of the engine speed. In other words, if you double the engine speed from 3,000 to 6,000 rpm, the forces acting on the piston dont double they quadruple.
I was hoping you would say that.
This car only has 2 gears, its a powerglide.
In first gear so long as the shift occurs into peak power for 2nd gear it doesn't make any difference what the RPM is even in a racing environment.
It doesn't make sense to spin the engine RPM any higher than needed to generate a peak power shift. Waste of stress.
For other cars, lets say have 5 or 6 gears. Things happening too quickly in first and second gear to build the kind of boost pressure and power needed to attain these figures. The only thing protecting the rod cap with this kind of output:displacement is the exhaust gas pressure, if this engine ran 7k rpm with a 5 or 6 speed transmission in 1st or 2nd gear it would be damaged. The internal forces are too high to be reliable without a linear, smooth onset of power through a gear, and 1st and 2nd gears of such manual 5 or 6 speed transmission are too short to give the kind of smooth onset of torque application necessary to maintain reliability. If an engine was going to spin 7k in such a gear ratio with a short duration it would need very light internal parts to reduce stress, and then it would be like a corvette engine and fragile at significantly higher outputs due to low internal weight by design. There is a give and take with components. Truck engines like 2002 LM7 and 2005 L33 can handle 800 to 1200rwhp because they are using heavy robust internals designed for large stress loading, but these make insane high internal forces at high RPM unsuitable for such high operating speeds, but capable of high power output with reduced RPM say 6000rpm 6500rm, even 7,000rpm is potential if the onset of torque is smooth applied and using a turbine to generate protective exhaust gas pressure for the OEM rod caps. I won't waste my time anymore it is clear you have anchored psychology in this. But others can use this information I am sure.
The bottom line is there is no excuse, rhyme or reason to spin such high RPM for any amount of power if we can make the same power at reduced RPM more reliably in a non-racing environment. Power is power, at 5k 7k the same power is the same acceleration, just reduced engine stress at 5k and enhanced longevity with low RPM. Available to people that know how to get the power and reliability they desire.
It isn't worth the risk for daily drivers and reliable vehicles.
We knew since the early days of SBC How much excess stress involved with engine RPM
If you can get what you want at 5k 6k rpm then why spin 7 8 9? Nonsense. Useless.
Generally speaking, if you make, say, 400hp@6,000 rpm, and you really have no big drop, or increase, in power by going to 6,600 rpm, you'd want to go to 6,600 rpm so the upshift would land you, say, at 5,500 rpm, rather than shifting@6,000 rpm, because the engine will be making more power@5,600 rpm than it is@5,000 rpm, i.e., in a meatier part of the powerband. This is obviously in a drag racing situation. My .02......
Generally speaking, if you make, say, 400hp@6,000 rpm, and you really have no big drop, or increase, in power by going to 6,600 rpm, you'd want to go to 6,600 rpm so the upshift would land you, say, at 5,500 rpm, rather than shifting@6,000 rpm, because the engine will be making more power@5,600 rpm than it is@5,000 rpm, i.e., in a meatier part of the powerband. This is obviously in a drag racing situation. My .02......
You're absolutely correct. You're also wasting your time.
Generally speaking, if you make, say, 400hp@6,000 rpm, and you really have no big drop, or increase, in power by going to 6,600 rpm, you'd want to go to 6,600 rpm so the upshift would land you, say, at 5,500 rpm, rather than shifting@6,000 rpm, because the engine will be making more power@5,600 rpm than it is@5,000 rpm, i.e., in a meatier part of the powerband. This is obviously in a drag racing situation. My .02......
1. If engine make 400hp at 5000rpm, and 400hp at 6000rpm, and you shift at 6000rpm back to 5k, you still have 400hp, doesn't make sense to run to 6600+ right?
Some types of racing put you in strange gear ratio situations where extra RPM is desirable. But again see #2
2. Obviously if you are racing for some competition, money, goal, trophy, etc... you run the engine to the brink of madness. I did make a very clear statement that for NON RACING Situations, you would not surpass some sane limitation for engine RPM- why make all the extra stress and risk for non racing situations?
Agree. All that Atari dude does is come on here to argue with people.
The point of the forum for me is to have a discussion. If everybody always agree then what is the point? You just circle jerk and press like on each other's male posts.
Sorry but I don't want males to press like on my post. I want them to think, use your brain, be critical thinking and disagree with me. That is the scientific community, disagreement. I research and publish paper and starkly controversial arguments based on data, scientists love it.
I will never agree anything if I Can see some way outside the box. If you say you like red I will argue blue. If you like blue I will argue red. I always take the other side unless the issue is as clear as a blue sky and there can be only 1 outcome.
The worst thing about the internet is copy cat behavior. It becomes a popularity contest and people will jam together on a popular outcome without understanding what is really underlying cause. It is easy to copy somebody else or buy a product that makes ridiculous claims without thinking for yourself. Too bad that is the most common thing to use the internet for
1. If engine make 400hp at 5000rpm, and 400hp at 6000rpm, and you shift at 6000rpm back to 5k, you still have 400hp, doesn't make sense to run to 6600+ right?
Some types of racing put you in strange gear ratio situations where extra RPM is desirable. But again see #2
2. Obviously if you are racing for some competition, money, goal, trophy, etc... you run the engine to the brink of madness. I did make a very clear statement that for NON RACING Situations, you would not surpass some sane limitation for engine RPM- why make all the extra stress and risk for non racing situations?
If an engine makes the same 400hp at 5000rpm as it does 6000rpm....fire your mechanic and start over.
If an engine makes the same 400hp at 5000rpm as it does 6000rpm....fire your mechanic and start over.
Every turbocharged engine setup for street use has a completely flat power line from the onset of boost to redline. This is the definable, quality feature of a correctly setup cam and head configuration for a street vehicle such that no matter when you stab the throttle it will produce the exact same amount of power no matter what the gear ratio or vehicle speed is- since all street vehicles will start from various speeds at random this is ideal.
Its always a flat line
Nice and flat is perfection of the setup calculation come to fruition
The cam creates what we called a VE arc or hill at some point when the camshaft is static. If the cam creates the concave such that the derivative is zero in the center of the power curve, the power will be flat. If we choose a 'race' cam config the VE arc will put the derivative of zero near the redline and the power will increase sharply as the engine redline, like this 2.6L with VE arc at redline
But that is not a sufficiently street setup, not a 'fun' car as it would be with the arc in the center and a flat power curve.
Its a personal preference but I never go the the racing configuration unless the vehicle is specifically for racing.
Because Like I've been trying to say this entire time- having to redline the ******* thing every single time you leave a stoplight is tiring both to the driver and the engine, it will wear out rapidly on the street, and becomes difficult to control properly from every different road conditions and situations, and choosing the perfect gear ratio all the time to hit that perfect peak - ah! But what a disaster to have for a street car setup.
Every turbocharged engine setup for street use has a completely flat power line from the onset of boost to redline. This is the definable, quality feature of a correctly setup cam and head configuration for a street vehicle such that no matter when you stab the throttle it will produce the exact same amount of power no matter what the gear ratio or vehicle speed is- since all street vehicles will start from various speeds at random this is ideal.
Its always a flat line
Nice and flat is perfection of the setup calculation come to fruition
The cam creates what we called a VE arc or hill at some point when the camshaft is static. If the cam creates the concave such that the derivative is zero in the center of the power curve, the power will be flat. If we choose a 'race' cam config the VE arc will put the derivative of zero near the redline and the power will increase sharply as the engine redline, like this 2.6L with VE arc at redline
But that is not a sufficiently street setup, not a 'fun' car as it would be with the arc in the center and a flat power curve.
Its a personal preference but I never go the the racing configuration unless the vehicle is specifically for racing.
Because Like I've been trying to say this entire time- having to redline the ******* thing every single time you leave a stoplight is tiring both to the driver and the engine, it will wear out rapidly on the street, and becomes difficult to control properly from every different road conditions and situations, and choosing the perfect gear ratio all the time to hit that perfect peak - ah! But what a disaster to have for a street car setup.
