13
votes
Does an increase in horsepower allow a greater speed in any given gear?
The answer is no because you mention being limited by your redline. Regardless of power, a certain RPM will result in a certain speed for a given gearing. Chances are the gear ratios were chosen ...
- 13.3k
11
votes
Accepted
Does an increase in horsepower allow a greater speed in any given gear?
Summarized Answer
No, HP does not determine MPH in a gear, the gear ratio does. Although there are hypothetical ways that HP can seem to make the vehicle go faster in the same gear, it doesn't ...
- 3,284
11
votes
Accepted
How do old cars actually lose horsepower?
It depends on a ton of things and it won't be linear in most cases. Every car has different things that wear out at different rates and those things affect horsepower differently as they age. Not ...
- 1,935
10
votes
Accepted
Conversion from kW to HP?
Wikipedia has this nice table:
PS hp kW
1 PS = 1 0.98632 0.735499
1 hp = 1.01387 1 0.74570
1 kW = 1.35962 1....
- 7,047
10
votes
Accepted
Horsepower at wheels calculation
TL;DR
The problem you are encountering is the limited resolution of your speed plus fluctuation plus slightly different approaches to calculate power. And finally, you have to think about the term ...
- 7,047
9
votes
How do you plan an engine build?
bit of a braindump... Hard to get more specific without more specific requirements...
Is this a drag car, track car, street car, daily driver, etc. Basically this will lead you to - where do you ...
- 8,443
8
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Does an increase in horsepower allow a greater speed in any given gear?
Well the simple answer is (as you suspect)... No.
With fixed gearing, you are going to be doing the exact same speed at any given engine RPM with 100bhp or 600bhp.
6
votes
Shouldn't a loss of compression equal a loss of power?
Those numbers do not seem horrible, unless the 140psi is low. You might want to repeat the test with the engine warm. I generally feel that a cold test only reveals inter-cylinder differnces (in ...
- 12.4k
6
votes
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Shouldn't a loss of compression equal a loss of power?
Yes, it does lead to a loss of a power, but your compression is not worth worrying about. Every engine will loose some compression after a few years. New rings wear out faster at the beginning and ...
- 1,448
5
votes
Horsepower at wheels calculation
Two things to watch out for when using these equations
Consistency of units
If your mass is in kg, speed in km/h and acceleration in furlongs per week², you're not going to get power in horsepower. ...
- 39.1k
5
votes
Conversion from kW to HP?
It's like asking why do certain countries drive on the left side of the road and other on the right side?
kW is part of the SI system of units. Horsepower is a legacy from the imperial units system.
...
- 39.1k
5
votes
Work over time; humans versus automobiles
The engine creates those 390 Nm per rotation, and at peak flywheel
torque (≈ 2000 RPM), it rotates about 33 times per second.
Considering work over time, that results to some 110 horsepower.
I ...
- 39.1k
4
votes
Accepted
Which engine type gives more HP- two or four cycle?
Theoretically, with all other factors being equal, the 2 stroke engine should produce 2 times the power of the 4 stroke engine. The reason being that the 2 stroke engine has twice as many power ...
- 12.1k
4
votes
Accepted
Engine specifications for 10.2 liter Chevrolet V8
A Chev 622ci = 10.2l
I found dimensions for a Chev 632 cubic inch =10.3l
Stroke: 4.750"
Rods: 6.635"
Bore: 4.600"
Taken from here: http://www.jegs.com/p/Blueprint-Engines/Blueprint-Pro-Series-Big-...
- 1,552
3
votes
Accepted
Where did the term horsepower originate?
The origin of the word horsepower comes literally from the horse and buggy days. 1 horse pulling a load of 330 lbs of coal or whatever 100 feet above ground in 1 minute generated 1 horsepower.
1 Hp= ...
- 3,917
3
votes
Accepted
Please explain Horsepower and Torque
What you are missing is the concept of rotational speed. This is required to fully understand the relationship between horsepower and torque.
We'll start with the concept of torque. Torque is simply ...
- 456
2
votes
Accepted
How accurate and precise is a dyno and why?
Every dyno is going to read things differently. This is inherent due to several factors, which include, but are not limited to, atmospheric conditions (temp, barometric readings, etc), testing ...
- 153k
2
votes
Conversion from kW to HP?
They are just different units of measurement, kW is metric which is widely adopted in Europe so that is probably why they choose to publish their numbers in this unit.
1 kW is about 1.34 hp, the ...
- 416
2
votes
Work over time; humans versus automobiles
Not sure about the figures quoted already : the cyclist Chris Boardman maintained 450W for an hour see here:
https://books.google.ch/books?id=j3x9AwAAQBAJ&pg=PA73&lpg=PA73&dq=chris+...
- 34.6k
2
votes
Work over time; humans versus automobiles
I believe you have your calculations backwards. @0.5m from center, you'd need to cut the 390 in 1/2 ... down to 195Nm. In reality, the pedal is only about 0.2m from the center, which reduces it down ...
- 153k
2
votes
Does an increase in horsepower allow a greater speed in any given gear?
Let's forget the power for a while. The body of your question shows that you're in fact interested in this: can a custom air intake influence the exact RPMs at which you "redline"? Well... yes, sort ...
- 121
2
votes
Is horsepower determined by the pressure in the combustion chamber?
Cold air intakes increase power by reducing the air intake temperature which gives a higher (greater) density of the air charge : more available air means a better combustion and more power.
- 34.6k
2
votes
Lighten flywheel to increase top speed?
Flywheel weight will not impact the power output of your engine. The mass of flywheel will change the rate of change of speed of the engine:
A heavy flywheel will mean the engine is slow to speed up ...
- 21
1
vote
Is there such thing as horsepower per cylinder?
One can always define such thing, but I have not seen it in theory books and I doubt it could have a good practical use.
There are types of internal combustion engines (e.g. marine-use very high power ...
- 2,022
1
vote
Accepted
CC per HP in a 2-stroke engine?
A quick google search gives:
So, you can work out the power per cc for each and take an average.
You might, of course, need to check out larger engines and see how the performance is affected.
- 34.6k
1
vote
Does an increase in horsepower allow a greater speed in any given gear?
To add to other answers, the only time extra horsepower will increase speed in a given gear is for top gear, as often the maximum speed is where the engine runs out of power to overcome rolling/air ...
- 630
1
vote
Accepted
Work over time; humans versus automobiles
You can create any amount of torque with your bare hands. Just pick a long enough lever. Archimedes famously said: "Give me a place to stand and with a lever I will move the whole world." (source: ...
- 14.5k
1
vote
Is horsepower determined by the pressure in the combustion chamber?
Yes, of course (in theory). An internal combustion engine is a heat engine. That means it just works by combustion of fuel/air mixture which creates heat energy --> the pressure created by the heat ...
- 31
1
vote
How accurate and precise is a dyno and why?
Same day runs of the same car on the same dyno should be the same or very nearly the same (keeping in mind that a cold, a warm and a heat soaked car will all make different horsepower). This is one of ...
- 1,935
1
vote
How accurate and precise is a dyno and why?
The length of a line you measure is only as accurate as the rule you use to measure it with, a similar principal applies here. Essentially a dynamometer works by measuring the acceleration applied to ...
- 416
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