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0
votes
1answer
39 views

Who decides Idle engine rpm and how? [duplicate]

I was just searching for an answer to find how the idle speed of an engine is decided and who makes that decision. Is it the engine designer alone or is it based on the inputs from all the vehicle ...
1
vote
1answer
30 views

How to measure torque statically?

I am familiar with the concept of torque wrench. However, with a torque wrench, one can only apply a desired amount of torque. Is there a way to measure how much torque has been applied to a certain ...
6
votes
4answers
249 views

How to measure angle when ratcheting a bolt?

The torque spec for my Tacoma says that cylinder head bolts should be torqued (in a specific sequence) to 27 ft/lbs initially and then again each should be turned another 180 degrees in the same ...
6
votes
3answers
356 views

Torque curve on modern turbo-charged petrol engines

How can modern turbo-charged petrol engines have such constant torque plateaus over a broad rpm range. Does the mathematical relationship between torque and power still hold here? This looks totally ...
5
votes
4answers
674 views

Why does the power output peak and then drop as engine speed increases?

I have been looking at the power bands for my car (2000 Opel Agila 1.2) recently, as I want to work out when it is best to change gear and stuff, as I have no life! This is the approximate graph I ...
6
votes
1answer
86 views

Torque spec variance with Anti-Seize

I see a lot of variances with torque specs when a fastener is lubed with anti-seize. Some places say 25% less torque is required for same clamping load, some places say 40% less is required. I'm ...
4
votes
1answer
82 views

Could 1.9 Nm be enough to accelerate 130kg electric go-kart?

I'll apologize in advance for a fuzzy question. My problem consists of two parts. For starters, I'm trying to buy a DC engine for learning purposes and most of them only specifies the watt (which I ...
3
votes
1answer
54 views

What is the general rule, if one exists, for determining the difference between crank horsepower and wheel horsepower?

If a vehicle has a known crank or wheel horsepower rating, is there a method that can reasonably estimate what the other horsepower value should be? If so, what is that method? For example, if a ...
1
vote
1answer
95 views

Engine torque throughput curve is flat or wavy in low gears between 2000 and 4000 rpm

As the title says BMW's (93 E34 525i M50B25TU) engine misbehaves in low gears, namely in 1st and 2nd, most of the time when the engine is cold but sometimes even when it is properly warmed up. The ...
5
votes
5answers
73k views

What is the meaning of BHP and torque in bikes or cars?

BHP = Brake horse power. It says that it is brake horse power but it is generally relates with high pick up (your bikes reaches top speed in lesser time). So what does this actually mean?. Torque = ...
0
votes
2answers
444 views

Torque and engine power [duplicate]

What is the relation between Torque and engine power? Just wanted to know how power is distributed to wheels in a car.
6
votes
3answers
3k views

Aligning a castle nut with a torque spec to a cotter pin hole

The nuts at the knuckle on my outer tie rod ends are castle nuts, which are locked by cotter pins fed through holes in the studs. The nuts also have a torque spec (27.0±2.5 N∙m, in this case). If I ...
4
votes
1answer
260 views

What is the difference between an automatic torque wrench and a click wrench?

What is the difference between an automatic torque wrench and a click torque wrench? Right now the 1/2inch torque wrench I use on my Jeep is a really cheep one I bought on amazon and it clicks when ...
4
votes
2answers
145 views

If I were to convert a gas powered automobile to an electric car, would a difference in specs possibly damage the car?

I would like to convert a Mazda Miata into an electric car, I plan to remove the engine and the gearbox, and have the car be a direct drive. The motor I intend to use has twice the torque of a ...
5
votes
3answers
3k views

Does accelerating faster worsen fuel efficiency?

I've often heard that accelerating harder makes for bad fuel efficiency, but have yet to be given a sound explanation of why. Naturally this makes me question this advice. Now obviously when you ...
0
votes
2answers
146 views

Does torque decrease mathematically?

There are 2 cars, car A and car B. Car B is 20% heavier than car A. We all know that this means that these 2 cars will have same power if car B at the same RPM (revolution) has 20% more Nm. Can the ...
3
votes
1answer
194 views

Wheel re-torqueing, how is it done?

When putting wheels back on a car, you place them on and torque them to spec. Now, most if not all manufacturers say to re-torque them after 50 miles. What is the procedure for this? Do you just ...
6
votes
2answers
737 views

Do I need to lift my car up before adjusting lug nut torque?

I recently put new wheels on my car. I don't have off-street parking, much less a garage to work in, so I had the wheels installed by a mechanic. Since they were installed, they have been driven ...
2
votes
3answers
2k views

What is the torque and sequence for a '99 Jetta Oil Pan?

I have a '99 Jetta TDI (diesel) with a cracked oil pan. I'm looking for the sequence of tightening the bolts and the torque needed for each bolt. I've been doing to google-fu but can't seem to find ...
10
votes
2answers
1k views

Should a mechanical “click” Torque Wrench be set to zero when not in use?

I have a standard click torque wrench. I was told I should set it to zero when not using it in order to keep the accuracy high. Is this true? Secondly, I have not been doing this since I purchased ...
4
votes
2answers
522 views

engine underpowered in idle - what can be done to improve a diesel engine power at low RPM just a bit?

There is an engine which is a bit underpowered when idling, it can not even keep the car moving on a flat road when in gear and idling at 700..800 RPM - see link. What can be done to improve its ...