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22
votes
6answers
1k views

When is a cold air intake system beneficial?

Cold air intake must be one of the popular mods there is, and one subject to the most controversy as well. Manufacturers of such systems advertise 5-20 HP gains, yet there are claims that this mod ...
12
votes
5answers
54k views

What does the 'cc' mean on a motorcycle?

I'm relatively new to motorcycles, my flat mate taught me how to drive his two Royal Enfields around New Delhi, and for the past year and a half I've been taking care of them as they break down ;) ...
11
votes
6answers
256 views
+50

What is the difference between torque and horsepower?

A very basic question - what is the difference between torque and horsepower? Its all over Google, but I am really confused and can't get any satisfactory answers. I'll tell you my confusion: Torque ...
11
votes
4answers
22k views

Engine power specification at different rpm?

Car companies advertise power of an engine at different rpms. Car 1: 80 PS at 6000 rpm Car 2: 85 PS at 6500 rpm What does the power at different rpm mean? Does it mean Car 1 has better power than ...
9
votes
1answer
114 views

How does intake manifold runner length effect the power curve of a car?

Recently I learned that a number of things such as the cam profile, compression ratio and the intake manifold runner length and volume can all effect the power curve of the engine. Here is an ...
8
votes
6answers
65k views

The battery is fine but my car will not start not even a clicking sound

When I turn the key in to start all the lights on the dashboard go out completely and when I turn it back to the off position the dash lights back up. What could the problem be if the battery is okay? ...
7
votes
6answers
49k views

How many amps should my car pull while it is turned off?

I've recently started having a bit of trouble with my car. I typically drive my car to and from work each day. A couple weeks ago I went on vacation and when I returned, my car battery was as dead ...
7
votes
1answer
175 views

What should one do to reduce the HP lost at the wheels on an automatic transmission?

I have a 1990 Toyota Supra Turbo 4 speed auto. I've done some research about automatic transmissions and manual transmissions and what are the positives and negatives of each. (For example, MT is said ...
6
votes
1answer
358 views

Measuring Horse Power and torque without a dynamometer

I know I can take my car to a workshop and have a Dyno Run and can read the HP and torque figures from that. What I want to know, is there an alternative way to know the HP and Torque figures without ...
6
votes
2answers
66 views

Car battery appears good but car won't start

My 2005 Nissan won't start today. Battery is relatively new(about one year old) and I can turn the lights on, front headlights, and it appears fine. However, when I tried to start the car by turning ...
5
votes
5answers
1k views

What good is it for an engine to have lower CCs and higher BHP?

I was watching "The Perfect Road Trip 2" by Top Gear, where at some point Richard Hammond is driving a Mercedes A45 AMG. He says that the car develops a whooping 355 BHP, and all that comes from a ...
5
votes
5answers
11k views

How does cold, dry weather affect horsepower?

It's now properly winter over here in Australia, and the butt dyno is very favourable of the cold, dry air. It's like a free cold air intake for everyone, right?? I can think of two scientific ...
5
votes
3answers
206 views

Need to source PD-pump for small engine dyno school project

I am making a dyno to measure go-kart engine torque for a high-school project. I would like to use a water brake by varying input/output through a water pump and have read that this should be a ...
5
votes
3answers
4k 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 ...
5
votes
3answers
1k views

Larger cylinder volume, but less power, how?

KTM Duke 200 which has an engine of 200 cc, and, on the other hand, Royal Enfield Bullet 350 with a 345 cc engine. I.e. Enfield has 150 cc more than the Duke. But KTM produces 25 BHP of power, whereas ...
5
votes
2answers
55 views

How can head port volume affect the power curve of an engine?

Recently I learned that even more things other than the ones already mentioned here can effect the power curve that is produced by the engine. Here is an example of one. I understand that there are ...
5
votes
4answers
1k 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 ...
5
votes
1answer
105 views

Citroen C4 - Poor idle and low rev performance?

I have a Citroen C4 1.4 with 1360cc 16V KFU / ET3J4 petrol engine with 120.000 km. This problem appeared 3 - 4 years ago at around 40.000 km. When the engine is cold / hot there is a flat spot ...
5
votes
2answers
4k views

Problems with Power Door Locks

I have a 2009 Honda Accord with approximately 95k miles. About 2 years ago, I began having periodic trouble with the rear driver's side door lock. All other doors would lock/unlock with the power ...
5
votes
0answers
76 views

Rattling sound and loss of power

My brother's Toyota started making a funny rattling sound and lost about a quarter of its power. The rattling seems to come into play when it's under load, like when he's going up a hill or trying to ...
4
votes
2answers
75 views

What's an acceptable battery power drop on light load?

After an overnight rest in the warm weather (above 16 degC), unlocking my 2008 Jetta 2.5L SE, my OEM battery with the minimal "welcome" electronics -- remote open of the driver door a few seconds ...
4
votes
2answers
67 views

Can I use any portable powerbank to jump start a car

Say I have some ordinary portable powerbanks I use for my smartphone, I wonder if all of them are able to jump start a car with flat battery as long as I have a correct connector (e.g. clamp). Or ...
4
votes
1answer
127 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 ...
4
votes
1answer
152 views

how do i know if my lead-acid battery has been resurrected?

The OEM battery in my 2008 Jetta SE 2.5L has been nearly fully discharged one month back (had insufficient surface charge after a prolonged use without the engine running, but leaving it idle for 20 ...
4
votes
3answers
961 views

BMW e36 320i motor looses power significantly out of a sudden

I have a 1992 BMW e36 320i, when i start in the morning, or in cold weather, the cars functions normally and has a lot of power. However, after a little, or when the weather is hot, the car ...
4
votes
1answer
84 views

Alternator/Battery power question

Good Afternoon, I have a 2014 Ford Focus SE that i use as my Work Vehicle. I work in Emergency Roadside Assistance. I have to run a laptop In the car in order to direct calls to other employees and ...
3
votes
3answers
56k views

Possible reasons for loss of power, engine shaking, and smell of liquid fuel (not burning)?

The car (Renault Megane 1998 1.6e hatchback) lost power (about 500rpm in a bursty rhythm) after I re-ignited on a traffic light, the engine started shaking, and I could smell liquid fuel. There was no ...
3
votes
4answers
329 views

Mondeo MK3 power consumption and damaged radio

I'm not quite sure if this is the best Stack for my question but I will try. So from some time I noticed that in my car when engine is turned off there is still quite huge power consumption which ...
3
votes
2answers
519 views

Will an auxiliary battery hurt a vehicle's alternator?

I am going to be road tripping and living out of my SUV for a while. I need a way to power a tiny portable cooler/fridge 24/7 and would like to be able to power my cell phone, laptop, and maybe a few ...
3
votes
4answers
195 views

Why dual motor Tesla has more autonomy?

Maybe the question is more appropriate for Electronics Stack Exchange, I don't know. In the page http://www.teslamotors.com/models if we scroll down we see the several flavors Tesla sells its Model ...
3
votes
3answers
4k views

Does a car lose its pickup with age?

I bought a used 2001 Lexus ES 320 with 195K miles on it. It drives well, but I feel its pickup is not as good as I would expect from a 3.0L V6 engine. By pickup I mean the time it takes for the car to ...
3
votes
2answers
231 views

2006 Mustang GT: Left car for 1 week, no power when returning

I went on vacation for a week. The car was working fine before I left. I came back and there is no power. Can't turn on headlights or unlock/lock with remote, and the car gives a clicking sound when ...
3
votes
1answer
178 views

Will a 12 V cooler box significantly affect the performance/gas mileage of my car?

I have an Apollo brand 12 Volt Cooler/Warmer, designed to plug in to my car's 12 V cigarette lighter. I am wondering if the power this device uses will significantly affect my car's performance or ...
3
votes
1answer
130 views

MX5 lost power after spark plug change

I own a Mazda MX5 mk2 1.6L. I had severe problems with engine misfiring, caused by the valve cover seal, to leak. The oil that was leaking was concentrated near the spark plugs, and periodically it ...
3
votes
1answer
65 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 ...
3
votes
1answer
5k views

how fast does the alternator charge the battery?

It would appear that the common word of wisdom is that car alternators provide 50A of output. I actually looked at the supposed specs for my 2008 Jetta 2.5L on the internet -- a compact car -- and it ...
3
votes
2answers
1k views

would a sulfated discharged 12V battery charge at 12.5V?

I got a Stanley FATMAX RE-CHAGEiT 8AMP Automatic Battery Charger & Maintainer from Walmart for 29,97 USD, which appears to have three states of charging the battery -- detecting the voltage, rapid ...
3
votes
1answer
655 views

2001 Hyundai Santa Fe power steering leak

Where is the power steering return hose on a Hyundai Santa Fe? Is there a diagram somewhere that shows how it is run?
3
votes
1answer
442 views

1995 Chevy s-10 4 cylinder running hot but not overheating

I am having an issue with my s-10. It runs hot but is not overheating. It started when I replaced the temperature sending unit and thermostat. I put in an additional thermostat to make sure the first ...
3
votes
0answers
45 views

SAAB 9-5 wagon throws P1549 Code (Boost control valve)

I called an ASE-certified mechanic. He charged some $60 for the visit and $60 diagnosis and really he didn't quite spot on anything. Left me where I was - work-wise , diagnosis-wise and ...
3
votes
0answers
190 views

97 Jeep Cherokee check gauges light came on and then my battery gauge dropped down to 9 didn't lose any power?

I'm so confused I had just left my house and got 3 blocks away and my check gauges light came on, then my battery gauge dropped down to 9v. My Jeep didn't lose power, and the radio, heat, lights and ...
3
votes
0answers
139 views

2001 Subaru Legacy L Wagon - Gas smell and light shaking

So... It is really freezing and has been really cold these past few days. But, my 2001 Subaru Legacy L Wagon started acting up. First, here are things I know been replaced before I got it - Tires, ...
3
votes
0answers
261 views

1992 Mitsubishi 3000gt sl. no power and won't go above 2k rpm

I bought an automatic 1992 Mitsubishi 3000gt sl 2 days ago. I got it cheap knowing it would have problems, and that's why I'm here. When I put it in drive and slam on the gas the car just simply ...
2
votes
3answers
136 views

Effects of significant draw on alternator and battery

Hypothetically speaking, let's say I've equipped a vehicle with an aftermarket audio system with an amplifier that has a higher draw (in amps) than my alternator produces causing my average voltage ...
2
votes
2answers
31 views

Loss of engine power when using headlights

i have a nissan march 2003 (K12). when i turn on the headlights, it loose its engine power. alternator and battery are ok. anybody knows what would be the cause? thank you in advance.
2
votes
3answers
122 views

Is there a fuse that will turn off with a delay after turning off car?

I've installed LED lights in my car and I wanted to find a power source that will let it stay on for a while after turning off my car. I noticed that the power windows still work after turning off ...
2
votes
1answer
341 views

Engine, sudden reduced power with soft shaking

I have a 2007 Holden with a 2.0 Turbo engine. On one day I decided to go through a light that had just turned orange- so I pressed down, not completely as I new how much power I needed to go through ...
2
votes
1answer
26 views

Toyota Camry 2003 drive seat won't move forward

We have a 2003 Toyota Camry. Its driver seat power track won't move forward as it turns to the right after about 1/4 inch movement and cannot go forward. However, it does go backwards all the way. ...
2
votes
1answer
53 views

Honda Shadow VT750 louder exhaust noise, low power

Recently, my motorcycle got smashed by my girlfriend (who was driving behind me) in the rear. As a result of the impact, I got propelled into the rear of the car in front of me. Both fenders are ...
2
votes
1answer
157 views

A Suzuki GZ125 marauder that won't power on at all

I've been having a problem with my bike. I went to go to work in the morning and it turned on ok. Left to run for a few minutes then cut out. It turned over again and same thing ... I tried a third ...