Hot answers tagged

42

The main advantage to a lower flywheel mass on race cars is that the reduced mass allows the engine to rev more freely. The overall weight loss to the car is really not the key thing, it's letting the engine vary RPM really quickly. Being able to change RPM quickly can mean faster shifts, getting to a power band more quickly, etc, etc. It also makes the ...


23

cdunn's answer is spot on. To add a bit (especially for cars), in a race car you often want to be dropping from something like 7000 rpm to maybe 5500 rpm (or an even higher band, depending on the engine) in a split second to make an upshift. Especially at higher engine speed, that's a lot of energy to bleed (and goes as a function of the weight of the ...


17

I agree with your praise for this car, I had one back in the day and I have never loved a car as much since. To get more from this Wankel powered beauty, it's all about two things: Getting it to breath better Replacing parts that won't take the higher RPM The good news is that the only part that needs to be replaced, is the RPM gauge sender on the face ...


11

The flywheel keeps your engine spinning The inertia of a flywheel is in direct proportion to the mass of the flywheel. Newton's first law of motion states, "An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force" With that in mind, motorcycle engines ...


11

Physics dictates that rotational inertia impedes acceleration... which is why a lighter flywheel is considered to be a performance mod Less rotating mass = more acceleration, if all else is equal But rotational inertia helps an engine idle stably which explains why manufacturers don't go for lighter flywheels from the get-go If they opt for a lighter ...


11

One of the reasons is loads of extra weight added by safety features and options. 8 airbags, 12 speaker stereo, 14 way adjustable seats, tons of insulation all around, power windows, power locks, 18 computers with hundreds of sensors, etc. Also consider the size/power output of the engine. It looks like your car had a 4 speed manual. Most cars today ...


10

A six pack usually refers to the Chrysler (Mopar) carburetor setup which is three-two barrel carbs on an intake. You'll most often hear of it as a 440 Six Pack, the 440 referring to the Big Block Mopar engine displacing 440 cubic inches. Here is an image of such a setup: The interesting thing about these is they are setup sequentially, where the main 2-...


8

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 need power and how much do you need. "Speed costs money, how fast do you want to go?" Just about everything is a balance of top end power vs bottom end power. ...


8

Gasoline is made in large batches. Each batch has a number of attributes that should be met; Octane, specific chemistry, volatility, contaminates, ethanol content, and others. The output is dependent on the crude that went into the refinery and the processes the refiner has at hand to process it. Refineries vary in there capabilities. There are over 60 ...


8

NOTE: The following example assumes output in lb-ft & horsepower. Dynamometers can also measure torque output in Newton Meters or Kilowatts just as easily, or any other measure of torque and power, for that matter. First off, let's get everyone on the same sheet of music. When it comes to vehicles, there are two basic types of dynamometers: engine & ...


8

Just like with any other internal combustion engine, there are two ways to increase power output: add more cubic inches of displacement; make the motor think it has a larger displacement. More Displacement The rotary engine (Wankel) is a different breed. You cannot just bore/stroke the engine like with other piston based engines, so you have to go a ...


7

Generally, in the automotive world, there are two different types of dynamometer (or dyno for short) which might be used: chassis dyno; engine dyno. I'll discuss the general procedures for each type of dyno. Every dyno operator has their own procedure and will operate it how they see fit. You have to allow for this mainly because it's their dyno, they paid ...


7

The short answer is no. The engine is most efficient at the RPM when maximum torque is achieved. It's easiest to explain with a picture. Power is a function of torque and RPM. Maximum torque is achieved because the engine is able to move the maximum amount of air and fuel in and out of the engine. The power continues to climb even when the torque starts ...


7

A cam... in its most generic sense converts rotary motion into linear motion or vice versa using solid egg-shaped actuators (lobes)¹. An engine camshaft... refers to the shaft which houses a series of cams that actuate the opening/closing of the intake and exhaust valves on a four-stroke engine. A performance camshaft... is just a camshaft whose ...


7

This question and answer from @BobCross is very illuminating and may help you in your decision making process. Have a look.


7

One thing which hasn't been mentioned here about why a lightweight flywheel may not necessarily be a good thing for the street is, just like brakes, the rotational mass of a regular weight flywheel will allow for better heat control which is caused by engaging/disengaging the clutch during normal operation. The mass of a regular flywheel will be more ...


7

Forging is a process where hot metal of the rough shape is then very forcibly squished by exact shape dies, severely compressing the metal or alloy molecules. There are internal tensions created within the structure, which ultimately resist sheer and tension stresses by having a reserve of counterbalanced "forces" due to the myriad of tiny forge-created ...


6

Upstream the throttle body A dirty intake by itself isn't the problem, but it is a sign of contamination of related components: MAF sensors don't take kindly to dirt This will usually lead to the fouling of the hot-wire(s), resulting in the underreading of air mass flow, which will lead to positive fuel trim correction. If the contamination is bad ...


6

Engine Remap One way of increasing the power from your engine, depending on the car is to get your engine "remapped". This effectively means that your cars on-board computer (or ECU) has had its software changed and as a result the engine is told to produce more power. It should also be noted that changing the software used by the car can also be referred ...


6

Mow much money do you have? :D In all seriousness: Swap in a later 13B engine and give it a fresh rebuild. Install a Racing Beat header and exhaust system. The Racing Beat intake is also pretty good. Mind you, this is setup for the upper rev range. Put a good carburetor on it, like a Holley 600 (mechanical secondaries). Do not remove the belt driven fan! ...


6

Short answer: Yes, yes and yes. BUT: A tire doesn't have an expiry date. The reason for all three points is that the rubber gets harder over time and looses its grip / traction, especially on wet ground. Keep in mind grip is not only important for acceleration and braking, but it also keeps the car on the street in curves. Rubber not only gets harder, but ...


5

I'd say the only realistic option with a 1.3 liter turbodiesel besides an engine swap is chiptuning/remapping. And even then I'd research the potential of this engine, you'll be shortening it's life considerably. Many performance oriented modifications will work, but in my opinion are simply not worth the investment with this engine, as the gains will be ...


5

That's a broad question, and I'm a Subaru geek, not a VAG geek, but I'll share my never-humble opinion. Any flash that increases performance obviously increases stresses. A proper remap with careful logs and monitoring might improve the longevity of any performance enhancement. Then again, you never get something for nothing (despite the billion-dollar ...


5

There isn't any performance to be gained from spark plug wires, just better build quality, which gives you not a better spark, but rather maintains an appropriate spark for more miles/years before their performance degrades to the point of needing replacement. You cannot tell build quality by reading the side of a box, it is a manufacturer reputation more ...


4

Performance cams have various cam lobe configurations where the valve lift and duration are changed from OEM to provide better efficiency for the combustion process. I would like to make a distinction between efficiency for the combustion process and efficiency of fuel consumption. Combustion efficiency can be related to how much air and fuel can get into ...


4

Would there be a substantial enough of a horsepower boost to be noticeable? The most you could see from such a modification is 15hp. This would not be enough for the seat dyno to register, unless there are plenty of hemorrhoids to detect it. More then likely you'd see a measly 5-10hp, and then only at the higher RPM levels would this be apparent. You would ...


4

Tl;dr: it might be better for noise, vibration and harshness than for handling. Once upon a time, I had a Fox body mustang. I remembered it being chock full of rattles and squeaks. It was definitely a source of sideways looks from the WifeUnit back in the we have no money days. After doing a little research, it appears that the greatest measurable ...


4

Your sample may just be non-representative. All the ones I know (I'm mostly into Japanese performance cars) have oil temps. Even many non-performance cars have an indicator that goes out once the engine is up to temperature (such as my wife's Honda Jazz) I think cars like the M135i have some cost based design decisions in order to meet their price point - ...


4

Iridium spark plugs are not going to give you more performance compared to copper types. You will notice increased performance only if the current plugs are in bad shape to begin with. The advantage of iridium spark plug is that they last a lot longer compared to the copper ones. So you don't have to change plugs that often. So it is up to you to decide if ...


4

No, the engine speed at which maximum fuel efficiency is obtained is different. In fact, the faster you go in any given gear the worse the resultant fuel economy will be because it takes increasingly more power to overcome the vehicle's drag forces. It worsens because the power required to overcome drag forces on a vehicle at a constant speed is ...



Only top voted, non community-wiki answers of a minimum length are eligible