How to go from Vrrrrrrrrooooommmm to Vrroomm Vrroomm?

Question

What parts make a car's naturally aspirated gasoline engine rev quicker?

I remember when I had an '87 Mustang with the 5.0LV-8 engine and it rev'd (up and down) quickly when it tapped the gas peddle. But I've had 4-cylinder cars that did not rev nearly as quick. At first I thought it had to do with how much power the engine had, but I've had a '04 Maxima with 265 hp (65 more hp than the Mustang -side note: the '87 was originally rated at 225 hp, but later calculations confirmed that it only had 200 hp) and although it accellerated as fast, the engine did not rev nearly as fast when you tapped on the gas.

So, if I had a stock engine that didn't rev that fast, what aftermarket high-performance parts would I need to get to make the engine rev faster? A rocker cam? Light weight lifters? Light weight crankshaft?

Answer 1

The first answerer is off, but the second is headed in the right direction. It all has to do with what sort of loads the engine has to bear against and how well it can breathe.

The most direct reason, and where I suggest you start for the biggest results, is the mass of the flywheel. Addressing your experiences, the Mustang was a muscle car, and was built accordingly; the engine has less initial resistance (i.e. its flywheel is lighter), translating to quicker response and more power to the wheels. The Maxima is a "performance sedan," meaning it will behave nicely while still having a bit of get-up-and-go (read: heavier flywheel, but more horsepower). So, there is the comparison: the Maxima has more overall power, but a greater percentage of the Mustang's power actually gets to the wheels, making them feel about the same in acceleration.

The reason you found that the four-cylinder engines didn't rev-up as fast is because, you guessed it, the flywheel. Automakers do this to make the vehicles more fuel-efficient: if the engine is already spinning from the residual inertia stored in the rotation of the flywheel, then less energy (fuel) has to be spent maintaining or raising this speed.

To answer your question, I recommend you get an aftermarket aluminum flywheel, or just have the stock one drilled for lightening holes (I do not suggest altering the thickness, for you may see some adverse clutch response). As indicated above, this is also a great way to increase (usable) horsepower. Other improvements (having significantly less noticable effect) would be done is this order:
larger throttle body/carburetor(s)
larger exhuast (the best being mandrel-bent pipes) *NOTE* you can have too large of pipes, so do some research on you engine
performance cam
lighter crankshaft
lighter lifters

After adding/changing these things the only thing left would be to remove the compressor for your AC system, but I figure one should not be without such creature-comforts.

If this were going to be a drag car, you could also switch from power steering to rack and pinion, eliminating the power steering pump.

All of these suggestions are *just* to increase rev response. You could have all sorts of engine machining done which would raise the dispacement and indirectly increase rev response. Adding a tubor/supercharger will add load to the engine, but of course the added power would compensate for this.

As a warning, reducing the flywheel mass will have a drastic effect on the driveability of the car and will take getting used to. Find someone who has the same or similar vehicle, but set up for racing, so you can get a feel for the other side of the spectrum. Aluminum flywheels cost several hundred dollars (new), but if you go the drilling route you can slowly decrease the wieght untill you find what you like (though this is *very* labor-intensive).

Have fun wrenching!

Answer 2

well some r right but all r wrong. ignition and timeing and exhaust r the most critical for fast revs. the more and faster an engine can intake and exhaust the faster the revs. i would go with slighly higher lift cam, but not to high cause ull be throwing ur valves through ur pistons, good t-body, lighter valve springs, adjust timing, go with a bigger diameter exhaust, find some tubing and fabricate a bigger intake breather, do a full head rebuild and increase valve size, if possible, but of all the first 2 are the most critical

Answer 3

u can use any after market part to make the car fast and rev faster. turbo, supercharger, light weight lifters and light weight crackshaft might work but i wouldnt reccommd changing them.

Answer 4

Air filter, exhaust... anything that will make the engine heavier or more clumsy then it needs to be.

Answer 5

Just move your foot faster on the gas pedal.

Answer 6

cam pistons .488 .513 rear end

Answer 7

just better stuff