V6, V8, V10,V12,V16 ?

[FrustratedUser]

Originally posted by: 91TTZ

Originally posted by: FrustratedUser

You are right, it does not say anything about the configuration BUT as you also said it has everything to do with volumetric efficiency.

I know, we are really getting into details now. :beer:

Yes, that is true.

I think it's interesting figuring out all the parameters of an engine's design. When you really start to look into things, each extra level of detail opens up another can of worms that has its own formulas, calculations, tradeoffs, etc.

Good stuff.

Very interesting indeed.

 

[SuperSix]

An engine is basically an air pump. The more air it can pump, the more power it can produce. So displacement is power. Except in cases of forced induction, which should almost be called forced displacement. Engine configuration has almost nothing to do with power.

W0ot!

We have a winner!

That's why the "little' 231CI Buick Turbo motors can tear ass like they do - forced induction!

I'd rather be blown that stroked.

 

[EyeMWing]

Originally posted by: clarkey01
How come the Mclaren F1 from 12 years ago (top speed 242 mph) is still one of the fastest cars ever ? how come the enzo only does 218 mph ? is it cost ?

Supercars are strange. It's not like building a sports car. Once you're over 200mph or 500-some odd horsepower, nobody cares how fast you are, it's about the car's personality. The F1 is a very raw, animal vehicle, more like an jet fighter than a car. The Enzo is much more refined. When you're rich enough to shop around for a supercar, you don't look at quarter mile times or top speeds; you determine which car connects with you on the most zen-like level.

To challenge the F1 would also be to challenge the reputation of one of the greatest designers that ever lived. He's not around anymore, so the F1 will remain the pillar of speed until someone with better ideas and vision comes along. Steve Saleen is getting there, in my opinion. The S7 is a work of art, and supposedly a trip to drive, but it'll take a bit more than that to get the european supercar manufacturers to notice. In particular, the S7 bears just a little too much resemblence to the F1, particularly in the rear end.

 

[Demon-Xanth]

Originally posted by: nakedfrog

Originally posted by: Demon-Xanth
What limits engine output is money. If you got money, you can buy power. Boost, displacement, and tech all cost money. Consider these four engines:
Ford 5.4L V8, supercharged, 3 valve, 550HP, 500LB-ft, ~550LBs (est weight based on 4.6 SOHC and DOHC setups)
BMW 5.0L V10, tons of high tech, 503HP, 383LB-ft, 530LBs
Chevrolet 7.0L V8, 500HP, 475LB-ft, 400LBs.
Ferrari 4.7L V12, tons of high end tuning, 513HP, 347LB-ft, 430LBs

Four ways to get 500HP, but the displacement does NOT indicate the engine weight.

How's that saying go?
"Fast, reliable, cheap. Pick two."

Heh, but in my example, all of those engines probably cost about the same (except the Ferrari which is stupid expensive) An example of "pick two" would be in making more power from the same engine. A 100 shot nitrous kit offers some good punch cheap, but will affect reliability if that's all you do. You can make it reliable by rebuilding the bottom end, but then it won't be cheap. Leaving it alone is cheap and reliable, but then it's not fast.

 

[Brian23]

More Vs == more power!!!!11one

 

[91TTZ]

Originally posted by: EyeMWing
[
To challenge the F1 would also be to challenge the reputation of one of the greatest designers that ever lived. He's not around anymore, so the F1 will remain the pillar of speed until someone with better ideas and vision comes along.

What do you mean by "he's not around anymore"?

 

[Howard]

Originally posted by: 91TTZ

Originally posted by: FrustratedUser


You are almost right but configuration still plays a role.

If you look at the formulas for power production, there is no mention of configuration. The configuration determines things like engine smoothness and engine weight, but as far as making power it doesn't matter.

What changes the variables in the formula for power production? Torque and RPM aren't just pulled out of nowhere.

The fact is, engine configuration DOES affect maximum power.

 

[flamingelephant]

Certain racecars (i cant remember which ones, F1, indy, cart.. something like that) could go alot faster/have more power than they do, but there are rules about what they can do to the cars. On one of these, there are rules about how much air can be forced into the engine. The cars are fitted with "blow-valves" that will pop if the pressure gets to high and therefore really slow down the car when it does. These valves are installed by the racing body, so they cant be tampered with or modified. There is also a tube that runs from the valve to the helmet of the racer, when the valve gets close to popping, the driver gets a "hiss" of air to know to slow down or it will pop. I'm sure lots of other stuff like this exists, but only the die-hard racing enthusiast would know. Those cars could go alot faster, but there is no point.... its not worth it on the risk side of the equation

 

[Demon-Xanth]

A lot of racing leagues could go alot faster than they do. NASCAR has restrictor plates and carb restrictions, LeMans has restrictor plates, boosted series usually have blowoff valves to limit boost. Even Top fuel has a supercharger and displacement restriction.

 

[vshah]

Originally posted by: FrustratedUser

Originally posted by: DingDingDao

Originally posted by: clarkey01
How come the Mclaren F1 from 12 years ago (top speed 242 mph) is still one of the fastest cars ever ? how come the enzo only does 218 mph ? is it cost ?

Gearing, I think. I'd be willing to bet that when you get to the top of the tach in top gear (7th in the Enzo, I believe), the engine would probably still have more to give.

Wrong. Cost and reliability. The Enzo is made to last longer than a F1 engine. The engine in an Enzo also does not rev up to 19000 rpm.
Never ever compare a racing engine to a production engine.... ever.

he's comparing the Enzo to the Mclaren F1 production road car, not a formula one race car. the mclaren had a 627hp bmw v12 IIRC.

 

[Zenmervolt]

Originally posted by: AMDZen

Originally posted by: BullyCanadian
"Theres no replacement for displacement."

That is the only thing I have to say, take it for its worth.

This was true once. Not anymore.

Now and days there are a lot of factors. The engineering behind motors is quite complex. OHC (over head cam) motors are typically more efficient (power and gas wise) than an OHV equivelant (over head valve). Those are the two distinct variations in motor design. Then you have the V configuration, inline and boxer style cyllinder placement. These all change how the motor performs as well.

More cubic inches is not always better nor will it always mean more power. This is the mentality of the by gone muscle car era. Because back then, all they did was take a motor and make it bigger, no further engineering was done. People bought it because it made more power and was indeed faster. It was also easier to get more power out of a bigger motor. This is not at all true any longer. In fact, most car companies who re-engineer motors make them smaller, yet more powerful.

An example of this is the new Ford V-8 TD (turbo diesel). They went from a clunky, and not very fuel efficient 7.0 liter V8 motor down to a 5.something (cant remember) V8 which produced more HP and quite a bit more torque. In fact, the old 7.0 liter had 520 torque or so and the new more which is almost 1/3 less in size makes 560 lb-ft torque and a bit more HP. Thats because they designed the motor that way. Ferrari is another example. They get specific output out of their V8 motors. But everytime they redesign it, they make them smaller AND more powerful.

This isn't to say bigger isn't better. Because if your an every day Joe "drag strip" Doe, and all you care about is your 1/4 mile time, then you could probably do more to a big block chevy V8 then a small block. The whole "bigger is better" mentality came from an American mentality from the 60's. Where all they cared about was this, drag strip times. All they cares about was more power.

All I have to say is that handling and breaking in a daily driven car is resoundingly more important. If you don't have the big @ss disc brakes and good suspension, you have no business getting more power. That power needs control. Thats why they design cars around such different criteria now.

You're introducing additional inequalities into the equation aside from simply displacement. If all else is equal, a larger engine will make more power. Engineering can help smaller engines increase their specific output, yes, but that same engineering, when applied to a larger engine, will result in more power than from a smaller engine.

You're comparing a lot of extra variables that aren't relevant to the actual discussion at hand.

ZV

 

[jagec]

Originally posted by: aRCeNiTe
cylinders != horsepower
cylinders = smoothness

BMW's 12cyl makes just as much power as their 8cyl, but it's a shitload smoother

True...in the marine industry, they build some FRICKIN' HUGE engines with only one or two cylinders (sometimes). Not the smoothest things in the world, but they get the job done. And obviously they make a LOT more horse than any car engine.

 

[FrustratedUser]

Originally posted by: vshah

Originally posted by: FrustratedUser

Originally posted by: DingDingDao

Originally posted by: clarkey01
How come the Mclaren F1 from 12 years ago (top speed 242 mph) is still one of the fastest cars ever ? how come the enzo only does 218 mph ? is it cost ?

Gearing, I think. I'd be willing to bet that when you get to the top of the tach in top gear (7th in the Enzo, I believe), the engine would probably still have more to give.

Wrong. Cost and reliability. The Enzo is made to last longer than a F1 engine. The engine in an Enzo also does not rev up to 19000 rpm.
Never ever compare a racing engine to a production engine.... ever.

he's comparing the Enzo to the Mclaren F1 production road car, not a formula one race car. the mclaren had a 627hp bmw v12 IIRC.

My bad then.

 

[Ophir]

try reading this.

Originally posted by: FrustratedUser

Originally posted by: Chadder007

Originally posted by: nakedfrog

Originally posted by: FrustratedUser

Originally posted by: DingDingDao

Originally posted by: clarkey01
How come the Mclaren F1 from 12 years ago (top speed 242 mph) is still one of the fastest cars ever ? how come the enzo only does 218 mph ? is it cost ?

Gearing, I think. I'd be willing to bet that when you get to the top of the tach in top gear (7th in the Enzo, I believe), the engine would probably still have more to give.

Wrong. Cost and reliability. The Enzo is made to last longer than a F1 engine. The engine in an Enzo also does not rev up to 19000 rpm.
Never ever compare a racing engine to a production engine.... ever.

Yeah, how many miles can you drive the McLaren F1 between engine rebuilds? One or two thousand, tops?

They were some of the most reliable engines in a car of that type.....so no. They could race seasons using those engines without a rebuild.

NO!
Please send me some of the stuff you are smoking.

I think they are referring to this McLaren F1, not a formula 1 racer.

I think the production F1 topped out in the 210 - 220 zone, can't remember exactly what speed. IIRC either the rev-limiter was removed or it was re-geared to hit 240something.

As for the McLaren vs Enzo, here's a good read.

Supercar Stats

edit: This article states the production top speed was 231 and the rev-limiter was removed to hit 240.

 

[jlee]

Production McLaren F1's top speed was 231-232mph, IIRC...not 100% sure, though.

 

[clarkey01]

is it easier to get more BHP from a bigger engine (sorry im new at this),say why not stick a V16 instead of a V12 say in one of my fave cars a Vanquish ? or is that just crazy ?

What would a V16 do ? is it smoother the more valves you have ?

 

[Howard]

Originally posted by: clarkey01
is it easier to get more BHP from a bigger engine (sorry im new at this),say why not stick a V16 instead of a V12 say in one of my fave cars a Vanquish ? or is that just crazy ?

What would a V16 do ? is it smoother the more valves you have ?

You could, but how would you fit it? Also, it would cost a lot more (don't forget R&D) and would be heavier.

No, smoothness is generally related to engine configuration, displacement per cylinder, flywheel mass (and how it's distributed), etc...

 

[Demon-Xanth]

Cadillac had a V16, it was reported to be very smooth. But like straight 8's, it was VERY long and heavy. GM was considering doing a small run set that'd push about 1000HP, but decided that it's too niche. One outfit was actually selling a V16 setup made from small block Chevy engines.

 

[clarkey01]

I forget the name, but VW are bringing out a 1001 BHP V16 beast

 

[91TTZ]

Originally posted by: Howard
[
What changes the variables in the formula for power production? Torque and RPM aren't just pulled out of nowhere.

The fact is, engine configuration DOES affect maximum power.

The variables are based on volumetric efficiency, displacement, and RPM. The engine configuration doesn't come into play. A 5 liter engine vs. a 3 liter engine would make a difference, but a 5 liter V6 vs. a 5 liter V8 wouldn't make a difference, all else being equal.

 

[Howard]

Originally posted by: 91TTZ

Originally posted by: Howard
[
What changes the variables in the formula for power production? Torque and RPM aren't just pulled out of nowhere.

The fact is, engine configuration DOES affect maximum power.

The variables are based on volumetric efficiency, displacement, and RPM. The engine configuration doesn't come into play. A 5 liter engine vs. a 3 liter engine would make a difference, but a 5 liter V6 vs. a 5 liter V8 wouldn't make a difference, all else being equal.

Really now. Do you think a 4L I6 would make the same power as a 4L V12?

Because the 4L V12 will make more power.

 

[91TTZ]

Originally posted by: Howard
Really now. Do you think a 4L I6 would make the same power as a 4L V12?

Because the 4L V12 will make more power.

Yes, I do. And it will.

The 4L V12 will be smoother, but being a V12 in itself does not make it any more powerful.

 

[FrustratedUser]

Originally posted by: 91TTZ

Originally posted by: Howard
Really now. Do you think a 4L I6 would make the same power as a 4L V12?

Because the 4L V12 will make more power.

Yes, I do. And it will.

The 4L V12 will be smoother, but being a V12 in itself does not make it any more powerful.

You can't just say that.

 

[Howard]

Originally posted by: FrustratedUser

Originally posted by: 91TTZ

Originally posted by: Howard
Really now. Do you think a 4L I6 would make the same power as a 4L V12?

Because the 4L V12 will make more power.

Yes, I do. And it will.

The 4L V12 will be smoother, but being a V12 in itself does not make it any more powerful.

You can't just say that.

Yes, I can. The V12 will be able to rev up higher than the I6 will. And assuming the intake/combustion chamber/exhaust geometry is good, specific torque output will remain about the same.

EDIT: Yes, assuming the bore/stroke ratio is the same. The V12 will have a cylinder displacement half that of the I6 - easier to breathe at high RPMs, especially since valve area will be almost the same as in the I6.

 

[Zenmervolt]

Originally posted by: Howard

Originally posted by: FrustratedUser

Originally posted by: 91TTZ

Originally posted by: Howard
Really now. Do you think a 4L I6 would make the same power as a 4L V12?

Because the 4L V12 will make more power.

Yes, I do. And it will.

The 4L V12 will be smoother, but being a V12 in itself does not make it any more powerful.

You can't just say that.

Yes, I can. The V12 will be able to rev up higher than the I6 will. And assuming the intake/combustion chamber/exhaust geometry is good, specific torque output will remain about the same.

EDIT: Yes, assuming the bore/stroke ratio is the same. The V12 will have a cylinder displacement half that of the I6 - easier to breathe at high RPMs, especially since valve area will be almost the same as in the I6.

How on earth can the valve area be almost the same when each cylinder would have to be half the size? You'll lose a hell of a lot of valve area on the V12.

ZV

EDIT: The V12 will also have higher frictional losses, and will have more parasitic loss from the valvetrain.