I bought a 2008 Honda S2000 AP2 with the F22C 2.2L engine back in May. One of the things I thought was unique in a production engine was the 8,000 RPM redline that has the 4 little slugs rocketing up and down the cylinders at about 4,900 ft/sec. Lordy, that's almost a mile per second. The original F20C 2.0L engine in AP1 S2000's redlined at 9,000 rpm but with a shorter stroke, the piston speed was about the same.

I was shocked when I started researching the G35 and found that the VQ35HR variant of Nissan's ubiquitous 6 cylinder found in our cars redlines at a similar 7,500 rpm. That's an engine almost 60% larger than the Honda spinning at nearly the same speed. I didn't bother to calculate the stroke/piston speed but it's surely impressive.

The old corporate V6 ain't what she used to be. There is some amazing manufacturing precision in an engine that can rev like that and still be warranted by the manufacturer for 70,000 miles. And based on VQ engine history, 150,000 miles is not out of the ordinary.

Personally I love high revving engines more than I love engines like the GM LS2 or LS3 that produce gobs of low end torque but are pretty much done by 6,000 rpm. There's something about the scream of an engine at 6K+ that just sounds like a race car. Ferrari agrees with me.

Oh well, just an observation.

 

Have you looked into a porsche GT3? It creates much more power/torque than a VQ37VHR, and redlines even higher at 8400.

If you have a S2k, you know that the engine can go well beyond the factory redline safely.

the VQ is not a square engine like the F20C/K20. It is a big big bore engine; the stroke is actually not that long.

Funny part, is that the VQ is making more power than ever, but the torque is dropping. They're going the way of honda.

 

thats exactly right, they have the rev the **** out of it to claim the high HP.

this goes back to the tax that all *** cars suffer in japan if they have large displacement. so instead of making torky large displacement engines, they make small displacement engines that they rev and FI the **** out of.

thats how they can get 130 hp out of a 600 cc bike engine, by making the red line at 15,000+ rps.

here is a famous quote, HP sells cars, but torque wins races.

 

Doesn't the M3 V8 rev to something like 8k?

 

That's why Carol Shelby's cars cant beat the Vettes.

If torque won races, a GT500 would have no problem spanking a Z06.

I can put out 1000ft/lb's of torque. Do you think I can make a car move 200 mph? I'm only good for about 3hp.

Torque is the amount of force available at any given moment in time. Horsepower is the amount of force available over a given period of time.

Horsepower available (your powerband) is the ONLY factor in determining how fast a car is. High torque gets you moving from a stop better than low torque, because even that low in the powerband, you're making more horsepower.

Double torque at any RPM, and your horsepower doubles as well.

Simple math, but much easier to understand with a basic knowledge of calculus.

Then there's gearing, which is mechanical torque multiplication.

High revving S2k's come with a 4.1 final drive. The hardcore guys use 4.57 or even 4.77 final drives.

 

the calculation for hp is as follows
Horsepower = (torque x rpm) / 5252
yes it is simple math, HP is relative to torque, and rpm

6 or 1/2 dozen, which every way you want to look at it, all im saying is if you have lack of torque, you can raise Hp numbers by raising rpm. and that is exactly where gearing comes in, as you stated.

 

Just curious, what's the weight difference? Does the Vette have a power-to-weight advantage?

Help me out with this one? I'm not being sarcastic, but isn't torque power a given time, as opposed to power over time (i.e. you generating 50 pounds of torque at a time, over multiple hours)?

If this was true, we would be faster than BMW 335s, because we have more hp (306 vs. 300, or 312 vs. 300 at speed). The BMW wins because its torque (and as you say, HP) comes on much earlier. It's area under the curve, not the max point of HP or torque.

 

here is a VERY good article on this whole situation.
its about bikes, not cars. but all the descriptions and conclutions about engine output, speed, torque, hp and RPM are correct.

http://www.vmaxoutlaw.com/tech/torque_hp.htm

 

Of course it does, but that's besides the point.

Torque is instanteous power. Horsepower would be that power applied over a period of time. The unit of measurement for torque does not involve a unit of time, while the measurement of horsepower does.

Simple example with theoretical engine.

The engine does 300 ft/lbs for it's entire powerband. At 2000 rpm, the engine puts out double the power of 1000 rpm, because it is spinning twice as fast. (this is where the unit of time comes in)

Torque is measured in foot pounds, while horsepower cannot be measured without a rotations per minute reading.

So yes, torque is power at a given moment of time, while horsepower is power over a measured period of time.

The BMW's powerband is actually very similar to ours at the top end; the torque drop-off on the BMW, however, is slightly greater.

The BMW is faster at lower speeds, because the engine is actually underrated; a 335 will dyno higher than a G35, both stock, on the same dyno.

I believe multiple publications have shown that the 335 is underrated, just how the GT-R is.

Yes, the power curve of the BMW is superior; and is MUCH more daily drive friendly.

Look at the top gear 30-50 and 50-70 acceleration times....

It's painful.

 

point I'd like to make:

NA engines are limited to a max of roughly 75 ft/lb/liter...

3.5x75 = 262.5 (g35's do 270 or 268 [hr])
2.0x75 = 150 (F20C in S2000 does 153)
2.2x75 = 165 (F22C in S2000 does 162[2.15liters])
3.6x75 = 270 (3.6L in the Carrera does 273)
3.8x75 = 285 (3.8L in Carrera does 295)
6.0x75 = 450 (6.0L in Vette does 428)
4.6x75 = 345 (4.6L in Mustang GT does 320)

It is possible to go over this approximate limit, but 'exotic' materiels are required, and engine life is compromised.

 

Mike, you're a wealth of information. Great read!

 

Actually, he's right! As long as you're talking about drag racing. It's drag racers that usually throw this quote around along with......

"There's no replacement for displacement" or "There's no substitute for cubic inches"

All true....as long as you're looking for acceleration and not speed. Torque is much more important in a drag race since you're looking for maximum acceleration for a brief few seconds and not necessarily maximum speed for sustained periods.

In a road race (real race) on the other hand, torque is much less important. Just look at F1 engines, torque wimps but power monsters that spin like a dremel tool at 15,000 RPM+. You don't care so much about acceleration because the goal is to carry as much speed from turn to turn as possible. A car that can do that will embarass a car with even a sizable power (or torque) advantage. It takes gobs of power to close the gap on a car with a say 3 mph advantage through a turn. The tighter the track, the more truth to this statement.

 

Oh yeah, Hondata will reflash the ECU for $600. Redline raised to 8,500 RPM and transition to the high speed cam (VTEC) lowered from 6,000 to 5,600 RPM. No peak power gains but area under the curve is increased around the 6,000 RPM neighborhood of the powerband. I havent had mine reflashed yet. I just rolled over to 5K miles yesterday.

 

Wait for around 15k miles before you reflash. You're not fully broken in yet.

The reflash increases the area under the curve slightly, but more importantly it allows you to stay in VTEC on your 1-2 shift, and gives you more revplay for HPDE.

Have you looked into getting the Kraftwerks s/c?

Dyno queen/Drag imports all use HUGE turbos, and their area under the curve absolutely blows except at the very end. Yet, they'll run 8's and 9's with 150+ traps.

In fact, their low end torque is so pathetic that your average street car will EASILY pull on them. Yes, grip is the biggest issue with those cars, but HP is what lets them rip those times...

the S2k is an excellent example. A launched s2k with do 0-60 in ~5.5, but a 5-60 time would be in the realm of 7.5-8 seconds. The launch allows the s2k to stay in its powerband, even though the powerband sucks.

F1 cars carry speed through turns, but that's because of their Aero and tires, not their engines. They still do 0-120mph in ~8 seconds.

 

Re: F22C

Here's the amazing thing. The engine was designed so that from the factory, it can take a 1 gear redline mis-shift with no damage (excluding a 2->1 mis-shift). E.g., a 3->2 shift from redline wouldn't do any damage to the engine unless you sustained it for an extended period of time.

The CDV was primarily put in place to protect the diff (reinforced for AP2), and to keep the clutch slipping just enough to keep you in VTEC during a 1->2 shift.

And its really 2.15 liters