[captainslow]

So this is somewhat of an odd question, but I have a 335i which weighs roughly 3600 pounds and has 300 horsepower and 300 ft pounds of torque. My friend has a Toyota RAV4 V6 which has 260 horsepower and 250 ft pounds of torque. I realize these are differences, but my car is soooo much faster and I'm trying to figure out why other than just the 40 horsepower difference. What makes one car with pretty much the same specs as another car much faster? For example the aerodynamics on my car are better and the transmission is definitely better, but what else exactly would contribute to the difference? When I floor my car at 80 it takes off and his car at 80 it barely accelerates. Just trying to learn. Thank you

[ian3924]

Turbos, powerband, fuel octane, drivetrain loss, total weight, aerodynamics, transmission, cooling, tuning, and the amount of stickers on your car are all factors that affect overall acceleration. Also the 335i is underrated at 300hp/tq.

[captainslow]

Drivetrain loss and fuel makes sense, but don't cars have around the same drivetrain loss and the 300 horsepower in my car is based on 93 octane and the 250 in my friends car is based on regular gas. And I don't get why turbos makes a difference. Whether a car has 300 horsepower using no turbos or not I wouldn't think it would make such a significant difference.

[TrAcK TRaP]

[pits200]

The HP difference is even bigger than you think, these cars are underrated. HP difference at crank is probably closer to 60hp and 80tq.

Take into account power to weight and powerband and this is a silly topic tof discuss any further. Peak numbers on cars can beasily deceiving and auto manufacturers love when people spout them off

[captainslow]

Ok then let's use a different car. The 2006 e500 Mercedes has 302 horsepower and 339 ft pounds of torque and again above 80 it barely moves?

[captainslow]

My question is really more about why some cars even with decent power die at higher speeds compared to other cars. I don't think it is all aerodynamics?

[Turbo_power4ever]

I thought this discussion was gunna be about 2 335i's lol. not a 335i vs a Rav 4... lol

[captainslow]

Originally Posted by Turbo_power4ever

I thought this discussion was gunna be about 2 335i's lol. not a 335i vs a Rav 4... lol

I realize it sounds odd haha, but from the factory I'm just comparing two cars with similar power and weight. I'm just trying to understand why some cars drastically die at higher speeds. I'm genuinely just trying to learn here and not trying to start anything

[Sgop335]

Hey buddy, like most not a useful post or at least belongs in the general section. Since you say you want to "learn" give a shot...

Na engines dont have high torque at lower rpm like the 335. Def gives you the feeling of better acc. Higher speeds need more power to accelerate. Why? Power needed=massxaccxspeed

[bokyo1987]

Power to weight ratio, gearing, torque curve, etc... There's a ton of other factors why cars with similar peak output won't accelerate at the same rate.

[Lshaw]

[Varjo]

Some of the reasons posted above are good, others are less so.


There are some HUGE factors that a single horsepower or number doesn't reflect:

1) Peak horsepower is really pretty unimportant, area under the curve (or at least under the curve inside some useful RPM range, like 4k to 6k, is what matters).

2) The above point only paints a complete picture assuming infinite gear ratios and instant shifts (sort of like a CVT). In reality, we have a finite number of fixed ratios, because of this, gearing and engine torque become a factor as well.

3) Companies rate engines very very differently. BMW engines are quite underated.


When you combine these factors, you start to see why there are such large differences. Sure, the 335i might have only 40 peak horsepower on the rav4, but it has a much broader torque band, meaning the area under the curve is much larger. Couple this with the fact that we have more gears, a faster shifting gearbox (if auto), and that our 40 extra peak horsepower is more like 60 or 70 and you start so see why there is such a huge difference.


Other factors mentioned are less important and somewhat secondary:

Aerodynamics - Not such a huge factor at normal road speeds, unless you're getting up to triple digits, this isn't huge.

Weight - This is important to be sure, but a rav4 doesn't actually weigh that much more than a 335i.

Cooling - Only really a factor in extreme temps or on the track (or back to back pulls). Not a big factor when driving around town and doing one pull.

Drivetrain loss - Going to be relatively consistent on modern cars, say 15 percent ballpark on an auto. Not to say it won't matter, but it's not a huge difference.

Fuel octane - Rav4 doesn't require premium to make its stated hp, so this is irrelevant.

[mj6234]

Riveting technical discussion here. Glad I came in!

[TemjinX2]

Turbo tq vs NA tq

its hard to go back to NA once you go turbo since you get use to the early tq from the turbo, unless you moving to a large displacement v8.

even a turbo 4 will feel faster on the butt dyno then a na v6

[MJ80.]

I cant even believe you cunts are even entertaining this discussion, most ridiculous shit ive ever read on here.

[Delta0311]

What you think I rap for, to push a fucking RAV4!!!!!!!!!!!!

[Vongolet]

Originally Posted by ian3924

and the amount of stickers on your car

[PourBoi-Jay]

WTF.....this is the section I come to to get away from the asinine discussions in the General Section.......I guess nowhere is safe...

[Antetokounmpo]

Area under the curve.

[captainslow]

Originally Posted by Varjo

Some of the reasons posted above are good, others are less so.


There are some HUGE factors that a single horsepower or number doesn't reflect:

1) Peak horsepower is really pretty unimportant, area under the curve (or at least under the curve inside some useful RPM range, like 4k to 6k, is what matters).

2) The above point only paints a complete picture assuming infinite gear ratios and instant shifts (sort of like a CVT). In reality, we have a finite number of fixed ratios, because of this, gearing and engine torque become a factor as well.

3) Companies rate engines very very differently. BMW engines are quite underated.


When you combine these factors, you start to see why there are such large differences. Sure, the 335i might have only 40 peak horsepower on the rav4, but it has a much broader torque band, meaning the area under the curve is much larger. Couple this with the fact that we have more gears, a faster shifting gearbox (if auto), and that our 40 extra peak horsepower is more like 60 or 70 and you start so see why there is such a huge difference.


Other factors mentioned are less important and somewhat secondary:

Aerodynamics - Not such a huge factor at normal road speeds, unless you're getting up to triple digits, this isn't huge.

Weight - This is important to be sure, but a rav4 doesn't actually weigh that much more than a 335i.

Cooling - Only really a factor in extreme temps or on the track (or back to back pulls). Not a big factor when driving around town and doing one pull.

Drivetrain loss - Going to be relatively consistent on modern cars, say 15 percent ballpark on an auto. Not to say it won't matter, but it's not a huge difference.

Fuel octane - Rav4 doesn't require premium to make its stated hp, so this is irrelevant.

Thank you this is exactly what I wanted to know! A lot of people made fun of me, but for me at least this is helpful information

[Wolf 335]

This was entertaining for a bit.