V8 M3 at altitude a disappointment....

[adamr]

Well i stay at altitude and buying an M3 here in Johannesburg will be more of a status thing ... the motoring in the star newspaper tested the M3 vs RS4 vs 335i ... and the 335i was quicker ... bottom line it is just quicker ... i got the M3 ordered and now just wonder if i should cancel ... really not keen anymore .... its like the golf 5 R32 vs Golf 5 Gti .... will post a scan of the article ...

still have not driven it ... my dealer drove the car at gerotek and he said he is disappointed

[888]

+1



BUT, it is faster than the RS4 and much more “hard-core” than the 335.

M3 = image (I get mine soon )

[JEllis]

Yeah any NA car at altitude is going to suffer the same way. Even a Z06 is going to lose power. Should be no surprise

[NavNurs]

My $0.02
Though slower, the M should still be more fun to drive. My S2000 is as slow as a neon, but is one of the best times to be had behind the wheel of any car today. I must say, if Hyundai made a four seat which out performed the M in all ways, I would seriously consider buying one.

[13eastie]

Originally Posted by adamr

Well i stay at altitude and buying an M3 here in Johannesburg will be more of a status thing ... the motoring in the star newspaper tested the M3 vs RS4 vs 335i ... and the 335i was quicker ... bottom line it is just quicker

Did the article quantify the difference at all? Looking forward to the scans.

[JEllis]

^scans already exist in other threads

[Romo]

Originally Posted by Keto

Really, you should move to sea level.

Here in the Netherlands, half the country is below sea level

Maybe it will ad some extra HP...............................

[swiss_cornholio]

Originally Posted by adamr

Well i stay at altitude and buying an M3 here in Johannesburg will be more of a status thing ... the motoring in the star newspaper tested the M3 vs RS4 vs 335i ... and the 335i was quicker ... bottom line it is just quicker ... i got the M3 ordered and now just wonder if i should cancel ... really not keen anymore .... its like the golf 5 R32 vs Golf 5 Gti .... will post a scan of the article ...

still have not driven it ... my dealer drove the car at gerotek and he said he is disappointed

Altitude?? Joburg is at 1700 something meters. A N/A engine looses about 10% per 1000m. So in this case it's not even 20%. 420*0.8=336, so the 335i comes close but doesn't outperform the M3. In Switzerland we have several mountain passes >2000m and N/A cars don't feel extremely slowed down there.

[ILC32]

Originally Posted by Romo

Here in the Netherlands, half the country is below sea level

Maybe it will ad some extra HP...............................

I think Keto is below sea level as well . . .

[Keto]

I live about 2-3 feet above. No Katrina floods 4tw.

[Just_me]

Where are the scans?

Was the M3 quicker than the RS4?

[Gabri343]

Originally Posted by adamr

Well i stay at altitude and buying an M3 here in Johannesburg will be more of a status thing ... the motoring in the star newspaper tested the M3 vs RS4 vs 335i ... and the 335i was quicker ... bottom line it is just quicker ... i got the M3 ordered and now just wonder if i should cancel ... really not keen anymore .... its like the golf 5 R32 vs Golf 5 Gti .... will post a scan of the article ...

still have not driven it ... my dealer drove the car at gerotek and he said he is disappointed

Have you a scan?

[lakerfan007]

Originally Posted by swiss_cornholio

Altitude?? Joburg is at 1700 something meters. A N/A engine looses about 10% per 1000m. So in this case it's not even 20%. 420*0.8=336, so the 335i comes close but doesn't outperform the M3. In Switzerland we have several mountain passes >2000m and N/A cars don't feel extremely slowed down there.

Now if you drive the same car at Sea Level, you will definetly feel the difference, I live in colorado, at 5000ft my X5 can't even beat a neon off the line, and it's worse when i go upto Vail Pass which is >7000ft...... at sea level though, the car is more responsive and the power band is much greater

[paulyd]

Originally Posted by Romo

Here in the Netherlands, half the country is below sea level

Maybe it will ad some extra HP...............................

hahaha

[ShinySteelRobot]

Originally Posted by lakerfan007

Now if you drive the same car at Sea Level, you will definetly feel the difference, I live in colorado, at 5000ft my X5 can't even beat a neon off the line, and it's worse when i go upto Vail Pass which is >7000ft...... at sea level though, the car is more responsive and the power band is much greater

My dealer mentioned they're putting the N54 twin turbo as an optional engine in the X5 next year. Should alleviate the problem of losing power at altitude.

Not to mention an X5 with twin turbos and PROcede would be pretty sick.

[Just_me]

What about the RS4, 335i and M3 faster than the RS4 in the review?

[Jason]

Sorry, all off-topic posts removed. Let's please keep these threads on-topic. Thanks.

[joema]

Originally Posted by adamr

Well i stay at altitude and buying an M3 here in Johannesburg will be more of a status thing ... the motoring in the star newspaper tested the M3 vs RS4 vs 335i ... and the 335i was quicker ...

That is easily possible. Altitude-induced power loss is about 1% per 100m, so at a typical Johannesburg altitude, hp will be down 17.6% from altitude alone.

However -- the engine doesn't feel altitude above sea level, but density altitude -- which includes temperature and humidity. This can easily result in a much higher effective altitude.

E.g, on a muggy 85F summer day in Johannesburg, the density altitude could be 9,000 ft (2743 m). That equates to about 27.4% power loss.

Like horsepower, torque is also reduced by altitude. Even at sea level the 335i has more torque than the e90 M3, across a much wider range. This differential would be magnified at higher altitudes.

Because of all these effects, it's easily possible a 335i could out-accelerate an e90 M3 at higher density altitudes.

However the same is true for many normally-aspirated vs turbocharged comparisons. In Johannesburg, or Flagstaff, AZ on a hot day, a Dodge Neon SRT-4 could probably out-accelerate a Porsche 911 Carrera.

It doesn't mean I'd rather have a Neon than the 911, but it illustrates how great the effect of density altitude on vehicle performance.

[swamp2]

Originally Posted by joema

That is easily possible. Altitude-induced power loss is about 1% per 100m, so at a typical Johannesburg altitude, hp will be down 17.6% from altitude alone.

However -- the engine doesn't feel altitude above sea level, but density altitude -- which includes temperature and humidity. This can easily result in a much higher effective altitude.

E.g, on a muggy 85F summer day in Johannesburg, the density altitude could be 9,000 ft (2743 m). That equates to about 27.4% power loss.

Like horsepower, torque is also reduced by altitude. Even at sea level the 335i has more torque than the e90 M3, across a much wider range. This differential would be magnified at higher altitudes.

Because of all these effects, it's easily possible a 335i could out-accelerate an e90 M3 at higher density altitudes.

However the same is true for many normally-aspirated vs turbocharged comparisons. In Johannesburg, or Flagstaff, AZ on a hot day, a Dodge Neon SRT-4 could probably out-accelerate a Porsche 911 Carrera.

It doesn't mean I'd rather have a Neon than the 911, but it illustrates how great the effect of density altitude on vehicle performance.

• You are right that an engine only "feels" air density, not altitude but "density altitude" is not a real term.
• At Sea Level the 335i has about 1.5% more torque than the M3 but is delivered across a much NARROWER rpm band than the M3, NOT A BROADER band.
• Although torque and hp are affected by density the width of the curves is NOT affected.

[joema]

Originally Posted by swamp2

[LIST]
You are right that an engine only "feels" air density, not altitude but "density altitude" is not a real term.

Density altitude is a real and standard term, and has been used for many years: http://en.wikipedia.org/wiki/Density_altitude

Originally Posted by swamp2

At Sea Level the 335i has about 1.5% more torque than the M3 but is delivered across a much NARROWER rpm band than the M3, NOT A BROADER band.

According to this test: http://www.m3post.com/forums/showthr...highlight=dyno at sea level the 335i peaks at about 8.5% more torque than the M3. Rather than exceeding the M3 torque over a "much narrower" range, it exceeds M3 torque from about 2,200 rpm to 5,600 rpm. IOW the 335i torque is greater than the M3 over the majority of the captured M3 rev range.

Originally Posted by swamp2

Although torque and hp are affected by density the width of the curves is NOT affected.

You're right curve width isn't affected by altitude -- the M3 would still rev to 8,400 rpm, albeit making much less hp and torque. By contrast the 335i would still rev to its redline, making about the same hp and torque as sea level. IOW at altitude, the 335i torque would exceed the M3 over a broader range than at sea level.

[Keto]

Ok, we have definitely achieved our quota.

/summon Procede posts.

Seriously, how long can we go on talking about the idea that an engine with a design that incorporates parts designed to operate at altitude bests an engine that does not include those parts?

Sell the OP some fenders from the other thread and call it a day.

[thedoctor]

All these theories and calculations sound good, but how do you explain that the Z4 M Coupe is quicker than the new M3 according to tests both conducted in Johannesburg by the same magazine? 5.3 vs 5.6 sec (cars in action)