Sport Mode

[lovemycarM35]

Ok guys I'm still learning this car so I've been playing around with sport mode, and I noticed that the car does respond much better but a few times it held on to low gear petty long is this normal? I've read a few other people reported that. or is this mode meant for speed only.

Thanks

[DredM56]

Sport mode is for aggressive driving. It will rev out each gear more even without full throttle. It will engine brake when hard on the brakes especially downhill. Sometimes in my G you would get on it a bit and when you let off it holds the rpm high for sometimes a little long before upshifting.

Haven't used sport mode that much yet on the M but I would imagine that it does similar things. My girl would sometimes get worried something was wrong cause it would be holding 5k rpm for a bit long for your normal person

[lovemycarM35]

thanks for replay I thought something was wrong with my M. So can I use sport mode all the time standard mode is way to soft for me at times when i need power?

[DredM56]

Yeah shouldn't be an issue just have to live with the higher rpms

[DredM56]

I forgot to add to each mode gives you different throttle response. Snow mode dulls the response a lot.

[Ilya]

I'm in sport mode 99% of the time when driving, and 50% of that time I'm also in manual.

[ArmedAviator]

Sport mode is fine and won't break anything. I prefer Sport mode solely for the faster throttle response. I prefer the relaxed shifting of Normal mode generally.

[Larz]

I felt it was strange as well so I did some reading about this and if I understand correctly, here is the basic reasoning:

With any gear box, there is a 'sweet' spot where torque and hp are at optimum levels at the same time. Generally, low gears require higher revs from the gear box, higher gears not so much revs. Because of that, at lower gears, you have higher torque but lower hp. The car leaps forward with torque, but you can't get to a high speed in a low gear. In higher gears, you get a little less torque but increased hp to reach higher speeds. During these changes, the engine and gear box are not at the same revs. Sport mode makes the engine and gear box match revolutions and mesh together as one so you can reach that 'sweet' spot with the best mix of torque and hp in each gear which makes the car respond quicker and reach higher speeds in less time. It actually maximizes that blend of torque and hp to get the fastest response. I'm told it also increases 'engine braking' to assist the brake pedal when decelerating from a high speed.
It holds the engine and gear box at the same revolutions (for a time) so if you lift your foot off the pedal, and mash it again, there is no delay between mashing the pedal and the gear box propelling you forward again. When decelerating, each lower gear requires the gear the gear box to rev higher so upon coming to a stop, you will feel and hear the engine rev jump to match the gear box as it shifts back into first gear. It's like getting the 'feel' of manually doing all the skillful work to do rev matches and gear shifts without you having to do it.

[lovemycarM35]

wow that was a handful but I think I understand would love to hear what other peoples experience with sport mode. I'm also going to do the ECU relearn I heard that improves performance.

[insanex1]

98% sport mode, manual mode, traction control off.

[lovemycarM35]

98% sport mode, manual mode, traction control off.

is there a reason you turn traction control off?

[insanex1]

yes, sometimes when I step on it from a start and the rear wheels slightly spin the breaks come on and slow me down. With the traction control off I have more control.

[Ilya]

VDC in this car is WAY restrictive. Sometimes I just want to make some wheel noises (to quote Jeremy Clarkson lol) and it doesn't let me. Wish there was a way to toggle it on/off so in the summer I could just have it off all the time, etc.

[infinitedrift]

Sport mode 99% manual mode 99% ..lol.

[ArmedAviator]

Larz's explanation is on the right track, although not quite correct.

A few things to explain...

1) HP = (torque [lb-ft] * RPM) / 5252

Torque is the important number. Torque is a measure of force. HP is merely an expression of torque at a specific RPM (look up dyno graphs). The calculation above also explains why every dyno graph shows torque and HP meeting at 5252 RPM.

Given the same throttle position and air charge, the engine will always produce the same torque (and therefore HP) at any given RPM. I said, based on air charge as well, because as we all know, hot air is less dense and therefore the engine produces less power.

Every engine does have a "sweet spot," or more accurately, a "sweet range." This range is where the engine produces it's greatest torque. Every engine model is different. Small things can change this such as exhaust mods, intake plenum, etc.

The engine will accelerate the vehicle quickest in ANY gear within this "sweet range." The "sweet range" is not specific to any gear - it is the same in any gear.

2) Every gear has a different gear ratio which means different torque multiplier

As we increase gear (1st through 6th), we decrease the gear ratio. I'm not certain off hand of the Infiniti's 6AT ratios, but here's a simple example of what happens.

Let's make our hypothetical situation as follows:
1st gear: 3:1
2nd gear: 2:1
3rd gear: 1:1
4th gear: 0.75:1
Engine torque (pretending it's constant): 100lb-ft.

This simple math would give you the following:
1st gear wheel torque: 100 * 3 = 300 lb-ft.
2nd gear wheel torque: 100 * 2 = 200 lb-ft.
3rd gear wheel torque: 100 * 1 = 100 lb-ft.
4th gear wheel torque: 100 * 0.75 = 75 lb-ft.

(Note: This example assumes a final drive ratio of 1:1 which is not what these vehicles (or any vehicles) are equipped with.)

You can plainly see how keeping it in a lower hear has the advantage in accelerating the car. As Larz said above, the top speed per gear is DECREASED as the gear ratio is INCREASED, so you can't benefit from the increased torque forever.

Another hypothetical example with the same information as above: (assuming max speed is engine redline)
1st gear top speed: 100 / 3 = 33 MPH
2nd gear top speed: 100 / 2 = 50 MPH
3rd gear top speed: 100 / 1 = 100MPH
4th gear top speed: 100 / 0.75 = 133 MPH

So what do these 2 things have to do with the effectiveness of Sport Mode?

Sport mode keeps the lower gears engaged longer during acceleration because even as the engine revs past that "sweet spot" of maximum torque, having a torque multiplier of (per our example) 3:1 is better than 2:1. In addition, when you delay the shift, the next gear will now be engaged when it's deeper into the revband, and therefore probably closer to a better torque output.

It's all about using extracting maximum torque.

The second thing that Sport Mode does, which was also touched on is engine braking - although this is not the primary purpose this occurs in Sport Mode.

Engine braking occurs when the engine is left in a lower (i.e. 2nd instead of 3rd) and when you let off the gas, the engine is spinning much faster to keep up with the wheels. Normally, and automatic transmission has a coast gear which engages so it doesn't have much engine drag, but this is suspended, at times, in this driving mode.

The reason the engine RPM should remain higher is so when you DO get back on the gas, the engine is already at speed and applying maximum vacuum. This allows for faster fuel/air charge to reach the cylinders as they are sucking air as best they can when you get back on the throttle AND the transmission doesn't need to downshift and bring the RPM up again - they are already up. The increase in vacuum is what is trying to slow the engine down rapidly (which is more directly "tied" to your wheels because of the exclusion of the coast gear in this mode) and therefore causes more noticeable engine braking as a side-effect.

Finally, and the main reason I use Sport Mode alot is it's more instantaneous reaction with throttle input. Normal Mode throttle input is obviously buffered which is obnoxious as hell to me. When I hit the gas, I expect it to do as commanded NOW (also why I hate Airbus fly-by-wire aircraft and prefer Boeing's fly-by-cable-to-hydraulic-servo approach). Sport Mode isn't instantaneous either, but it's much closer.

Hope this information helps somebody.

[Frog]

Nice write up ! What's your ride measured in Mach ?

[ArmedAviator]

What's your ride measured in Mach ?

CRJ-900 Next Gen. Redlines at Mach 0.85.

[stm37s]

I drive my car in sport mode all the time and love how she sounds and handles.

[lovemycarM35]

That was a good write up,,thanks

[austin713]

driving around city, i get significantly worse MPG than standard mode. its way more fun though.

[lovemycarM35]

ok so i'f I'm driving alone and I need power, does sport mode kick in once it's activated or will i need to come too a complete stop?

[ArmedAviator]

It kicks in once it's activated.

But if you're driving along and you "need power," hit the accelerator harder and you'll get the power in Normal or Sport modes. Eco mode takes alot longer to respond.

If you're preparing to somebody on a two-lane country road, than by all means, use manual mode, downshift so your RPM is around 3.5-4k and then mash the gas when you're ready to go around.

[Debonair]

If you're preparing to somebody on a two-lane country road, than by all means, use manual mode, downshift so your RPM is around 3.5-4k and then mash the gas when you're ready to go around.

This. Just don't forget to put it back into auto and rev up like crazy. A friend of mine did that once.

[Mjkkb2]

sport mode 99% of the time; manual 99% of the time (mainly to control the auto shifting issues and I'm from Europe

[spirod]

I only drive in Sport and manual mode. Car is much more responsive. The programming on the 7AT is horrible even after the update. Had similar issues with my G37. Had a G35 with the 5AT and liked it much more than the G37 7AT.

I have been noticing a clicking sound coming from underneath the car. This occurs all the time when driving in manual mode in the parking lot when I release or press on the throttle. The noise also occurs in D mode but not as often. Anybody else experiencing this noise?

I will bring this up with the dealer when I go in to replace my power steering pump.

[agoodall]

Manual mode 99% of the time
Sport as needed (usually on the highway to get around dummies)

And I clear the "ecu learned behavoir" after every other oil change

[jmissile]

I only drive in Sport and manual mode. Car is much more responsive. The programming on the 7AT is horrible even after the update. Had similar issues with my G37. Had a G35 with the 5AT and liked it much more than the G37 7AT.

I have been noticing a clicking sound coming from underneath the car. This occurs all the time when driving in manual mode in the parking lot when I release or press on the throttle. The noise also occurs in D mode but not as often. Anybody else experiencing this noise?

I will bring this up with the dealer when I go in to replace my power steering pump.

I have the same noise and occurs exactly as u described,not sure but i think I read somewhere that this is normal?

[lovemycarM35]

Manual mode 99% of the time
Sport as needed (usually on the highway to get around dummies)

And I clear the "ecu learned behavoir" after every other oil change

do you see improvement after clearing the ECU I'm going to try this tonight?

[agoodall]

Manual mode 99% of the time
Sport as needed (usually on the highway to get around dummies)

And I clear the "ecu learned behavoir" after every other oil change

do you see improvement after clearing the ECU I'm going to try this tonight?

The car is definitely much more responsive to input. Moves a lot quicker off the line.

[spirod]

I only drive in Sport and manual mode. Car is much more responsive. The programming on the 7AT is horrible even after the update. Had similar issues with my G37. Had a G35 with the 5AT and liked it much more than the G37 7AT.

I have been noticing a clicking sound coming from underneath the car. This occurs all the time when driving in manual mode in the parking lot when I release or press on the throttle. The noise also occurs in D mode but not as often. Anybody else experiencing this noise?

I will bring this up with the dealer when I go in to replace my power steering pump.

I have the same noise and occurs exactly as u described,not sure but i think I read somewhere that this is normal?

Thanks for letting me know. First was the cold start-up noise that had me worried now this clicking noise. I will ask the dealer to look into it when I bring in my car sometime in July when they receive the power steering pump. Almost hoping that something is wrong - clicking noise is annoying.