Torque Dip: Why all the fuss?

[Trettiosjuan]

Most gearboxes practically half revs from 1st to 2nd. Unless you redline it in first, try to do that elegantly mid curve, if you even can downshift smoothly into 1st without upsetting balance, you'll end up in the dip in 2nd. (Talking commited driving here again, not saucing around town).

No dip => no problem.

[robwbright]

Originally Posted by Bristecom

My impression each time was, "Oh, this has pretty good low-end torque." Then, suddenly.. "Is something wrong? I'm losing power?" Then I look down at the tachometer and realize I'm in the torque dip. Now a lot of people say they don't often floor it on the roads but with this type of car and in my driving environment, I very often floor it.

Well, if you floor it at 3500 or 4000 rpm, you're not going anywhere particularly fast. It's just the way it is. As others have mentioned, down shift. If I'm going to pass someone I always switch to the gear that will have me right around 5,000 rpm... even if that means shifting directly from 6th to 4th or 5th to 3rd. If you do that, you'll have no trouble getting around them quickly. According to the Torque Pro app, my 40-60 time in this basically stock car is just under 3 seconds. 60-80 right around 4 seconds. 40-80 in under 7 seconds is plenty fast enough to get around a slow driver (and to get a ticket for doing it).

It's similar to the 2 stroke motorcycles a previous poster referred to. To ride a 2 stroke 125 MX bike fast, you will never let the revs drop below 9,000 rpm (with redline at about 12,000). A skilled rider giving it to a 2 stroke 125 is a sight to behold (and amazing to hear - if you haven't witnessed it in person before, you'd would probably think the engine is about to explode. Sounds like a beehive - as heard about 15 seconds into the following video)

[ame="http://www.youtube.com/watch?v=kdgy09G61v8"]Yz 125 pinned - YouTube[/ame]

There's a LOT of shifting between gears 2, 3, 4, 5 in that video. 2nd in most corners with a lot of clutch. Might be as high as 5th or even 6th in the straights. A good 125 rider will probably shift through 75 times in a lap.

The MX equivalent to a V6 is a 250 4 stroke - which runs in the same class as the 125 2 stroke and has just slightly more peak HP, but a lot broader powerband. On those 250 4 strokes, you can ride just as fast as the 125 2 stroke anywhere from, say, 6,000 rpm all the way up to the peak of 13,000+/- rpm. You can hear the 4 strokes in that video above - much deeper sound.

So the 250 4 stroke is EASIER to ride fast... but multi-time MX champ James Stewart used to win lots of races on a 125 2 stroke when most of the other pro riders were on a 250 4 stroke. Speed is a whole lot more about the rider/driver than it is about some "torque dip".

That said, I switched from 2 strokes to 4 strokes some time ago... and I, too, plan to get rid of the torque dip.

[Quentin]

Originally Posted by tahdizzle

that's a nice graph. But just because you CAN doesn't mean the transmission likes it.


Its all moot, because you're still in the torque dip.

"You almost had me? You never had me - you never had your car... Granny shiftin' not double clutchin' like you should."

Stupid F&F quote aside, you should be able to rev match and get into first. Is this not the case? I don't have my FR-S yet, but I haven't noticed any nuances like that on the 30 miles or so I have behind the wheel.

[tahdizzle]

Originally Posted by Quentin

"You almost had me? You never had me - you never had your car... Granny shiftin' not double clutchin' like you should."

Stupid F&F quote aside, you should be able to rev match and get into first. Is this not the case? I don't have my FR-S yet, but I haven't noticed any nuances like that on the 30 miles or so I have behind the wheel.

heel toe shifting.... and I am not pro at it. Something I need to work on admittedly. No time to double clutch to rev match...

but it would STILL BE IN THE TORQUE DIP. Holy broken record Batman!

[Quentin]

Originally Posted by tahdizzle

heel toe shifting.... and I am not pro at it. Something I need to work on admittedly. No time to double clutch to rev match...



but it would STILL BE IN THE TORQUE DIP. Holy broken record Batman!

As long as you aren't at the beginning of the dip, where torque is dropping with RPM increase, being "in the dip" isn't a problem. If the gear change put you at the beginning of the dip where torque was falling off, you'd have a flatter power profile, which is bad. The dead feeling is as you fall into the dip. Coming out or just on the outgoing edge should still have pretty good thrust.

I'm still convinced that the dip was a compromise. They could choose a cam and VVT profile for the given displacement that gave a flat curve that tapered off earlier or a curve flat in the low range and the performance driving rev range.

[tahdizzle]

Originally Posted by Quentin

As long as you aren't at the beginning of the dip, where torque is dropping with RPM increase, being "in the dip" isn't a problem. If the gear change put you at the beginning of the dip where torque was falling off, you'd have a flatter power profile, which is bad. The dead feeling is as you fall into the dip. Coming out or just on the outgoing edge should still have pretty good thrust.

this is all in regards to auto x and the effects of the torque dip. A to b driving there is not a problem. But when even a thousandth of a second can put you above the next guy in pax. You really wish the dip wasn't there.

[Tromatic]

500 bucks will go a long way to shrinking the torque dip.

Originally Posted by Quentin

Stupid F&F quote aside

I think you found the source of the problem.

[Chad86]

Originally Posted by Tromatic

500 bucks will go a long way to shrinking the torque dip.



I think you found the source of the problem.

Ecutek tune?

[N1rve]

I don't even notice it when I drive it normally.

[dirtymax]

How can you not notice the awful torque dip of this car? Every day driving your sitting right before the dip all day long which makes this car soooo slow unless you rev the piss out of it everywhere, or a second gear pull out of a 90* corner, or a stop light, or etc...

I have a whole garage full of bikes and it doesnt make my cars tq dip any better

[Dezoris]

The TQ dip hit me so hard yesterday I almost cracked my face open on the steering wheel.

It's an over blown issue, like most things.

[Quentin]

Originally Posted by Tromatic

500 bucks will go a long way to shrinking the torque dip.



I think you found the source of the problem.

F&F has created expectations that the only way to be fun is fast acceleration? I'm on the Miata/S2000/Elise end if the car enthusiast spectrum.

[tahdizzle]

It's been stated. In normal a to b driving, like 90% of people do, the torque dip is not an issue. In competitive driving it is an issue.

All of you people chiming in with "get a tune" need to understand a couple of things:

1. Tunes are not warranty friendly.
2. There are things called "rules" in sports. In the cs auto x class, tunes are not legal
3. We all don't live a quarter mile at a time.

[Trettiosjuan]

Any good driver can drive around the dip in competitive or "committed" driving no problem. Remains that it demands some attention that could go elsewhere. Most cars have flaws like this in one way or another, but that doesn't mean one can't strive for an even better driver experience.