Shift Points

[Houston Kid]

I only have 700is miles on the car. I am so use to an engine that does not rev as high. Imagine that.
At what point should I be shifting for maximum performance?

For example for a 0-60 run, should I take the RPM all the way to 8250 or 8000 etc?
I have been shifting around 7500-7800. Am I leaving some split seconds on the table by shifting too soon?

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[dron_jones]

[ame]

 

[Houston Kid]

Not good at math but I took away from the video redline that MOFO!
Unless the torque is less compared to the next gear ratio but I am guessing not the case with the GT350.
THX

 

[xt6wagon]

Its at redline, but short shifting isn't much of a deal with the peak power at 7,500 and the close ratio box. In fact I'd short shift 1st anyway since hitting the limiter is worse than the short shift and it picks up RPM so fast. The powerband is 4K-8.25K with 6-8K being the heart of it. 4-6K isn't as strong, but don't be afraid of it on a road course as avoiding a shift pays off most times.

Edit: also 0-60 in this car is a absolute mess for a 500hp car. Its very very good when already moving.

 

[Houston Kid]

Its at redline, but short shifting isn't much of a deal with the peak power at 7,500 and the close ratio box. In fact I'd short shift 1st anyway since hitting the limiter is worse than the short shift and it picks up RPM so fast. The powerband is 4K-8.25K with 6-8K being the heart of it. 4-6K isn't as strong, but don't be afraid of it on a road course as avoiding a shift pays off most times.

Edit: also 0-60 in this car is a absolute mess for a 500hp car. Its very very good when already moving.

I agree with your edit and I know the car was designed more for the track than drag strip or 0-60 but I would like to improve on my 0-60 time which according to the app in the car is 4.8. That was on hard concrete with no "tire warm up" and repeated about 5 times over the course of a few days. Never better but a few 4.9's mixed in. I need to find a nice sticky black top with a posted speed of 60 and a red light. LOL.

 

[jasonstang]

For max acceleration, to the redline of course.
More horsepower to the wheels more speed.

 

[lemers]

I need to find a nice sticky black top with a posted speed of 60 and a red light. LOL.

The is a road in el paso

 

[Zombo]

Based on an analysis I did a year ago, for the GT350, it's redline. That is not always the case - for other cars, a equivalent analysis would need to be done.

 

[ElAntonius]

Generally speaking, the car will accelerate the hardest at the torque peak in a gear.

"AHA!", you say, "So I should shift well before the redline?"

No, because of how gearing works. In most cars (and this includes the GT350), the torque to the wheels at redline is higher than the torque to the wheels at the same speed in the next gear up.

IOW: the wheel torque at redline in 1st is higher than the peak torque in 2nd. So shift at redline.

I set my shift lights to 8000 RPM on the 350 and that works well for me. If I set it to 8200 I find I'll hit the limiter in 1st and 2nd.

---

The above also discounts traction. In a lot of cars short shifting 1st can be beneficial as you're overwhelming the tires in 1st anyway, but that's more the art than the science of it.

 

[nastang87xx]

I set my shift lights to 8000 RPM on the 350 and that works well for me. If I set it to 8200 I find I'll hit the limiter in 1st and 2nd.

Same, I'm at 8100.

 

[THX 138]

Based on an analysis I did a year ago, for the GT350, it's redline. That is not always the case - for other cars, a equivalent analysis would need to be done.

What am I missing? Based on the numbers in this PDF, it looks like the shift point should be right at 8,000, not 8,250, for virtually every shift. (Higher output torque in-gear and in the next gear.)

 

[Zitrosounds]

Same, I'm at 8100.

Ditto! 8100!

 

[ElAntonius]

What am I missing? Based on the numbers in this PDF, it looks like the shift point should be right at 8,000, not 8,250, for virtually every shift. (Higher output torque in-gear and in the next gear.)

I dont see that?

The only one where there's even an output torque higher in the next gear at any RPM compared to the lower gear at 8250 RPM is the 4th to 5th shift, and that's minor.

What you want to think of is "if I shift now, will my output torque go up?". If the answer is no, then you don't want to shift. Sure, if you short shift you might get into a meatier part of the powerband in the next gear up, but the problem with that is that no matter how meaty it is on the GT350 it's all but guaranteed to not beat the torque multiplication from the lower gear.

 

[Zombo]

What am I missing? Based on the numbers in this PDF, it looks like the shift point should be right at 8,000, not 8,250, for virtually every shift. (Higher output torque in-gear and in the next gear.)

If you look at the second page, there is always more torque at the wheel in the lower gear, up to redline, then the next gear at it's equivalent RPM (for the vehicle speed).

Take 1 to 2, for example. If you are at 8250, first is putting down 943. If you shifted at 8000, you'd be at 814 in second, hence, it is better to hold first.

BTW, these are not the actual torque to wheel numbers, as the final drive and tire diameter, which are constants, are not accounted for in these values.

 

[Zitrosounds]

Watch the video shared in this thread

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