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If all you care about is acceleration as stated above shifting at or near peak power is best rather than at peak torque.
 

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I remember motortrend saying to dump it at 2k revs, ride out first and slam into second. Got them a 5.9 to 60. I'll post a video of their test for ya.


I am sure members have found better ways though. Good luck on your quest.
 

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Okay so I found that revving the car past 5400-5500 ish rpm is kind of useless. But to each their own, you are only going to carry your Horse and Torque for so long throughout the RPM range anyhow. Why shift past the point where your turbo falls flat on its face? (around 5700+ rpm)
 

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Yep you want to learn what your car is capable of whp/tq wise and based on that curve drop (no more power gain) is where you base your shift point on. If you are programing a shift light into the equation, set it 200rpms before your wanted shift point. Normally that is common reaction for response time, from sight of light going off to physically shifting your gear into the next.
 

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don't shift out of 1st until your road speed is 40. you can shift 2nd just before redline and definitely get out of third around 6000
 

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Yep you want to learn what your car is capable of whp/tq wise and based on that curve drop (no more power gain) is where you base your shift point on. If you are programing a shift light into the equation, set it 200rpms before your wanted shift point. Normally that is common reaction for response time, from sight of light going off to physically shifting your gear into the next.
Good point about the shift light, I just changed mine. I would also add the AP reads higher than the tach too. Not sure which one to go by for sure.
 

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Finding the optimal shift point is much less subjective than "just past peak." The ideal shift point is based on the power curve and gear ratio. Use HP as the power figure since gear ratios change you must use a derivative figure based on RPM rather than fixed torque.

3.231 1st
1.952 2nd 39.6%
1.321 3rd 32.4%
1.029 4th 22.2%

The % is the reduction in ratio per gear change. This means that the the difference in RPM will be reduced by 39.6% shifting out of 1st into 2nd. You would then get equal acceleration in 2nd as you would in 1st if the power increased by an equal factor. Using the dyno chart from Project Silver Lining for a stock ST:

HP at 6700 is 174.51

174.51/(1-.396) = 288.92

This means that after you shift out of first to get equal acceleration you would have to make 288 HP. And you don't, ever. So riding out first would be correct.

2nd shift at redline would then need 258.15HP to pull as hard in third, which it doesn't. Ride out 2nd.

For 3rd gear shift, at 6700 you'd have to hit 224.3HP on the shift to continue the pull. However at 6700 in 3rd, the 4th shift would hit at 5200 rpm and power would be at 237. This definitely means you went too far and have to shift earlier. My advanced algebra hasn't been used in too many years to make an equation that would find the intersecting points for me... but it is equatable via math.

The unknowns you have to account for are other problems, like heat soak and wheel spin. Pulling through all the gears is going to produce more heat than just a 4th gear dyno pull. So as you go through the gears the power drop-off can become more of a factor and you are forced to short shift. Also excessive wheel spin in the lower gears could rob power versus being able to put it down by shifting into a higher gear.
 

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I don't know if you guys are trolling or maybe I'm not being clear, but why would I care about MPG when I'm doing a 1/4 mile run at the track?

I'm just trying to figure out the best rpms to shift at for the quickest acceleration

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Boy this guy is really smart. Explain what what you want from us. So we know how to answer your question. This is like me asking Can I run 1000 cc injectors? Then when the community ttys to answer I tell you guys are a bunch tools I am running E85. :lol: Oh I forgot to mention this.
 

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Boy this guy is really smart. Explain what what you want from us. So we know how to answer your question. This is like me asking Can I run 1000 cc injectors? Then when the community ttys to answer I tell you guys are a bunch tools I am running E85. :lol: Oh I forgot to mention this.
I thought he was pretty clear when asked for "quickest acceleration"! I can't think of any reason someone would worry about MPG when wanting to accelerate quickly, but then again I'm Canadian. lol
 

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No one is trolling. Shifting certain RPMs keeps the car in its power curve which = quicker acceleration. DO NOT shift while the car breaks traction. Always wait till the car is done spinning its tired before shifting.

If you wait too long, boost starts to drop off, and you are actually accelerating slower after the ~5300rpm mark. If you watch your boost gauge, you will actually see the gauge drop in pressure. Every gear is different, and only after driving the car a lot, and doing a bunch of runs will you learn what YOUR cars peak performance mark is.
 

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The ideal shift point is based on the power curve and gear ratio.
In short THIS^^

NEVER shift an peak, always some point past peak but the exact RPM will vary on gearing.

The idea is to maintain as much area under the hp curve for each gear.
I couldn't find a decent graph but this one is good enough and will help illustrates gubbs3 post:
Notice how the 1/2 shift occurs much later than any of the others. You want the HP at the shift point to equal the Hp at the start of the next gear

52848-transmission-intergear-ratios-vs-proper-shift-points-shift-point-illustration.gif
 
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