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Old 10-22-2008, 05:50 PM   #1
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Originally Posted by ROCKLAND TOYOTA View Post
DON'T NEED NO STINKiN TACH, ive gotten used to listening to my motor......
LOL - my friend is trying to convince me to get a tach. I tells him i don't needs it, so whatever! you don't NEED a tach when driving a manual. If it was truly NEEDED, Toyota would have installed it.

As for PK's (?) numbers being different from the owner's manual... well, that was just HIS preference. We all shift at different speeds. Also, i believe the original queston (sort of, as it was more like TWO parts) was...
I'd like to know how fast I can go in each gear in order to achieve maximum acceleration.

You wont achieve max accel from redlining these motors.
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Old 10-22-2008, 05:53 PM   #2
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Originally Posted by justjesus View Post
LOL - my friend is trying to convince me to get a tach. I tells him i don't needs it, so whatever! you don't NEED a tach when driving a manual. If it was truly NEEDED, Toyota would have installed it.

As for PK's (?) numbers being different from the owner's manual... well, that was just HIS preference. We all shift at different speeds. Also, i believe the original queston (sort of, as it was more like TWO parts) was...
You can use the speedometer as an indicator for red-line in each gear, which is the point of this thread.

I put little marks on the face of the speedometer on my 1997 Tacoma 2wd. I used the stick on "pin striping" tape that I bought for a couple of bucks somewhere. I marked it per the "maximum shift points" in the owner's manual. It worked fine.
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Old 10-22-2008, 05:56 PM   #3
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You can use the speedometer as an indicator for red-line in each gear, which is the point of this thread.

I put little marks on the face of the speedometer on my 1997 Tacoma 2wd. I used the stick on "pin striping" tape that I bought for a couple of bucks somewhere.
not a bad idea, the pin striping.

Oh, also. I believe the manual calls for 1,000 MILES break in distance. The sad part, they mention, is you can't just take a long drive, or keep it at certain speed for "extended periods" or something like that. So my idea of a Vegas trip to break it in was thrown out the window. booooo. LOL
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Old 10-22-2008, 06:01 PM   #4
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You wont achieve max accel from redlining these motors.
I'd love to see you prove that empirically.

Peak HP occurs at 6,000 RPM. Redline occurs at 6,500 RPM.

You'll want to shift at or near red-line for peak performance, even though engine horsepower falls off after 6,000 RPM. Why? Because doing so will put the engine closer to its horsepower peak in the next gear (immediately after the up-shift) while ensuring peak obtainable drive-wheel torque at all vehicle speeds.

Precise shift points would be determined in the fashion discussed in this link:

http://www.allpar.com/eek/hp-vs-torque.html

Generally speaking, shifting at red-line is a good "rule of thumb" for maximizing acceleration. That tends to be especially true for higher revving, small displacement DOHC engines (e.g. Yaris engine).

I've been told that the Yaris's owner's manual recommends the following shift points for maximum acceleration:

1 to 2: 31 MPH

2 to 3: 59 MPH

3 to 4: 86 MPH

Assuming that's true, I suspect that each of those shift points corresponds to engine red-line in the Yaris models equipped with tachs.
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Old 10-22-2008, 07:46 PM   #5
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Originally Posted by PK198105 View Post
if you like i could scan the page relating to this from the actual manual. let me know.

as for max power best way would be to do a dyno run and see the RPMs at which power peaks, Garm i believe has acces to a dyno
Please scan that page of the manual if you don't mind.


Peak power (106 HP @ the flywheel) occurs at 6,000 RPM - just like Toyota says it does. Peak power will be less when measured on a chassis dyno, though the RPM at which it occurs will be identical.

That says little about determining shift points for optimal acceleration, though, as explained here:

http://www.allpar.com/eek/hp-vs-torque.html

Generally speaking, one wants to shift at engine red-line (ABOVE PEAK HP RPM) in order to maximize acceleration. That's particularly true with "peaky," small displacement, DOHC engines (e.g. Yaris 1.5 liter).
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Old 10-22-2008, 08:02 PM   #6
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Originally Posted by 09TRD View Post
Peak power (106 HP @ the flywheel) occurs at 6,000 RPM - just like Toyota says it does. That says little about determining shift points for optimal acceleration, though, as explained here:

http://www.allpar.com/eek/hp-vs-torque.html

Generally speaking, one wants to shift at engine red-line (ABOVE PEAK HP RPM) in order to maximize acceleration. That's particularly true with "peaky," small displacement, DOHC engines (e.g. Yaris 1.5 liter).
i have no tach and hence rely on engine sound so i can attest to to the claim about peak power. i say this cause when i shift at redline i notice a slight bog in power but when i shift JUST before im spinning 18inch tires in second gear and third doesn't have that lag you get around 60 mph........
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Old 10-22-2008, 08:35 PM   #7
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Originally Posted by ROCKLAND TOYOTA View Post
i have no tach and hence rely on engine sound so i can attest to to the claim about peak power. i say this cause when i shift at redline i notice a slight bog in power but when i shift JUST before im spinning 18inch tires in second gear and third doesn't have that lag you get around 60 mph........
How does the rolling diameter of 18" set-up compare with the OEM set-up?

If it's off, indicated speed will differ from actual speed.
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Old 10-22-2008, 09:36 PM   #8
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Originally Posted by 09TRD View Post
I'd love to see you prove that empirically.

Peak HP occurs at 6,000 RPM. Redline occurs at 6,500 RPM.

You'll want to shift at or near red-line for peak performance, even though engine horsepower falls off after 6,000 RPM. Why? Because doing so will put the engine closer to its horsepower peak in the next gear (immediately after the up-shift) while ensuring peak obtainable drive-wheel torque at all vehicle speeds.

Precise shift points would be determined in the fashion discussed in this link:

http://www.allpar.com/eek/hp-vs-torque.html

Generally speaking, shifting at red-line is a good "rule of thumb" for maximizing acceleration. That tends to be especially true for higher revving, small displacement DOHC engines (e.g. Yaris engine).

I've been told that the Yaris's owner's manual recommends the following shift points for maximum acceleration:

1 to 2: 31 MPH
2 to 3: 59 MPH
3 to 4: 86 MPH

.
And I'd love to prove it as well. If i had easier access to a track, I'd do it. Would you settle for a measured distance (1/4 mile) vs time (stopwatch)?

It's nice to have peak HP so close to redline, as it makes your point that much easier to work with. And, for most people (as well as the common point of view), shifting at redline would be best.

Last edited by justjesus; 10-22-2008 at 10:04 PM.
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