SS Shift Point
 

I've noticed on the SS gauge cluster that the tach is blue to about 6k, with a blue line crossing at about 6250 RPM, then it is red to 6600, then red hashed past that. I am fully aware that the red hashing at 6600 is redline, but what about the area between 6250 and 6600 that's red, and what about the blue line crossing at 6250??? My guess is that it may be the optimal RPM to shift at for the 6-speed... Any other guesses?

Sorry about there not being a pic for reference, but it's on the new camaro site listed below and it's the last picture in the set.

http://www.chevrolet.com/allnewcamaro/#camaro=photos

You may have something there.

Thats a good question...will it have a shift light?

find out what the ls3 vette guys are shifting at... simple as that:) Seems to me gm makes the tach, rev limiter, and engine to where you shift within 250rpms of the limiter. So just shift like 250rpm before the red or like 6500

Shifting at the highest rpm you can is not always the quickest. There is a point where the next gear will have more power than the gear you're currently in. Although the car may spin to 6,500rpm doesn't mean that shifting at 6,250 is the best shift point. Maybe someone can post a link to a chart to compare rpm to gear shift points.

you will never have more power in one gear than the other, your engine just has more leverage over the drivetrain in lower gears.

the rpms=power (as far as the engine is concerned) 6000rpms in first is no more or less hp than 6000 in 5th, there's just a difference in speed

I was only speaking from experience with my ls1. I used to shift at 5500 which is where the red dot dot dot starts and I used to get horrible track times. That was back when I didn't know any better. I learned from all the other guys to shift at 6000 on my car. I started kicking ass after that:)

Also did you guys ever notice how the 97-04 ls1 vettes always were spec'ed at more power than our F-bodies? I noticed also that the same engine in the vette was spec'ed to something like 345 or 350hp@6000rpms with 350tq@5600rpms or something like that. Well for the fbodies they said 325hp@5500rpms and 325tq@ 4500rpms.

Why would it be different for the same exact engine? ITS NOT! Just something for you new guys to think about.

I also agree that the highest rpm is not always the best, but if the ls2 and ls3 follow after the ls1 then it is...

the difference in power ratings is all in the tuning. the LS3 in the vettes is rated at 436hp (with the exhaust package). we have the same engine, but due to differences between the two vehicles, they required slightly different tunings.

as for the shift points, it really depends on the gear you're going to. you want to shift to where the next gear puts you in the sweet spot of your power band. a taller gear will need to rev higher before you shift into it than a shorter gear. take my truck for example: during normal driving, my 2-3 shift is around 2500 (going from a 2.32 to 1.40) anything much less than that starts to bog if i'm accelerating. my 3-4 shift (1.40 to 1.00), however can easily accelerate at a 2000 rpm shift.

i know that example's a bit different than racing, but not much and the principle's the same. it all depends on where the next gear will put your engine speed. hope that helped

The bolded statement is not true.


Mathematically speaking, if (when x = current gears ration, y = next gears ratio, R = redline, and T = torque)

http://wolflord88.googlepages.com/equation1.JPG

than you'll need to short-shift.
- Xanthos

great explanation... for DGthe3!

care to tell us normal guys what that means?!

Heh. I put in a picture so you can see the equation better.


Basically what it means is that if you divide the new gear ratio by the old gear ratio, and multiply that by the ratio of the flywheel torque at the new RPM divided by the flywheel torque at the redline, and get a number greater than one, you need to short shift at the highest RPM where that number would be 1 or lower.

For example. An electric motor has the following torque curve.

http://wolflord88.googlepages.com/theoreticalmotor.JPG

and a 2 speed transmission, with first gear being a straight 1:1 gear and the second being a 0.5:1 "overdrive" gear.

At the 10,000 RPM "redline" in first gear, the motor would be producing a net 2 ft*lbs at the wheel. But at 5,000 RPM after the shift, it will be making 3.5 ft * lbs. Meaning there is a point where you could have short shifted for a larger net "power under the curve."

Heres a visual representation of this.

http://wolflord88.googlepages.com/theoreticalmotor2.JPG

As you can see, the total area under the curve is higher in the short shifted instance than it is when you shifted at the redline - because while the curves are nearly identical, for that split second after you shifted (leading up to when you WOULD have shifted) you have more power.

This happens very rarely with modern transmissions (once you have a lot of gears to play with you can prevent this pretty easily), but it is a theoretical possibilty, especially once you start modding.
- Xanthos

:hitcomputer::hitcomputer: :popcorn:

english is appreciated on this forum lol

xanthos you must do alot of work with some type of motor or engine, or way to much free time to do research lol:respekt:

cuz im like :iono: kinda

No that is not right, jeez here it is.