manual transmission shift points?
manual transmission shift points? Something I just figured out from my dyno graph. My "proper" shift points in my car.
Basically, in each gear, acceleration is found by gear X torque at a given rpm. To find out where to shift out of first, you take your TQ in 2nd gear times the second gear ratio, then divide by the first gear ratio. When you go below that TQ amount in first gear, you should shift. Right? This is as long as there aren't more drivetrain losses in different gears or something.
From my dyno graph, My shift points should be....
1st to 2nd- 6800 rpm (at 6800, 2.66 x 234tq = 1.78 x 350 tq)
2nd to 3rd- 6600 rpm (at 6600, 1.78 x 255tq= 1.3 x 350tq)
3rd to 4th- 6200 rpm (at 6200, 1.3 x 269tq = 1 x 350tq)
This kinda surprised me that they were all so different. I guess it makes since because of the spacing of the gears. 2.66, 1.78, 1.3, 1.0, .74, .5
The biggest gaps are from 1st to 2nd, and from 5th to 6th.
Does this make sense? What are your shift points like?
Basically, in each gear, acceleration is found by gear X torque at a given rpm. To find out where to shift out of first, you take your TQ in 2nd gear times the second gear ratio, then divide by the first gear ratio. When you go below that TQ amount in first gear, you should shift. Right? This is as long as there aren't more drivetrain losses in different gears or something.
From my dyno graph, My shift points should be....
1st to 2nd- 6800 rpm (at 6800, 2.66 x 234tq = 1.78 x 350 tq)
2nd to 3rd- 6600 rpm (at 6600, 1.78 x 255tq= 1.3 x 350tq)
3rd to 4th- 6200 rpm (at 6200, 1.3 x 269tq = 1 x 350tq)
This kinda surprised me that they were all so different. I guess it makes since because of the spacing of the gears. 2.66, 1.78, 1.3, 1.0, .74, .5
The biggest gaps are from 1st to 2nd, and from 5th to 6th.
Does this make sense? What are your shift points like?
On The Tree
Joined: Nov 2004
Posts: 143
Likes: 0
From: NY
I just shift everything at 6000. I dunno but anything higher just seems like its passed the powerbands high point. Just seems like revving out for no extra gain. I know everybodys setups are different, but I'm just talking a completely stock 2000 LS1 here like mine.
