setting and changing shift points with TH400
Thread Starter
Safety Car
Joined: Feb 2006
Posts: 4,855
Likes: 2
From: Columbia South Carolina
setting and changing shift points with TH400
Guys, Lets say I have a theoretical engine that makes 425hp and 405 ft lbs of torque, the peak torque is at about 5000 RPM and the peak HP is at 6000. My torque is above 400ft lbs from 4000 to 5500RPM.
Let me know if more info is needed I can use my Chevelle as the example.
Setting this car up for quarter mile performance, assuming street performance needs would be different.
Where would I want my shift points to be, just past peak torque? Also, How far should I want the RPMs to drop for each shift point, just below peak torque?
I am using a theoretical sbc and TH400 trans.
Discuss please.
Let me know if more info is needed I can use my Chevelle as the example.
Setting this car up for quarter mile performance, assuming street performance needs would be different.
Where would I want my shift points to be, just past peak torque? Also, How far should I want the RPMs to drop for each shift point, just below peak torque?
I am using a theoretical sbc and TH400 trans.
Discuss please.
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Guys, Lets say I have a theoretical engine that makes 425hp and 405 ft lbs of torque, the peak torque is at about 5000 RPM and the peak HP is at 6000. My torque is above 400ft lbs from 4000 to 5500RPM.
Let me know if more info is needed I can use my Chevelle as the example.
Setting this car up for quarter mile performance, assuming street performance needs would be different.
Where would I want my shift points to be, just past peak torque? Also, How far should I want the RPMs to drop for each shift point, just below peak torque?
I am using a theoretical sbc and TH400 trans.
Discuss please.
Let me know if more info is needed I can use my Chevelle as the example.
Setting this car up for quarter mile performance, assuming street performance needs would be different.
Where would I want my shift points to be, just past peak torque? Also, How far should I want the RPMs to drop for each shift point, just below peak torque?
I am using a theoretical sbc and TH400 trans.
Discuss please.
Thread Starter
Safety Car
Joined: Feb 2006
Posts: 4,855
Likes: 2
From: Columbia South Carolina
cant you make custom gear ratios? Not sayin I would, just asking if its done, like the M20 vs M22 4 speeds.
Race Director
Joined: Oct 2000
Posts: 15,009
Likes: 79
From: central FL, near the beach.
Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
Your quickest times will typically be had by shifting past peak HP a few hundred RPM.
Exactly where will have to be found through trial and error.
Also, your optimum 1-2 shift point & the 2-3 shift point, arent always at the same RPM.
Usually the 2-3 will be shifted higher than the 1-2.
Last edited by DRIVESHAFT; Aug 7, 2008 at 03:39 PM.
Melting Slicks
Joined: Jun 2001
Posts: 2,264
Likes: 546
I see a lot of people cutting up their cars to change governor springs. It will come out if turnned correctly for clearance. Easier on a lift, but I've changed springs under the car at the track. If you need help picking which springs in the B&M kit to use for different rpms, pm me.
