Gears, 2.73 vs 4.10 and up
11-14-2004 | 10:06 PM
#1
Gears, 2.73 vs 4.10 and up So my instinct is 4.10's will make my car pull like crazy, I used to own a viper and loved how it was geared also.
The time for a new rearend is soon, the 408 already makes a lot of power and im sure its hard on the stock rearend, now twin turbos are going on and that will destroy my stock gm 10 bolt in no time.
My question is, how will lower vs higher gears effect the et and trap speed of the car if its making huge power? What kind of gears give me the best acceleration from a freeway roll? I've seen some fast DSMs that have to shift through all their gears before the end of the track because of how steep the gearing is, and it seems to me like it would be better to have a lot longer gears, with a manual tranny and turbo car.
The time for a new rearend is soon, the 408 already makes a lot of power and im sure its hard on the stock rearend, now twin turbos are going on and that will destroy my stock gm 10 bolt in no time.
My question is, how will lower vs higher gears effect the et and trap speed of the car if its making huge power? What kind of gears give me the best acceleration from a freeway roll? I've seen some fast DSMs that have to shift through all their gears before the end of the track because of how steep the gearing is, and it seems to me like it would be better to have a lot longer gears, with a manual tranny and turbo car.
11-14-2004 | 10:23 PM
#2
To maximize your E.T.'s you want to go through the trap at or near redline of your transmissions 1:1 ratio gear (4th for the T-56) This will ensure your engine stays in it's peak HP range. As an added bonus this will help keep your turbos spooled up.
For example with the 2.73 gear, your RPM's will be to low when you shift, you will have to build up more rpms to be in the peak portion of your HP curve.
One downside or 4.11 gears is the traction issues off the line. Obviously there are plenty of suspension upgrades to take care of this.
Assuming traction is not an issue you will have the best e.t.'s with a gear that will allow you to be at peak rpms through the trap.
If you know your HP and weight, you can estimate your trap speed.
With this trap speed, go to the web site below and choose a gear that will allow you to go through the traps at peak RPMs in 4th. Note, that tire growth will change your speed calculations.
http://www.f-body.org/gears/
For example with the 2.73 gear, your RPM's will be to low when you shift, you will have to build up more rpms to be in the peak portion of your HP curve.
One downside or 4.11 gears is the traction issues off the line. Obviously there are plenty of suspension upgrades to take care of this.
Assuming traction is not an issue you will have the best e.t.'s with a gear that will allow you to be at peak rpms through the trap.
If you know your HP and weight, you can estimate your trap speed.
With this trap speed, go to the web site below and choose a gear that will allow you to go through the traps at peak RPMs in 4th. Note, that tire growth will change your speed calculations.
http://www.f-body.org/gears/
11-16-2004 | 10:48 AM
#4
Damn! A TT 408 will be making a ton of power. How high will you be spinning the motor, and what size slicks? I would think youll be stepping up to a 28" tire for the track, no? What are you hoping for in terms of trap speed? If youre not sure, you can get a rough idea by calculating from estimated HP and race weight.
-T
-T
