Top Loader to a TKO600, Any Regrets?

[eschaider]

Unless you get the Liberty shift kit and carbon fiber synchs (or equivalent) the 2/3 shift is going to be disappointing.

Because of the way Tremec chose to manufacture the countershaft there is a 0.140" or so mis-alignment between the main shaft and countershaft third gears. If you make ~ 500 - 600 ft/lbs of torque and can properly speed shift into third and also hook up in third gear you have an improved chance of breaking third gear.

In fairness the poor 2/3 shift quality of the stock box goes a long way to protecting third. Even if you get the 2/3 shift fix you still have to be able to hook it up in third gear - which at the 600 ft/lb TQ level can be challenging. Bottom line is you probably won't break it, unless you are very good.

You will love the OD on the highway. The 0.82 OD feels more like a next gear. The 0.64 OD feels like a big gulp when you let the clutch out. If your motor has a lumpy idle and challenged drivability is high gear below 2000 rpm you will not find the ODs as attractive as you might suspect. The 0.64 OD on a engine with driveability issues below 2000 rpm will feel like a land speed record gear because of how fast the car will be going to get away from the bucking and farting of the engine at high load and low rpm.

On the other hand an engine with good drivability and manners below 2000 rpm will be an absolute pleasure to put into (.82) OD on the expressway. The .64 OD will still feel a lot like a LSR gear but with much reduced bucking and farting.

Ed

[mkassab]

I started my build with a TKO 600 with no complaints. In conversations with other Cobra owners I most often hear I wish I had a 5th gear..... and have never heard the opposite.

Mark

[Great Asp]

Originally Posted by eschaider

Unless you get the Liberty shift kit and carbon fiber synchs (or equivalent) the 2/3 shift is going to be disappointing.

Because of the way Tremec chose to manufacture the countershaft there is a 0.140" or so mis-alignment between the main shaft and countershaft third gears. If you make ~ 500 - 600 ft/lbs of torque and can properly speed shift into third and also hook up in third gear you have an improved chance of breaking third gear.

In fairness the poor 2/3 shift quality of the stock box goes a long way to protecting third. Even if you get the 2/3 shift fix you still have to be able to hook it up in third gear - which at the 600 ft/lb TQ level can be challenging. Bottom line is you probably won't break it, unless you are very good.

You will love the OD on the highway. The 0.82 OD feels more like a next gear. The 0.64 OD feels like a big gulp when you let the clutch out. If your motor has a lumpy idle and challenged drivability is high gear below 2000 rpm you will not find the ODs as attractive as you might suspect. The 0.64 OD on a engine with driveability issues below 2000 rpm will feel like a land speed record gear because of how fast the car will be going to get away from the bucking and farting of the engine at high load and low rpm.

On the other hand an engine with good drivability and manners below 2000 rpm will be an absolute pleasure to put into (.82) OD on the expressway. The .64 OD will still feel a lot like a LSR gear but with much reduced bucking and farting.

Ed

Spot on.

E

[Grubby]

I went from a wide ratio toploader with 3.07 to a TKO600 / .64 with 3.54.

First gear was too long and hard to start moving easily with the 4 sp. In addition 3.07 did not feel like enough gear. The car felt somewhat weak.

Now in town driving is wonderful and the car is really strong off the line.

I do a mix of driving from 4 lane highway to interstate. On the highway the .64 is to high and you can't use it, but it is just right to cruise at 70-80mph.

The TKO is a great trans.

John