manual trans

[cobrabritt83]

I'm looking to get a manual trans for my cobra build but i'm not sure on which one to get. I'm looking at a 5 speed or a 6 speed trans that can handle a 427 S/O that puts out around 550 horse and 550 ft/lbs of torque. I'm not drag racing or doing road racing with it just cruising and maybe getting on it once in awhile. Any thoughs on what trans to go with would help thanks.

[cobrakiwi]

Tko 600

[flaflier]

+2 Tremec TKO 600 - 5th based on your rear gear, I have the .82

Jim

[cobrabritt83]

the rear end gear is a 370, is the tko 600 with the 5th gear 0.82 better or the 0.68

[cobrakiwi]

I would go with the .64 if you are not going to be doing any racing.

[Clois Harlan]

If you are just crusing and NOT ROAD RACING ON LONG COURSES such as Road America, Road Atlanta, etc. then I would suggest the .68 5th gear. I just switched my gears from 3.70 to 3.5 in my coupe because I do want to put it on a road course. I am running a TKO 600 with .82 5th gear. I had a .68 5th gear I was running in my tko 3550 and when I was at Texas World Speedway (near College Station) the long straight-a-way needed the .82 5th gear. And yes my Cobra is a FE 427 C.O. with about 550 HP or so I the 3550 works great.

Clois

[bobcowan]

The TKO is a great trans - been around for a while, and enjoys a good reputation.

It used to be you could get a wider gear ratio spread - mostly meaning a lower first gear - with the high torque rating. But that doesn't appear to be true any longer.

The "Problem" with all the TKO's is that 5th gear is .64. which is a good ratio for highway driving when couple with a 3.55 to 3.75 rear gear. But, 4th is 1.00. It's a big drop from 1.00 to .64 - that equates to something like 1,000 rpm drop. But you're cruising down the highway at a fairly mild 2,400 rpm's (80mph). There are a lot of times on the 2 lane highways I wished I had an intermediate gear.

You can get the .84 5th gear, and you get a much smaller drop in rpm's, easily keeping the engine in the power band as you drive around town and the back roads. But that puts you at around 3,300 rpm's on the highway. IMO, that's too many rpm's for an easy highway cruise.

If I were building again - or I needed a new trans - I would probably get a 6 speed. I would take a serious look at a T-56: 700 ft/lbs of torque, 2.97 1st gear, .74 5th gear, and .50 6th. That would work really well with 3.70 rear gears.

Tremec Transmissions, Technology in Motion

I bet Mike Forte could get you one at a good price - along with all the parts and fasteners you needed, too.

[blykins]

Never been a T-56 fan.....big ole transmissions, heavy, long, and with the engines that guys put in Cobras, a .5 OD puts the cruising rpm in a spot where you get the "buck." In addition, a lot of different situations require modifications to the midplate on the T-56. This involves some machine work so that interference with the clutch fork doesn't occur. There has also been issues with the rear seals and I've had to send out some replacements.

That's what you have to worry about with overdrive transmissions. Most Cobra engines have thumpier cams than usual and they're usually not efficient until around 2000 rpm. If you try to lug the engine below that, you get a bucking sensation while you're cruising.

The TKO 600 is a great transmission and I sell a ton of them. The .82 OD's outsell the .64's because of the reasons I mentioned above.

Mike Forte could probably offer you a good deal, but that guy from B2 Motorsports can offer you a good one too.

[joyridin']

I have a T-56 in my Cobra. I would absolutely recommend NOT going with a 6 speed. Mine has a .54 6th gear. I can run 2200 rpm at 70mph and I have 4.56 rear gears. First gear is maybe 15 mph.

Go with a 5 speed.