Quote:
Originally posted by coyled
Richard, I spoke with tremec today and there tko plus has a hardend third gear and hardend cluster. These were made in a limited number and there are only 4 left. The good news is that they have not had one break yet. The peek torque is 530 foot pounds at 5700 rpm. They tell me in road racing, since I shift like a little old lady, the downshift into third, then the rear tires snatch, then the third gear climbs out of the cluster enough to snap the teeth off. I guess these cases flex a little. I really like the tremec shifting wise and the other options are expensive and require bell housing, starter, driveshaft, shifter hole changes and the driver learning to shift a dog ring gear box. As a note, I have to lift at the entry to 8. A couple of times I was crossing my fingers to get the car straight enough to brake for the entry to 9. My cobra does not like braking in anything but a straight line or the car starts to pitch. I may have a bit to much rear bias, but I like the brakes. 7300 rpm on the front straight in fourth with 3.89 gear. what ever speed that is. scott
|
Scott,
1. they are saying that your shifts are causing the problem? If you are not matching revs, I can see some extra pressure loading on the back side of the syncros, but I find it hard to believe that the loading is too much for the box. (Unless they have some pressure angle problems in the box)
2. Case flex is doubtful. I would think that the problem would be in the mainshaft and layshaft stiffness. But the tremec shafts are quite close coupled and I really doubt that flexure is the problem.
3. Haven't you had a gearbox problem berfore with this current box? I seem to remember something you posted before. If so, there could be a problem in the tolerances in your particular gearbox. I would recommend that you get with someone that really knows how to properly "blueprint" the box before you spend any money on a new one or go to the effort of changing to a Jerico or a tex racing unit. These are very good boxs indeed, but quite expensive as you have probably seen. (By the way, shifting a dog ring box is easy. Easier than a syncro box in my estimation.)
Also, 7300 with a 3.89 gear and 26.25 tires is 145 mph. Are you sure that you have a 3.89. I would think that at Elkhart you would be running out of revs on the back section with that gear.
Of course you have to back off for 8. You drive a Cobra.
As to the braking problem, It would be my guess that your rear dampers are too soft in rebound, allowing the pitch that you are speaking of.