Max power weal link
Discussion
Guys have got my m12 up to 420-hp 400 lbs torque the chaps at Jetstream did a cracking job but ....was told transmission will likely go pop both 5 speed or 6 speed if i up power much more anybody have a solution and what is the next weakest link? am i wating my time with much more than 400hp?
btw valve springs started floating so need a set of stiffer ones.. and the tool to change them with heads on if anyone can help much appreciated... cheers LG
btw valve springs started floating so need a set of stiffer ones.. and the tool to change them with heads on if anyone can help much appreciated... cheers LG
Power is not the problem.
Torque is what will kill your box in the end.
You can map around the torque to a certain extent. (yellowshed on here is THE man for mapping)
A re-worked, shot peened box with the plastic bits replaced with metal is a good way to go, gearbox man as suggested above can do this for you.
Re valve float, What is your rev ceiling?
You may find lightening the valves and collets a better option (less strain on cam lobes etc)than heavier/stiffer springs.
F.C.
Torque is what will kill your box in the end.
You can map around the torque to a certain extent. (yellowshed on here is THE man for mapping)
A re-worked, shot peened box with the plastic bits replaced with metal is a good way to go, gearbox man as suggested above can do this for you.
Re valve float, What is your rev ceiling?
You may find lightening the valves and collets a better option (less strain on cam lobes etc)than heavier/stiffer springs.
F.C.
The six speeds that we have in the States seem to be coping fine with the amounts of power that we're running. We have seen problems that have to do with poor driver's inputs - if you pop the clutch for drag racing, don't rev match your shifts, jam your shifts with a poorly adjusted linkage, etc. you can break the box, but we haven't seen any failures solely due to torque. We do modify our gearboxes a little, by stripping them down, replacing all the plastic bits, treating all the moving parts, and we do add a cooling system for the transmission fluid.
Right now, we see the tires, clutch, and half-shafts as the "fuses" in the system - they let go before the transmission breaks. The last drivetrain failure that we experienced was during a rolling-start drag race in our Darth Vader car - as we came on power, both of the half-shafts broke, but the tranny was intact. We debated designing new, stronger half-shafts, but decided it's a lot cheaper and easier changing half-shafts than gearboxes. Same thing with tires - we could go to full racing slicks, but probably would end up breaking more things in the drivetrain than it's worth. Much better to haze the tires than to break the gearbox. However, we are upgrading the clutch to one of our triple-disc clutches, which will hold much more torque than our uprated single-disc clutch, just because it's such a pain to change the clutch...
Right now, we see the tires, clutch, and half-shafts as the "fuses" in the system - they let go before the transmission breaks. The last drivetrain failure that we experienced was during a rolling-start drag race in our Darth Vader car - as we came on power, both of the half-shafts broke, but the tranny was intact. We debated designing new, stronger half-shafts, but decided it's a lot cheaper and easier changing half-shafts than gearboxes. Same thing with tires - we could go to full racing slicks, but probably would end up breaking more things in the drivetrain than it's worth. Much better to haze the tires than to break the gearbox. However, we are upgrading the clutch to one of our triple-disc clutches, which will hold much more torque than our uprated single-disc clutch, just because it's such a pain to change the clutch...
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