Cusco Close Gear set

[Fa20Toybaru]

Thank you very much, for breaking this down. I have looked at all the recommendations, that have been laid out before. I ask you this, in my research, from this forum to other forums. Is the manual trans, the weak point or is it the auto trans that seems to fail at high torque loads?
I have upgraded axels, LSD, and driveshaft. I just want to nail this section before i move on. Thank you for all your help

[gpvecchi]

Regarding the close gear set, is there anyone who paired it with 4.3 FD?

[churchx]

Weak? How can that be. It's strong enough, if one doesn't overtask it with insane load it never was designed for. Works fine with NA power, should last long enough. Adding unnecessary strength would just net higher cost, redundant weight, increase drivetrain losses.
I don't think it's normal to expect throwing at gearbox 2-3x times torque from high-power forced induction and if it doesn't handle it without breaking down, call it weak. +15-20%, maybe, some resilence for abuse should be there. Not 2-3x times.
Recall watched video of SU-57 development tests. Where they subjected it's structural parts for loads it was designed to withstand, and expected that for element (eg. wing) to break soon after increasing load further. Sooner (past designed/planned load limit), the better, as that meant that there is no excess material that needs to be lugged around as deadweight, and in case if eg. that wing had been much stronger in tests then planned, they would need to return to simulations/drawing board/remaking prototypes so that they aren't overbuilt.
As you see, most alternatives for more reliable gearboxes for high power are usually retrofits of them from more powerful cars in stock. Or sometimes - from older cars, when engineers often overengineered parts. Or from popular gearboxes that serve in many models with varied power including high power. These alternative gearboxes were designed for that. Our isn't. But put it as fault is wrong.

[Fa20Toybaru]

Thanks for taking the time to explain that. I am however looking to take it to 400bhp-500bhp. So at those levels of load, then it would cause a failure in our stock transmission. What i am looking for, is a solution to this. I wouldnt want to make a mistake, and add all this BHP and torque, then not address the drivetrain. That why i have worked on suspension first. Then LSD, Final Drive, Axels, and Drive Shaft. In doing that i realized that my gearbox, needs to be addressed. So that why i am looking for guidance in this stage of the build. I appreciate your insight. If you have any suggestions, i am open to it.

[Fa20Toybaru]

I have the Cusco final drive, i unfortunately have not combined the close gear set with it. The combination of final drive, pinion collar, and the R.S. LSD have proved their worth. I feel acceleration is quicker. I will not sell you that it added any horse power, because it was not meant for that. I will however state that it has increased acceleration, and made it so that in third gear im not losing any power through out the power band. It has helped give the car a push, and reaction that i was looking for.

[churchx]

Yeah, close ratios gear set is from things i'd love to have in mine, and even better, paired also with different final drive and proper clutch type LSD .. should add some extra life in stock NA lack of power. Pity that gearset is so expensive . IIRC MFactory had similar gearsets & FD for a bit less then TRD/Cusco.

[olsonpg]

Got nothing but great things to say about Jacks Transmissions. Incredibly knowledgable people and great to work with.

After I grenaded 4th gear they took another used trans and put the PAR gearset 1-6 in there alongside their carbon synchros and verus clutch fork.

400 whp and no problems since.