Not Ranked
Hi Rog. I went down this path recently with my Harrison and R33 4.11 diff. A couple of things... whether to go 5 or 6 speed, work out what your RPMs will be in 5/6th gear (depending on box, tyre size, etc) using one of the many online gear calculators. Just google it. Then consider that 6th is just a second overdrive and will you need that top speed or the comfort on the highway... probably with 4.11s yes you will want 6th. Then with gears 1 thru 4, have a look at the ratios and what speeds you're doing in each gear at the top of the torque curve, whether you want to fit a big cam that makes less power down low (go shorter gears), etc. Speak to Mal Wood b/c the T56 comes in quite a few configurations with various gear ratios. He's very experienced and will probably be able to narrow it down for you - that is if you're prepare to fork out nearly twice as much as Holden wants - you get what you pay for. Lastly I would settle on the final drive ratio now because if you change the diff later your ECU will need to be edited for the speedo to be accurate, plus those gearbox ratios (if custom) won't be as effective if/when you go to a different ratio.
There's a summary of the main considerations I took into account. Ended up with the 3.7 centre from the S15 200SX for about $400 extra and using the stock VZ Holden T56. The diff and axles from the S15 are a straight swap and easily done. PM me if you want the name of a good source in Sydney or search for my thread on the subject.
Sambo
Edit: of the 2 gearboxes you have, which one is tougher, easier to service, better condition, known history, etc?
|