Originally Posted by
ChattyMatty
I'm not sure of it fitting, evo4 had a different FDR than evo5/TB03, but I think that was due to a different tooth count on the pinion gear. But even if it does fit, I wouldn't run a aluminum ring/crown gear in the car. There isn't really a need to. It will just eat up the pinion gear. The stock stuff is really strong. If there is a weakness I see on the TB03 drivetrain wise, I would suggest getting the aluminum drivecups for the driveshaft. Tamiya 54053 will cover the rear of the car and it also comes with a lightweight aluminum what they call a "propshaft" to replace the steel one used in the TB03. Then use Tamiya 3454578 for the front. Or if you wanted to, you could just use 2X 3454578 and keep the stock steel propshaft. If you do this upgrade you will need 2 more items. 9805823 is a rollpin you need to lock the cups to the propshafts, and then you need 2X 9808069 7mm O-rings that will act as retainers to hold the rollpins from coming out of the propshaft.
At my last race for whatever reason I needed to take my rear drivecup off...I can't remember why, and I broke the plastic retainer clip. So I went ahead and put the aluminum cups on, but didn't have any orings so I just used heat shrink tubing
