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S13 diff ratio swap worth it?

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Am putting an S15 centre into my diff. Car is a CA so has 4.3 ratio standard. Have seen there's a 4.6 I could use.


Car is track use, only makes 200rwkw and 365nm at the wheels.


Am I going to gain much response/acceleration swapping to the 4.6?


Car get's used at Winton and I'm only just changing into 5th at the end of the straight at 170 or so - also gets used at the Logic centre (small 1.2km tight circuit).


Wheel spin is a little bit of an issue on tight corners now, but mainly due to diffflaring I think, hence the diff swap. I'm also looking at running wider rubber. from 235 to 255 maybe.

Edited by ActionDan

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So many factors will affect diff ratio.


Are you in between any gears at the moment coming off corners?


Otherwise I'd keep 4.3. With 200kw I presume all of your torque and horsepower is in the mid range, which essentially means you don't want to be shortening up the ratio and making it rev more and also introduce more gear changes.


Winton is a short track, with a short straight. With an over drive gearbox you are never going to pull max revs in top gear, so you should be gearing for the corners and yor powerband.


Again I'm not sure as I haven't raced there.

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There's only one place on the track where I get "caught" either having to over rev 2nd or lumber a bit in 3rd, but otherwise it's fine for the most part.


Was just looking for easy gains.

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