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street racing team

Evo i to iii gearbox

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Hi,

Our evo ii pushes 4th gear out the side of the box.

It's a improved production car so it runs a restrictor.

It's got about 220 -230kw atw. But runs massive torque.

We have dropped the boost to drop it from 250kw which has helped

Due to the restrictor it runs out of puff at 5500rpm, due to this we have put longer diffs in it

We've only got 2 gearboxes left so we're a little concerned if we break another.

What are the options whilst still retaining the standard housing?

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Talk to Aaron Evo88u he can build you a PPG box which will fix your problem.

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Hey Ross,

Thanks for the inquiry.

Yes this is a common problem in the VR-4's that make big torque too. 4th gear is a biscuit compared to 1st-3rd in these boxes.

As far as options I can offer, shot peening and ISF/REM will improve the situation but it's not a silver bullet. The main problem is the helical angle of the gear forcing the shafts apart, as well as the width of the gear. There are also factors like clearances and preloads that need to be set carefully to prevent shaft separation as much as possible. Also keeping heat under control is really important. One of the bi-products of ISF/REM is that it drops oil temps across all torque ranges by about 5*C. An external oil cooler would help here.

I'd be happy to help you out with your spare box. Do you build them yourself? We can still process the gears for you regardless, otherwise we can build it for you. PM if you're interested, and we'll work something out.

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And yes, the PPG option would solve your problem, as straight cut gears don't force the shafts apart. They are H pattern and we build them if you wanted to go there. I can price you up if you want.

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