987 6mt in 986

[NickB]

Great info thanks! One last question - cross checking the p/n compatibility for flywheels looks like using a 987 clutch disc and pressure plate may work with the 2.5 flywheel - is that correct?

[itsnotanova]

Originally Posted by NickB

Great info thanks! One last question - cross checking the p/n compatibility for flywheels looks like using a 987 clutch disc and pressure plate may work with the 2.5 flywheel - is that correct?

I think it will but don't quote me on that. Why are you using a 987 6 speed?

[NickB]

Originally Posted by itsnotanova

I think it will but don't quote me on that. Why are you using a 987 6 speed?

Ok thanks, appreciate the help! Planning to use a 987 because our maths shows the ratios are a little better optimized for road racing, also had a really hard time finding a 986 6mt.

[itsnotanova]

Is this with a 2.5? There's lots of optional gear ratios with the 5 speed if you're only worried about gearing. That transmission came in a few different cars for many years. Even among the boxster there are 3 different transmissions with different gear ratios

[NickB]

Yes 2.5. We looked at options for VW/Audi 5 speed ratios. Couldn’t find any reports on how easy it would be to mix and match - but if there’s already a path would love to get more info. Lower 5th from the Audi/VW 02W (i think) helps paired with a 2.5 standard final, however really need a longer 2nd and 3rd from other Audi/VW transmissions though, goal is to maximize the output from a 2.5 between 45-130mph, so the plan is to use either aftermarket 3-6 ratios or a lower final in the 987 box. Similar options exist for 986 6mt however apparently unavailable at the moment. None of these are what one would call cheap though …

[itsnotanova]

Sounds like you've been doing your homework. I'm not sure which years or models can be used together. I would think the 986 2.5 and 2.7 5 speeds should interchange with no problem but the 987 5 speeds have larger synchros and might not work. I've heard that you can't buy any new 3 & 4 gears from porsche anymore either. Have you thought about playing with tire diameter? I went from a 26 inch tall tire to a 23 on my rallycross car and it was like night and day.