Swap transmission
 

I've been noticing a little slip in my clutch when autocrossing, and everything is hot. I'm replacing the clutch. Has anyone ever thought about changing the boxster 2.7 5 speed out with a 3.2 s 6 speed. I have all the normal modifications and some extra. So the horsepower is not an issue. Any information?

Aside from the expense I don't see an issue. I have one for sale if you are interested.

Will it bolt up the same?

I had asked about 6 spd swapout some time ago.
don't know how to link the threads but if you search using "6 spd mated to 2.7L?", there's some info there

I have a cayman tranny. You just need a six speed clutch disc and flywheel and pressure plate.

Changing to a 6 speed will not be god for your autocrossing as it has higher gearing than the 2,7. If you go the other way and change to a 2,5 I guess that acceleration will be really improved for autocross.
Also drive shafts has to be exchanged if you go for the 6 speed as they are different in length

Why? The 6 speed has a chasm between 2nd and 3rd, and 5th is useless. I gues it's a little stronger but are you having problems with gear teeth breaking?

if u have transmission issues you could give these guys a call GBOX

I have never done business with them but i have talked to them before and are very helpful

no issues
 

I'm not having any problems with my transmission. I'm replacing my Clutch. pressure plate, and flywheel. I saw a coulpe good prices on 6 Speed. The 03 manuals say every gear is a higher ratio with less span between every gear, .62 span between 1-2 on the 5spd . 38 on the 6spd. , .69 span 2-3 on the 5Spd, .68 on the 6spd. The only down side I saw was top ratio .84 on the 5spd and .89 on the 6spd which means worse fuel economy. The number should produce a quick acceleration curve, minus shifting time.

Look at the final drive ratio too.

I have a Boxster S with the 6 speed, and I was thinking about going the other way and converting to the 5 speed for autocross - want to swap?

Actually, the final drive ratio on the 6 speed is ususally a handicap for most autoccross courses. It is numerically quite low, and so you give up some acceleration.

The 6 speed in 2 nd gear does not red line until about 74 MPH which is a rare top speed for autocross. For best acceleration, you would want red line to occur at a more normal 65 MPH or so maximum top speed for autocross.

Is the actual ratio in any gear is the (transmission gear ratio X the final drive) or is it transmission divided by the rear ratio.

You multiply, so a 2.95 first and a 4.10 rear give a total gear reduction of 12.095.