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Discussion Starter · #1 ·
In coming from a 987.1 Cayman 2.7 with the 5-Speed to a 987.2 Cayman S with a 6-Speed one of the more noticeable changes is how much taller the gearing is in the S.

The 2.7 had closely spaced ratios that made it great fun to work the gear box while the S sort of feels like you can drive 3rd gear reasonably on almost any road if you wanted to.

In a recent GT4 video there was a complaint about the taller gearing in that car as well and the Porsche Engineer commented that this was due to fuel consumption targets. If indeed these larger motored cars are given a taller gearing to help with fuel mileage then I figured there'd be an aftermarket for at least alternate final drive gears and possibly internal gear sets as well.

I opened up Panorama (the PCA monthly magazine for those of you not in the US) and saw an add for different gears for the Cayman.

How frequent a change is it for folks to change their gearing on their Cayman? I know the early NSXs were known to be geared quite tall and it was common to change the final gear ratio on that.

Anyone who's done this I'd love to hear how it turned out for you. I could go for the first 5 gears getting shorter and keeping 6th about where it is (or possibly a touch taller).
 

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Try getting in touch with Gbox in Boulder, CO.
 

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Interesting. I have been asking about the final gear ratio for a while, but I haven't really seen anything on that to be frank. I know the 997 RS guys have been doing it though.

Anyway, I came from an S2000, so the Cayman S definitely felt a kinda tall. However, I actually find it quite nice in where I live as traffic speeds can vary a lot even on a 2 mile road - traffic would go from 70km/h down to 30km/h and then back up within a tight space all the time. So having the gearing on the Cayman S is kinda nice to get through that. Otherwise, I would wish the Cayman S had slightly shorter gearing around mountain roads.
 

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It would be nice to have the feeling of closer ratios. I will say that opening up the air into and out of the engine with a good map changed the response through the gears. It truly has made the time through gears much shorter than stock. Also much more response within the gear at lower revs. The new map made all the difference in the cars torque delivery. May be worth investigating before gears. Good luck
 

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You can also change out the ring and pinion on the 987 gearbox. These are now available, and I would be happy to help.

The shorter ratio was designed to more closely match the PDK gearboxes ratios. It is 4.44 so quite a bit shorter than stock.

Give me a call if you are interested in more information.

Happy to help,

Erik Johnson
The Race Line
(970) 344-7761 phone
 

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Given the offsets it might be relatively easy to get a set of 19" wheels from a 987 and put them on your car and go for a drive. The wheels are about 1" smaller in diameter (26.3" verses 27.3") I don't know if this would mess with your ABS or PVT or other system, but it would mean your speedo would read incorrectly, but that's not a real problem.
 

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Here are a couple gear charts to help see the difference this new ring and pinion makes.

Happy to help. If anyone is in need of one of these give me a call, we can also help with installation if needed.

Erik Johnson
The Race Line
(970) 344-7761 phone

G87.20 stock gear chart.jpg G87.20 with 4.44 ring and pinion gear chart.jpg
 

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Discussion Starter · #11 ·
It would be nice to have the feeling of closer ratios. I will say that opening up the air into and out of the engine with a good map changed the response through the gears. It truly has made the time through gears much shorter than stock. Also much more response within the gear at lower revs. The new map made all the difference in the cars torque delivery. May be worth investigating before gears. Good luck
When you say letting more air into and out of the engine are you speaking specifically about a computer mapping or actually reworking the plumbing (headers exhaust, possibly something on the intake side)?
 

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Discussion Starter · #12 ·
You can also change out the ring and pinion on the 987 gearbox. These are now available, and I would be happy to help.

The shorter ratio was designed to more closely match the PDK gearboxes ratios. It is 4.44 so quite a bit shorter than stock.
Wow, 4.44 sounds really short, probably fantastic on the track, but what about something more street applicable? I might track my car once or twice a year at most so I'd mostly be looking to get the gear box in a better comfort zone for street.
 

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This gear ratio increase amounts to an increase in engine speed and torque (which is multiplied by any change in gear ratio) of 15% Doesn't sound like much, but it produces effective torque in an CS greater than a GT4, 314 versus 309 lb-ft. So an S with this gearing could accelerate faster than a GT4, at least in the lower gears, assuming the GT4 has the same ratios as the stock CS. The downside is on long trips when cruising at 70-85 mph, your engine is humming 15% faster. That means my CS at 83 mph indicated would be spinning around 3700 rpm instead of 3200. Not that bad, but if u do a lot of fast hwy cruising, u might not like the higher rpm. I don't think I'll use mine a lot that way, so I would certainly consider, especially if installing some type of LSD, which my CS without PTV already needs.
 

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In coming from a 987.1 Cayman 2.7 with the 5-Speed to a 987.2 Cayman S with a 6-Speed one of the more noticeable changes is how much taller the gearing is in the S.

The 2.7 had closely spaced ratios that made it great fun to work the gear box while the S sort of feels like you can drive 3rd gear reasonably on almost any road if you wanted to.

In a recent GT4 video there was a complaint about the taller gearing in that car as well and the Porsche Engineer commented that this was due to fuel consumption targets. If indeed these larger motored cars are given a taller gearing to help with fuel mileage then I figured there'd be an aftermarket for at least alternate final drive gears and possibly internal gear sets as well.

I opened up Panorama (the PCA monthly magazine for those of you not in the US) and saw an add for different gears for the Cayman.

How frequent a change is it for folks to change their gearing on their Cayman? I know the early NSXs were known to be geared quite tall and it was common to change the final gear ratio on that.

Anyone who's done this I'd love to hear how it turned out for you. I could go for the first 5 gears getting shorter and keeping 6th about where it is (or possibly a touch taller).
The claim that Porsche changed the wheel sizes from 17", 18" and 19" for the 987 series to 18", 19" and 20" for the 981 while keeping the tire aspect ratios at 45, 40 and 35 to increase fuel economy is likely true. When you think about it this was a fairly cheap way to have in effect longer gearing and as a result increased fuel economy. My suggestion as to a way to shorten the gearing would be to drop to lower aspect ratio tires if running 18" or 19". If running 20" rims drop back to 19" rim with 35 aspect ratio tire. The problem with changing the final drive ratio is that, if you compete at autocross as I do, you are no longer in a stock class in either PCA or SCCA.
 

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Both, you need the map to tell the computer that you have increased the flows. Counter to that, mapping alone, without modification will only minimally increase efficiency and power; not worth the price for the power gain.
 

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I have the 2005 Boxster S. To me it seems like first is a granny gear. Actually 1 3 and 5 are all short. 2 4 and 6 are tall.

I personally would like first to be a little taller, leave second alone and make third a little taller. 4th, 5th & 6th are fine for highway speeds we're tickets just the way they are.
 

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Funny you mention this. I don't have a massive experience of Porsche Just collected my first 2 weeks ago,2009 987.2 Boxster S and i find the gear rather short and punchy? 6 gear I think is 50mph at 2200rpm I presume you reach top speed in 6th on these or is it a overdrive? My car has factory fitted 911 S 2 19's

It's feels much shorter geared than the E46 M3 I've come from that's for sure.
 

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Guard Transmission will gladly modify your gearing on a 987. But, it will cost you dearly. While you are at this project with the transaxle out, you might as well add a Guard LSD. Matt may give you a deal.
 

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Here's a prime example of at least the first four gears... Of course some idiot messed up 4th. ;)

Does anyone have experience with capturing phone output and saving this video? I would like to capture my torque pro and display the RPMs, speed, torque and horsepower.

Search YouTube for "Boxster S Zero to Buck Thirty-Five"
 
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