BGB Motorsports

For the 3rd time we have taken a non-DFI 987 (2.9L 987.2 base car in this case) and have turned it into a 3.8L 987.2 making about 415 horsepower thanks to a factory reman Porsche crate engine, Cargraphic stainless steel longtube racing manifolds and an IPD Plenum mated to an 82mm Throttle Body; the coding is a result of our in-house staff, the amazing folks from Cobb Tuning and special thanks go to KSV Looms for expediting our "987.1 - 987.2 conversion harness."

Thanks to our staff for another great build. The pricing on these base 2.9L 987.2 cars is right and the economics work well for creating a 3.8L Cayman that doesn't break the bank!



Cargraphic 987.2 Modular Headers for Off-Road Race Track use ONLY.

IPD Plenum & 82mm Throttle Body

ChicagoSpeed996

MyNameIdeasWereT

I love seeing the baby Porsches made into bigger beasts.

daylorb

Very cool - for a while I thought the best option was to convert an S - is the base just as easy now? PDK?

BGB Motorsports

It was indeed always easier to start with the 3.4L 987.2 Cayman S or Boxster S because the 2.9L base cars were non-DFI cars running the older Bosch ECU and not the Siemens DFI ECU. With the help of some wiring partners we have found a way to basically update the engine control of the car and replace the existing ECU with the new Siemens ECU and then code the entire car as a 987.2 3.4L so that every single thing works as intended from the factory. The car thinks it's a 3.4L 987.2 and then we custom tune the engine software for the larger 3.8L engine. For the longest time i was the one telling people to NOT start with the base because of the issues described above but now that we have a solution you can get a base and go from there. The owner saw us do this with a previous build, went out and found the cheapest base 2.9L manual he could find and then brought it to us. The 2.9L cars have the shorter gearing so he was stoked to go that route. All it really needs are some red calipers at that point. The car pulls like a champ and roasts the tires in 1st and 2nd gear with the addition of the lightweight flywheel / clutch! It's a nice piece and should shock a few educated folks at the next DE that think it's just a little 2.9L.

ekam

You'd think it'll push more hp like the GT4 but I guess there's a reason why they went to dual intakes on the 981.

BGB Motorsports

Dual intakes would definitely improve the top end power but every single owner of one of these swaps says they have no problem running down the GT4 in a straight line. Up top it's breathing better via headers, intake and tuning. A GT4 would have to have stage I mods to compete on acceleration. Our 3.4L 981 race cars that run the full bolt-on Stage I kit pull more mph than the GT4 street cars and Clubsport race cars; again, it's not apples to apples since you're comparing a stock car with stock intake and exhaust.

ekam

Sorry I was comparing this against GT4 with this package pushing 450hp at the crank.

https://rennlist.com/forums/gt4/9264...e-package.html

BGB Motorsports

I haven't been able to make over 400rwhp on a Dynojet which is 457HP at the crank without adding the X51 intake cams, heads and manifold. The engine won't digest enough air to get there.

daylorb

Interesting - you guys rock - such cool stuff you are doing. Hoping to get one going one of these days.

dfysang

is this still using the trans from the 2.9l?

BGB Motorsports

Thank you! Give us a call when you're ready!

Yes, re-uses the existing 987.2 2.9L trans.

MyNameIdeasWereT

What are the gearing ratio difference between the 2.9L and the 3.2L?
Is the 2.9L transmission considered as robust as the 3.2L's?

In the Volvo tuning world, a lot of people would opt for replacing the economical 6 speed transmission in the turbo models with the 5 speed transmission from the N/As because they provided a better power delivery in 2nd and 3rd gear for tighter tracks and autocross.

BGB Motorsports

When the transmission changed for the Cayman/Boxster lineup in 2009 I believe it was already 6-spd box that came from a FWD diesel Audi in Europe. We had a great deal of success with these transmissions and never lost one when we endurance raced these cars. The syncros were carbon lined and beefy. The gearbox can handle the power of the 3.8L engine without any issue and it's even handling a 4.0L X51 we built for a customer. The ratios are indeed different; the 2.9L car has a shorter 1-2 and a shorter 5-6 while 3-4 are the same as what's in the 3.4L S cars. It definitely is an added benefit to start with the 2.9L transmission.

Kramykram

I know this is an old thread, and I hate to dig up the past. But this is my first Boxster, but not my first Porsche. Seeing this thread and the fact that 3.8 will bolt to my 6MT is fantastic. I do have the 2.9efi. But I wish I had drove more models before my purchase. But the 2.9L seems to of been one of the engines with the least problems and dirt cheap to replace with a used one from what I’ve searched. But this is a project I would take on myself. Seeing that it can be done is awesome. I couldn’t imagine this little car with that kinda of NA hp. I have seen others have did there own swaps. How detailed is the wiring if. I know how to read schematics, Just in a higher voltage ac/dc scale. I know you guys are in business to make money. But just curious. Fabbing mounts is easy, buying the wiring harness doesn’t seem to difficult to find these days since time has passed and these cars have been wrecked.