I need a picture of the underside of a Tiptronic bumper, not the inlet, but the bottom, bottom where it screws to the car.

There is a difference between the manual and tip car bumpers (confirmed by the part numbers) and I want to make sure that I appropriately modify my bumper to allow proper airflow out the back of my recently installed third radiator.

Yes, I know, I will hold none of you responsible for what I do with the photo. Also, once I get the picture and make any changes, I will amend my radiator installation write up.

Cheers,

Many Thanks for sending in a PM the Information regarding fitting the Central Radiator (especially the bit about the extra parts needed.........)

I plan to install a GT3 Grille on the top of the bumper - in your opinion will that be enough to allow proper airflow?

Possibly this may be an answer for you, so you do not have modify the underside?

__________________
Cheers Karel

'Power is Nothing without Control..........'

kareldeeley,

You will see when you get the parts installed that the 987 tip radiator leans back and is surrounded by a duct (upper retaining frame) that directs the air downward.

The air will need to be ducted out the bottom of the bumper, so no I do not think the GT3 grille will work properly (or at all).

I will need to look at the GT3 parts catalog, but I believe it uses a different frame and duct design to direct the air upward through the grille.

Cheers,

I found this on the RennTech.com Site........ You might have to register to access it

https://techinfo.porsche.com/techinf..._2_KATALOG.pdf

Does this help at all? Seems like the radiator is different and a different (simpler) mounting mechanism (996 part numbers)

__________________
Cheers Karel

'Power is Nothing without Control..........'

Stitchy to the rescue! Thanks for the photos.

Below is a picture of the underside of the bumper on a Tiptronic. Note the four square holes cut into the bumper. These are not present on the manual cars and exist to allow the air ducted through the third (center) radiator to exit.

Those installing the center radiator will need to create similar holes in the bottom of their bumpers. I do not remember, but the backside may already be scribed.

I will be making the change this weekend.

Cheers,

OK, Many Thanks -
I will arrange for my new SpeedArt Bumper to have these lower vents installed as well as the GT3 Upper Vents...........

Will it make me drive faster? Not a chance, will it make me feel better..........? Undoubtedly!

__________________
Cheers Karel

'Power is Nothing without Control..........'

Btw, I think it's the jumbled up air pathway through the 3rd radiator that drops the Tiptronic Cayman's Cd from .29 to .30. Does anyone know of any other aerodynamic changes between the 6 speed and tip?

douzzer,

The front wheel housings are also slightly different, directing the airflow from the side radiators more to the outside rather than under the car.

This is likely to compensate for the larger amount of air flowing under the car after it exits the center radiator.

Cheers,

Job finished. Holes are now cut in the bottom of the bumper to facilitate the airflow from the center radiator.

I would post a picture, but it looks jut like the one above (very OEM).

I made a template from a Tip car on a dealer lot and cut the holes with a Dremel tool (cutting bit and guide). Entire job took less than 1 hour.

Edit: rough sketch attached (with dimensions)