roadie13

So it was time to add a couple of reliability upgrades, namely a deep sump oil pan and a third radiator in front. The deep sump is really only relevant if you like to take your car to the track, but the third radiator
is useful for spirited driving in any warmer climate, which these days pretty much includes the Northeast in summer.

The third radiator kit is originally Porsche but only costs about $214 for the 997.1, which is way cheaper than for the 997.2. There are at least two excellent diy guides on rennlist on how to install the radiator, so this is a good project if you have the time and the space. I had neither so this was done at a shop.

Now, installing the third radiator requires cutting four vent holes into the lower part of of the front bumper; these are pre-etched in the stock bumper. These vent holes are necessary because otherwise the hot air from the radiator has no place to escape.

So there was significant head scratching in the shop when they discovered that my bumper was already pre-configured for the third radiator. Basically, its lower part was at a slightly steeper angle, which means that the bumper was proud of the body panel it gets bolted to by about an inch or so. This inch-deep gap was fitted perfectly to the sculpted air guide that comes with the radiator kit. (There is a center bit which is indented so the bumper can be screwed in as normal. It looks like that viewed from underneath and behind ___/---\___. )

The upshot of all this is that my manual transmission car for some reason came with a tiptronic style bumper, because all the tiptronic cars had a third radiator installed by the factor so they got a special bumper; weird!

So either this was an odd occurrence in the Porsche factory when my car was built or a previous owner replaced the front bumper with a tiptronic bumper, but why? (Would be a bit annoying as the car came with clear car fax and the shop claimed all original panels and paint; hey, would they lie to me ).

At any rate I am very happy with the surprise, as the cut-out solution does perturb the air flow under the car to some degree, and this sculpted backward facing vent seems much nicer.

TheTorch

Nice to hear of a positive surprise. So many times they are "this should be straightforward, but we got under there and you'll never guess what we found."

Petza914

Cool. Got a photo of what you're describing?

roadie13

Indeed, your heart usually skips a beat or two when you get called into the shop to look at something...

Should have taken some pictures when the car was up on the lift. Here are some efforts from me crawling underneath and saying "cheese" to my phone, so that it takes pictures.
Both are taken in direction of travel. One shows the gap between bumper and guide that lets the air escape, the other shows the center attachment. Neat!



Upper lip is the air guide from the radiator kit, lower lip is the tiptronic bumper.

Center attachment of the tiptronic bumper, looking forward from underneath the car. Air flows out backwards through the gap.

Petza914

Thanks for thr photo effort. Always like to add to my 997 knowledge base.