986 aero & cooling mods

[j.fro]

In the past couple of months there's been some thread content regarding aero and cooling mods. Didn't want to hijack, so here's a thread for this subject. The recent "no bumperettes" thread had some questions about getting heat out from around the muffler, so here's pics of my solution.


First off are the rear bumper vents. Unfortunately, between the aluminum bumper and the body there is a body seam that blocks flow. I bent this downwards, opening a gap between the two. I have also removed all of the heat shielding from beneath the trunk and around the aluminum bumper. I've had the car set up like this for more than a year. No noticeable differences in coolant temps, but when the car is in grid, I'll put my hand over the vents and can feel plenty of heat coming out.
The second pic is new for this year. I've opened up the rear wheel housings to increase airflow to the muffler. We'll have to see how it goes.

[Allen K. Littlefield]

Thanks Fro, interesting approach.

AKL

[The Radium King]

I've thought about the 'parachute' effect when the oem muffler was replaced with a smaller aftermarket muffler, and how you could vent the rear bumper cover to avoid it. also thought about adding something like this that would run from the transmission pan to the rear bumper cover (trim the cover so that the diffuser came just under the licence plate) - one on each side of the exhaust outlet:

Universal Rear Diffuser Kit Under Body Spoiler Increased Down Force Reduce Drag | eBay

[j.fro]

The universal diffuser is interesting. I've thought about adding something like that and exiting the exhaust behind the rear wheels.
Anybody got a DIY for making a wind tunnel?😃

[woodsman]

Originally Posted by The Radium King

I've thought about the 'parachute' effect when the oem muffler was replaced with a smaller aftermarket muffler, and how you could vent the rear bumper cover to avoid it. also thought about adding something like this that would run from the transmission pan to the rear bumper cover (trim the cover so that the diffuser came just under the licence plate) - one on each side of the exhaust outlet:

Universal Rear Diffuser Kit Under Body Spoiler Increased Down Force Reduce Drag | eBay

That looks like a good price for what it is but I doubt it will have enough positive effect to offset it's weight (if you care). Seems perfect for a civic or BRZ. I've thought about splitting the exhaust as well and building a deep diffuser up to the height of the bumper but really don't understand how they work- it's got to earn it's keep on my car. I've wondered if I could trade a diffuser for a wing on a track car to decrease overall drag while sucking the rear down...Porsche did real aero and anytime we let airflow in somewhere
we risk adding drag and/or increasing lift.

[The Radium King]

Originally Posted by woodsman

Seems perfect for a civic or BRZ.

or a boxster spyder:



or a 918:

[woodsman]

With respect to the rear diffuser, Porsche forgot the 'form follows function' rule on the Spyder- but not the 918.

[JAAY]

I will say that I noticed something a couple years ago at brbs. I was parked next to a new spyder and my aerokit 1 rear spoiler was pretty much exactly the same slope and shape as a new spyder. Quite interesting when I noticed it. Not a great comparison but it was cool to see in person.

[tonichristi]

Originally Posted by woodsman

Porsche forgot the 'form follows function' rule on the Spyder- but not the 918.

Are you some kind of expert in aerodynamics, rear diffusing and aesthetic design? More so than Porsche? I'm sure Porsche would love to hear from you. Just shut up, already.

[KRAM36]

You could buy this Duraflex rear bumper, cut it out and use mesh like in the picture.

[IMG]http://www.****************************************/images/duraflex/body-kits/104994-2.jpg[/IMG]

1997 2004 Porsche Boxster Duraflex Maston Rear Bumper Body Kit | eBay

I bought one to put on my car, unfortunately it arrived damaged. I can tell you this though while it was in my hands. They don't do a great job on the fiberglass laying. Will need lots of prep work.

[j.fro]

Did Porsche ever publish aero data for either of the 986 aero kits?

[jaykay]

Kirk on here did this...



Bumper off so one might see where to trim the heat shield..

[Reebuck1]

WOW !! This is great.

[jaykay]

....and Toms BSR

[Allen K. Littlefield]

Originally Posted by jaykay

Kirk on here did this...



Bumper off so one might see where to trim the heat shield..

Boy that sure changes the back end. Can I ask again where can you get those LED taillights? Thanks for the pics.

AKL

[Dlirium]

Originally Posted by jaykay

Kirk on here did this...



Bumper off so one might see where to trim the heat shield..

I really want to hate this, but it is WAY too cool!

[jaykay]

Originally Posted by Dlirium

I really want to hate this, but it is WAY too cool!

Yep gotcha....I am a bit of purist when it comes body kit mods .....but this is even has me wavering a bit

[woodsman]

Originally Posted by KRAM36

You could buy this Duraflex rear bumper, cut it out and use mesh like in the picture.

[IMG]http://www.****************************************/images/duraflex/body-kits/104994-2.jpg[/IMG]

1997 2004 Porsche Boxster Duraflex Maston Rear Bumper Body Kit | eBay

I bought one to put on my car, unfortunately it arrived damaged. I can tell you this though while it was in my hands. They don't do a great job on the fiberglass laying. Will need lots of prep work.

Did this picture make anyone else feel sad?

[The Radium King]

dunno about tail lights, but that's a gemballa rear bumper. unobtainium currently, and requires a special exhaust to match it. probably have to assume the bumper is gone in that install as well. ever looked at what eric did with his rear bumper cover - removed everything below the trim line.

[j.fro]

Moving on up the car...
Who's had those little air dams in front of the wheels get taken out? Maybe a better question is, who's still got 'em intact?
Here's my mod, fabbed from a special Porsche Tequipment landscape edging: