Regarding your question about the material choice for the underbody panels (aluminum or plastic), how about both? :D

Given the choice I'd prefer metal for durability, but at the same time I know the plastic is likely to cost less and would do better with any heat that might be generated by boxes, and durability would only be an issue if one is running over things consistently or having to remove the panels often for maintenance. But if you can do both, I say do both and that way we have an option for preference. Maybe see if there are some existing points you can use to bolt these into place, or in the case of plastic, maybe look into some sort of snap-fitting style?

Aluminium skid plate that protect everything. From the coolant drain over the headers, over the oil pan, covering the tranny.

Easy to make I would think. The 911 world has them. I am tired of smacking my oil pan on speed bumps.

I thought the reason why those parts are exposed from underneath is to allow air to flow through to prevent heat soaking?

In that case maybe they could be designed to still allow air flow throughout that space while being able to provide protection to all of those components and connections.

What is required to get an oil temp displayed on the radio?

http://www.cb-racing.com/boxster_AC.html

Check that out, Miken.

I know it's not the radio, but it's a way for you to see it.

EDIT: And I just realized by your sig that you've got an 06, so I'm not sure that this would apply any longer, but still an interesting thing to know.

my bad; i meant the ac unit not the radio.

ps; you r2specracing guys rock; this is excellent.

Car diagnostic tricks which works on 1997- 2000 boxsters.

There is some sort of serial data stream or CAN interface that allows the AC (manufactured by Audi) unit to display engine parameters. Here is a list of what can be seen:

To switch from F to C:
Hold down the recirculating button then push both the temperature + - buttons.

To access diagnostics:
Hold down the Recirculating & Air up buttons for 5 seconds.
The + - buttons go up and down through the list of "c" codes.
The center vent button switches the left display between the "c" code and its actual value.
Press the Auto button to exit.

0c - ERL
1c - Oil Temp?
2c - Inside temp. Sensor mounted in the aspirator assembly at the side of the dash.
3c - Outside temp. Sensor located inside the air inlet of the A/C unit.
4c - Outside temp. Sensor located in front grill of the radiator. The data is fed to the climatronic from the instrument cluster. When not moving, the instrument cluster OBC temp display retains it's last setting until moving. This is to prevent heat emanating from the radiator affecting the temp. sensor. The A/C unit uses the lower of the two outside air temp values in determining fresh-air temp.
5c - Outside temp. (matches with OBC outside temp display)
6c - Coolant temp.
7c - Footwell discharge temp.
8c - Sun sensor (dash top)
9c - Sun sensor.
10c - Passenger compartment fan speed.
11c - Passenger compartment fan voltage.
12c - Temperature mix Flap command 1=COLD, 100=HOT
13c - Temperature mix Flap position
14c - Central Flap command
15c - Central Flap position
16c - Footwell/Defrost Flap command
17c - Footwell/Defrost Flap position
18c - Recirculation Valve command 1=OFF, 100=RECIRC
19c - Recirculation Valve position (feedback)
20c - Vehicle speed in kph, updating only once per second. (real speed, not speed+safety margin as in the speedometer)
21c - Engine RPM in hundreds. This too only updates once per second.
22c - ?
23c - ?
24c - Sun sensor, exterior lights switch & panel lights control (term. 58 & 58d voltage) - used for A/C panel display illum.
25c - ?
26c - ?
27c - ?
28c - Fan speed?
29c - ?
30c - Engine run time in seconds (255 max.)(=0xff)
31c - Timing counter
32c - Displays test
33c - Software version? Mine states 3.4
34c - ?
35c - Outside temp. from inlet sensor (filtered?)
36c - temp?

Happy Boxstering,
Pedro

An aluminum skid plate is very doable, we can design it with air vents to help get rid of the heat from the manifold. If its fuel lines those don't get that hot anyway usually.

There is another advantage to running a skid plate, Improved aerodynamics.

Most of the drag created by a car is created under the chassis. The smoother and flatter you can make the chassis the more down force the car will generate, and the more stable it will be at high speeds. Thats why the underside of a 911 is so flat.

In theory a flat belly should make a significant difference.

Timothy, thank you I'll send you a pm to get your contact info. I'm going out of town for a little while but Andrew (by partner) will call you and set up a meet :)

harryrcb, I just sent you a Pm thanks for the help :)


Edit: oh I just remembered something, with exhaust you want the pipes to be as hot as possible so trapping the heat may actually be a good thing. The hotter the pipes the hotter the exhaust gases, the hotter the exhaust gases the greater the flow velocity inside the pipes. This will create more power, theoretically.

This is why header heat wraps and thermal coatings make power.

The danger would be transmitting heat to other components, but thats something we would compensate for during the design phase.

also this is a pretty cool shot from one of the tests we did. Its basically showing the temperature distribution through the tube.

This is assuming oil temperatures of 400 degrees and direct heat of 1075F on the tip.
http://img97.imageshack.us/img97/955...stribution.png

Its not accurate because after we did it we found some other things we didn't factor in, in reality this part will never see any temperatures remotely close to this, because the heads are cooled by the cooling system. The idea behind doing this test is to make sure the part will not melt or expand under usage.

Regarding the underbody trays, since we're talking aerodynamic advantages, how about seeing if one of your alternate designs can involve some diffusers that blend well with the rear of the car? Since we've got a center exhaust that leaves plenty of room on either side for some functional diffusers :)

I tried that sequence on the 987 and got nothing. I'm guessing that the data is still in the DME; any other thoughts of retrieving water/oil temps from the 987 DME?

that process only works on early 986 cars. any of the aftermarket obd devices should give you that; there's even apps you can get for your ipod i believe.

OMG, yes, diffusers - please!!! An underbody tray(s) which led up to some nice aggresive diffusers would have me 100% sold.

I really would like something like this, carbon would be nice, but alluminium or plastic would be fine:
http://www.kokeln.com/images/undertray.jpg

Regards,
Sam

+1, those look awesome! I'd probably color match them, but that looks great, and looks like it works. :D

Your 03 doesn't have tubes, they are cast into the head on 03-up cars. A 6061 spark plug tube would be a GREAT idea for the earlier cars though.

I think some undertray and diffuser pieces would be neat to see.

A back dating 7.8 DME kit would be cool, but that's not exactly an easy proposition and I'm not sure how much market there is for it. I specifically looked for an 03/04 when I decided to stuff a 3.8 into my car.

Count mer in for this as well, maybe a carbon lip spoiler (a bit GT3 like) that would fit on a 986 S as well would be cool

Any news from the engineering dept.? ;)

I guess I should start by introducing myself. I am the other R in R2. I am a mechanical engineering student entering my final year of study. I am not a traditional student; I served in the US Navy from 2000 to 2006. I've always loved Porsche cars and I can't wait to own one!

Just to fill everyone in on Rayner, he is currently working an internship at Virginia International Raceway. I got to admit I'm a little jealous, but hopefully he will get some valuable experience.

I got the coil I needed for testing (thanks Harry) and everything looks as we expected. I am going to have the machine shop start on the prototype tomorrow. They will be machined out of 6061 Aluminum on a CNC Lathe. It will look amazing when finished. After a few tests, the part should be ready.

The AOS is presenting a unique challenge. I need to learn more about how the AOS works on the 986. I have looked at some stuff for Subaru, but I don't know how many modifications would be necessary to make it compatible. We can design one from scratch, but that could raise us to Porsche Motorsports price range. Stay tuned.

The skid plate seems fairly simple. I'm sure that feeling will change when I actually see the underside of a 986. I can't settle on a material. I've seen 911 skid plates made out of stainless steel and steel. I like aluminum, but it will not last nearly as long as steel. We don't have the facilities for carbon fiber, but I do have a contact that designs carbon body parts. If there is enough interest, I could ask him for a tentative quote.

On a side note… R2 Spec Racing is currently looking for a 944. We plan to begin our motorsports career with Spec 944. If anyone knows of a good 944 near Dallas, TX at a reasonable price, than let us know.

on the issue of the skid plate; carbon fiber would not work. one good hit and it would shatter. The 911 version of this is stainless steel.
Just sheet metal.

there is also a nice metal front skid plate. I have gone through a plastic set already.

The rear diffuser would be nice in carbon fiber.


Also another nice idea would be if you could make a aftermarket Air box that bolted to fender like the OEM, but allowed for the placement of the cone filter (Evolution motor sports) so that it is sealed and can act like a ram air system without the hot engine air getting in.

Steel skid plate sounds good to me. I think the potential weight gain is worth the protection.

As for the diffusers, I know carbon fiber is highly desired, but how much more viable would ABS or fiberglass be for you guys to fabricate the part?