aftermarket aero for B8

B8 S4
#81

I’ve been cooking up some #westlogic I’d like to share with everyone. First up is front aero. The hood is a high pressure zone which limits the cooling efficiency of the heat exchangers, and forces warm air into the wheel wells which creates lift on the front axle. I’ve been noticing the hood vents on 2000-2008 Mercedes cars and I think they’d drop into the S4 hood nicely. I don’t want to replace the OEM hood because I think an Alibaba hood would blow off of my car at 130 MPH - I’m not even certain how you attach the OEM latch to it or if it’s strong enough to attach at a single point to a big sheet of plastic. I don’t want to get involved with hood pins.

S class hood vent

http://i63.tinypic.com/296cfo8.png

Vent placement

http://i67.tinypic.com/19mrlz.png

Second order of business is rear aero, and I think I might actually be smoking a crack pipe. HPDE events require us to run with the driver and passenger windows down. I’ve got no back seats and a clear path to the trunk. What if I cut a rectangular hole in the trunk behind the license plate, allowing air to flow through the windows and out the back? In normal driving I’ll have the license plate on but at the track I can take it off and expose this vent. It should completely destroy the low pressure zone behind the trunk and make the whole cabin into a spoiler.

I also highlighted some spots where I’m going to trim away the rear valance to let the rear wheel wells vent better (the liners are 1/3 removed).

http://i65.tinypic.com/2cpok0z.png

#82

Taking some pointers from skypilot? :stuck_out_tongue:

There is definitely drag running with the front windows down. I wonder if that’s lessened a bit if you drop the rear windows too? Not sure where you run your numbers though.

#83

Doors?

Nascar it up man!

#84

You can find a lot more info on that 86 build here.

http://www.vsport.com.au/case-studies-preview/timmy-86-world-time-attack

#85

Damn none of these pics are coming up at work. Site must be blocked.

#86

a little slicing here, some dicing there… like I said before, this car will be gutted eventually! ;D

#87

Fits nicely in between the hood creases. Now to find a body shop that doesn’t think I’m crazy.

http://images.tapatalk-cdn.com/15/12/31/9b43cbef91452355e5ed601e1352e279.jpg

http://images.tapatalk-cdn.com/15/12/31/41a4f595e138ee910f55a3ef689fa4d5.jpg

#88

That vent looks like it should help with removing heat from the engine compartment.

#89

It’s more for giving the air that entered the trapezoid grill a place to exit quickly, at speed. Ultimately I want to move more air past the heat exchangers.

#90

Remove the weather stripping above the firewall - that’ll be another outlet.
IMO you are better off getting someone to cut up the hood rather than play with these vents. These vents will never work as well as a properly vented hood. Check this out:

http://www.vorshlag.com/forums/showpost.php?s=3be23b16863058690b4d60191ce32b78&p=57713&postcount=238

http://vorshlag.smugmug.com/Projects/Vorshlag-2011-Mustang-GT-build/i-KQBMGtM/1/S/_DSC1057-S.jpg

You want to vent from the rad? This is venting from the rad/heat exchangers. Though admittedly, you are constrained in how the car is packaged. But there are some ways around it.

#91

This guy is legit. I checked and they are actually not functional. Mind blown.
http://images.tapatalk-cdn.com/16/01/01/f9daf4561b83bb9d649d0e1083209e67.jpg

#92

The Mercedes vent is really just a screen, to give the channel a finished look. If you look at the new Porsche models the bottom of the hood is a vent just like this.

#93

The camaro you posted…that’s oem!!

#94

http://images.tapatalk-cdn.com/16/01/07/c01a1aa8052f98568fe1ead9abb630b3.jpg

#95

Might as well pickup a carbon hood to put that vent in and shave a few http://www.uspmotorsports.com/Exterior/Seibon-Carbon-Fiber-Hood-Audi-B8-A4-S4-OEM-Style.html

#96

One does not simply add a carbon hood. If it was $10,000 it would work. But the cheap plastic ones from Alibaba are not suitable for attaching the OEM latch. It would come off the car at 130 MPH. You’d need to devise a whole new pin and anchor system. Might as well just tie nylon from a sail on the engine bay if you’re going that far with weight.

#97

huh? no carbon hood uses the stock latch, you use aerocatch hood pins, the latch is fairly flush with the hood. They are less than 100 for a set. You do not need an expensive carbon/carbon hood a carbon/fiberglass hood is just fine and one I/m sure can be had with the required vents.

#98

here is a Pic of the Carbon Hood on my Old B6 with aerocatch hood pins

http://i195.photobucket.com/albums/z284/mguerra81/6c5330d7.jpg

#99

The alibaba units I looked at for the B8 were just a panel, no latches or anchors. Presumably you are supposed to transfer your OE latches. Anyway I’m not going that route.

A carbon carbon hood would be bad ass because it would be strong enough to take an OE latch. But the mold alone would cost over $100k.

#100

so wrong, real race cars don’t use stock latches. The mold doesn’t change that the fact that stock latches aren’t designed for so little weight with that light of a hood you want multiple latches anyway, hell you could make you old mold with fiberglass for a few hundred bucks of materials. Doesn’t matter if you don’t do it, but please have the facts, It doesn’t cost 100k to make a mold, and the mold doesn’t dictate its overall strength. That gets dictated may by the weave and material that the body panel is ultimately constructed from