Time Trial Build Thread (aero, widebody, any other nonsense)

[truegearhead]

Originally Posted by JayG

You are doing proper analysis.
Kudos to not just throwing stuff on your can and using a butt dyno
Aerodynamics is at least a little complicated and without modeling or wind tunnel testing, you can easily do something that makes it worse

Well done

Thanks, I can’t take any credit for the aero model though. Nine8Six Shared it with the forum months? Years? Ago. I should have given him credit. It’s incredible
To have this available. Aero is very tricky, I’m sure what I’m doing isn’t anywhere near as effective as it could be (or maybe even at all) but it’s time consuming which is exactly the kind of thing we all need now.

[truegearhead]

I'm really getting into the danger zone now I've started another project while I wait for parts. The first picture (credit to Eric who took the photo) is what I'm after. Flares are arriving on Friday and I'm going to incorporate this vent into them. I have a replacement for this banged up fender so worst case I have a backup.

[truegearhead]

I started the flare install yesterday so far the $30 Amazon flares are working out

[itsnotanova]

I have fender flares and wider tires on my rallycross boxster. I had to do some trimming on the rear wheel well for clearance. For the front I also had to cut the rocker panel back flush with the wheel well and some of the bumper cover. I don't have the side radiators anymore but the wide wheels would not have fit in the front if I still had them.

I notice you have a wing and a large spoiler on the rear. I've never seen anyone have both and I've never seen anyone use such a large spoiler on a boxster that races at a high speed. The only guys I see using large spoilers are in autocross where they rarely even get out of third gear.

I forget what they're called but that picture of the cup car has them in front of the front tire. I've been told you can find them on eBay for cheap. Do you have those on yet?

[truegearhead]

Originally Posted by itsnotanova

I have fender flares and wider tires on my rallycross boxster. I had to do some trimming on the rear wheel well for clearance. For the front I also had to cut the rocker panel back flush with the wheel well and some of the bumper cover. I don't have the side radiators anymore but the wide wheels would not have fit in the front if I still had them.

I notice you have a wing and a large spoiler on the rear. I've never seen anyone have both and I've never seen anyone use such a large spoiler on a boxster that races at a high speed. The only guys I see using large spoilers are in autocross where they rarely even get out of third gear.

I forget what they're called but that picture of the cup car has them in front of the front tire. I've been told you can find them on eBay for cheap. Do you have those on yet?

Did you widen the front of your car with spacers? I widened mine by extending the control arms, thrust arm, sway bar links, tie rods, raising the strut in the hub and moving the shock tower mounting points out. Not the easy way to go but this avoided increasing the scrub radius and will avoid having to move the radiators and cut the rocker panel.

As far as the wing and spoiler go they look silly but accomplish two different things. The spoiler reduces lift and drag and the wing provides downforce. Take a look at Porsche’s factory wings, they all incorporate both. I run the car in time trials at tracks like VIR and summit point so yes high speed. Back to back runs the wing reduces VIR lap times by 3 seconds, there isn’t a single car in my group without a huge wing running time they’re critical.

Finally if you’re referring to the canards on the cup car I don’t have them. I do though have a large splitter and a hood extractor (you could almost crawl through it). The hood extractor creates downforce by forcing air through it with a longer path than the air traveling over the bumper (same idea as wing). Here’s some photos, I’m going to redesign this to be fed with a diffuser in the splitter instead of a hole in the bumper.

The NACA ducts in the headlights are brake ducts in case you’re wonder.





In process shot showing the inside

[itsnotanova]

Originally Posted by truegearhead

Did you widen the front of your car with spacers? d. Back to back runs the wing reduces VIR lap times by 3 seconds, there isn’t a single car in my group without a huge wing running time they’re critical.

I used very thick wheel spacers. It's not something I plan on using for long. I'm testing out some tire theories and the wheel/tire combo wouldn't clear the struts without them.

Hard to argue with the spoiler if it shows it improves lap times. I might try it for my too

[truegearhead]

Turbos are bolted on! They just fit below the trunk lid, next I'll need to get the charge pipes fab'ed up, the waste gates installed and then wiring and oil plumbing. Soooo much work to do, I feel like I've gone off the deep end with this project

[truegearhead]

Its been awhile since my last post so I thought I'd give a quick update, I've made a lot of progress on a lot of small things but I still have a long way to go. The oil system is just about done with the exception of the oil cooler which is roughed in, you can see the two AN fittings pointing towards the back of the car that will supply and return the oil from the missing cooler. Most of the piping is back at the fab shop getting some adjustments made so the charge pipes, exhaust, waste gates and blow off valve are all in a holding pattern.

[truegearhead]

The fender intercoolers are done, definitely more work than I anticipated and I still have some metal clean up work but its all plumbed up and looks like it'll work.

[truegearhead]

Another small update. With the help of a buddy of mine we started actually welding stuff together. This “exhaust” plan is crazy, I hope I don’t regret it.

[truegearhead]

I'm sure I'm going way overboard on these micro exhaust updates but it has been such a pain to get these at the same angle (since the turbos sit at different angles) I thought I would at least add a post to make myself feel a little better. They're now aimed just below the wing, I've also sold my wing so I can replace it with an aluminum (fire resistant one)