CFD analysis of BRZ/FRS rear diffuser

[F1point4]

My streak of applying functional mods held!!! [until I put that MaxFlow LOL-Off Valve on my car]

[Wonderbar]

Originally Posted by mav1178

In an ideal world, the front of your diffuser would link up (and bolt to) the JDM underpanels.

I currently have the underpanels and am interested in this rear diffuser for my car. May be interesting to see how the two can be blended together.

Sidenote: do you have pictures of the car on a lift, of the front part of the diffuser near the rear subframe?

-alex

I plan on building my own complete system of underbody panels and body aero. If I can come up with a solution, the entire bottom of the car will be flat.

[Wonderbar]

Originally Posted by Chris@Phastek

Awesome! Great data.

Thanks guys! If you'd like one for your shop car, contact me.

[Wonderbar]

So, I have brainstormed a mod for the diffuser I'll be trying to fab and test over the next few weeks.

[ATL BRZ]

I have an idea too

Ferrari 599xx diffuser



With air evacuation fans to literally suck the air out from under the car and blow it straight out the back where the tail lights once were.



#becauseracecar

But really though, I'm eager to hear what the DPL diffuser mod will be.

[Wonderbar]

That shit is crazy! Yeah, nothing like that... Lol

[Gunman]

Originally Posted by ATL BRZ

I have an idea too

Ferrari 599xx diffuser


With air evacuation fans to literally suck the air out from under the car and blow it straight out the back where the tail lights once were.


#becauseracecar

But really though, I'm eager to hear what the DPL diffuser mod will be.

Interesting idea. I'm curious how much the vacuum effect messes with the diffuser. The Chapparall 2J skirted the sides, and rear, and all the air was sucked out via snowmobile engines.
http://antholonet.com/EngineersCars/...aparral2J.html


I was just having a talk with one of our more experienced guys at the shop about ground contact side skirts, and what works best.

[AZFA20]

Hey guys,

I was directed to this thread by Yo from ft86speedfactory after a conversation I had with him about my experience thus far with the driveway labs diffuser. I actually have not been on the forum much recently because I have been so busy with the fr-s and several other projects. I didnt know anything about this thread prior to talking to Yo and its quite crazy how spot on my description to him of my experience is compared to the simulation data. For someone who is very sensitive to vehicle character changes, you will notice this difussers effects on the car especially at high speed. The rear is more stable and eliminates that same feeling you get when you pass a semi truck with wind variations. The vacuum on the rear side can be felt as well and was one of the main things I described to Yo as noticeable. Without the diffuser the lift on the rear end was always obnoxious to me. I run the Greddy EVO 3 exhaust so there is a rather massive cavity in the back that is now completely covered.

My difusser is sitting about 1.5" lower than intended to be mounted because I built aluminum stand-offs to fit the EVO 3 mufflers and clear my APR rear spats without modification so mine is slightly different front intended install but purely to accommodate my specific exhaust and spats.

So far I am super happy with the diffuser and the effects it has had on my personal track car. APR GT-250 here I come.

[Wonderbar]

Originally Posted by AZFA20

Hey guys,

I was directed to this thread by Yo from ft86speedfactory after a conversation I had with him about my experience thus far with the driveway labs diffuser. I actually have not been on the forum much recently because I have been so busy with the fr-s and several other projects. I didnt know anything about this thread prior to talking to Yo and its quite crazy how spot on my description to him of my experience is compared to the simulation data. For someone who is very sensitive to vehicle character changes, you will notice this difussers effects on the car especially at high speed. The rear is more stable and eliminates that same feeling you get when you pass a semi truck with wind variations. The vacuum on the rear side can be felt as well and was one of the main things I described to Yo as noticeable. Without the diffuser the lift on the rear end was always obnoxious to me. I run the Greddy EVO 3 exhaust so there is a rather massive cavity in the back that is now completely covered.

My difusser is sitting about 1.5" lower than intended to be mounted because I built aluminum stand-offs to fit the EVO 3 mufflers and clear my APR rear spats without modification so mine is slightly different front intended install but purely to accommodate my specific exhaust and spats.

So far I am super happy with the diffuser and the effects it has had on my personal track car. APR GT-250 here I come.

Great to hear!

Would it be too much to ask for you to send me a couple snaps of your setup? Either pm or email, driveway.labs@gmail.com

[Gunman]

Dropping the diffuser that much, is the leading edge catching air, taking it over the top of the diffuser?

[Wonderbar]

Originally Posted by Gunman

Dropping the diffuser that much, is the leading edge catching air, taking it over the top of the diffuser?

In theory as long as the lead edge is above the 7 degree line off the bottom of the rear diff, should be fine. It's why I asked for photos

[FRSfan111]

Also interested in seeing pics. Got tracking info on my diffuser!

[Gunman]

Originally Posted by Wonderbar

In theory as long as the lead edge is above the 7 degree line off the bottom of the rear diff, should be fine. It's why I asked for photos

In theory, but we're not dealing with laminar flow along the bottom of the car either

[Wonderbar]

Originally Posted by Gunman

In theory, but we're not dealing with laminar flow along the bottom of the car either

True, but my layman design skills make me think that I can get an 80% solution from the last edge of the car before the diffuser, which is the diff and rear lca's.

It be a pretty uniform and smooth flow once I get my panels complete.