Aerodynamics discussion

[sw20kosh]

Originally Posted by robispec

well I did a STUPID experiment with aero and ended up with a melted bumper..
So I'm in the market for one!

Oh no! How did that happen? Exhaust flow was directed upward toward bumper? Exhaust piping too close to bumper? This is a constant concern for me as I install my diffuser.

[kask2_6.0]

Originally Posted by sw20kosh

teaser

Looks awesome man. That's exactly what I had in mind 7

Originally Posted by sw20kosh

Can anyone guess what car this diffuser came off of? I made the grill and brackets to attach it but the diffuser itself is from another sports car an actually fits under the 86 perfectly.

Elise!!

[sw20kosh]

Originally Posted by kask2_6.0

Looks awesome man. That's exactly what I had in mind 7


Elise!!

Actually it is a tiny bit short. Ill just fab up ~6" worth of aluminum sheet to close off the rest of the gap so it sits up against the rear axle/subframe

[kask2_6.0]

Originally Posted by sw20kosh

Actually it is a tiny bit short. Ill just fab up ~6" worth of aluminum sheet to close off the rest of the gap so it sits up against the rear axle/subframe

Is that the OEM diffuser or a difflow? Can't wait to see how it looks on the car

[sw20kosh]

Originally Posted by kask2_6.0

Is that the OEM diffuser or a difflow? Can't wait to see how it looks on the car

Oem. Got it used for $150. $35 for grille sheet. $20
for odds and ends and aluminum for brackets. $800 Custom exhaust.

Ok this isn't done, but here is another teaser. Need to get black bolts to replace those shiny ones, get some weatherstripping for the grille edges so it looks more finished. Need the exhaust. etc.



This is a photoshop I made of my car that I am using as my inspirational guide:



or

[Captain Insano]

It looks like the exhaust will melt the plastic above... with ur black car that is nice though as exhaust carbon would be imperceptible. I love the work so far man. Pretty awesome custom work.

[OrbitalEllipses]

Very interesting @sw20kosh.

[kask2_6.0]

Originally Posted by sw20kosh

$800 Custom exhaust.

Have you considered using a Perrin exhaust? The design of the muffler/ pipe routing looks like it would work perfect for this. The muffler inlet is in the center and out of the way. Also pretty small and sits more toward the front of the car. The only modifications needed would be to cut off the outlets and move the bends closer to the muffler. May be a little more tweaking than that but it would be an excellent starting point and there is a GB for $770 shipped or something.

[kask2_6.0]

Could offer a few different options pretty easily. Just and idea.

[Shankenstein]

Honestly not sure if there's enough room... but could a mufller fit longitudinally?

If you size the muffler properly, a quick bend behind the differential, fit the muffler front-rear tilted upwards, tips installed on the outlets.

The minimum size Mangaflow offers has a case length of 14". Total length with inlets and outlets is 20". I imagine that might fit with some coercion. LINK



With regard to melting things, it's simple enough to cut the mesh and weld a ring into place that leaves sufficient room for the tip to jiggle (3/4" clearance or so, if mounts are fairly solid). Heat shields or a wrap would be nice, but it may not be necessary with how open that design is. We shall see.

Thanks for being innovative, @sw20kosh !

[OrbitalEllipses]

I'm relatively certain there's no way to fit an off-the-shelf exhaust to that diffuser without hacking up the diffuser OR the exhaust, so you might as well go custom.

[Dave-ROR]

Originally Posted by kask2_6.0

Have you considered using a Perrin exhaust? The design of the muffler/ pipe routing looks like it would work perfect for this. The muffler inlet is in the center and out of the way. Also pretty small and sits more toward the front of the car. The only modifications needed would be to cut off the outlets and move the bends closer to the muffler. May be a little more tweaking than that but it would be an excellent starting point and there is a GB for $770 shipped or something.

$770 + custom re-working = more than $800

[sw20kosh]

As a few have pointed out, no point in hacking up a brand new exhaust. It would need lots of manipulation. I thought a lot about the exhaust and its design for this.

With the diffuser brackets and the Y pipe in the stock muffler compartment it is not feasible to have a muffler back there. My exhaust man and I decided to put a nice long cylindrical race magnaflow muffler under the middle of the car sort of like the borla set up.

There are some trick race magnaflows that are 6" in body length and 4" or 6" in diameter. Very compact. I initially thought about using these in stock location.

To have the exhaust exit like I want it to the bumper beam will need two holes cut into it. Alternatively I could use the hole in the diffuser which was originally intended for exhaust on the Elise/exige. I just don't like that location because it defeats the point of a diffuser...

[Hancha Group]

We just got done creating a new, and more accurate CFD model for the FRS. This will be used for our development of the car. Below are some post-processing pictures of a stock FRS with Rota Grids.











Cheers,
Paul Lucas
paul@hanchagroup.com