Aerodynamics on a 245 for 200mph standing mile?

Getting slowly started with this. Using sheet metal to make first versions and upgrading later if they seem to be working.

Did right side of rear diffuser:

Made a bar under the bumper for install. Bolts to the bumper frame and diffuser is pressed tightly from behind to the gap between bar and bumper. Some glue could be good for final install. Attachpoints under the car are still lacking. I have to change exhaust outlet to make left side doable. Might have to drill holes to the bumper for removing air that packs behind it?

Today started with the wing and this is how it looks now without supports:

Dunno if the shape is too steep? Was going to make it straight but then decided to try curved. Sides curve slightly towards the center. Back edge is 29cm/11.4" from rear window.

Was going to make it so that trunk lid stays untouched and wing is just pressed on with clamps around the edges. But decided to put rivet nuts above rear window. It'll be easier to change different spoilers/wings if I have the interest to make more. Now I'll just have to buy some nuts and loan pliers. And of course modify the wing.

Rest of the pics here. Mostly nasty cellphone pics, camera broke

mikep,
With the sideskirts I meant that would it be better to keep the air under the car than letting it out? If/when air comes out to the side and detaches from rear edge of the side, it might have a negative impact on drag? It would have better flow behind the car because of the diffuser.

Shape might be too steep... that undertray looks great tho.

Also LOL because talking about standing mile, but you still have trailer hitch.

How do you intend to affix it?

FWIW the undertray (front) on my Evo I use twist locks so I can drop it quick.

DZUS quick releases that is.

It's not a real brick if it doesn't have a trailer hitch

There are no service points under the rear diffuser so I'll just bolt it in. If you mean the wing, it wont be that much work to use bolts. Going to make it so that nothing is seen above.

I love both the front pan and the diffuser!
Can we have a few more pictures from underneath?

Also : why the diagonal braces on the front pan are on the bottom : hiding them on the top side would make a smoother underneath surface.
Sorry about my bad English : I'm from Northumbria.

Nice work! Is there already a grill block? I've pondered myself using vents behind the grill routed up and out of the hood (with depressions in the hood on each side) to turn some lift into downforce but for this endeavor a full block may have more advantage/less drag. The kammback idea is cool...stay with it!

Check out this build thread of an aero 242. it has some front end ideas for ya http://www.turbobricks.com/forums/showthread.php?t=289884

Body and Aerodynamics
The general shape of the car will stay the same, but in order to fit the 18?12 wheels with the wider track width in the rear, I will extend the quarter panels out to make a widebody. Similar modifications will be done to the front fenders to fit the 18?10 wheels, but not as extreme as in the rear. The front of the car will have a sheetmetal air dam and splitter to create a high pressure zone for the intercooler, oil cooler, and radiator, as well as to speed up the air flowing underneath the car. The car will have a flat bottom by using aluminum sheetmetal panels, as well as an aluminum rear diffuser. In 2009 I made a 1/10th scale model Volvo 240 as one of my final projects for my bachelor’s degree, and conducted wind tunnel testing on the model.











From the wind tunnel testing I learned that the body creates lift, and lots of it. To counteract this, a large rear wing will be mounted high up on the trunk lid, but I have not purchased this part yet. I am planning to use a Nascar Car of Tomorrow wing if I can find one available somewhere. Check out the video below for awesome wind tunnel spool-up noises and brick-like aerodynamics:
<iframe width="560" height="315" src="https://www.youtube.com/embed/rMbhiGEfUD4" frameborder="0" allowfullscreen></iframe>

Lots of other work has been done to the car over the years that I am either forgetting about or leaving out of this post. I’ve covered the big parts of the project, and future posts from here on out will be more detailed and technical.
Finally, though not complete, here is a concept of what the car should look like. The color I have chosen to finish the car in is Toyota 1A1 “Anthracite Metallic”.

Salt flat 242 http://forums.turbobricks.org/showthread.php?t=106706

Yeah solid.

I know it's very small gains compared to what you're looking at on the front and rear of the car but don't forget to consider the sides. That kammback should also slope "in" on the side profiles.

You won't want to increase frontal area with anything bulging out so front skirts on the fenders/wings won't really be advisable but DO look at a skirt for the rear wheel wells and add some simple mudflaps in FRONT of the tires, so the air isn't going up and into the wheelwell. Look at a Prius or other newer econo car to see examples of these. Similarly, side skirting made out of something rigid but semi-flexible will help keep air from under the car. Some flatter wheels/covers will help, if you don't add a skirt.

If all else fails, MOAR POWER!

Dirty Rooster said:

I love both the front pan and the diffuser!
Can we have a few more pictures from underneath?

Also : why the diagonal braces on the front pan are on the bottom : hiding them on the top side would make a smoother underneath surface.
Sorry about my bad English : I'm from Northumbria.

Click to expand...

Not much to show on that area yet. Only what is here as a picture or a link.
My Showroom thread covers pretty much everything else.

Those are not braces but air guides to reduce amount of air going to the wheelwell. At least hoping to achieve that.

sikbrik said:

Nice work! Is there already a grill block? I've pondered myself using vents behind the grill routed up and out of the hood (with depressions in the hood on each side) to turn some lift into downforce but for this endeavor a full block may have more advantage/less drag. The kammback idea is cool...stay with it!

Click to expand...

I have not done a grill block yet. I want to make the air flow under the car better first. I might block most of the grill and leave holes in the front spoiler open or partially open. Blocking all holes in the spoiler could create a situation where air tries to create more lift under the bumper before moving to sides?

I changed the rear wing shape to milder and now rear edges are ~4cm/1.6" higher. Height of the center can be changed a bit when making supports.

BillyMaysHere:
As said before, I'm not doing any major body mods. But keeps on thinking and hadn't read those threads before. That salt flat car is a reason why I was thinking of doing a air dam under the front edge of the bumper. Could be good but that doesn't look nice nor "stock"

sikbrik said:

I know it's very small gains compared to what you're looking at on the front and rear of the car but don't forget to consider the sides. That kammback should also slope "in" on the side profiles.

You won't want to increase frontal area with anything bulging out so front skirts on the fenders/wings won't really be advisable but DO look at a skirt for the rear wheel wells and add some simple mudflaps in FRONT of the tires, so the air isn't going up and into the wheelwell. Look at a Prius or other newer econo car to see examples of these. Similarly, side skirting made out of something rigid but semi-flexible will help keep air from under the car. Some flatter wheels/covers will help, if you don't add a skirt.

If all else fails, MOAR POWER!

Click to expand...

I could make removable extensions under the rear wing for the sides. But those I would use only if the changes done now aren't enough.

Some type of air guides in front of the wheels seem to be in somewhat any modern car, if the manufacturer is interested in that. Hence the guides in the front pan. Yes, wheels might a bit of a problem. Polaris is the only 17" original rim for 240 and i'm not into spacers to fit FWD rims. It would give many better options with flat spokes and surface. If 16" and spacers would be an option, I'd use S40/V50 Drive Libra.

I'm hoping that ~800hp with these mods would be enough. There are so many things that can go wrong in the engine compartment, so I'm not too confident in adding more power. For a run this long, dyno is a different thing. Also ~800hp without electric boost control means 900-950Nm/663-700lb-ft torque which is close to the clutch max capacity...

Anything more will exceed my knowledge so I'll just keep watching this but I want to say again...Amazing car/build! You've done an incredible job, the car looks great and very "stock appearing" with tasteful mods. It's hard to believe it's that fast with that much power. Good luck with your effort to reach 200!