Rear downforce options

[Mad Hatter]

Lots of good stuff to digest! When you say "Balance the Wing" do you mean with a splitter?? Am leaning more about making a wing now, Talking to a airplane mechanic who works with Carbon fiber. If that does not work out then probably out of aluminum.

I have several events in January and February but the points races do not start till March, have time to get every thing sorted!


Hope everybody had a great Christmas and ate too much!!

 

[steveespo]

If you have a splitter already then the rear wing may make the car feel a little "pushy" which you ideally want to balance with more front downforce. lowering the splitter by 20mm-25mm makes the splitter a little more efficient without compromising front suspension travel or geometry. If you don't have a splitter yet, you need one, front aero lift needs to be addressed, splitter and Tiger hood have been proven to work well to plant the front of the car at high speed. A rear wing without front downforce work will be fairly dangerous and way out of balance.A stock S197 body without any aero aids is about +275 lb Front LIFT, 70 lbs Rear Lift. Lowering the car by 25mm, adding the Ford LS or WC splitters and the Tiger hood zeros out the front lift and slightly reduces the rear lift by moving the center of pressure rearward and relieving the packed in air under the hood. The G Stream wing can add over 600 lbs of downforce, most at the rear, but some effect at the front too, so the car will have a significant amount of downforce but a rearward bias. Adding some "dive planes" or "flippy things" on the nose helps splitter efficiency as does the lowering of the splitter itself closer to the track which will help balance the car aerodynamically. Also with the downforce spring rates and shock settings need to be looked at and primarily stiffened on the rear, springs can be left alone up front and compression on the struts softened slightly to dial out understeer. Hope this is helpful and hope it all actually works since this setup below probably won't work. Merry Christmas to the TMO Family.
Steve

 

[Mad Hatter]

Great, Crystal clear!. I hope everyone ate too much, I certainly did!

 

[dmichaels]

Great info Steve, I'll need to have you help me set up my new suspension with the aero this spring. My first time with adjustable suspension... separate compression and rebound adjustment and I have no clue

Back to aero - my car with the front splitter, canards, and rear wing felt incredibly planted but I'm sure I can extract a lot more once I get some help adjusting it right!

 

[steveespo]

Great info Steve, I'll need to have you help me set up my new suspension with the aero this spring. My first time with adjustable suspension... separate compression and rebound adjustment and I have no clue

Back to aero - my car with the front splitter, canards, and rear wing felt incredibly planted but I'm sure I can extract a lot more once I get some help adjusting it right!

You set the car up right Derek. Fine tuning is all that will be needed per driver feedback.

 

[302 Hi Pro]

If you have a splitter already then the rear wing may make the car feel a little "pushy" which you ideally want to balance with more front downforce. lowering the splitter by 20mm-25mm makes the splitter a little more efficient without compromising front suspension travel or geometry. If you don't have a splitter yet, you need one, front aero lift needs to be addressed, splitter and Tiger hood have been proven to work well to plant the front of the car at high speed. A rear wing without front downforce work will be fairly dangerous and way out of balance.A stock S197 body without any aero aids is about +275 lb Front LIFT, 70 lbs Rear Lift. Lowering the car by 25mm, adding the Ford LS or WC splitters and the Tiger hood zeros out the front lift and slightly reduces the rear lift by moving the center of pressure rearward and relieving the packed in air under the hood. The G Stream wing can add over 600 lbs of downforce, most at the rear, but some effect at the front too, so the car will have a significant amount of downforce but a rearward bias. Adding some "dive planes" or "flippy things" on the nose helps splitter efficiency as does the lowering of the splitter itself closer to the track which will help balance the car aerodynamically. Also with the downforce spring rates and shock settings need to be looked at and primarily stiffened on the rear, springs can be left alone up front and compression on the struts softened slightly to dial out understeer. Hope this is helpful and hope it all actually works since this setup below probably won't work. Merry Christmas to the TMO Family.
Steve

Hi Steve: This post is really good information written in terms that are easy to understand without an Areo PhD. Keep us posted on your test results from the new rear spoiler.

Yep, good stuff!
2HP

 

[blacksheep-1]

Low buck food for thought....if you REALLY want some downforce this is the fast and dirty way to get it, other than that the IMSA wing is the way to go along with the matching splitter, the PWC stuff is a little "serious" for a street car, whatever you do, keep it imsa/imsa or pwc/pwc, don't mix and match the splitter/wing combos, you won't like it.

http://drivefast.org/forum/viewtopic.php?f=18&t=1533

 

[Mad Hatter]

When you say imsa...do you mean something more like the Steeda wing or this one... Its the Tiger wing at http://www.chicane23.com/shop/body/boss-plus-rear-spoiler/

About the quick and dirty fix, I think I saw the same thing in a article for the z28. Randy Pobst complained that the z28 he drove had a over-steer problem. Chevy stuck a lip to the rear spoiler and fixed the problem.

I would like to keep the car street legal, I get a kick beating track only cars....though its going to get a lot harder now.

 

[dabossinnne]

Pretty good vid of B302S wind tunnel testing. Amazing how much air that Tiger Racing hood extracts...I'm sold! Also shows clearly the flow over the G Stream wing:

https://youtu.be/Gr40fdYmd2I

 

[VoodooBoss]

When you say imsa...do you mean something more like the Steeda wing or this one... Its the Tiger wing at http://www.chicane23.com/shop/body/boss-plus-rear-spoiler/

About the quick and dirty fix, I think I saw the same thing in a article for the z28. Randy Pobst complained that the z28 he drove had a over-steer problem. Chevy stuck a lip to the rear spoiler and fixed the problem.

I would like to keep the car street legal, I get a kick beating track only cars....though its going to get a lot harder now.

I'm not a big fan of the looks of this wing and have never seen any wind tunnel test results or downforce claims. It's very "chunky" looking IMO. It's essentially a LS wing raised with end plates and is designed to mount to the stock LS holes in the deck lid.

 

[Grant 302]

I'm not a big fan of the looks of this wing and have never seen any wind tunnel test results or downforce claims. It's very "chunky" looking IMO. It's essentially a LS wing raised with end plates and is designed to mount to the stock LS holes in the deck lid.

My issue with that wing is I see it as a bit of a bastardization of a relatively elegant OEM design. I don't only mean aesthetically, but totally agree on that note too.

The LS wing pedestals functionally channel and expand the air on the underside. Aerodynamically, it is both a wing and a diffuser. Not in the 'underbody' definition, but the pedestals are intentionally *not* parallel and form a controlled expansion area/volume for the air under the wing in 3 separate channels.

 

[Grant 302]

And FWIW, I think the LS design was good enough to 'evolve' into the GT350R wing design.

 

[Mad Hatter]

Maybe the LS wing would be more in line with my "street" car.

I found this price for one...

http://www.chicane23.com/shop/body/2010-2014-boss-302-laguna-seca-rear-spoiler/

 

[Mad Hatter]

This one must have some down force...but way too Frankenstien like.

 

[Fabman]

This one must have some down force...but way too Frankenstien like.

NASCAR style....I like it.

 

[VoodooBoss]

Maybe the LS wing would be more in line with my "street" car.

I found this price for one...

http://www.chicane23.com/shop/body/2010-2014-boss-302-laguna-seca-rear-spoiler/

That one is good. You want the OEM piece and not an aftermarket copy.

 

[Grant 302]

Maybe the LS wing would be more in line with my "street" car.

I found this price for one...

http://www.chicane23.com/shop/body/2010-2014-boss-302-laguna-seca-rear-spoiler/

I'd look for/expect just under $300 for an OEM one, last I looked.

 

[Mad Hatter]

Got the price down to about 285, looking too see how much lower I can find it.

 

[Grant 302]

Got the price down to about 285, looking too see how much lower I can find it.

That sounds right. I figure you just gotta find the vendors that will ship internationally.

 

[Mad Hatter]

I usually use a shipping address in Miami and then gather a big shipment of parts with our Hoosier rep here in Chile. That way we keep the price down. Shipping/taxes etc adds about 40% to everything :'(