Diffuser Myths Begone - Page 2

reflexx · 09-28-2006, 09:29 AM

Your rake angle is so high flow will detach and might even make more drag than without it

feral4mr2 · 09-28-2006, 10:20 PM

oh... didnt seem that much steeper than many i have seen.

maybe its the angle/view of them pics.

thanks.

reflexx · 09-29-2006, 12:10 AM

probably most anything you saw on a street car is a gimmick, is why

Ferrari's street car diffusers are one of the only ones that actually work. Here's a 430's, it looks steep here but i think that's just the end of it plus a weird angle of the photo, i've seen it in real life and the beginning is quite shallow and gradually becomes steeper. the whole piece is maybe 2 feet long:

here is a real, 100% working racing diffuser. Note the angle. This is more like what kind of angle actually works.

feral4mr2 · 09-29-2006, 04:56 AM

yea, i see with that last one how it doesnt kick up at the end, just a slight curve. where the 1st one does look rather steep.

got imageshack to work, just a couple other angles. (i know the cut out where my exhaust tip isnt good, gotta do something with it)...

was going to continue it on underneathe more. 1st attempt at something like this.

cheers for your info.

reflexx · 09-29-2006, 09:12 AM

Hi,

the most important angle is the one where the 'diffuser' meets the horizontal line - that should be as smooth as possible. In other words, if the end of the diffuser is quite steep, that might be OK as long as the point where it meets the flat underbottom is not. In other words, this: \____ (sharp angle) should be avoided at all costs. Also, in the closeup pic, you can see that the underside of the bumper is going to catch air instead of work like a diffuser. You have to take metal sheet and seal off the bottom of the car to get anything out of the setup.

It's a street car, and it's not nearly low enough to take advantage of ground effect anyway, so who cares if it works - it looks cool!

dsf3g · 10-23-2006, 09:25 AM

Quote:

Originally Posted by reflexx

probably most anything you saw on a street car is a gimmick, is why

Ferrari's street car diffusers are one of the only ones that actually work.

I'm pretty sure the Lotus Exige also a functional diffuser. The whole point of the Exige was to add downforce through aerodynamics, and Lotus were the guys who inveted ground effect cars to begin with:

reflexx · 10-23-2006, 10:11 AM

exige does an OK job, it's more about handling/light weight than downforce (although it does make some).

If you want to talk real downforce, the Noble is the king. Everything in this car was designed around downforce and it generates like 1700lb (AFAIK) @ 120mph.

fidget · 10-23-2006, 12:04 PM

What about front splitters? Do or would they help at all?

reflexx · 10-23-2006, 01:45 PM

front splitters do a great job, IF

1) the splitter is very low to the ground. we're talking 1-2 inches.

2) the rest of the car is relatively smooth and low to the ground. underbelly trays, 2 inches clearance.

steven0720 · 10-24-2006, 02:21 AM

hmmmm , very interestin , so where can i find one?

reflexx · 10-24-2006, 09:30 AM

Gotta build one

Might as well relocate your exhaust while you're at it.

Mach2 on the boards is fabricating a full front splitter, undertray, diffuser after a few conversations with me. Might want to ask him about his project.

Carbon fiber or aluminum are good choices, aluminum might be better for the undertray as it won't break if you bottom out or hit a speedbump (not to mention easier to work with).

PearlJammzz · 02-01-2007, 11:07 AM

Any progress made in this?

trdny · 02-19-2007, 03:10 PM

Quote:

Originally Posted by dsf3g

I'm pretty sure the Lotus Exige also a functional diffuser. The whole point of the Exige was to add downforce through aerodynamics, and Lotus were the guys who inveted ground effect cars to begin with:

Just read a article about the car and they say it makes 90lb @ 100mph

reflexx · 02-19-2007, 03:23 PM

90 is kinda crappy... the ferrari 360 makes a few hundred lbs at that speed IIRC and the Noble makes 550? Gotta find the numbers.

PearlJammzz · 02-19-2007, 03:38 PM

pretty good for a 40k dollar car I think...

Mark_Dorman · 07-21-2008, 07:39 PM

Quote:

Originally Posted by reflexx

90 is kinda crappy... the ferrari 360 makes a few hundred lbs at that speed IIRC and the Noble makes 550? Gotta find the numbers.

Yeah, but for a car that weights ~2000lbs compared to the ferrari at ~3000lbs it's still pretty good. Plus the lotus is tiny and doesn't have an much to work with to create downforce. The noble is just ridiculous...

Raptor13x · 07-21-2008, 07:44 PM

Also keep in mind the average car creates a rather large amount of lift, so just getting lift down to zero is a pretty big accomplishment for your typical street car, let alone generating downforce.

Basement Digital · 07-21-2008, 10:19 PM

I'd love to see the visual aids restored on this post.

Dance_Business · 07-21-2008, 10:57 PM

I believe Reflexx was banned for being the boldest liar I can remember. The Mods would have to have the images from a back up.
I would like to revisit this thread, too. I have some honeycomb AL that could work as a splitter...

Basement Digital · 07-22-2008, 01:07 AM

Quote:

Originally Posted by Dance_Business

I believe Reflexx was banned for being the boldest liar I can remember. The Mods would have to have the images from a back up.
I would like to revisit this thread, too. I have some honeycomb AL that could work as a splitter...

Crazy. Lying about aerodynamics?

07-21-2008, 10:57 PM	#39 (permalink)
Dance_Business Mad Dance Skills Join Date: Apr 2006 Location: 20 minutes to Graceland Posts: 1,011 Thanks: 78 Thanked 8 Times in 8 Posts My Google Map iTrader Rating: (4/100% )	I believe Reflexx was banned for being the boldest liar I can remember. The Mods would have to have the images from a back up. I would like to revisit this thread, too. I have some honeycomb AL that could work as a splitter... Last edited by Dance_Business; 07-21-2008 at 11:00 PM. Reason: mistaken identity

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09-28-2006, 09:29 AM	#21 (permalink)
reflexx Banned Join Date: Aug 2006 Posts: 539 Thanks: 5 Thanked 0 Times in 0 Posts iTrader Rating: (1/100% )	Your rake angle is so high flow will detach and might even make more drag than without it

09-28-2006, 10:20 PM	#22 (permalink)
feral4mr2 ghetto modder Join Date: Sep 2006 Location: Western Australia Posts: 128 Thanks: 0 Thanked 9 Times in 9 Posts iTrader Rating: (1/100% )	oh... didnt seem that much steeper than many i have seen. maybe its the angle/view of them pics. thanks.

09-29-2006, 12:10 AM	#23 (permalink)
reflexx Banned Join Date: Aug 2006 Posts: 539 Thanks: 5 Thanked 0 Times in 0 Posts iTrader Rating: (1/100% )	probably most anything you saw on a street car is a gimmick, is why Ferrari's street car diffusers are one of the only ones that actually work. Here's a 430's, it looks steep here but i think that's just the end of it plus a weird angle of the photo, i've seen it in real life and the beginning is quite shallow and gradually becomes steeper. the whole piece is maybe 2 feet long: here is a real, 100% working racing diffuser. Note the angle. This is more like what kind of angle actually works.

09-29-2006, 04:56 AM	#24 (permalink)
feral4mr2 ghetto modder Join Date: Sep 2006 Location: Western Australia Posts: 128 Thanks: 0 Thanked 9 Times in 9 Posts iTrader Rating: (1/100% )	yea, i see with that last one how it doesnt kick up at the end, just a slight curve. where the 1st one does look rather steep. got imageshack to work, just a couple other angles. (i know the cut out where my exhaust tip isnt good, gotta do something with it)... was going to continue it on underneathe more. 1st attempt at something like this. cheers for your info.

09-29-2006, 09:12 AM	#25 (permalink)
reflexx Banned Join Date: Aug 2006 Posts: 539 Thanks: 5 Thanked 0 Times in 0 Posts iTrader Rating: (1/100% )	Hi, the most important angle is the one where the 'diffuser' meets the horizontal line - that should be as smooth as possible. In other words, if the end of the diffuser is quite steep, that might be OK as long as the point where it meets the flat underbottom is not. In other words, this: \____ (sharp angle) should be avoided at all costs. Also, in the closeup pic, you can see that the underside of the bumper is going to catch air instead of work like a diffuser. You have to take metal sheet and seal off the bottom of the car to get anything out of the setup. It's a street car, and it's not nearly low enough to take advantage of ground effect anyway, so who cares if it works - it looks cool!

10-23-2006, 10:11 AM	#27 (permalink)
reflexx Banned Join Date: Aug 2006 Posts: 539 Thanks: 5 Thanked 0 Times in 0 Posts iTrader Rating: (1/100% )	exige does an OK job, it's more about handling/light weight than downforce (although it does make some). If you want to talk real downforce, the Noble is the king. Everything in this car was designed around downforce and it generates like 1700lb (AFAIK) @ 120mph.

10-23-2006, 12:04 PM	#28 (permalink)
fidget No Skills Join Date: Oct 2006 Location: Jacksonville Florida Posts: 247 Thanks: 13 Thanked 8 Times in 8 Posts iTrader Rating: (1/100% )	What about front splitters? Do or would they help at all?

10-23-2006, 01:45 PM	#29 (permalink)
reflexx Banned Join Date: Aug 2006 Posts: 539 Thanks: 5 Thanked 0 Times in 0 Posts iTrader Rating: (1/100% )	front splitters do a great job, IF 1) the splitter is very low to the ground. we're talking 1-2 inches. 2) the rest of the car is relatively smooth and low to the ground. underbelly trays, 2 inches clearance.

10-24-2006, 02:21 AM	#30 (permalink)
steven0720 Some Skills Join Date: Oct 2006 Posts: 78 Thanks: 2 Thanked 2 Times in 2 Posts iTrader Rating: (2/100% )	hmmmm , very interestin , so where can i find one?

10-24-2006, 09:30 AM	#31 (permalink)
reflexx Banned Join Date: Aug 2006 Posts: 539 Thanks: 5 Thanked 0 Times in 0 Posts iTrader Rating: (1/100% )	Gotta build one Might as well relocate your exhaust while you're at it. Mach2 on the boards is fabricating a full front splitter, undertray, diffuser after a few conversations with me. Might want to ask him about his project. Carbon fiber or aluminum are good choices, aluminum might be better for the undertray as it won't break if you bottom out or hit a speedbump (not to mention easier to work with).

02-01-2007, 11:07 AM	#32 (permalink)
PearlJammzz Cage Fighter Join Date: Feb 2006 Posts: 2,139 Thanks: 9 Thanked 70 Times in 66 Posts My Google Map iTrader Rating: (7/100% )	Any progress made in this?

02-19-2007, 03:23 PM	#34 (permalink)
reflexx Banned Join Date: Aug 2006 Posts: 539 Thanks: 5 Thanked 0 Times in 0 Posts iTrader Rating: (1/100% )	90 is kinda crappy... the ferrari 360 makes a few hundred lbs at that speed IIRC and the Noble makes 550? Gotta find the numbers.

02-19-2007, 03:38 PM	#35 (permalink)
PearlJammzz Cage Fighter Join Date: Feb 2006 Posts: 2,139 Thanks: 9 Thanked 70 Times in 66 Posts My Google Map iTrader Rating: (7/100% )	pretty good for a 40k dollar car I think...

07-21-2008, 07:44 PM	#37 (permalink)
Raptor13x Legendary Join Date: Apr 2006 Location: Farmington Hills, MI Posts: 3,987 Thanks: 7 Thanked 40 Times in 34 Posts My Google Map iTrader Rating: (5/100% )	Also keep in mind the average car creates a rather large amount of lift, so just getting lift down to zero is a pretty big accomplishment for your typical street car, let alone generating downforce.

07-21-2008, 10:19 PM	#38 (permalink)
Basement Digital MR2 Loner Join Date: Jan 2008 Location: Portland, OR Posts: 340 Thanks: 47 Thanked 26 Times in 11 Posts Blog Entries: 1 iTrader Rating: (1/100% )	I'd love to see the visual aids restored on this post.