downforce games
Something like the custom diffuser on the first page but without any fins or the aggressive slope that it has?
Does anyone have more info on the custom rear diffuser posted on the first page?
Does anyone have more info on the custom rear diffuser posted on the first page?
Last edited by dudical26; Apr 24, 2007 at 10:28 AM.
what about it? it's been tested at two tracks (if i remember). almost as much df as the stock wing... and i say almost as in it DOESN'T have as much but DOES produce a noticeable (SIGNIFICANT) amount.
you can pretty much deduce how it's made with the pictures given. there's no secret sauce. rivets and a sheet metal bender.
i'm makin' one for myself but i'm modifying the construction a bit, more welding less rivets. more skeleton less bracket.
i want to mount mine like the apr rear diffuser, to those two hefty bolts but that requires a skeleton or at least a "backbone".
i'm makin' one for myself but i'm modifying the construction a bit, more welding less rivets. more skeleton less bracket.
i want to mount mine like the apr rear diffuser, to those two hefty bolts but that requires a skeleton or at least a "backbone".
Interesting discussion on rear diffusers here: http://www.ten-tenths.com/forum/showthread.php?t=95701
It has always been my understanding that a smooth underbody with a rear diffuser can be setup to create less drag than a stock setup on a street car _and_ create more downforce. Essentially going from a setup of no undertray/no rear diffuser/stock wing to a setup of undertray/rear diffuser/no wing should net less drag and a similar downforce.
l8r)
It has always been my understanding that a smooth underbody with a rear diffuser can be setup to create less drag than a stock setup on a street car _and_ create more downforce. Essentially going from a setup of no undertray/no rear diffuser/stock wing to a setup of undertray/rear diffuser/no wing should net less drag and a similar downforce.
l8r)
if the bottom is smooth there is no reason for a diffuser. what they're describing in the thread you linked is that the wing can air in scavenging air from under the car because it will bird tail he flow upward which will create more void closer to the ground of the car.
but you dnot' want to evacuate the bottom of the car in a drag race... that will produce downforce, that will produce bad traction.
notice in salt flat races, they try to make the car a torpedo. notice in drag racing you never see a diffuser on a well prepped car. just torpedos.
but you dnot' want to evacuate the bottom of the car in a drag race... that will produce downforce, that will produce bad traction.
notice in salt flat races, they try to make the car a torpedo. notice in drag racing you never see a diffuser on a well prepped car. just torpedos.
if the bottom is smooth there is no reason for a diffuser. what they're describing in the thread you linked is that the wing can air in scavenging air from under the car because it will bird tail he flow upward which will create more void closer to the ground of the car.
but you dnot' want to evacuate the bottom of the car in a drag race... that will produce downforce, that will produce bad traction.
notice in salt flat races, they try to make the car a torpedo. notice in drag racing you never see a diffuser on a well prepped car. just torpedos.
but you dnot' want to evacuate the bottom of the car in a drag race... that will produce downforce, that will produce bad traction.
notice in salt flat races, they try to make the car a torpedo. notice in drag racing you never see a diffuser on a well prepped car. just torpedos.
Actually the biggest thing I missed would be to lower the car as much as possible for drag racing - similar to what the Veryon does in its top-speed mode.
l8r)
wow I'm loving this thread! 
I don't want to add any pointless posts so I have one question..
Why don't we have any diffusers that are like
These seem more practical since they don't trap any air above or act like a shovel forcing air into the bumper.. We could totally just seal off the bottom of the bumper then just have this below it.. Would it work as well?
I don't want to add any pointless posts so I have one question..
Why don't we have any diffusers that are like
These seem more practical since they don't trap any air above or act like a shovel forcing air into the bumper.. We could totally just seal off the bottom of the bumper then just have this below it.. Would it work as well?
I'm not sure I understand and/or agree. What do you mean by downforce resulting in bad traction? I would think that the point of a drag car is to minimize drag while still retaining enough downforce to keep the car from losing traction as it nears the end of its run. IIRC, an Evo riding at a stock ride height starts to generate a significant amount of lift at higher speeds. The stock aero setup on a VIII is not enough to completely overcome the amount of lift generated. Therefore I am surmising that adding a smooth undertray along with a mild rear diffuser would be the way to go. It should result in less drag than no undertray and a wing, and still create a similar amount of downforce.
Actually the biggest thing I missed would be to lower the car as much as possible for drag racing - similar to what the Veryon does in its top-speed mode.
l8r)
Actually the biggest thing I missed would be to lower the car as much as possible for drag racing - similar to what the Veryon does in its top-speed mode.
l8r)
high downforce has proven in several cases to produce slower drag times.
this fact alone amkes downforce engineering of a drag race car VERY particular, in fact it's probably HARDER than to try to generate a full fledged maxed out downforce car even within stringent guidelines.
with a drag car only testing will tell you what is too much and what's not enough.
this fact alone amkes downforce engineering of a drag race car VERY particular, in fact it's probably HARDER than to try to generate a full fledged maxed out downforce car even within stringent guidelines.
with a drag car only testing will tell you what is too much and what's not enough.
high downforce has proven in several cases to produce slower drag times.
this fact alone amkes downforce engineering of a drag race car VERY particular, in fact it's probably HARDER than to try to generate a full fledged maxed out downforce car even within stringent guidelines.
with a drag car only testing will tell you what is too much and what's not enough.
this fact alone amkes downforce engineering of a drag race car VERY particular, in fact it's probably HARDER than to try to generate a full fledged maxed out downforce car even within stringent guidelines.
with a drag car only testing will tell you what is too much and what's not enough.
Having said that, I'll amend my earlier list to state that for drag racing you'd want to:
- Lower the car as much as possible
- Eliminate the rear spoiler
- Run no front splitter
- Install rear diffuser (minimal angle of attack)
- Smooth out the underbody
- Install a vortex generator
- Tape the seams if you must (IMO a lot of effort if you're not a pro)
Thoughts?
l8r)
