They are decreasing frontal area by eliminating 1in^2 of frontal area due to reduced wing end plate. Very innovative design...Originally Posted by Will Velkoff
They are decreasing frontal area by eliminating 1in^2 of frontal area due to reduced wing end plate. Very innovative design...
Chris Livengood, enjoying underpriced ferrous whizzy bits that I hacked out in my tool shed since 1999.
Very interesting, thanks for the info.
where are they getting these bad boys?
Nothing special. Take out your trusty jig saw and saw your endplates off.
DaveW won the Sprints a few years back using a momopole/single element rear wing. Same basic idea, less drag. You might also have less downforce. But diffuser designs are helping make up for less rear wing.
this is the same right? what way the brackets mount to he wing looks different, up and over instead of below the wing.
http://www.apexspeed.com/forums/showthread.php?t=42476
the up and over mounts are the newer Elan stock lower element mounts
Kevin Firlein Autosport,Inc.
Runoffs 1 Gold 3 Silver 3 bronze, 8 Divisional , 6 Regional Champs , 3x Drivers of the year awards
Our CFD and wind tunnel data show that it is the elimination of the square inches of the upper main and flap elements that is the critical drag reduction. The reduction in end plate size showed up as a minor component. Several years ago we helped put a WF1 DSR in the Ford 130 mph full size wind tunnel to do back-to-back testing on the stock Stohr biplane design compared to our single-plane design, and with proper placement of the main element vis the diffuser exits, rake angle and ride height, were able to generate the same downforce with about 10% less drag.
To test this theory we brought our Ralt RT-41 FA to the 2009 Sprints. Unfortunately, we didn't have the setup quite right, so were a bit disappointed in the results, but subsequent progress has born out this approach.
Last year we helped Michael Skully develop his DSR with the same approach, and he was able to set a new DSR class record with the same wing profile shown on our Ralt, though with the greater span permitted in that class. Progress was enough that he could remove the flap entirely and still generate the downforce he needed.
That car is now owned and raced by Lee Alexander, who, with further development (including some new whizzy bits flown in overnight from our Skunkworks) put it on pole at this year's Runoffs with a 2:00.97, the fastest club racing lap ever recorded at RA. Unfortunately, Lee did not get a great start and ended up with the silver, but all of the front runners in DSR have now removed their upper elements at RA in an effort to keep up.
The bottom line is that a DSR can expect a solid 2 mph top speed increase at RA with the same downforce using a single-plane rear wing if the setup and aero are done correctly. Obviously, an FC is a somewhat different kettle of fish, but as we see in this year's and last's FC results, the same approach of taking drag off the car without sacrificing downforce can have very good results. We haven't yet had the right opportunity to do FC testing at RA, but we have enough data from East and West Coast tracks that we are confident our FC wings can do the job with RA-specific endplates.
Last edited by Stan Clayton; 09.18.13 at 7:55 AM.
Stan Clayton
Stohr Cars
I'm pretty sure that Chris was joking about reduced frontal area with the shorter end plates! If he wasn't, he should have been.
There are two factors in play here. One is the position of the upper wing element. A lower position can potentially reduce drag at a small cost in downforce. We tried several positions when we had an '02 Van Diemen in the wind tunnel, but nothing as low as the Arms Up guys are running. They do a lot of testing at Road America, so I'm assuming they've found that combination to work well for their aero package at that track. It may or may not work as well with another combination of parts and setup.
The other factor is single element versus two element upper rear wings. All else being equal, a properly designed single element wing will always be more efficient than a two-element wing (up to the stall angle of attack). A two-element wing will allow a steeper angle of attack and more downforce. If you aren't running your two-element wing at a high angle of attack you will see a benefit going to a single element wing, especially at a track like Road America. We've seen significant gains in top speed (with no decrease in downforce) at Road Atlanta, Lime Rock and Watkins Glen with our single element wing versus our two element wing, gains consistent with our CFD and wind tunnel results.
If you only want to use one rear wing or you run at higher downforce tracks (Mid Ohio, for example) I would stay with a two element wing.
Nathan
little pocket cam pictures contribution
thx for exciting race guys
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