2010 USF2000 Car - Pictures

[bhayes]

I saw pictures of the 2010 car posted here....
http://www.trackforum.com/forums/sho...d.php?t=131356

Looks like a standard VD, with a different rear wing and diffuser. Probably has the PFC brakes, but can't tell form these pics.

[Purple Frog]

Pix from the floor of the PRI show.

Please realize these will not be, nor were they ever intended to be legal cars for the SCCA FC. They will be USF2000 spec cars. Just like Skip Barber cars weren't built to be SCCA FC compliant, nor were Paul Russell cars. The only likeness is that they are 2 liter cars. Don't confuse the issue. I was told by a higher up SCCA official that they could easily be fit into the FA class much as the old Cooper spec Zetec was allowed to run in FA.

With the strict testing rules in USF2000, don't expect to see their series cars running in SCCA events.

Steve had some nice B/W pictures of the Mazda installed in the new VD chassis. He did a nice job.

[Dan Andersen]

Nice pictures, Mike. One clarification...the cars are essentially SCCA legal for FC unless and until the PFC aluminum calipers are added (they are optional) and the Mazda engine is added, which is also not a mandatory engine for 2010. Everything else is in conformance to SCCA's FC rules. The aluminum calipers are also legal in your series, if I understand your 2010 rules, and maybe (we both hope) SCCA will one day allow them into club. As to SCCA races, we do allow our competitors to participate in club events, as our test ban exempts those for interested teams.

[Stan Clayton]

Does the car in these photos have a Mazda engine installed? I thought the MZR has its intake on the left side.

[Dennis McCarthy]

As to SCCA races, we do allow our competitors to participate in club events, as our test ban exempts those for interested teams.

Dan,

Can you explain this further?

[KevinFirlein]

I read it as you can run an SCCA event as a ' test'. Same rule as F2KCS which I think is a good rule.

[Purple Frog]

Kevin, I may have mis-understood, but i thought USF2000 competitors could not "test" at tracks that the USF2000 series races on. i.e. Road Atlanta, NJMP, and Road America.

Dan can clarify.

Dan,

Saying the the USF2000 Mazda powered car is SCCA FC legal except for the engine, is like saying an old Cooper Series car was legal for SCCA FC except for the engine. The 170 HP engine is a long way from being introduced to FC, me thinks. Yes, the chassis on display is wonderfully SCCA FC compliant (except we are still fighting for brakes as modern as a FSAE car )

[S Lathrop]

The Mazda poewered cars will be running this year? Can the championship Zetec engine compete with the Mazada at a place like Iowa?

With a 15 hp deficite, why would a car want to compete? At Iowa, the national cars might be a hazard going that much slower. Can a national car win both national and championship money?

[nulrich]

Kevin, I may have mis-understood, but i thought USF2000 competitors could not "test" at tracks that the USF2000 series races on. i.e. Road Atlanta, NJMP, and Road America.

This was one of the topics discussed at the PRI meeting this morning. Dan et al were asking for input on testing limitations, but I believe they are planning to allow at least "National" class cars to run SCCA events at series tracks, and likely "Championship" class cars as well. The A class cars would obviously have to either run as Atlantics (assuming SCCA allows them) or put in the restrictor and SCCA map (if they are Zetecs).

The Mazda poewered cars will be running this year? Can the championship Zetec engine compete with the Mazada at a place like Iowa?

My understanding from the meeting: both Mazda and Zetec engines will be allowed in A class this year, and perhaps in 2011. Steve Knapp will have the enviable job of making the power output and power curve identical for the two engines. They will add ballast under the engine to the Mazda-powered cars to make up the weight difference (the Mazda engine is 30 lbs lighter). Dan said Mazda had no expectation that they would have to win races this year.

With a 15 hp deficite, why would a car want to compete? At Iowa, the national cars might be a hazard going that much slower. Can a national car win both national and championship money?

Dan said they would likely use a different map and/or a restrictor at the oval tracks to reduce speeds. Presumably they would narrow the gap between A and B class engine power to prevent high closing speeds.

Not sure about prize money, but in response to my question, Dan said they would not change the maps if someone running a B class car happened to be competitive with the A class cars. 15 hp is a big discrepancy, but the A class cars have an awful aerodynamic package (limited to stock Van Diemen wings), so the difference may not be extreme at faster tracks. Not sure why anyone would accept that kind of handicap to race, but who knows? Didn't there used to be an A and a B class in F2000 many years ago?

Nathan Ulrich
Radon Sport LLC

[Wren]

Didn't there used to be an A and a B class in F2000 many years ago?

Back in the cooper series days they had the gold cup for SCCA spec cars. Cole Morgan ran it and was faster than several of the higher HP cars. Then the Cooper series failed.

[Rick Kirchner]

Interesting the way they hung the rear wing off the top and the deep endplates like the stillborn Ferrarri Indy car. somebody's paying a lot more attention to rear aero.

[TrackBrat]

The way the rear wing is braced from the top is how I think most wings will be braced in the future. The cars that have started this trend were ALMS/Le Mans LMP cars. With the rules that reduced their wing length they have tried what ever they can do to reclaim the loss of downforce. The first cars to show the new swan neck design was the Acura AX-02a, designed by Wirth Research, and the Audi R15 TDI.

The idea of the wings being braced on the top is that they do not have any contact with the underside of the wing. The wing is of course the opposite of an aircraft, with the low pressure area on the underside of the wing. This low pressure area is most sensitive area, and the supports of the wing can disrupt the airflow and thus decrease downforce. With the wing mountings on top they do not disrupt this airflow thus increasing downforce with minimal increase of aerodynamic drag.

For more information and detail data on this design feature check out the link. It is a fantastic sight to learn about car designs of LMP cars.

http://www.mulsannescorner.com/AcuraARX-02-4.html

[CSHAW]

Looking at the rear wing mounting

Just intuitive insight, but it looks like there is a very high degree of mechanical advantage that the entire wing assembly has in those two very fragile looking mounts. Between the two wing elements and the end plates, I wonder if a diagonal blast of airstream might twist them right off or flutter make them fatigue to the point of failure.

This is nothing more than an observation, not a diss, that has been leaving me scratching my head a bit.

[nulrich]

The swan neck mounting is certainly not a new idea, but it was especially well executed in the Acura LMP car. The way Elan copied it missed the whole point, though, which was to get the vertical section of the rear wing support well ahead of the leading edge of the wing.

The goal is primarily to reduce drag, so making your rear wing supports with square leading and trailing edges, doubling the thickness with an adjuster, and then pocketing out your adjuster defeats the whole purpose! Still better than the original mount, and with a spec car it just doesn't matter how well it works, it's all about marketing.

Here are some examples of rear wing mounting.

Nathan Ulrich
Radon Sport LLC

[iamuwere]

"Road to Indy"
"I Starts Here"???? Or is that a "1"?

[CSHAW]

Nathan, I am not questioning the mounting concept, been there done that. I am looking at the moments in relation to the applied force distribution, the material size, shape, mounting tabs etc... I am just wondering how sturdy this specific wing mounting is on the specific car shown in the pictures. If standing next to it, it would be hard to resist the temptation to reach out, take hold of the upper corner and give a little wiggle.

[Brands]

The primary goal of top surface wing mounts is to allow the low pressure side of the wing to work better. Traditional lower surface mounts produce a wake that reduce this effective area. If you could back to back test the old and new Elan rear wing it should be possible to use a flow vis(ualisation) fluid to determine if the new pillars are in the correct place. Of course, as mentioned above square leading and trailing edges are not ideal. A chamfer on the trailing edge can be supprisingly effective and not hard to do. I'm not sure what the current F1 thinking is (the BMW pic) but I know that by supporting the upper elements with pylons they can run very thin rear wing endplates (that could not otherwise support the upper wing).

[nulrich]

The primary goal of top surface wing mounts is to allow the low pressure side of the wing to work better. Traditional lower surface mounts produce a wake that reduce this effective area.

This is correct. However, it is not the whole story. Improving flow on the low-pressure (lower) surface of the wing is a good idea, but not always accomplished just by using top-surface mounting. The new Elan mounts, for example, are much too close to the leading edge of the wing. That, and the fact they have blunt leading and trailing edges, mean you are introducing turbulent flow directly in front of the entire center wing surface. I'm sure they are better than the old method with the big aluminum spacers blocking lower-surface flow, but not nearly as effective as the Acura method or a good streamlined lower surface mount.

If you could back to back test the old and new Elan rear wing it should be possible to use a flow vis(ualisation) fluid to determine if the new pillars are in the correct place.

We've done that on the old style mounts, as well as using smoke in the wind tunnel to characterize the flow in that area. As awful as you would expect, and pretty much identical to what we've seen in CFD studies. Haven't done anything with the new mounts (yet), of course, but it's obvious they won't work very well. Streamlining the profile and using a different wing angle adjustment method would make a big difference, but I assume that won't be legal in Dan Andersen's series.

I'm not sure what the current F1 thinking is (the BMW pic) but I know that by supporting the upper elements with pylons they can run very thin rear wing endplates (that could not otherwise support the upper wing).

There are about nine different approaches in F1...and soon to be twelve . Obviously very different from FC, since they have a lot more power to spare, and their rear wings are actually slightly narrower than ours! What matters most in F1 under the current rules is interaction with flow over the engine cover and how that influences the upflow from the undertray. There is no one best solution.

Nathan Ulrich
Radon Sport LLC

[Rick Ross]

Nathan,

Not asking you to divulge any secrets, but I would love to know more about your wind-tunnel testing. What type of tunnel did you conduct your wind-tunnel tests in? What scale model was used, and were the Reynolds numbers realistic? Were you able to measure any surface pressure distributions, or conduct any wake surveys?

Cheers,

Rick

[S Lathrop]

Where is the rear attenuator? Especially given that this was a part the IRL pioneered in an effort to improve safety.

The old under the wing mount system did provide something of a rear crush structure. The swan mount puts the end of the gear box closer to the wall.

In spite of not having an attenuator, the wing mount is very nice. The fact that it sits right behind the transmission and is close to the rear of the rest of the car, tapering the edges is probably not worth the time and cost. The stress at the bend/arch is very high. It will be very easy to under design that part.

[nulrich]

Nathan,

Not asking you to divulge any secrets, but I would love to know more about your wind-tunnel testing. What type of tunnel did you conduct your wind-tunnel tests in? What scale model was used, and were the Reynolds numbers realistic? Were you able to measure any surface pressure distributions, or conduct any wake surveys?

Full scale tunnel (fixed ground plane). Here's a link to a story and a short video:

Story

Video

We plan to make many of the results available, including an aero map of our wings and diffuser. That material will be up on our web site once it's finished.

A fixed ground plane tunnel has limitations, but they are well understood at this point. One of our aerodynamicists works at MIRA in the UK, and they don't have a moving ground plane in their tunnel, so he understands the correlation quite well. Under his direction, we also made a couple of modifications to the setup of the car in the tunnel to compensate for the lack of a moving ground plane.

Of course, if someone wants to pony up the $4800/hour for the Windshear tunnel, we'd be glad to go there!

[TrackBrat]

I love all this talk of aerodynamics and such, it a racing anorak dream discussion. The swan necks have already been used on a FC car since runoffs maybe even June Sprints. Arms Up ran the short wings at Road America, I can't remember if they had the swan necks at June Sprints or not. As for the design of the wing now It could just be used for mock-up of the car. The final design could still be a bit away.

Got any more info and such on the windtunnel testing? Do you guys use CFD at all or is it all physical windtunnel testing?

[nulrich]

Got any more info and such on the windtunnel testing? Do you guys use CFD at all or is it all physical windtunnel testing?

We'll put some more info and data from the wind tunnel up on our web site when it's launched. We'll also be back in the tunnel in February with our new car.

We do LOTS of CFD. Wind tunnel testing is useful for some things, but not for design work. We have one computing cluster that has been running flat out since January doing CFD on these cars, and we added a second in October. This is real formula car CFD supervised by a former McLaren F1 aerodynamicist and using the same software that several F1 teams use (low end software like FloWorks, etc can't accurately model formula car aerodynamics).

We'll have more news later this week, including pretty pictures and animations.

Nathan Ulrich
Radon Sport LLC