Radon Rn.10 Photos

[nulrich]

I can neither confirm nor deny anything. But I will tell you our spring (and damper) motion ratios are exactly 1:1 on all four corners.

Nathan

[starkejt]

You said 4 corners, you did not say 4 dampers or 4 springs....

[Rick Kean]

Front pitch spring, ala TK's Piper DF3 FF?

Torsion bars, in lieu of front coils?

Rick

[nulrich]

I looked pretty carefully at a third spring (separate heave spring). We might try that eventually, and there is provision for it, but no reason to complicate things during initial development.

Torsion bars are very nice, and I designed the rear rocker geometry so we could try them at some point. But they are unfamiliar to most formula car racers, and it's hard to beat the price and availability of coil springs.

We'll see how things go this week!

Nathan

[SMRacing]

Wow.


That thing is incredibly sexy. It's really nice to see all (most) of the bits and pieces together. I know how hard you guys have worked on this thing. It looks great!

-Tim

[matt_tighe]

Car looks great Nathan, much more pleasing to the eye than the new RFR. Any plans to ship any to the UK ;-)

I've noticed the car seems to have a raised nose, without the chassis tubes visible at the front - but difficult to tell from your pictures?

[nulrich]

Hi Matt:

We'd be glad to ship to the UK, anything to counteract our motorsports trade deficit! Is there a class it could run in over there?

The structural floor is flat (within the 1" allowable deviation) but it's angled, which allows us to raise the nose. The roll cage, braces, and a 16 gage 4130 steel floor run all the way to the aluminum bulkhead reinforcement you see. (In fact, we added additional cross tubes to the bulkhead to satisfy the requirements of the rules as interpreted by the Court of Appeals.)

I can't show that area...yet...because I'd have to show some other features that we are trying to keep confidential as long as possible.

Nathan

[matt_tighe]

It could run in Formula 4 with an 1800 Zetec on carbs or a 1600 Duratec with injection as used by the UK FFord championship. The market would be small though as it's a club championship only.

I'd be interested in prices and specs when they are available in any case. Assume you'll be updating your website once the cars have run in public a little?

Can't wait to see some pictures of the car running.

[asw]

There should be a UK F2000 as well

[greg pizzo]

Nathan .. way to go !! .... WOW ... the car is really a step UP from what we are used to !! nice execution !!
Really be interested to see how this car goes !

NICE !!

[ericlangbein]

Congratulations Nathan- looking forward to seeing you guys at Mosport!

[Reddog]

Interesting ! A pull rod rear suspension? Beautiful car !

Makes a lot of sense, as the pull rods are in tension ... please chime in to suggest pull rods are not acceptable [pros or cons] ... just saying ...
regardless it is a work of art

[nulrich]

Thanks. Pullrods and pushrods can both work well. As you point out, pullrods only see tension loads, so you don't have to worry about buckling, which allows you to use tubing that is slightly more slender. On the other hand, you have to be mindful of the resultant forces in the wishbones (as you do with pushrods).

I designed both a pullrod and a pushrod rear, but the pullrod allowed a steeper angle from horizontal while keeping the top of the engine cover low. It also works better structurally at the bell housing, allowing the rockers to be in double shear, and has a slighter lower center of mass. Not a huge advantage, but every little bit helps.

Nathan

[DaveW]

The knock against pullrod suspension early-on used to be the motion ratios which, IIRC, always increased dramatically in bump. Also, some of these earlier suspension designs put the rockers in vulnerable positions such as wearing through rubbing on the ground. These problems gave pullrods a bad name.

With proper modeling and design, they can work very well, as Nathan said above.

[Reddog]

a response from two of the best ... I'll have a ... ...
any thoughts on a front pull rod system ... rasied nose is problematic [sp?]
but there is real talent here [not me] well ... neverrmind ...

[Christopher Crowe]

-- on a closer look, I'm curious about your diffuser. Is it a double-decker? Care to (generally) show its configuration?

Also, curious about the additional small (internal) ports in the radiator ducting. Are those pre or post the radiator's front face?

Thanks!

[Christopher Crowe]

The ports are pre-radiator. Are they designed to relieve some pressure residing in front of the radiator? Again, it would sure be neat to see a little diagram. Your car looks absolutely great.

Cheers

[nulrich]

For obvious reasons, I'm not going to show a drawing or detailed photos, but it is a double decker diffuser. The internal splitter (you can only see the end of it) has an specific airfoil shape, it's not just a constant cross-section. We originally introduced it as part of our Van Diemen aero package, and in the wind tunnel the diffuser produced the single biggest gains in downforce and aero efficiency. Tom Fatur (2009) and Phil Lombardi (2010) both won F2000 masters class championships with that package.

The version on the Rn.10 is slightly different, but the same basic approach.

The cross tubes in the radiator duct, contrary to some rumors running around, are only for crash attenuation. They are not open to the duct internally or otherwise. They are designed to absorb energy and protect the driver in a side impact like the attenuator tubes required in F3 and F1.

Nathan

[Matt M.]

Since it's been too warm to skate on my rink - I was updating my race resume and noticed that Radon has a new website up.... Looks like not enough pictures of me - but I guess it's not my website
http://www.radonsport.com

I'll be running the Fast Matt Driving Academy at The VIR pro race and putting on clinics at other races this year.... If anyone would like a tour of the car - chassis #4 is my favorite - or would like an autograph please make arrangements well before the season starts....

If you like to complain about a car you have never seen - there are possibly new angles of things you can only speculate about the legality of...... The more traffic the better!!

[Christopher Crowe]

What is the car's dry weight?

Where does the double deck diffuser draw its air from? Underside or top side?

Thank you,

Chris

[nulrich]

~980 lbs with a Zetec engine. For lighter drivers we add a steel plate under the engine so they don't need as much ballast, which brings it up to just under 1000 lbs. We could do a 960 lb car fairly easily if there was demand.

The diffuser is fed from underneath.

We'll be adding content to the web site soon, but right now we're too busy building cars!

Nathan

[greg pizzo]

finally a proper website ! nice job !!
car looks great !!