Unsprung Weight

[Will98Cobra]

Looking to see what other teams have seen for their unsprung weight.

William Austin
ODU Motorsports
Chassis/Suspension/Controls

[Denny Trimble]

As measured on our '03 car, by blocking the chassis up, placing scales under the wheels, and disconnecting the shocks on the chassis side, we have 31lbs at each front corner, and 29lbs at each rear. This is with 13x7 Hoosiers on Kodiak rims, with 10" steel rotors and wilwood calipers up front, and inboard brakes in the rear. Each tire + wheel weighs 18lbs.

University of Washington Formula SAE ('98, '99, '03, '04)

[jack]

i would be interested in knowing what people's wheels weigh. i thought ours were way too heavy at 16lbs a piece (not positive on the weight, im pretty sure they're 16--thats wheel, tire, brake rotor). oh, if your wondering why i include the brake rotor with the wheel/tire--check out the website.

thats 10" wheels.

jack @ WWU
http://www.etec.wwu.edu

[RagingGrandpa]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Denny Trimble:
As measured on our '03 car, by blocking the chassis up, placing scales under the wheels, and disconnecting the shocks on the chassis side...<HR></BLOCKQUOTE>
I would think rod end resistance would make that a significant underestimate... unless they're worn in to the point of worn out heh

"...with powershifts and tiresmoke for all"

[Denny Trimble]

Well, we "break in" our rodends before putting them on the car (drill press), and that car had 100 hours on it at the time of the measurement. Plus, the numbers are an average of "dropping" the wheel on the scale, and pressing down then letting it rise. Both methods produced +/- 1lb readings.

Jack, your numbers sound good for 10" wheels and rotors. The 13's are a significant weight penalty, but that's not the whole ballgame. I hope to see your car running soon!

Oh, and since we failed to get our driver cut done last weekend (screwed up the engine swap), we'll be doing it again this weekend. Hopefully next weekend we'll invite you guys down for another drive.

University of Washington Formula SAE ('98, '99, '03, '04)

[clausen]

Jack,

Chalmers wheels weigh about 1.2 kg http://fsae.com/groupee_common/emoticons/icon_smile.gif

Regards

Paul Clausen
Uni of Adelaide

[jack]

i weighed the wheel without the rotor--13lbs (5.9kg) i think we will drill a bunch of holes in the rim and tire to lighten things up. http://fsae.com/groupee_common/emoticons/icon_wink.gif

is 1.2kg (2.65lbs) for the rim or whole wheel?? i would be very impressed if that was the weight of the whole wheel. anybody know what kind of tires they ran?

jack @ WWU
http://www.etec.wwu.edu/fsae/

[clausen]

I'm not sure what you mean by wheel exactly.

It was 1.2 kg for the actual wheel, the whole thing that the tyre mounts onto http://fsae.com/groupee_common/emoticons/icon_smile.gif

It's two piece, aluminium and carbon.

I heard they were running goodrich tyres I think. When I looked I couldnt find any brandname on them at all.

Regards

Paul Clausen
Uni of Adelaide

[jack]

...yeah..1.2kg for the wheel without the tire...with the tire it would weigh more than 1.2

thats what i ment...

jack @ WWU
http://www.etec.wwu.edu/fsae/

[PatClarke]

Chalmers tyres were Uniroyals, same as used by Brunswick, whose tyres were branded with a bright orange logo. These are radial ply tyres, especially made for these cars and would be well worth exploring. Only in 13" as far as I am aware.
PDR

Rudeness is a weak mans imitation of strength

[formula_geek]

Pat-

Were the Uniroyals a one-off construction especially for FSAE? Were they based on a current tire in another (European??) series?

Anyone else, information regarding the availability of the tires themselves and data would be appreciated.

Travis
KU FSAE

[PatClarke]

I was told Uniroyal made these tyres especially for Formula Student in Europe (essentially the same thing). Whether they are based on an existing tyre/carcase I have no Idea, but I am sure a little Googling would come up with an address where you might ask.
I assume these tyres came from Europe, though I thought Uniroyal was a US company.
PDR

Rudeness is a weak mans imitation of strength

[Will98Cobra]

We don't have our tires yet, but our rims weight 7 lbs with hub, the rotors weigh 1.8 lbs. The wheel is 13 x 7. Does anyone have any tire weights on the 20.0 x 6.5 goodyear.

William Austin
ODU Motorsports
Chassis/Suspension/Controls

[vinHonda]

I've done extensive research into different compounds for FSAE. And MTS tested A LOT.

The boys from Brunswick were indeed using a Uniroyal/Continental tire. This is a special deal they have with the gentlman at Continental, where Continental will supply only German teams. The mans name is Ruaidhri Gleeson. I even offered to MTS test their tyres and supply data in exchange for 3 sets....but their "budgetary constraints will only allow them to supply to German teams" this year. The deal with Continental is similar to the deal we have with our "tyre partner": Continental will pour the Germans a compound that is more oil based and basically is a 'mistake' tyre. Obviously this has benefits in FSAE with our low weight cars. Speaking to Ruaidhri Gleeson at FStudent, he told me his tyre is "soft enough to only last 1 endurance". So there you go.

I've also tried to ask Bill Bedont @ Goodyear to pour us a 'mistake' tire, again in exchange for the data we have on the R65 compound vs. the Hoosier R25A compound.....they obviously won't because they can almost supply half the field.

So we will be sticking with our magical compound again this year.

Cheers!

Vinh

University of Toronto Formula SAE Racing Team
www.fsae.utoronto.ca (http://www.fsae.utoronto.ca)

[PatClarke]

Interesting Vinh, because as far as I know, Chalmers did not wear out any tyres, and they completed everything there was to complete in Adelaide, including two Endurod, despite the place being fearfully hot.
Perhaps the early dust on the surface helped them?
PDR

Rudeness is a weak mans imitation of strength

[Charlie]

They told me that this was the first time they'd raced on the radials. (At least I beleive that's what they said). http://fsae.com/groupee_common/emoticons/icon_wink.gif

Compound is just part of the equation, these cars are so light, have such small Iz, and many are stiffly sprung (or at least stiff in roll). So given that where does most of your transient response come from? And of course how much of your vehicle movement is from the tire spring rate which has unknown damping.

There are some tires out there with very very soft compounds off the shelf and readily available but they aren't worth a damn on the track.

Not pretending like I know the answers to all these questions. http://fsae.com/groupee_common/emoticons/icon_wink.gif

-Charlie Ping
Auburn University FSAE (http://eng.auburn.edu/organizations/SAE/AUFSAE)

[vinHonda]

I had no idea Chalmers were running the same tires as the Brunswick boyz. At Formula Student, they had Avons on.

I know the Brunswick tyres (radically accented with grooves coloured reddish/orange) were the ones I was talking about....and are supposed to wear down in 1 endurance.

Pat, was Chalmers running this tyre?

Vinh

University of Toronto Formula SAE Racing Team
www.fsae.utoronto.ca (http://www.fsae.utoronto.ca)

[PatClarke]

No Vinh, the tyres they were both running were slicks, with the tyres you are talking about mounted as wets.
Let me know your email address and Ill send you a pic or two. Still don't know how to post on here...despite some kind offers to host pictures.
PDR

Rudeness is a weak mans imitation of strength

[vinHonda]

Pat,

I don't know how to post pics either! Yes, you are correct, I am talking about the wets; I'd love to see what they were running.

My email: vinh@fsae.utoronto.ca

Thanks!

Vinh

University of Toronto Formula SAE Racing Team
www.fsae.utoronto.ca (http://www.fsae.utoronto.ca)

[Mi_Ko]

I've also met an talked with mr. Gleeson at formula Student.
We talked about a sponsorship, but continental is going to supply only German teams. http://fsae.com/groupee_common/emoticons/icon_frown.gif
If someone will have his email:
name.surname@conti.de - replace name and surname with ruaidhri gleeson (i'm sure he doesn't need more spam!)

I remember he told me, the conti compound is a bit harder than that from hoosier. (which are the softest tyres at FSae, together with Avon.)

Didn't Chalmers run BF goodrich?

2002/03 University of MARIBOR - Team Member

[ben]

Glad I didn't bother doing a full marketing pitch to the guy then :-)

We have found another source of tyres. Roll on the FSAE radial revolution!

Ben

University of Birmingham
www.ubracing.co.uk (http://www.ubracing.co.uk)

[RagingGrandpa]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by jack:
i weighed the wheel without the rotor--13lbs (5.9kg) i think we will drill a bunch of holes in the rim and tire to lighten things up. http://fsae.com/groupee_common/emoticons/icon_wink.gif<HR></BLOCKQUOTE>

Drilling holes in the tire eh??? http://fsae.com/groupee_common/emoticons/icon_eek.gif

"...with powershifts and tiresmoke for all"

[vinHonda]

I'm pretty sure Mr. Gleeson said his compound was the softest ever. But..... then again....I think our special tyres are the softest ever!

Last year seemed to be the start of some 'special' tyres at FSAE. I remember Yuki from Cornell brought out a special Yokohama from Japan and I had our special Avon.

Ben, what have you sourced out? Or is it a secret as well?

cheers

Vinh

University of Toronto Formula SAE Racing Team
www.fsae.utoronto.ca (http://www.fsae.utoronto.ca)

[Mi_Ko]

Maybe you're right Vinh. I talked vith mr. Greeson only about "normal" tyres. He didn't mentioned any special compounds.

If I remember, he said Hoosier and Avon have their softness set about 45 Shore and Conti about 50!. Our tyres (2 year old Goodyear, which are gone now!) had 60. Some teams had also tyres above 70 Shore.
(I'm sorry if i'm wrong, but my conversation with mr. Gleeson was a long time ago.)

2002/03 University of MARIBOR - Team Member

[vinHonda]

I'm confused by your "Shore" scale. What is it?

To me, a satisfactory fsae tire will provide more grip then the competition, and to save our budgets, ie last long.

Vinh

University of Toronto Formula SAE Racing Team
www.fsae.utoronto.ca (http://www.fsae.utoronto.ca)

[Mi_Ko]

It's something simmilar like Hardness Brinell, Vickers and other, but usable only for very soft materials, like rubber.
Mr. Gleeson had one Shore meter (I think it was) with him. A simple gauge with a needle.

Something like this:
http://www.inspection.pwallen.co.uk/Product_Images/largedi0073.jpg

2002/03 University of MARIBOR - Team Member

[ben]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by vinHonda:
I'm pretty sure Mr. Gleeson said his compound was the softest ever. But..... then again....I think our special tyres are the softest ever!

Last year seemed to be the start of some 'special' tyres at FSAE. I remember Yuki from Cornell brought out a special Yokohama from Japan and I had our special Avon.

Ben, what have you sourced out? Or is it a secret as well?

cheers

Vinh

University of Toronto Formula SAE Racing Team
http://www.fsae.utoronto.ca<HR></BLOCKQUOTE>

www.silverstone.com.my (http://www.silverstone.com.my)

We're using the Formula Malaysia front. We will be exhibiting on Silverstone's stand at Autosport International next month.

Ben

University of Birmingham
www.ubracing.co.uk (http://www.ubracing.co.uk)

[Mi_Ko]

Oh, you has success with Silvestone?

I tried to contact them (mr. Russell Palmer) and he didn't even replyed. Can you reccomend me any other people at Silverstone that shall I contact?

2002/03 University of MARIBOR - Team Member

[ben]

Not really, we have been talking to Russell.

We originally started working with them before Formula Student and tested a set in June. All our driver training had been on Hoosiers and we didn't want to change for the competition hence why you saw us on R25As at Brunty.

Subsequent testing has been good. We should also have one on our tyre rig soon.

Ben

University of Birmingham
www.ubracing.co.uk (http://www.ubracing.co.uk)

[Andreas]

Hello!

We ran avons in England which we were satisfied with. Formula student resulted in that we got sponsored with a couple of sets of the bruswick uniroyal tyre which are radials compared to the avons crossply and we got the tyres so late that we didn't have time to test them before we went to austrailia. We were able to make a proper setup for the competition whick is quite different to the cross ply. We ran the same tyre during all events and they worked well until the last endurance. They weren't worn out meaning they hadn't lost much rubber at all but anyway we didn't have any grip in the front end so they were useless with lots of rubber left.

About the rim, it's 1450 grams where the carbon is 500g and alu 950grams.

And the topic about unsprung weight we were about 10 kilos each front corner and about 12 kilos at each rear corner

Andreas

Beanie University of Technology

[PatClarke]

Miko, the tool you show is in every tyre technicians toolbox. It checks the hardness of the tyre, quoted in 'Shore' units.
40 shore is very very soft, 60 to 70 shore is typical of dry racing tyres and I guess road tyres are even harder.
I discussed this subject at length with some Goodyear technicians a couple of years ago, and they pointed out that Shore hardness at ambient temperature is meaningless, rather, it is the hardness at operating temperature that matters.
Some classes of racing (especially in karting) have tyre controls set on the Shore hardness, yet I have seen these tyres melt off the rim at racing speed.

Andreas, what you describe is a classical case of the tyres 'going off'. This is usually the result of too many heat cycles curing the tyre, or more likely at Tailem bend, overheating causes the tyres to get greasy and loose grip. Usually, when this happens, they tyre cures when it cools and is pretty well useless afterwards.

Bedding tyres in before use is a good idea. Run them for enough laps to remove the 'skin' on the tread at about 3/4 pace. Don't abuse them or slide on them. Then put them in a cool dark place for a minimum of 24 hours. These tyres will then be pretty stable for their entire life. Unfortunately, in one lap events straight out of the box like Autocross, brand new tyres are usually quicker....and thats not how you want to bed them in.
PDR

Rudeness is a weak mans imitation of strength

[Andreas]

Strange with this brand new tyres, because our brand new uniroyal was the most slipery thing i've ever driven before they were 'scrubbed in'. After the first enduro we could see that our tyres weren't 100% but we had finished the first enduro with our best drivers so we didn't bother change tyres, instead we wanted to just finish the other enduro as a reliable check and have a neat sunday drive. therefore we saved the next set to another occation.

Andreas

Beanie University of Technology