Does Anyone Know What the Heck is Going on at Goodyear!?

[Cardriverx]

So we just got a letter that says quote "After a careful review of the business case associated with developing a 10" tire, Goodyear has decided not to pursue developing the tire will therefore be exiting FSAE support".

Has anyone spoke directly with Goodyear or gotten this letter? It sounds like they are fully pulling out of the competition, which I need to know ASAP seeing as it makes all of our months of research on tire data a somewhat moot point. For people that have not got this letter, sorry to be bearer of bad news.

-Steve Karkenny
University of Pittsburgh

[RANeff]

You are saying that since they dont want to make a 10 inch tire, they wont make any? A year after developing the 2704?

Anyone else have any info on this?

[SNasello]

After looking at the Goodyear racing home page under products, there is no longer a Formula SAE link. If you google "Goodyear racing formula SAE" you can find the page, but as soon as you navigate somewhere else on the site, the link is gone.

If this is true, this is sad news for the FSAE/FStudent community, and will also set us back on development.

[rmk36]

I would encourage everyone to write a letter to Goodyear Racing thanking them for their support and emphasizing how important their program has been to FSAE. Also, respectfully urge them to continue working with the FSAE community and explain the impact it can have.

It goes without saying, but a resentful tone isn't going to encourage positive results. Keep it classy.

[Cardriverx]

Please respond to me PM ASAP. Thanks


Originally posted by GoodyearFSAE:
Unfortunately I can confirm this as accurate. At this time Goodyear is making serious revisions to the tire lineup produced by the racing division. The current FSAE line is one of several products being discontinued.

Last week SAE and several of the schools we have worked closely with in the past were notified of these changes.

- Plans to develop a 10" tire have been dropped.
- Goodyear sponsored track days including the Fall Shootout have been cancelled.
- As of this time there are no plans for further production of the D2704 or D2703.

We apologize for the impact this will have on many teams development cycles. This was not a decision that was made lightly.

[theTTshark]

Sounds like quite a few teams are going to get thrown under the bus because of this decision. Hopefully they can transition to another brand early enough to change their design.

[Ben K]

This does not bode well....for a lot of teams.

Ben

[Mike Cook]

I thought it was strange when I emailed Brian the other day and the email bounced.....Oh well...Hoosier won.

[Moop]

And we were just about to switch to the D2704s http://fsae.com/groupee_common/emoticons/icon_frown.gif

[Claude Rouelle]

If Goodyear gives up their FSAE tire / program that is a sad news. FSAE needs diversity in colleges, nations, culture etc.. and suppliers. Goodyear was a major player with good ex-FSAE engineers helping FSAE / FS team and these guys knew what they were speaking about. Again if this is true, it is a loss.

That being said, 3 quick comments:

1. I keep being puzzled by the lack of research made by the students; there are many tires on the market from 8" diameter to 15" and over which could make a VERY good tire in FSAE / FS competitions. Goodyear is (was) a good, proven solution and so is Hoosier but there are not the only ones.

In some case, tire companies build specific tires for 1 or 2 FSAE teams, gives them the tires, the technical support, access to testing facilities ... and a budget! But that is for teams who gave them test report, engage in real engineering partnership and test at least 4 months before the competition (old story)


2. If I had to build a FSAE car and weight and inertia reduction were major targets, I would at least consider 8" tires. Lots of space constraints in such a small rim... but possible. Major issue: lack of TTC data for tire newcomers.


3. I feel the pain for the guys who already started to design their car (especially suspension) around the Goodyear tire )(that is if they use the TTC data properly) That being said, as a design judge, that is question I often asked to students: IF circumstances force you to switch from tire A to tire B, what would you change (or have changed) in the car suspension concept and in your car setup (spring, damper, ARB etc..). For some teams this hypothetical question does become a reality.

[dazz]

Originally posted by Claude Rouelle:
" many tires on the market from 8" diameter to 15" and over "

Claude, in reference to rule:
T6.3 Wheels
T6.3.1 The wheels of the car must be 203.2 mm (8.0 inches) or more in diameter.

Would you consider this dimension to refer to the rim diameter or the outside diameter of the tire (I am feeling a little sleepy - tyre)? To me, the wheel consists of both the rim & tire as well as whatever connects the rim to the hub.

The rule could read '203.2 mm (8.0 inches) or greater rim/tire size' to be clearer, or if the dimension is intended to relate to the outside diameter of the tire (surely not?) then it should read as such! It could open the floodgates to karting wheels with very interesting suspension & braking packages starting to appear!

Ultimately a rules committee clarification, but a little discussion here couldn't hurt?

[EPMPaul]

Yeah, well, we just completed our design(are about to, putting fasteners and the electrical loom in the CAD as we speak).. with the Goodyears.

Anyways, gonna have to look into other tire solutions. Also, we've managed to provide some adjustability on the chassis side so we should be able to figure something out. (sometimes being an anal team leader pans out http://fsae.com/groupee_common/emoticons/icon_biggrin.gif)

As a side note, anybody have an idea of how many Goodyears are still in stock?

Tomorrow s gonna be a gold rush if any are left

[SNasello]

Paul,

We tried buying some new Goodyear tires before FS Spain and Goodyear Motorsport Germany told us there aren't anymore. Perhaps in the US/Canada there are still some sets. Some teams from Australia have also e-mailed us asking for tires, so apparently there aren't any in Australia anymore either.

[Moke]

Originally posted by Claude Rouelle:
That being said, as a design judge, that is question I often asked to students: IF circumstances force you to switch from tire A to tire B, what would you change (or have changed) in the car suspension concept and in your car setup (spring, damper, ARB etc..). For some teams this hypothetical question does become a reality.

This. Welcome to the rest of your lives, design for one thing then have to change at the last minute due to supply issues.

This will be hard on the teams just starting testing for FSAE-A.

[Pete Marsh]

Oh no, this is sad news.

If any teams want to sell their current stock of 2704s to change to an alternative brand UWA would be interested in buying them from you.

Pete

[Edward M. Kasprzak]

Originally posted by dazz:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Claude Rouelle:
" many tires on the market from 8" diameter to 15" and over "

Claude, in reference to rule:
T6.3 Wheels
T6.3.1 The wheels of the car must be 203.2 mm (8.0 inches) or more in diameter.

Would you consider this dimension to refer to the rim diameter or the outside diameter of the tire (I am feeling a little sleepy - tyre)? To me, the wheel consists of both the rim & tire as well as whatever connects the rim to the hub.
</div></BLOCKQUOTE>

I believe the rule is clear. To put it simply, the wheel is the metal part and the tire is the rubber part. Tires are mounted on wheels, and the wheel does not include the tire.

[PatClarke]

Way back whenever, the 8" wheel diameter rule was introduced to specifically rule out the use of 5" and 6" go kart tyres. I seem to remember it was part of the 'anti go kart' movement that introduced the 2" suspension rule.

So, Ed is right. 8" minimum diameter refers to the wheel, not including the tyre.

Cheers

Pat

[Tilman]

Originally posted by Edward M. Kasprzak:
To put it simply, the wheel is the metal part and the tire is the rubber part. Tires are mounted on wheels, and the wheel does not include the tire.
I'm just a curious non-native English speaking guy: How do you call a tire mounted on a wheel? Wheel assembly?

In German there are two words that can refer to the wheel (the metal/CFRP part). One of them refers to the wheel only ("Felge") while the other ("Rad") may refer to the tire & wheel assembly but also to the wheel of a carriage/horse buggy. Moreover, the word for tire ("Reifen") often refers to the tire & wheel assembly, not to the tire alone.

[BillCobb]

The wheel would be a rim, a tire would be a tire, and a wheel would be a tire + rim + gas(maybe) + stem plus liner plus flap, etc...

[Tilman]

Originally posted by BillCobb:
The wheel would be a rim, a tire would be a tire, and a wheel would be a tire + rim + gas(maybe) + stem plus liner plus flap, etc...
Hmm, obviously http://fsae.com/groupee_common/emoticons/icon_smile.gif Forgot the word rim ...

[EPMPaul]

Just called every supplier on the east coast. They're all out and have been for a while

[Mbirt]

Hurry up and buy the rights to produce the tire, American Racer!

[Claude Rouelle]

For me a bolt is the assembly of a screw and a nut. That is what I was taught in engineering design course. But that was in French http://fsae.com/groupee_common/emoticons/icon_smile.gif Similarly I look at a wheel as the assembly of a rim and a tire. Sometime we get confused and mix the name of the assembly and the part. That is just a question of vocabulary. In any case we all understand that the minimum diameter of the rim (call it wheel without the tire if you want) is unequivocally 8 inches.

[Racer-X]

Tillman, we use the wrong word for plenty of things in English. The correct usage of tire is of course just the tire, and a wheel is just the wheel that the tire is mounted to. Then rim can also be used to describe a "wheel" but is technically the outer edge where the bead seals.

Though most people use wheel to describe the whole assembly as we don't actually have a word for the wheel & tire assembly.

[Cardriverx]

Between RCV shutting down all carbon work/possibly more And goodyear pulling out... this year should be an interesting one haha

[Warpspeed]

Originally posted by Claude Rouelle:
For me a bolt is the assembly of a screw and a nut.

I believe the correct definition of a screw or a bolt only refers to the head.
Screws are internally wrenching, where a tool fits into an internal cavity or a slot.
Bolts are external wrenching where a tool fits over the outside of the head, which commonly has flats.

Alan screws have parallel threads and can use a nut.
Coach bolts can be screwed into wood, using a spanner!

Anyhow, back on topic.
As more than a few FSAE teams are from non English speaking countries, the exact wording of the rules needs especial care.
I believe a wording change to "wheel RIM diameter" would clear up any future ambiguity.

[Jersey Tom]

Well that sucks they had to pull a tire that was pretty sporty, even if it's a small market. But hey, it is what it is.

Even then, as much as it would have been nice to have for competitive advantage, if you switch tires how much do you really have to change on your cars to re-balance it? A test and tune day (or half of one) perhaps, but I'd have a hard time imagining it being a total catastrophe.

Just my gut feeling.

[Ben K]

Originally posted by Jersey Tom:
Well that sucks they had to pull a tire that was pretty sporty, even if it's a small market. But hey, it is what it is.

Even then, as much as it would have been nice to have for competitive advantage, if you switch tires how much do you really have to change on your cars to re-balance it? A test and tune day (or half of one) perhaps, but I'd have a hard time imagining it being a total catastrophe.

Just my gut feeling.

+1 -- Real world testing is always better vs spending hours and hours dialing it in 100%

Ben

[Pete Marsh]

Even then, as much as it would have been nice to have for competitive advantage, if you switch tires how much do you really have to change on your cars to re-balance it? A test and tune day (or half of one) perhaps, but I'd have a hard time imagining it being a total catastrophe.

Just my gut feeling.

Not just a competitive difference or balance change, the size and rates of the tyres are different making a direct swap not always OK. A REAL big problem for at least one concept I'm familiar with, and still a hassle with bodywork rules etc.

I notice the post from Goodyear does not totally rule out the possibility of another manufacturing run of the current tyre?

Pete

[Claude Rouelle]

A test and tune day (or half of one) perhaps, but I'd have a hard time imagining it being a total catastrophe.

if you switch tires how much do you really have to change on your cars to re-balance it? A test and tune day (or half of one) perhaps, but I'd have a hard time imagining it being a total catastrophe.

Some of the students will need to be careful with this argument. In the design event some of the teams make a big case of why they choose tire A compared to Tire B using lots of TTC data. But then if you just need or 1 or 1 and 1/2 day to just adapt the car to another tire what was the big deal...

I only can tell you this: in LMP1 if a car have been designed and tuned around Dunlop tires and you switch to Michelin (or the other way round) you would be lucky if you will get similar performances. I agree that a FSAE is not an LMP1 car and the difference Dunlop - Michelin may be greater than Hoosier - Goodyear and I also agree that FSAE students are far from exploiting cars as LMP1 drivers do.

But still...

[Claude Rouelle]

In case you do not know this there also could be a major issue to find Hoosier tire next year: the company has just been bought by Yokohama.

The 2 companies have decided to join their efforts and make a new tire brand called Hoosiermama.

Could not help!

http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Markus]

Nice one Claude. http://fsae.com/groupee_common/emoticons/icon_smile.gif

We went through changing from Hoosiers to Goodyears in the States this year and have to say that there was quite a lot of trouble in the end.

The nominal diameter difference of 0,5" proved to be over 1" in real life which was enough to cause some heavy issues. And then was the tuning...

We could make the Goodyears faster than Hoosiers but couldn't exploit them to their full potential as some changes would've required part manufacturing.

Luckily (AFAIK) the new car is designed to run both Hoosiers and Goodyears with all required setup parts to switch between, so we can balance testing with the Goodyears we have in stock. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Jersey Tom]

Originally posted by Claude Rouelle:
Some of the students will need to be careful with this argument. In the design event some of the teams make a big case of why they choose tire A compared to Tire B using lots of TTC data. But then if you just need or 1 or 1 and 1/2 day to just adapt the car to another tire what was the big deal...

I only can tell you this: in LMP1 if a car have been designed and tuned around Dunlop tires and you switch to Michelin (or the other way round) you would be lucky if you will get similar performances. I agree that a FSAE is not an LMP1 car and the difference Dunlop - Michelin may be greater than Hoosier - Goodyear and I also agree that FSAE students are far from exploiting cars as LMP1 drivers do.

But still...

Certainly in a purist environment (such as the design tent) or in an ideal case, one would like the students to be able to use some predictive method to determine what component-level or conceptual design items need to change switching between Tire A and Tire B. While ideal, that may not be within (a) the skill set available for a given team at any time, (b) the fidelity of their vehicle model, (c) the fidelity of available tire data. Even if all those requisites are met it will still ultimately have to be validated by a track session.

I would make the case that broadly in engineering, 'build and test' is not inherently a bad thing. With time efficiency being at a premium, I'd say the engineer must ask themselves, "As things stand now what is going to get me to the correct answer the fastest - going out and testing it, or using a predictive process / simulation?" Could go either way! If it were 5 years ago and I were put in this position, I would have to go with the former approach... and in the design event I wouldn't be shy to say that the predictive capability was well outside our reach (to be developed in the off season) and a weekend test session was the best way to bring a competitive package to the event. I think that's still effective engineering.

In any event - the point I was trying to make earlier was more that [relative to some other vehicles I've been exposed to recently] these cars are fairly simple. They are symmetric, with generally linear force elements (not coil binding for example), and at least the last time I was involved in it many teams ran suspensions so stiff and with so little travel that their kinematic curves could not only be boiled down to a 1st order approximation, but perhaps 0th order (also mitigating a lot of damper effectiveness). As such I'd make the argument there are relatively few tuning knobs and one could make a sweep on them in a reasonable amount of time.

Certainly there are times that switching tires requires a fundamentally different vehicle design - but that doesn't mean it's always the case. If a team were to switch from Goodyear to Hoosier (perhaps a poor assumption - as you say there are many good tire suppliers out there) my gut feeling is that you could still make the best of it with relatively few adjustments - on the premise that you don't have that many adjustments you can even make to begin with.

The "making the best of it" part is key. As much as TV announcers sometimes like to speak of "making the tires work with the car" or vice versa, it is easy to lose sight of the fact that there are fundamental handling characteristics inherent to the tire which you cannot tune out with any realistic amount of kinematics, springs, bars, or differential adjustment. Some things are inescapable.

You may not ever be able to make a Hoosier drive exactly as well as the Goodyear (opportunity for personal bias? yes!) - but I think you can work around making the Hoosier the best it can be.

[EPMPaul]

+1 on the Goodyear seeming real good. Had a lapsim with some simple assumptions(WD,LLTD, steady state) and a tire model. based design off of that, turned out the goodyear was faster (of course this is student simulation so to be taken with its extremely large grain of salt). Didn't check the continental or the avons for supply chain reasons but they could be viable options. As Claude said, lots of tire suppliers out there for tires. I also recall Claude mentionning something how a lot of adjustability was critical on these things. http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

[Charles Kaneb]

On the 8" tire front:

Our team has contacted several different companies who make racing tires, sometimes even 8" racing tires, about an 8" soft-compound slick.

The results weren't pretty.

One company, which already manufactures an 8" slick and slick tires in a soft compound, was initially receptive. They quoted a surprisingly modest price with only a fifty-tire minimum. We decided to go ahead with it and called back with a credit card in hand. Their response was that management had decided not to make the tire. Further attempts, including offering a significantly higher price and a significantly larger order than they originally quoted on, have met with either failure or silence.

Another company said that they would require an order of 20,000 tires per year, and that any smaller volume wouldn't fit their business. This is larger than the entire market for FSAE tires.

A third company, manufacturers of 8" treaded dirt racing tires, was absolutely uninterested in our business.

I have not found any other company in the Americas that makes 8" tires. A couple calls to tire companies that do not have an 8" mold indicated that it would be a major business decision to begin making tires in a different diameter.

[Claude Rouelle]

Charles,

Whether you look at 8", 10', 13" or even larger inside diameter tires, look at the type of racing series which are similar in duration / distance as well as car power and weight. And of course look also outside the US. There are tires out there which are already manufactured and that you can buy. There is actually at least 2 brands that, amazingly, I never saw in FSAE/ FS competitions which I believe would give a significant advantage....

[Ben K]

Originally posted by Claude Rouelle:
Charles,

Whether you look at 8", 10', 13" or even larger inside diameter tires, look at the type of racing series which are similar in duration / distance as well as car power and weight. And of course look also outside the US. There are tires out there which are already manufactured and that you can buy. There is actually at least 2 brands that, amazingly, I never saw in FSAE/ FS competitions which I believe would give a significant advantage....

This should narrow it down a bit?

http:// en. wikipedia. org/ wiki/ Template:Class_of_Auto_racing

http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

Ben

[OspreysGoSWOOP]

Originally posted by Claude Rouelle:
In case you do not know this there also could be a major issue to find Hoosier tire next year: the company has just been bought by Yokohama.

The 2 companies have decided to join their efforts and make a new tire brand called Hoosiermama.

Could not help!

http://fsae.com/groupee_common/emoticons/icon_smile.gif

HAHA! That joke never gets old.

[Claude Rouelle]

That is one of the seminar jokes. In fact the OptimumG seminar is free of charge; you just pay for the jokes. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Rex Chan]

Originally posted by Pete Marsh:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Even then, as much as it would have been nice to have for competitive advantage, if you switch tires how much do you really have to change on your cars to re-balance it? A test and tune day (or half of one) perhaps, but I'd have a hard time imagining it being a total catastrophe.

Just my gut feeling.

Not just a competitive difference or balance change, the size and rates of the tyres are different making a direct swap not always OK. A REAL big problem for at least one concept I'm familiar with, and still a hassle with bodywork rules etc.

I notice the post from Goodyear does not totally rule out the possibility of another manufacturing run of the current tyre?

Pete </div></BLOCKQUOTE>

How much?

[NickFavazzo]

Originally posted by Rex Chan:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Pete Marsh:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Even then, as much as it would have been nice to have for competitive advantage, if you switch tires how much do you really have to change on your cars to re-balance it? A test and tune day (or half of one) perhaps, but I'd have a hard time imagining it being a total catastrophe.

Just my gut feeling.

Not just a competitive difference or balance change, the size and rates of the tyres are different making a direct swap not always OK. A REAL big problem for at least one concept I'm familiar with, and still a hassle with bodywork rules etc.

I notice the post from Goodyear does not totally rule out the possibility of another manufacturing run of the current tyre?

Pete </div></BLOCKQUOTE>

How much? </div></BLOCKQUOTE>

About 20mm on Diameter as well as being different width and different spring rates.

[Claude Rouelle]

To Jersey Tom an all,

One of my best employers was ORECA for which I was the Formula 3 chief race engineer many, many years ago. We won 100 % of the championships and more than 60 % of the races we compete in. After a while I noticed that race debriefings conducted by Hughes de Chaunac, the team owner, were always 3 times longer when we won race than we lost them. I asked Hughes why and he told me:" I want to know why we win. If we do not know why we win, we won't know what we lose"

That phrase has has been with me with for the rest of my career. In my own words it became "win, know why, win again"

I can't agree with the "build and test or with the "cope the best you can" with the tire brand change philosophy. Even less in FSAE which, let's remember, is a design and project management competition based on a race car, not a racing series.

As a design judge I expect the students to scientifically and objectively use their tire data, all the simulations tools and the recorded track data analysis to justify the tire choice they made, to show how they design and tune their car around that tire and what they would change if they had to do it again and WHY. It is not a disaster if they made an error, providing they can explain what the error was, what they should have done (or will do next time) to avoid it. Similarly I expect them to explain what they change in their car design and WHY if circumstances force them to switch from tire X to tire Y. Possible tire switch should have been part of a plan B anyway.

Here is an abstract of an interview on Ron Dennis (Mac Laren F1) in 1998: "... in fact, the needs of all Formula 1 cars are invariably served by the same technical exercise. The fact is that the car - and the kinematics of its suspension - must be developed hand in hand with the tire. As I indicated earlier, optimum results can only be achieved when the two sides are prepared to share their most secret and sensitive data"

In the "real" racing world, I have seen too often very good tire engineers and as good race car design and development engineers... but speaking together and not enough long term strategy and design of car around tires and vice versa. Believe me or not, I know some excellent ex FSAE students who joined race car design department of team attacking big challenges (such as Le Mans) where they have been asked to design the suspension kinematics ... without tire data! As Doug Milliken told me one day "they are asked to solve engineering problem ... without engineering data".

If they succeed they are good if they fail they are idiots. I disagree with that tactic. Even less in FSAE where students do have access to TTC tire data

It is not about winning; it is about knowing why. It is about the constant search for knowledge and best practice.

I can say that I am proud that my company customers have been winning race and championships in many different racing series for several years simply because as vehicle dynamics consultant we use and developed simulation and data analysis tools allowing both race tire manufacturers and race car manufacturers (or race teams) to get the best of each other information. That is also an approach and a methodology that we present in our seminars.

I know how much energy, money and time is often wasted by acting without thinking, designing without communication or enough understanding, testing without simulating, developing without attentively analyzing previous test data. I made that mistake too often myself.

Doing the best you can with a new tire around which the car was not necessarily designed? Sure: that is part of the challenge. Knowing WHAT to change and WHY; and prove it on the race track; THAT is the real challenge.

Students can still win the competition without necessarily giving brilliant explanations in the design event. Especially if they have good drivers and a reliable car. But that is not what prepare them for a good engineering career.

[Rex Chan]

I'm not sure I agree with this. If your aim is to win FSAE, and you can do that with good drivers and a reliable car (with not great VD understanding), then I would say you have successfully addressed the engineering problem.

[PatClarke]

Rex,

You are missing the point!

Pat

[Rex Chan]

Originally posted by NickFavazzo:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Rex Chan:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Pete Marsh:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Even then, as much as it would have been nice to have for competitive advantage, if you switch tires how much do you really have to change on your cars to re-balance it? A test and tune day (or half of one) perhaps, but I'd have a hard time imagining it being a total catastrophe.

Just my gut feeling.

Not just a competitive difference or balance change, the size and rates of the tyres are different making a direct swap not always OK. A REAL big problem for at least one concept I'm familiar with, and still a hassle with bodywork rules etc.

I notice the post from Goodyear does not totally rule out the possibility of another manufacturing run of the current tyre?

Pete </div></BLOCKQUOTE>

How much? </div></BLOCKQUOTE>

About 20mm on Diameter as well as being different width and different spring rates. </div></BLOCKQUOTE>

Sorry - I meant to reply to Pete MArsh's post. How much for a set of D2704?

[MCoach]

Originally posted by PatClarke:
Rex,

You are missing the point!

Pat


Rex,

While you may have a point against the problem, it's in the right direction for the wrong reasons. If the car is pretty much settled and already designed around a different tire (as I am aware is the case in the upcoming Australia competition) then there isn't a whole lot of room to redesign and manufacture things. So, the problem becomes re-situate the car or change the product requisition strategy to match the current market (no new tires, dwindling supply of old tires).

As you've demonstrated, you've changed strategy and are clamoring for the last of the Goodyear tires.

Claude and Pat are trying to show that it's about tackling the engineering (and management) problem when they present themselves rather than trying to get around it with brute driving skill and a MIG welder...

[Mike Cook]

Wouldn't it be funny if you just switched the G brand with the H brand and your car went faster right out of the box. hmmm

[MCoach]

Funny you say that...

[Claude Rouelle]

Rex (and all passionate readers of this forum)

As Pat wrote, you missed the point.

So let's say you win FSAE. So what now? What if your brain is only as full as your conscience of not having done the best you could?

Let me tell you a story that may help you to understand what is in my mind.

A few years ago I ask a team suspension student during the design part of a competition in Europe what the critical damping was.

The student did not know. At all.

I am thinking "OK that the guy is a bit panicking, let's ask another one" Second one did not have an answer either.

OK so I think it must be my English or theirs and we have a communication problem. So I ask more students and soon we have 4 students involved in chassis and suspension + the "technical director" + the "team manager" 6 guys: still no answer.

So I asked "Do you have your design specification sheet here? " They had it. I showed them "look here it is written that in bump at 50 mm/sec you have 87 % of the critical damping on your front dampers? 87 % of what? " NO ONE COULD TELL!!

I insisted "OK you do not know what the formula is, that is OK but what does critical damping physically means" They would have told that if they push on their passenger car hood and release the effort and the car comes back at its initial ride height as quickly as possible without overshoot, and that was critical damping, that would have been OK but even no one of them could tell me that"

Sorry guys but whether you learn designing cars, bridge or aircraft you should at least have a vague idea of what critical damping is.......

So I went to ask several other questions such as basic definition of understeer and how they quantified understeer / oversteer in their tests but again no answer. How in that case do they quantify the progresses they made on the race track? Only with the lap time?

Well, believe it or not that team won that competition that year. And they even won a few more since. But still today they have a low knowledge of vehicle dynamics (or very low ability to express it) and they still can't really justify the choice they made in their car concept. They might be right but they do not know why.

Don't get me wrong: they won and they deserved it. The car looks really, really good on the track, bloody good drivers, a bit heavy but their manufacturing was superb and just looking at it, it did "inspire" reliability, lots of testing, and their organization is an example for the paddock. Much better in manufacturing (well with a lot of subcontracting...) and testing than in design, concept and simulation or data analysis.

But because there is more than the double of points in endurance than in design, in my mind it doesn't give them the right to ignore their weakness in justifications of their design choice.

Winning is good for the heart and the team spirit. Winning without knowing why is not so good for the brain. Or the soul.

If you do not know why you win, you won't know why you lose. See my point know now?

Well as I am bashing around students tonight and I can't sleep (jet lag) let me tell me another good one which occurred recently in last FSAE competition in Italy, which shows how poor the basic, basic knowledge of students who design suspensions sometimes can be. And which makes me... I still hesitate between laughing and crying.

Here was the dialogue
- What is the tire coefficient of friction?
- I don't know.
- Come on you should have me an idea...
- I really have no idea.
- Try...
- 0.4...
- 0.4? How many G (lateral) can your car pull in the corner?
- About 1.6 to 1.7 G.
- And you think that you can pull 1.6 to 1.7 G in corners with tires which have 0.4 of coefficient of friction?

The student looked a bit puzzled and you could see his bearings rolling... Then suddenly he looked at me and said:" Well I must be right right ... look 0.4 per tire and there are 4 tires so that makes 1.6! You see I wasn't too far off!

At least he made me laugh.

But he would have been a student of mine in any university I teach, he would have been told to come back next year or to chose another career...

Win. Know WHY. Win again.

[nick roberts]

Rex - Therein lies the complexity with the current competition structure. Winning this "engineering design competition" requires less engineering than one would think. Theoretically a team could rebuild the previous year's car, develop it for 3 months using only lap times to determine progress, completely bomb design, and still place very well. Sounds a little like Claude's example I suppose.

Arguably, testing and development are as much or more of engineering as the initial design work, but from my experience, vehicle dynamics should be very well understood if a team wants to obtain any useful results from their testing.

It all depends on which "engineering problem" you choose to address.


Mike - Sounds a little like our experience. ; )

Thankfully, after making the switch and immediately going 1-2 sec faster, we took the time to go back and figure out why. We feel like this work will be invaluable moving forward to actually design a car around the tires.


Claude - I'm curious. If you were a team leader in charge of managing a team, how would you structure the year? Which aspect of this engineering project would you prioritize? Assuming we have 10 months to design, build, and test a vehicle what would your target timeline look like?

Ours, regrettably, looked like this last year:
Design - 5 months
Build - 4.5 months
Test - .5 months


-Nick

[NickFavazzo]

Originally posted by Rex Chan:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by NickFavazzo:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Rex Chan:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Pete Marsh:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Even then, as much as it would have been nice to have for competitive advantage, if you switch tires how much do you really have to change on your cars to re-balance it? A test and tune day (or half of one) perhaps, but I'd have a hard time imagining it being a total catastrophe.

Just my gut feeling.

Not just a competitive difference or balance change, the size and rates of the tyres are different making a direct swap not always OK. A REAL big problem for at least one concept I'm familiar with, and still a hassle with bodywork rules etc.

I notice the post from Goodyear does not totally rule out the possibility of another manufacturing run of the current tyre?

Pete </div></BLOCKQUOTE>

How much? </div></BLOCKQUOTE>

About 20mm on Diameter as well as being different width and different spring rates. </div></BLOCKQUOTE>

Sorry - I meant to reply to Pete MArsh's post. How much for a set of D2704? </div></BLOCKQUOTE>

How much what? Pete was with me when I replied before. How much change to set up a particular tyre? Each tyre is very different, they like different things and you cant know those things just looking at new tyres straight out the bag..
How many combinations of settings do you have on your car? Which particular setting is the fastest/best for a particular event?

If you have no adjustments at all, not even tyre pressure then your only setup is the best, if you only have tyre pressure to adjust the you have all possible variations of TP to play with and find the "best"

You can make a car work and go around the track on any tyre but using that tyre to its best takes engineering and a little bit of magic...

[Rex Chan]

MCoach - just to clarify: we'd be willing to SELL our set of Goodyears to another team, if the money was enough.

I do not disagree that one should know WHY one does things a certain way. I certainly know why I did/do things a certain way on the engine. However, there are many things I do NOT know about the engine (such as how the inlet ports have been designed to flow air into the cylinder; I know very little about fundamentals of how our CBR was designed/intended to operate from a flow perspective). However, in my opinion, from the level we were at, it was not important to know these things, to achieve my goals, or the teams goals.

I am not against learning more, but there is a limit on how much time you can spend learning EVERYTHING about your system. Knowing enough to do the job you need to get done is what's important.

[Max Trenkle]

Claude, I believe your expectations are where they should be. However, it is my experience that universities do not have the same expectations... http://fsae.com/groupee_common/emoticons/icon_frown.gif

Rex, I believe you are describing 'optimization of resources'. If intelligence is qualified as a resource, then every FSAE team has a lot of optimization to do among themselves... http://fsae.com/groupee_common/emoticons/icon_smile.gif

I do feel awful for the teams that designed their suspension geometry for Goodyear tires.

Nick, I wonder what sort of 'magic and engineering' would help a team use their suspension geometry designed for an asymmetrical tire on 'any tire', most of which are symmetrical... http://fsae.com/groupee_common/emoticons/icon_smile.gif

[RANeff]

Just an update guys, some bad but workable news. Shelby Goodyear (great guys BTW) was working on getting the tire rebranded and marketed as a solo tire, which would make it available to everyone. Here's what trickled down finally:

"Well I finally got some news to pass along. The Goodyear D2704 will not be built in 2013. The door is still open for the future but will not be built next year. This news disappoints me very much as we had a great tire with that one but there is no sense in running teams along with hope. Sorry for inconvenience and I will keep in touch as I hear more news."

Here’s to hoping they don’t disappear for good