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Hi.
We are a recently started, and the first formula student team from Norway. We will participate at silverstone in 2012, class 1, and need some starting advice.
We will use a 600cc gasoline engine, most likely spcaeframe chassi.
Anyway I am responible for the tyre and suspension assembly.
I have found sortiments of tyres from Hoosier, Avon and Goodyear.
Anyone know of other suppliers?
Rims however seem to be harder to find, I have found some, but mostly street "racing" retro/replicas
Most likely we will use 13 inch rims.
Thank you
Ivar Alendal, team Revolve, NTNU
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Hi.
We are a recently started, and the first formula student team from Norway. We will participate at silverstone in 2012, class 1, and need some starting advice.
We will use a 600cc gasoline engine, most likely spcaeframe chassi.
Anyway I am responible for the tyre and suspension assembly.
I have found sortiments of tyres from Hoosier, Avon and Goodyear.
Anyone know of other suppliers?
Rims however seem to be harder to find, I have found some, but mostly street "racing" retro/replicas
Most likely we will use 13 inch rims.
Thank you
Ivar Alendal, team Revolve, NTNU
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First off--I would join the Tire Consortium. (Look at the forum post). You'll have most of the data you'll need to get started. There are plently of rim suppliers as well--keizer, bbs, jongbloed, etc.
Good luck.
Ben
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Hi
For rims, send an email to O.Z Racing, 13x7" <4kg, 110euro (two years ago)
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We are in the same boat so I will tell you what I've learned.
They very first steps to form the team were started in Jan 2010. Our goal was to compete by 2011 but unless you already have serious financial backing, a good fabrication lab, and shop space I highly doubt you will be able to get an entire car built by 2012 at this point.
Here is my experience.
It took a good 6 months to jump through university and SAE hoops to get the logistics setup (bank accounts, dedicated member base, initial money, shop space, etc).
By June 2010, we decided to compete in 2012 so this gave us roughly 18 months to work on the car.
Your biggest problems will organization and be lack of experience. Just because you want to build a car doesn't mean you can. You have to answer 'how' do we build the car. (unless someone on your team has built an FSAE car before). For example "How do we design a suspension?" That's a huge question that will take intense research and reading. I recommend getting a copy of Miliken's Race Car Vehicle Dynamics and making each of your members read it.
Starting a formula team is also a lot more than just ok we want to build a car. You will have to form a relationship with your local community to get donations. This means you need people who excel in public relations, marketing, and communicating. Most of these skills don't come naturally for engineers. I recommend reaching out to marketing or business clubs on campus and asking them for help.
You will need the support of your university.
Once all that stuff is in place then you'll need to learn the ropes and form design teams, form a timeline and hold people accountable.
I recommend visiting as many neighbor SAE programs as you can. You will learn so much from them.
I hope this helps. Lastly, I'll leave you with the basic steps we followed and some VERY important generic tips.
1. BEFORE YOU DESIGN ANYTHING. Read EVER article at Pat's Corner. Google 'FSAE Pat's corner' and the link will come up.
2. Avoid Rod ends in bending, regardless of what people tell you. Laern what they are and avoid them. It's a very simple thing to avoid and it's a common mistake by novice teams. People will flame me for this advice.
3. If you're doing Suspension and chassis design, read Chpt 17 in Miliken's Race Car Vehicle Dynamics, also read about chassis setup (Chpt 14 I think) and tires.
4. Do not bother with tire data. You likely on't have much money so spend it on more useful things than data. Likely you won't even know what to DO with the data if you get it. I wouldn't know because we don't have it.
5. Be a smart engineering team. Don't do things because that's the way Team A did it or 'everyone' does it that way. THINK with your noggin and come up with a REASON why you make your engineering decisions.
6. If you don't know the how to do something ALWAYS refer to Miliken RCVD and find the related chapter. Read the entire thing. THEN start asking questions on the forum or to neighbor SAE teams.
7. Visit a local race team if your town has one.
Ok enough ranting. Here are suspension specific steps that we followed as a first year team that worked out pretty well for us.
FYI your order of design for the car it outboard to inboard. Do not worry at all about the chassis until your suspension is thoroughly designed.
It goes like
Tires -> Wheels -> Wheel package (brakes, hub, calipers, rotors) -> Suspension (a-arms) -> Chassis
In the wheel package, your suspension and steering points dictate the design of your upright.
1. Wheelbase and Trackwidth. These numbers will 'box' your car design and give you initial spacial setup. For WB stay below 74in. For TW stay between 40in and 60in. These are not rules but just basic numbers to help you out. People may argue this. For TW consider the width of the course and the turns you'll be making.
2. Chassis Constraints. Mock up your box with tape on the ground and have a drive sit in it. Come up with rough numbers for the wdith of the chassis in the front where is legs will be. I think we used 16in or something. This is just to give you a rough idea where your outer and inner limits are so you can begin your suspension design.
3. Decided which tire/wheel you're going to run. This will give you a package to fit your outboard points inside. Once picked, I would not change this willy-nilly. It may significantly impact your suspension setup.
4. Suspension Design. We used software called OptimumK to help us design our suspension setup. It's amazing and easy to use. It will cost $400 but it's worth it. Learn the software and use it to check your pitch axis migration, roll axis migration, camber gain vs. body roll and bump steer. You can also use it to see how camber, caster, and toe affect your setup. Stick with 2in heave/jounce and 2 deg body roll for your simluations. You will have to calculate your steering numbers.
5. While suspension is being developed work on your wheel package. While working with suspension you can design your hubs, brake calipers, rotors, and uprights. When suspension is 100% finalized then wheel package can be 100% finalized.
6.Damper geometry and placement. This is a tough one and there is no right answer. You'll have to figure this one out on your own.
7. Load calculation. Use the following values from pat's corner to calc your forces in the a-arms. 1.5g longitudinal accel, 2g lateral, 3g bump. Make sure your design doesn't fail.
8. Steering. I forgot to mention steering. It's part of suspension but can be design somewhat indepentently. Steering affects suspension, but there are certain steering designs that you want to look into. Read RCVD steering chapter. There is no right answer.
When your points are nearly finalized you can begin drafting the chassis. Once you've reached this steps it's now a symphony of getting all the designs to fit together and yield the best performance (suspension, wheel package, steering, and chassis).
Once that's done I would focus on intake, exhaust, and drivetrain. Of course we want to develop those at the same time as your suspension so you can make compromises but IMO suspension is THE most important system on the car.
Holy crap I just wrote alot....
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Thank you guys!
We have dedicated teams for almost every case in our team and already have many sponsors, and found ourselves some workshops araound at the school.
So i dont need to hassle with that! http://fsae.com/groupee_common/emoticons/icon_smile.gif
I have been reading in RCVD and on pats corner, however i find it a bit hard to make conclusions abaout the different problems. Like how much trial or kingpin offset etc should i have, and most important why does x ammount of trail etc give better results. Maybe i get a better picture picture after reading the whole thing and on pats corner!
We also use optimum K, it is very easy indeed.
I do not have the whole picture on every case on the car cause we are divided into different teams, how do you work together?
I think we will have to choose basic components like engine and wheels, and then meet on the middle.
We have some guys with racing experience in ur team, but noone that has experience in FS (we are the first team ever in Norway :/) and sadly Norway is not well established in motorsports. But we have connections with a team in our neighbour country Sweden.
You say i should not struggle with tyre data, after reading pats corner and RCVD, do you still feel like having no idea how to use tyre data? I wold really like to have the idea abaut the different aspects (when judges ask) even if i will use the things i know or not, the fact that i learn something is what concerns me most.
Last option if everything goes wrong will be to make something that just holds the wheel (A-arms of course) just to be able to participate. That is the most important thing.
I really have the need for starting points, so I need to ask some q.
-What ride height should i atleast have?
-What is the typical Centre of gravity height of an FS car?
-What wheight distribution shoud we aim for? we will use a 600cc mc engine with its gearbox. weight of driver 75kg.
-What are the values in acceleration people get at the skidpads?
I have choosen a track width of 51 inches and 63 in Base, just to get started. and I think we will choose the tyre 20.0x7.0-13 by goodyear, the rim then fits other tyres too. So if we choose to use another tyre then we dont need to rearrange everything (caliper, upright etc) Is there a lot of difference in the tyres avaliable for FS?
Thank you and see you later!
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<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ivar Revolve:
You say i should not struggle with tyre data, after reading pats corner and RCVD, do you still feel like having no idea how to use tyre data?
-What ride height should i atleast have?
-What is the typical Centre of gravity height of an FS car?
-What wheight distribution shoud we aim for? we will use a 600cc mc engine with its gearbox. weight of driver 75kg.
-What are the values in acceleration people get at the skidpads?
I have choosen a track width of 51 inches and 63 in Base, just to get started. and I think we will choose the tyre 20.0x7.0-13 by goodyear, the rim then fits other tyres too. So if we choose to use another tyre then we dont need to rearrange everything (caliper, upright etc) Is there a lot of difference in the tyres avaliable for FS?
Thank you and see you later! </div></BLOCKQUOTE>
I spoke with Dr. Kasprzak on this matter (owner of the tire data). His advice was that the time spent using tire data would best be servered working toward your main goal. Getting a car to competition. I can only speak on my behalf and say that dropping $500 on tire data at the beginning of our project would not have helped us.
There are more important things to worry about on your first car, but you will get many differing opinions and there is no right answer, only the answer you choose.
Ride height. That will be determined by the setup of your a-arms which is based on your roll centers which creates your roll axis. Determine where you want your front and rear roll centers.
Not sure about typical CG of car. Get a model going in CAD and go off that?
Weight: I think the ideal is 50/50, but I can't explain why. I think 40/60 is more realistic. You may even have some teams running 30/70.
You can calculate values for skpiad acceleration. Better to do your own math then trust someone's number from the internet. Look at some past results, take an average on the skip pad score. Convert that to seconds, find the velocity required to travel the skidpad in X amount of seconds. Pick a radius and calculate your lateral accel.
I hope this helps and take everything I say with a grain of salt. Some other more experience more knowledgeable people can comment and correct me. I'm just trying to help.
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Just to be clear on where I stand: I think the TTC tire data is an amazing resource. Since any race car must be designed to make the best use of its tires, understanding what operating conditions your tires want and how they become forces and moments affecting the car is critical. In my opinion, any established team should be making at least some use of the tire data (we're pleased to see 250 TTC members worldwide).
That said, if you're just starting a team or haven't gotten one to competition consistently you need to make some choices on where to focus your resources--you're probably limited on manpower, experience and perhaps budget, too. I don't think the TTC data is in the critcal path for such a team. Lay a foundation for future success by establishing a good shop culture, finish your car as early as possible and test as much as possible. You'll arrive at competition with a car that runs, is likely to finish endurance (since you've already run the car a lot) and you'll go home with a very positive experience--even if you don't have the most amazing design. You'll be ready to tackle more in the following year, the team will be energized and you'll have learned a lot in the process.
Of course, nothing says a rookie team can't handle the TTC data. You may be able to make very good use of it. Just be sure to manage your time/people/buget/experience resources.
