My FSAE Car Designing Diary - [T51r]

[t51r]

the money $20000 is the cost to rent the facility for a day....then those uni which are interested will pay $500...Tire testing consortium collect and keep the money until they got $20000, they will rent the facility and test those requested tires on behalf of uni and send the data in DVD to those uni. as i know.....there are about 100 unis have paid for that data, those who need the data , try to ask your senior about that, they should know this.

chassis with tabs welded on and painted generally weighs about 27-30kg. No doubt RMIT is one of the best team with lightest car in the world. I've seen some cars weigh 160kg with driver and fluid, i would say that is incredibly light.......most parts are made from carbon, from bodywork to wheels.

I heard a rumor that a team from Germany got 1million euro budget every year....and this is funded from a F1 team. Well engineered, beautifully built car with most decent parts, the team is able to compete in several competitions a year.......also with the backup from alumi working in F1.

Last year the car from my uni couldn't managed to fire up due to some problem from started gear box, and ECU as well. Our car weighs 200-210kg with driver and fluid, powered by 250cc engine to compete in Class1(a) which is only 3 teams showed up during competition. The only carbon part is floor mount.

This year our uni is designing a new car with mcpherson on the front and trailing arm suspension on the rear. I guess they still stick to this configuration......

 

[xtremeleo]

iam studying in UniKL MIAT

well, ive read sum of the specs of machines for the previous competitions, and know dat my team's machine will be too heavy, but whattheheck.. we didnt have anything to work on. since budget wasnt released, ive to work in a very tight budget. weve planned to lighten the engine and fully balance it, gearings will be removed and reduction on the last 3 gears, gear box will be made outta a more durable but light material, carbon fiber shells, sumthing like dat. we were aiming to come out wit a 300kg car wit driver for a start, and go from there onwards.

ive chosen medium sized drivers and put them to training, even ask them (including me, looollll) to undergo a special diet for god's sake. lol

the problem we encountered was lack of resources, as it was the first FSAE plan for us. we asked info from UTP but got very lil

 

[cqloh]

macpherson strut and trailing arm????
why on earth would they want to do that?
its a formula car.... not a mitsubishi evo man...

sometimes i wish i was a student again with the knowledge i have.. hahah would be fun just to so it all over again...

 

[t51r]

in fact im not suspension guy.....but i have interest in it....my true knowledge is in engine.....

300kg is easily achieved......don't spend time to lighten the engine unless taking out 3 gears.......there is no point doing it in consideration of cost, performance n time for 1st year team. concentrate on intake n exhaust, suspension, diff, chassis, brake,fuel system, lubrication,cooling would be good idea....at least dont forget to baffle your fuel tank and especially wet sump...one of the fastest way to gain horsepower is using electrical water pump.

i don't know the real reason behind why they choose macpherson and trailling arm....i guess they have their own mind...actually i've seen these two configurations in competition, some teams even run solid axle??

 

[xtremeleo]

thanx for the suggestion, i wish ive known u guys before working on dat project :)

t51r, all dat uve said above has alredi thought out and put into the budget. funding was the only problem at dat time

 

[t51r]

The competition needs more mid range power instead of max horsepower....and...during skidpad or endurance.....15% of time is WOT......be aware of fuel consumption....some teams have a nice fast car but couldn't finish endurance, ran out of fuel at last 2 laps.....

 

[xtremeleo]

hoho.. uve tought of everything then

 

[cqloh]

the biggest excuse i hear from people involved in FSAE is that they have no funding...
not to be a hypocrite... i said the same thing when i was doing the project..

but like i said.. get a few years of experience under your belt and.. money while it is important.. isn;t the driving factor...
when it comes to racing in this country... no one has money... there are certain unscrupulous parties out there that get budgets from companies and 'other sources' to go racing.. but the money ends up in their pockets..
the people who build the cars get hurt.. we're given a short time frame and an impossible budget..
tough luck.. the day still goes on.. and you still have mouths to feed at home and bills to pay..
you can go home and sulk.. or you can take it like a man and do your job...

thats an interesting question... what is your job?
you guys sound like engineers.. heck.. maybe one day you guys might be engineers.. but just because you have a piece of paper that says you qualify to be one doesn;t you are one...
so the job at hand is to do what you are meant to do...

SOLVE PROBLEMS...

so you have no money.. you have a race car to build... you want to win..

sounds like a problem to me..

 

[klipsch]

cqloh, actually UTP entered FSAE australia in '06. Main reason they were terrible was coz mgmt directed them to enter the race even when there exist no car (again excuse perhaps haha). Anyway, i was involved in '07, we did not enter australia which is not very disappointing since i personally would prefer to get some money to just do testing locally...u know to learn the trade 1st and build a solid platform for juniors to carry on...alas just a dream :hmmmm:

cqloh, u seemed like a very interesting person...would love to meet u someday and talk about FSAE

t51r, all the best in your project

 

[cqloh]

cqloh, actually UTP entered FSAE australia in '06. Main reason they were terrible was coz mgmt directed them to enter the race even when there exist no car (again excuse perhaps haha). Anyway, i was involved in '07, we did not enter australia which is not very disappointing since i personally would prefer to get some money to just do testing locally...u know to learn the trade 1st and build a solid platform for juniors to carry on...alas just a dream :hmmmm:

cqloh, u seemed like a very interesting person...would love to meet u someday and talk about FSAE

t51r, all the best in your project

Again, i am not surprised...some people would rather spend money on foreign engineers than to properly train local ones, which causes a vicious cycle.. because when the local guys get something going.. people believe otherwise.. thats a different subject matter...

i think alot of the younger guys that have interests in cars, going fast, and racing in general lack the willingness to go out and study the right stuff and are willing to get their hands dirty.
Building a race car is exactly that... you have to be able to design it and then build it..
so besides being able to model the car and do the necessary calcs, FEA and materials testing... you need to know how to machine and weld...

i guess when you have a piece of paper saying you graduated with a bachelors in engineering... you would rather not be rolling around in the dirt..

i saw some of the formula varsity pictures... i'm a little shocked..
caroll smith and colin chapman would be rolling over in their graves...

out of curiosity and for analysis sake...
whats wrong with this picture?

and this picture?

there lies some serious engineering problems with these two cars...

 

[t51r]

i see unnecessary rear wing on such a low speed car in the first pic(actually i can only see a car with 4 wheels and a rear wing).....for 2nd picture.....i just wonder if the engine mounting point is strong enough...could the rear toe link work properly with this configuration?(i couldn't see the upright there,just curious)

toe link bracket on chassis is.....=.=ll...i could imagine the bracket flexes and change the toe angle on the track....if someone wants to change to the toe angle....he can just kick the toe link
the chassis is not stiff enough as well
battery & fuel tank are not secured properly

where is the master kill switch??
the fuel might split out from the tank if the car is tilted to 45degree

 

[klipsch]

Again, i am not surprised...some people would rather spend money on foreign engineers than to properly train local ones, which causes a vicious cycle.. because when the local guys get something going.. people believe otherwise.. thats a different subject matter...

i think alot of the younger guys that have interests in cars, going fast, and racing in general lack the willingness to go out and study the right stuff and are willing to get their hands dirty.
Building a race car is exactly that... you have to be able to design it and then build it..
so besides being able to model the car and do the necessary calcs, FEA and materials testing... you need to know how to machine and weld...

i guess when you have a piece of paper saying you graduated with a bachelors in engineering... you would rather not be rolling around in the dirt..


that was i aspired our team to have...strong foundation in fundamental engineering and dirty hands-on experience...those hands-on experience will only translate to better and practical design...

cqloh, would you be interested to give a talk to my juniors seeing with your vast FSAE knowledge and exposure?

 

[xtremeleo]

cqloh, i proudly build my own engine n turbo so getting dirty isnt any concern

as ur uni had been in dis kinda competition before, surely there were parts from the previous cars u cudve work wit..? i think dat explains y ur team cudve built the car up even witout any / limited funding? we had nuthin to work on

okie, if say i still want to build dis car, where shud i start? planning had been done, conclusions were as stated before. any idea on where to get the materials for the chasis? iam still learning on dis, ur inputs will be greatly appreciated and will be passed down to my teammates

Bump: 1st pix, on aerodynamics? 2nd pix, space usage, mountings, the brakes cudve been made into a single unit?

please enlighten us

Bump: 1st pix, on aerodynamics? 2nd pix, space usage, mountings, the brakes cudve been made into a single unit?

please enlighten us

 

[cqloh]

klipsch:

i'm just trying to give back to the industry what its given to be.. albeit it was a different country.. i started off with nothing more than interest in fast cars.. but it turned into an obsession that i struggle to control. so yes... we might be able to work something out.. i always believed in the power of people, provided they are given the correct direction and nurturing..

xtremeleo:

getting your hand dirty is a start.. but remember you have to keep asking why, when, who and how... you have you know why you did what you did..even if you followed someone else.. you have you ask why they did it..

to address your question regarding materials....
chassis materials in malaysia is terribly difficult to come by... but that is not to say its not possible... never underestimate the power that a university or an educational institute holds...
i only wish i had a university backing up my current ventures...
the first step is to find out what materials to use for your chassis.. if you plan to build a monocoque (and you really should) you need to speak to boat builders.. boats are usually made of composites, so they are the first guys you should speak to.. find out what proccesses they use (resins, composite weaves, cure times etc.. aluminium is an acception..which is why i think its the best way to go in malaysia).. if you take the conventional space frame.. you will need to find the treasured chromoly tube... we're talking cold rolled steel tube.. which is next to impossible to get (again.. if you can get it.. please let me know because i am dying to get my hand on it for my current projects).

i know that brian palmer from WRC (the guy thats popular for building roll cages for rally cars at exubrent prices in shah alam has the tube... but alas.. at far to large a diameter and gauge for FSAE)..

do not be fooled into using steam pipe (mild steel) for your chassis.. not only will it be weak it will also be extremely heavy...

the magic number you are looking for is EN704 is COLD ROLLED form.. at this point in time i can only find this material in solid and barstock form.. not in tube.

another serious problem with FSAE is that you get a new group of people each year.. so the developments are never recorded.. or some genius has an idea that goes way out of the direction of the car... so my advice is to keep tabs on the evolution of the car.. keep the direction certain and log everything that is of use.. so the new batch of students have a document to refer and to add to.. this ensures that teh car is ever so slightly different each year to satisfy the judging panel....



......................................................................................................................

now refer to the two pictures of formula varsity... no doubt alot of time, blood and sweat went into these cars.. so i salute those who put the effort into building these cars.. i've spent many sleepless nights building my own just to see the chequered flag let alone the podium...

these two cars lack the fundamental importance of a race car (among the other issues you guys have raised).. the chassis.. more importantly the torsional rigidity.. suspension and chassis guys will tell you that a perfect race car gets ruined by the driver and the engine.. this is because of the cavity needed to house these two items.. the example is simple... is you have a match box with the drawer of match in it.. it is a strong structure.. when you remove the drawer (where the matches lie in) the whole box becomes flimsy.. these two cars are essentially the match box without the drawer...

there is not enough triangulation in the chassis.. particularly where the engine lies and where the driver sits in.. if you disregard the shocks and replace them with solid shocks.. i would bet my ass on the line that the chassis would flex in bending and in twist...
so what happens then is that the energy needed to conduct the weight transfer from one shock to another is taken up by the chassis in twist.. hence resulting in an inefficient chassis ie a 'lazy' car....
i tell all my clients that engine power is important.. but it doesn;t win races.. you need balance..
but for what i see in F-varsity.. an overengineered, light chassis is the winning formula.. afterall.. how much power can you crank from a mat rempit engine?

not bad.. at least i got you guys thinking...
now the next step is to prove that i am wrong.. how do we measure tosional rigidity? afterall.. what i'm saying is just words.. we're all men of science.. how do we obtain a scientific result to prove that our chassis is indeed strong?

for those that think that aero at such low speed is unimportant.. let me refer you to this picture...

this is Monash Uni... they came in 3rd in FSAE-A 2008

Bump:

heres my chassis in 2005/6

the areas where you see that have just gapping squares were filled in with carbon panels..
in a traditional space frame sense.. they would have had a diagonal member to connect the chassis at the nodes to spread the loads generated by the suspension..

not what you would see at F-varsity...

ideas starting to sprout now?



Bump:

heres my chassis in 2005/6

the areas where you see that have just gapping squares were filled in with carbon panels..
in a traditional space frame sense.. they would have had a diagonal member to connect the chassis at the nodes to spread the loads generated by the suspension..

not what you would see at F-varsity...

ideas starting to sprout now?

 

[xtremeleo]

nice points cqloh, thank u very much..

on the regards of boat builders, ive worked closely wit a company called kaymarine and they build boats for marines, police, etc. i did ask for their assistance, and they were happy to obliege. material specified in the r&r had to be specially ordered and let me tell u they dont come cheap. dats where the problem lies

i had even booked the said engine, and were ready to start dat part but witout a car for it to be attached to, its gonna be wasted. what project r u working on now? can u post sumwhere for us to refer to?

 

[t51r]

showing me the monash uni car cannot prove the real benefit of the wings, there is no point jst copying a winner's car without engineering analysis just because they won the competition.


http://www.youtube.com/watch?v=jPT6B1WZdNs&feature=related
This is 2008 sprint run course in UK Silverstone race track....is indeed very low speed track

http://www.youtube.com/watch?v=NRWK4VNCWc8
this is 2007 endurance of FSAE UK...........again an extremely low speed track

With such a low speed track, i do not see the real benefit of running big wings to generate a little downforce for more grip, at a cost of so much time in r&d the wings, increased frontal area and weight, aero drag increases also(although not much at low speed). I would concern about if the car could run at its grip limit and driver's ability to make full use of car potential at those track. My point is based on the FSAE UK track, i know the speed limit of other competitions is higher thus is more beneficial.

 

[siputmagic]

sifu, what is the effect of the wheel track size if the rear larger than front and vice versa?
how about if the front same with rear?

 

[cqloh]

t51r: i think it justifies the use of the wings when your uni owns and runs the largest windtunnel in the southern hemisphere.. i think it also justifies it when manufacturers like ford, holden, honda and scania refer to your university regarding aero dynamics...

sifus are in china meditating.. i'm just another xin ka lan..

track size? good god.. what are they teaching you guys in uni?

there is a mathemaical equation that describes the load transfer of a vehicle...
find that formula.. or better still.. derive it for yourself..
and you will find out....

the results are extremely surprising...
i think if i told you the formula it would basically ruin the fun in designing a race car...
what i can tell you is that it has to do with the balance of the car...
it describes how the car drives and what it will tend to do..

if you're really really stuck... i'll keep pointing you in the right direction...
it took me a long time to figure this one out.. but it also made me much much more interested in building race cars... good luck!

 

[t51r]

i dont mean there is no benefit of big wing....just that i question is it necessary for formula student competition, is it worth the time?(if number of member is insufficient). I never doubt about the ability of monash uni, but there are alot more issues involved before a decision is made.

Stuttgart Uni got 4 champion in 2008 (FSAE UK, Italy, Australasia and FISITA World Cup) with 2 years formula student experience (started in 2006), they won the game without big wings with 209kg car weight. But this cannot prove that big wings is unimportant. I would like to say the time spent on big wings could be spent on vehicle dynamic or other area might be more beneficial.

their wheel base is 1650mm, but interestingly, track width is 1214mm(front), 1172mm(rear).....Rear track being narrower than front is commonly seen for some reasons (vehicle dynamic and minimize the chances rear wheel hitting cone), track width is usually chosen to be round number like 1250mm/1200mm/1240mm....i'm interested in the way their decision being made and what analysis had been done to choose those numbers (i guess related to tire performance and previous precious vehicle test info, i would say the assumptions made for early stage design is very very good n accurate)
(no offence..just my defence ^^)

 

[cqloh]

i've already given you a clue... Load Transfer...
thats how they determine the track of the vehicle..