450cc engine

[ftorque]

just registered my team for fsael. http://fsae.com/groupee_common/emoticons/icon_smile.gif
finalized a 1-cyl 450cc.
but its running a bit hot. will 2 griffin 12x8x3(core) radiator suffice.
thinking lightweight to beat the 600's in acceleration also.
but having problems getting carbon fibre parts in india. n e 1 plz suggest n e suppliers close by.
n big bird u rock. sir have you ever been to india. maybe apac16 2011.....

[Big Bird]

Thank you ftorque, you are too kind. I'm afraid I've never been to India, but hope to one day.

Some advice if I may.

You seem eager and enthusiastic. That is a valuable commodity - channel it. You seem so eager and enthusiastic that you don't have time to include some vowels, nor to structure your requests in a logical manner. I'm afraid that will bring you some ridicule on these forums. Please take the time to think through your queries, just as you should take the time to think through the whole FSAE design problem.

You do NOT need carbon fibre. For a novice team (and I'd say most established teams) carbon costs you more points than it gains. Our first 450 single car was nearly all steel, and weighed 200kg. It was fat, underpowered and robust. It won FStudent in 2004. We competed against Delft whose car was nearly all carbon, and weighed 127kg. Delft's car was lighter, our car was more complete. Complete beats light. Don't just assume you are the golden children who will magically do both - you won't.

Good luck with your project!

[Mbirt]

Originally posted by ftorque:
but its running a bit hot. will 2 griffin 12x8x3(core) radiator suffice. We might be able to help you if you give some more information. What coolant temperatures are you seeing? Under what condition is it running hot, does the radiator(s) have airflow, and what size radiator are you using now?

My team went way overkill with its cooling system on its first single-cylinder car by using two radiators that had been specced by Mahle for their 3-cylinder. I would advise you to to check that your cooling system is fully bled, verify that coolant is flowing efficiently, and then work on improving airflow to (and from) an approximately stock-sized radiator.

[Rex Chan]

fttorque: Assuming you mean 12" x 8" x 3"; that's a MASSIVE radiator. That's 304.5mm x 203.2mm x 76.2mm. First off, why is it so thick? We run a 600cc that uses a 300mm high and 40mm thick core. So assuming the core is of the same type (which it probaly isn't), its really big, considering we run a 4 cylinder 600cc. And you want to run 2 of them...

I have not seen many 450cc beat a good 600cc in Accel. They just make less power, but go around corners faster.

if you want to use carbon, most teams make their own parts out of carbon fibre cloth and resins. You don;t buy parts. You design them.

Big Bird: I've seen you use the concept of new teams thinking they will be able to do everything in these forums before. I think its a good one. Nearly everyone overestimates their ability, and underestimates the amount of work.

Based on this, I'm usually very dismissive of any electronic control (launch & traction). However, we (Melbourne Uni) has had good fortune so far this year, and so have a running car 2 months out from comp (hopefully it stays running most of this 2 months), and we're getting wheel speed sensors onto the car in the next day or so.

The result of this is that I'm tempted to try out launch control, just to get consistent launches in Accel event. Last year, we didn't get enough practice and poor driver controls meant inconsistent launches. This year, both are better. I've been reading up on how MoTeC allow slip for a given road speed (i.e. lots at very low speed, dropping down fast, then rising with road speed). Do you have any advice for someone who has never done this kind of thing before? We're running with M400 but no LC or TC enabled (didn't want people playing with it...), but I'm going to do it in the PDM, whcih updates at 50hz.

Front wheel speed triggers are 18 teeth/revolution. Rear wheel speed is through gearbox with 24 teeth (input shaft side pinion; 28 teeth on output gear), with ~4:1 final drive. As far I can tell, this means I will have lots of resolution at the back (~112/rev), but not a lot at the front.

[ftorque]

Thanks Big Bird for your immediate reply.
I was thinking of a two months testing of the car at the MRF race track in Chennai. Will that be enough.
I am a bit worried that a longer testing routine might bring out problems at the last minute(like structural damage) an we dont have the infrastructure to rectify it and bring a running car on time for the event.
I have been told to make a facebook page and a team link on college website for all information regarding the team and the car. I am much interested in making the car than doing this stuff.
But i will have to do it since they are giving the funds.
Still will keep you all posted when we get these things running.

[ftorque]

Thanks Rex Chan and Mbirt.
I will give you all the technical specifications as soon as possible but i am juggling between exams and making the car and at the same time.
Had the same idea that the radiator is to big for a 450cc but my faculty wont listen. They say the "The engine should be cool to function at its best." And they say "The boss is always right"
Got a 600cc engine just today from a friend. Should i test it also or stick with the 450cc and keep trying to arrive at a best possible solution.
Got very few in the team having proper knowledge, passion and love for engine music.
-Ashish
Lead Designer and Technical Head
Team-Veltech India.
Veltech University,Chennai,India.

[cvargas]

Originally posted by Rex Chan:
Nearly everyone overestimates their ability, and underestimates the amount of work.

Well its good to know I'm one step ahead of the game because I know enough to know that I know nothing at all.

[Kevin Hayward]

Rex,

Not sure why you would be very dismissive of electronic control such as launch and traction. With Motec both are very easy to setup. Playing around with the launch settings will take you about half a day to get a setup that will beat your drivers most of the time. Your resolution on the front triggers will be fine.

Traction control is much more time intensive to setup to improve laptimes, but is quite easy to setup to prevent the "idiot" spins. Just set the control to kick in under high slip conditions and a few spins will be avoided. It is worthwhile testing control with both slip and the difference in velocity front to rear. Tests of rubber sliding will show a peak friction at a given sliding speed. The Pacejka curve fitting obviously uses % slip. Practically the car will have behave differently as your speed changes dependent on which method you use. It is really yourt call as to what you are chasing, but some fundamental vehicle dynamics will help you on your way.

Back in the olden days when I was driving and setting up suspension I was against traction control (although loved launch) it always seemed like the car was always bogging down and going slower. However the stopwatch disagreed too often to dismiss it.

Also your early running this year is probably more a continuation of a few years of hard work rather than good fortune http://fsae.com/groupee_common/emoticons/icon_smile.gif

Kev

[ftorque]

Originally posted by cvargas:

Well its good to know I'm one step ahead of the game because I know enough to know that I know nothing at all.

That a very good line...

[bob.paasch]

Originally posted by Rex Chan:
I have not seen many 450cc beat a good 600cc in Accel. They just make less power, but go around corners faster.


FSAE California the last two years, acceleration was won by 450 singles. And there were some good 600s there.

[Rex Chan]

Really!?! Sorry, I did not know that. I suppose FSAE-A has less singles, and the faster teams in Accel have been 4 cylinders. But you guys are just FAST.

[Mbirt]

Oregon State @ FSAE California 2010: 4.033s
ETS @ FSAE California 2011: 3.916s

And there were 3 sub-4-second 4-cylinder cars behind ETS. It's a testament to the significance of the above-mentioned launch and traction control systems.

[Tom Wettenhall]

I can't really argue that a half-reasonable LC/TC system will improve laptimes, but I'd be worried that, during testing, it might disguise some of what's happening with suspension and driver inputs by putting in another set of inputs of its own. But then the logical conclusion is to turn it off during testing, which means you have a relatively untested system which may not necessarily be a boon at comp, in which case you should have been doing something else all along.
What's wrong with my thinking?

Also: I think one of the reasons MUR are wary of TC is, the last car we ran it on, got flipped over the front outside tyre during testing, supposedly as a result of an unexpected TC input.

[shark.ashwa]

Originally posted by ftorque:
Thanks Rex Chan and Mbirt.
I will give you all the technical specifications as soon as possible but i am juggling between exams and making the car and at the same time.
Had the same idea that the radiator is to big for a 450cc but my faculty wont listen. They say the "The engine should be cool to function at its best." And they say "The boss is always right"
Got a 600cc engine just today from a friend. Should i test it also or stick with the 450cc and keep trying to arrive at a best possible solution.
Got very few in the team having proper knowledge, passion and love for engine music.
-Ashish
Lead Designer and Technical Head
Team-Veltech India.
Veltech University,Chennai,India.

Hello ftorque,

Although I am really happy that more Indian teams are joining FSAE, I have been reading recent threads posted by individuals from this region and am honestly not very impressed with the amount of research that has been done before posting on the forum.
Regarding your current post,
"I was thinking of a two months testing of the car at the MRF race track in Chennai. Will that be enough.", Honestly, I dont know. It depends on the componets going into the car. If most of them are student designed, then a fair amount of testing time is required. Also the testing sessions must be orderly, concentrating on certain areas of the car that you think are not reliable, untested, etc. Random bashing of the car in a parking lot wont help.
"I am a bit worried that a longer testing routine might bring out problems at the last minute(like structural damage) an we dont have the infrastructure to rectify it and bring a running car on time for the event." I am not sure I quite understand your logic. Although fatigue does take its toll on certain components, I dont think that shortening your test session at the first sight of problems, just so you can resume at the event is reasonable.
"The boss is always right" Not the way to go for an FSAE team. How will the members learn?
Got a 600cc engine just today from a friend. Should i test it also or stick with the 450cc and keep trying to arrive at a best possible solution. I dont think you realize the complexities involved in swapping engines in an FSAE car. I would rather suggest you to do a pro-con analysis and decide on engine so that design of your components can start which we have no idea of!
"Got very few in the team having proper knowledge, passion and love for engine music." Althoug I do agree that passion and love for engine music is a bonus while working in an FSAE project, they are not the only things to have. Knowledge is always welcome. But determination and hard work also have a large role to play in your teams success.

Just my "rupees" worth of input.

Cheers,
Sharath