Tire choice for a new team

[Nbruno]

Hey guys, Syracuse University is restarting its FSAE program and we've started design for next year's car. We initially chose a 6in wide Hoosier
(20.5 x 6.0-13)based on discussions on this forum, but after a little thought I'm not so sure about that choice. With this car being our first in 10 years and nobody having experience designing racecars, I'm expecting the car to be heavy. Would going with a wider tire be a good choice for a heavier car? Thanks
Nick

[Nbruno]

Hey guys, Syracuse University is restarting its FSAE program and we've started design for next year's car. We initially chose a 6in wide Hoosier
(20.5 x 6.0-13)based on discussions on this forum, but after a little thought I'm not so sure about that choice. With this car being our first in 10 years and nobody having experience designing racecars, I'm expecting the car to be heavy. Would going with a wider tire be a good choice for a heavier car? Thanks
Nick

[sbrenaman]

I would recommend reading Paul Haney's High Performance Tire if you're new to tires and need to answer that question. http://books.sae.org/book-r-351 You'll get a good conceptual idea of how the tire behaves and will be able to conceptually answer your "would a wider tire be a good choice" question.

If you want to know the real answer you need to subscribe to the TTC data. You're going to have to know information for your 2012 car like weight transfer, slip angles, and chassis slip angles to know whether a wider tire is actually a better choice.

[cvargas]

If I recall correctly you should probably figure out what kind target weight you'd want for your car and then a theoretical steady state cornering force your car would produce and then go from there. I am a newb so I am still learning lol.

[Ben K]

I'd stick with the 13" inner so that you can have more room for packaging. Certainly easier to design around those--plus I think there are more suppliers of 13" rims (ergo--cheaper).

Join the TTC if you haven't yet.

Ben

[Boffin]

Avoid the 6" hoosier like the plague.

We recently did some testing with avon's (6" front, 7" rear) and worn out they still have more grip than a new hoosier.

My choice after seeing Monash at the car swap day, Goodyears.
Check the Aussie comp thread to see what people thought.

[Thrainer]

Boffin, did you also have 7" or 7.5" Hoosiers for testing that day? We tried 6" wide hoosiers in 2009 and weren't quite satisfied. After switching to 7" wide hoosiers, our car was much quicker. TUG had a very light car in 2010 (ca. 190 kg) and was running 7.5" Hoosiers, though.

So, to the original question, I would recommend 7" wide Hoosiers.

Regards,
Thomas

[Boffin]

No we haven't tried the 7" Hoosier.
I know a lot of teams run them and rate them quite highly, which I find hard to believe when the 6" are pretty rubbish. A 6" avon is ton's better than it's hoosier equivalent.

But it works for a lot of people, so I can't sit here and say they are wrong, when it obviously works.

Back to the OP's question.
Most people agree if your running around a 200kg car, then a 7" tyre is the best.
Since your a first year team, perhaps the choice of brand should come down to budget and availability.
No offence, but I'm sure once you get a running car your going to be able to get more time from setting up the car and improving things (like drivers), than you will get from the correct tyre choice.

Hell, I rate the 6" hoosier as rubbish, but we were able to be second in auto cross and endurance with them. Just set the car up to work on what ever tyres you get.

[Boffin]

As a semi interesting thing for myself, I've put this together from the 2010 Australian comp.
Fastest time is their fastest over the weekend.

Team/uni<span class="ev_code_WHITE">.......</span>Time<span class="ev_code_WHITE">.........</span>Tyre
Monash<span class="ev_code_WHITE">.........</span>47.5444<span class="ev_code_WHITE">......</span>7" Avon
Swinburne<span class="ev_code_WHITE">.....</span>48.3385<span class="ev_code_WHITE">......</span>6" Hoosier
Missouri<span class="ev_code_WHITE">.........</span>48.9961<span class="ev_code_WHITE">......</span>7" Goodyear
UWA<span class="ev_code_WHITE">..............</span>49.1792<span class="ev_code_WHITE">......</span>7" Goodyear
Sophia<span class="ev_code_WHITE">...........</span>50.2914<span class="ev_code_WHITE">......</span>Avons I think
QUT<span class="ev_code_WHITE">...............</span>50.3111<span class="ev_code_WHITE">......</span>Hoosier
Auckland<span class="ev_code_WHITE">........</span>50.4900<span class="ev_code_WHITE">......</span>7" Goodyear
Edith Cowan<span class="ev_code_WHITE">...</span>51.8995<span class="ev_code_WHITE">......</span>Hoosier
UTS<span class="ev_code_WHITE">................</span>52.0530<span class="ev_code_WHITE">......</span>7" Hoosier
Melbourne<span class="ev_code_WHITE">......</span>53.1284<span class="ev_code_WHITE">......</span>Hoosier. 6" front, 7" rear
Curtain<span class="ev_code_WHITE">...........</span>53.9683<span class="ev_code_WHITE">......</span>7" Hoosier

Considering the different design approach's of each car, that is a pretty good spread of tyres.
That said though. I believe Monash are switching to the Goodyear's, and we would have ran Goodyear's had we not been scrapped in favor of an electric car.

[ibanezplayer]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Thrainer:
Boffin, did you also have 7" or 7.5" Hoosiers for testing that day? We tried 6" wide hoosiers in 2009 and weren't quite satisfied. After switching to 7" wide hoosiers, our car was much quicker. TUG had a very light car in 2010 (ca. 190 kg) and was running 7.5" Hoosiers, though.

So, to the original question, I would recommend 7" wide Hoosiers.

Regards,
Thomas </div></BLOCKQUOTE>

What width rim(s) was this done on?

[Jersey Tom]

I have a feeling that the upper level teams on Goodyears are going to be VERY strong this year.

Just sayin'.

[sbrenaman]

We just switched to GY this year. But they're not the GY's that we wanted to run.

[Jersey Tom]

If you don't mind me asking, which Goodyear did you want to run and which will you be using?

[Thrainer]

Ibanezplayer, we've been using 13x7" rims (Keizer shells) the last three years, and they have seen Goodyear 7" (2008 model), Hoosier 6", 7" and 7.5" and Continental (7"? not sure, 2009 model) tires. We like the Hoosier 7" and 7.5" best, but haven't been able to test the newest Goodyear model (new compound since 2009, if I remember correctly).

Speaking of tires, I'm very curious how URE's 15" Vredestein tires will perform at competition. I think the term is "to pull a darmstadt" = "make your own tires".

[Zac]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Jersey Tom:
If you don't mind me asking, which Goodyear did you want to run and which will you be using? </div></BLOCKQUOTE>

Probably the one that's not for retail sale in the USA and illegal to sell in the EU.

[sbrenaman]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Zac:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Jersey Tom:
If you don't mind me asking, which Goodyear did you want to run and which will you be using? </div></BLOCKQUOTE>

Probably the one that's not for retail sale in the USA and illegal to sell in the EU. </div></BLOCKQUOTE>

Yep. That one. http://fsae.com/groupee_common/emoticons/icon_frown.gif

[Jersey Tom]

Ohhhh, you mean the one that pretty much will make your car faster than running unrestricted? Like not even fair?

Yeah, that's a good one.

[MalcolmG]

...sounds like Claude's 2-seconds-a-lap-white-elephant tyres.

[Scott Wordley]

We have run Avons for many years and liked them a lot.

However we recently tested on the new Goodyear 96s and were very impressed, particularly with the transient response, combined acceleration and excellent wear (= super long life).

We will definitely be running Goodyears in 2011.

[theTTshark]

We've always been a Goodyear team, and from what I've learned as well as heard from several others is that along with the Goodyear having very good grip levels they are also very forgiving. The Hoosiers seem to want to kick you in the behind a bit more if you mess up. But that's just my $.02.

Also...@Jersey Tom, can we have super better than unrestricted mega awesome sticky Goodyears? haha

[Zac]

Judging from Tom's signature, I would suggest that he is probably not the guy to ask for "special" tires. He could probably get you a sweet deal on a rental truck though.

[MegaDeath]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Zac:
Judging from Tom's signature, I would suggest that he is probably not the guy to ask for "special" tires. He could probably get you a sweet deal on a rental truck though. </div></BLOCKQUOTE>

Hey Tom, do you think when we go to Germany you can call you Germany Penske buddies and get us a deal on truck while we're over there? Thanks in advance!!