Boss 302 Advance Road Race Tire setup thread

Discussion in 'Brakes, Wheels and Tires' started by steveespo, Sep 11, 2013.

  1. Roadhouse

    Roadhouse Logan

    Messages:
    1,281
    Likes Received:
    2
    Joined:
    Jan 8, 2013
    Location:
    Tulsa, OK
    Re: Boss 302 Advance Road Race setup thread

    I'll piggyback on this thought. Has anyone run without a rear sway bar??

    I found this quote on Kenny Brown's website in the discussion about the AGS suspension systems for 05-13 cars. "Typically I’ll run my car with no rear sway bar. For faster tracks like Mosport or Atlanta, I recommend a small OE rear sway bar", according to Brown.

    Here is the link to the site
    http://www.kennybrown.com/press/kenny-brown-releases-fourth-generation-ags-suspension-systems-2005-2013-mustangs
     
  2. VoodooBoss

    VoodooBoss Rick Moderator

    Messages:
    20,165
    Likes Received:
    2,593
    Joined:
    Nov 30, 2010
    Location:
    90 Miles East of Sonoma Raceway
    Re: Boss 302 Advance Road Race setup thread

    Member YoPauly isn't running a rear sway bar with the Kenny Brown setup. So far he likes it but I'm not sure it made much of an impact on his lap times.
     
  3. 2012YellowBoss

    2012YellowBoss TMO Addict

    Messages:
    2,372
    Likes Received:
    10
    Joined:
    Dec 31, 2010
    Location:
    Sebring, FL
    Re: Boss 302 Advance Road Race setup thread

    All depends if the car is setup correctly first off and what the driver likes. While in time I have learned to like a car on the loose side, I don't like it wild loose. Some drivers like that but it takes a lot of skill which I don't have. If you make it to the races you can see the difference in car setups at sharp turns of more then 120 degrees. I like watching the races at Daytona by the east horseshoe, you can see the cars that are wild loose with good drivers drifting the turn lap after lap.
     
  4. Roadhouse

    Roadhouse Logan

    Messages:
    1,281
    Likes Received:
    2
    Joined:
    Jan 8, 2013
    Location:
    Tulsa, OK
    Re: Boss 302 Advance Road Race setup thread

    I figured it came down to personal preference of the driver.

    I am by no means a highly skilled driver either and my car is not set up to run sans a rear sway bar. I may try a smaller rear bar one day and see how I like it. No harm in pulling the rear bar completely and trying it that way too I suppose.

    Thanks for the info Bosses, both NFS and Yellow
     
  5. blacksheep-1

    blacksheep-1 TMO Addict

    Messages:
    1,624
    Likes Received:
    774
    Joined:
    Mar 12, 2013
    Re: Boss 302 Advance Road Race setup thread

    I think you'll be money ahead to build your car around that 18mm bar

    FWIW....

    found some images of the Roush cars in GS

    Braking.....

    [​IMG]

    [​IMG]

    center cornering

    [​IMG]

    [​IMG]

    [​IMG]

    acceleration

    [​IMG]

    Looks like marshmallows for the rear spring/shock/ bar setup to me
     
  6. ArizonaBOSS

    ArizonaBOSS Because racecar. Moderator

    Messages:
    8,088
    Likes Received:
    1,662
    Joined:
    Dec 6, 2010
    Location:
    Arizona, USA
    Re: Boss 302 Advance Road Race setup thread

    Softness/compliance = GRIP!
     
  7. 2012YellowBoss

    2012YellowBoss TMO Addict

    Messages:
    2,372
    Likes Received:
    10
    Joined:
    Dec 31, 2010
    Location:
    Sebring, FL
    Re: Boss 302 Advance Road Race setup thread

    Maybe I am thinking this wrong. I know the smaller bar gives you better grip power out of the corner, you can call that less oversteer. however I was under the impression that running no rear bar or a smaller one gives the car oversteer more in corner entry and mid-corner, plus I thought it can make the rear sway a bit in the brake zone. Correct me if I'm wrong on this.
     
  8. steveespo

    steveespo Lord knows I'm a Voodoo Child Moderator

    Messages:
    3,384
    Likes Received:
    616
    Joined:
    Mar 6, 2011
    Location:
    NY Metro
    Re: Boss 302 Advance Road Race setup thread

    In reference to the small rear bar, I changed to the 18mm bar but thus far have only run one wet weekend at Summit Point WVa. In the wet more compliance helped grip. I feel wet or dry the reduced roll stiffness will help the rear axle be more compliant and load the outside tire during cornering. With stock Boss or even bigger LS rear bar the rear seamed to not plant during cornering and exit, the soft bar made it easier for me to feel what the rear tires were doing and I could control wheelspin that I was getting coming off of Turn 10 onto the main straight. Under braking I found no adverse effects, in the wet braking from 127 to 40 mph, in the dry it would be 140 to 60 or so. No rear wiggle or additional dive.

    I will be running a hopefully dry day at Lime Rock on Nov 16 and will try and get some feedback on tire temps and performance. I am hoping to see a temperature increase at the rear indicating the rear tires are working more with the soft setting, taking some of the load off the front.

    Maybe I have it wrong but that's my initial impression.
    Steve
     
  9. KRost

    KRost TMO Intermediate

    Messages:
    51
    Likes Received:
    0
    Joined:
    Sep 25, 2012
    Location:
    Sioux Falls, SD
    Re: Boss 302 Advance Road Race setup thread

    It will be impacted by the rest of your setup. I have a Strano adjustable front sway with 380lb F/250lb R springs, Watts link, 52.5% F/47.5% R balance, and 50/50 crossweight with full fuel load. When I ran the 18mm rear it introduced a fair amount of high speed understeer on sweepers. When entering lower speed corners under heavy braking I had to trail brake a lot more then "usual" to rotate the car. Corner exit grip probably was improved a bit.....I ended up going back to my adjustable rear on it's softest setting which is stiffer than the 18mm. My driving style and setup didn't work with it, but I think it has more grip off corner potential for some cars that are closer to "stock" balance. It's definitely worth experimenting which is half the fun :)
     
  10. 2012YellowBoss

    2012YellowBoss TMO Addict

    Messages:
    2,372
    Likes Received:
    10
    Joined:
    Dec 31, 2010
    Location:
    Sebring, FL
    Re: Boss 302 Advance Road Race setup thread

    I would need to try it alone without changing other things. I put the 18MM bar on shortly after I got the coilovers, too soon to tell any real difference except being able to get into the gas earlier in the corner exit. I was getting a lot of rear end sway before the coilover in the brake zone, mostly after I replaced the stock rear sway with the FR 22MM bar. With the coilovers that problem is gone but again can say if the smaller bar made any difference.

    We are close on a lot the things you mentioned, my rear springs are close 275 but the front is 550. F/R and corner weight is close. Right now the car is fairly neutral with the bigger tires out back, even in sweepers. I have to switch back to a square setup soon, figured I would adjust the front bar (set in the middle now) as needed since my rear bar is not adjustable. I don't use trail braking that much, or try not to until I learn all the in and outs of it, and I have no problems getting the car to rotate. I guess the only real issue I could bring up is mid-corner, it does not take much to bring the ass end around there but still it is easy to manage when it happens.
     
  11. KRost

    KRost TMO Intermediate

    Messages:
    51
    Likes Received:
    0
    Joined:
    Sep 25, 2012
    Location:
    Sioux Falls, SD
    Re: Boss 302 Advance Road Race setup thread

    Staggered vs. Square is another big variable. I run square, if I kept the same suspension package and went staggered it would understeer way worse than just putting on the 18mm bar. The G-stream wing I have bolted on also helps keep the back end planted more than the Roush GS cars also. Such mods lead you getting labeled as a "Outlaw" at the Roundup at MPH, which is pretty cool in itself 8)
     
  12. blacksheep-1

    blacksheep-1 TMO Addict

    Messages:
    1,624
    Likes Received:
    774
    Joined:
    Mar 12, 2013
    Re: Boss 302 Advance Road Race setup thread

    OK kids! any info from this week? I'd like to see you guys develop your graphs so that you can start next year off on the right track.
    If you post some numbers here, I'll try to verify them, then you can build a graph and post it so everyone can use it...but you need the numbers..the more the more accurate the graph is.
     
  13. blacksheep-1

    blacksheep-1 TMO Addict

    Messages:
    1,624
    Likes Received:
    774
    Joined:
    Mar 12, 2013
    Re: Boss 302 Advance Road Race setup thread

    Thermal imaging on an F1 car.. I know it's not a Boss, but take a look at the tire patches on the tire.

    https://www.youtube.com/watch?v=iAVIhH8CyAM

    also a more detailed view..

    https://www.youtube.com/watch?v=DlLmF8LAHUM
     
  14. Grant 302

    Grant 302 OPM Spent: $587,402 Moderator

    Messages:
    6,508
    Likes Received:
    1,555
    Joined:
    Nov 23, 2011
    Location:
    In the OC
    Re: Boss 302 Advance Road Race setup thread

    Thanks for the vids and the reminder. I've got a hand-drawn graph started in my logbook. Going to run at Streets of Willow tomorrow. Right now all four tires are set the same temp/pressure (which I normally don't do) but to have a useable baseline tomorrow morning. Two data points for this street pressure are 83*/35.0 psi and 108*/37.0 psi. Based on my crude graph, I will drop the fronts 1# and the rears 2# to start and go from there.
     
  15. blacksheep-1

    blacksheep-1 TMO Addict

    Messages:
    1,624
    Likes Received:
    774
    Joined:
    Mar 12, 2013
    Re: Boss 302 Advance Road Race setup thread

    Sounds good, plz keep me posted
     
  16. blacksheep-1

    blacksheep-1 TMO Addict

    Messages:
    1,624
    Likes Received:
    774
    Joined:
    Mar 12, 2013
    Re: Boss 302 Advance Road Race setup thread

    bump..any info from this weekend?
     
  17. Grant 302

    Grant 302 OPM Spent: $587,402 Moderator

    Messages:
    6,508
    Likes Received:
    1,555
    Joined:
    Nov 23, 2011
    Location:
    In the OC
    Re: Boss 302 Advance Road Race setup thread

    Tires and rim temp were about 55 deg. and 33 psi when I set pressures. Based on my chart, I reduced the fronts 1 lb. and the rears 2 lb.

    Session 1:
    ....................Front....................
    Driver...........................Passenger
    P...40.5........................41.5
    T...129...132...146.......148...139...140
    Rim Temp 166..............180
    ....................Rear......................
    P...39.5........................38.7
    T...133...146...152.......141...139...127
    Rim Temp 166..............140

    Session 2:
    ....................Front....................
    Driver...........................Passenger
    P...40.4.........................43.0
    T...126...134...149.......162...160...174
    Rim Temp 153..............195
    ....................Rear......................
    P...38.1........................39.2
    T...112...119...127.......133...147...148
    Rim Temp 133..............160

    Drop right front 0.5 lb. at 86 degrees.

    Session 3:
    No data taken...10 minutes in hot pits late in the session to clean the track :( only two laps more run after the break.

    End of day:
    ....................Front....................
    Driver...........................Passenger
    P...34.2.........................35.0
    Rim Temp 66.................69

    ....................Rear......................
    P...33.0........................33.0
    Rim Temp 64................58
     
  18. blacksheep-1

    blacksheep-1 TMO Addict

    Messages:
    1,624
    Likes Received:
    774
    Joined:
    Mar 12, 2013
    Re: Boss 302 Advance Road Race setup thread

    these are continental 275-305 x 18s?
    if so the bold numbers are solid the pressures around 40 are starting to top out at the maximum for those tires, so there may have been some fluctuation at the extremes, especially using air. Also rim temps are important but most aluminum and mag wheels shed heat pretty fast, I'd get rid of that notation and replace it with an across the tire average.
     
  19. blacksheep-1

    blacksheep-1 TMO Addict

    Messages:
    1,624
    Likes Received:
    774
    Joined:
    Mar 12, 2013
    Re: Boss 302 Advance Road Race setup thread

    I ran some quick numbers and this is what I got..

    [​IMG]
     
  20. Grant 302

    Grant 302 OPM Spent: $587,402 Moderator

    Messages:
    6,508
    Likes Received:
    1,555
    Joined:
    Nov 23, 2011
    Location:
    In the OC
    Re: Boss 302 Advance Road Race setup thread

    I took the rim temps because the tire temps were dropping pretty rapidly in the wind at 55 degrees after the first session. At least that makes the case for getting a thermocouple probe type sooner than later.

    The tires are 275/35-18 hankook R-S3.

    I'm thinking some of the fluctuation is from water in the air. I've been using gas station air :(
     

Share This Page