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Boss 302 Advance Road Race Tire setup thread

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steveespo

Lord knows I'm a Voodoo Child
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Re: Boss 302 Advance Road Race setup thread

I added the Ford Racing spherical LCA during the "resurrection" and ran the at Watkins Glen for the first time.
Rear end felt much less roll sensitive during the different phases of cornering. The car just feels more connected during the transitions between braking, turn in, apex and exit. Much less steering correction needed when coming back on power to keep a smooth arc. I attribute this to lack of bind in the rear, as the axle loads and unloads there is less stiction and the weight transfer is more predictable. I felt the same way when I stiffened up the front control arm bushings. Hope this makes sense.
Steve
 
Re: Boss 302 Advance Road Race setup thread

Grant 302 said:
I thought the middle hole was recommended by FR? More corner exit grip should come from the lower hole, but will be more roll steer loose as boro92 notes below.

That is what I understand as well and where I have mine set. So far Rick you are the only person using this setting besides drag racers that I have heard of. I have been wanting to try the lower hole myself just to see what it would do but with all the recent changes made I am still not 100% use to my car as it is.

I found that adding the 18MM sway bar after the coilovers gave me great exit grip and I can power out of corners much earlier then before. I'm not sure how much more the lower control arm holes will help there. I did discuss this setting with the race team and was told to try it and see what happens, like stated here people like different feels to the car and one setup is not always correct for all . One thing I remember when talking about this is the car may feel less stable (for the lack of a better word) mid-corner and maybe corner entry. Some people may not mind this but it is something I know I would not like to feel.
 
Re: Boss 302 Advance Road Race setup thread

My bad I meant the middle hole and that's where mine are located.
 

steveespo

Lord knows I'm a Voodoo Child
Moderator
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Exp. Type
W2W Racing
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Cookeville TN
Re: Boss 302 Advance Road Race setup thread

Just to be clear, middle hole is 1st hole down from stock location right? With lowering P springs it corrected LCA angle so the rear pivot (axle) is lower than the frame pivot at static ride height. This angle puts anti squat geometry into the rear.
Steve
 
Re: Boss 302 Advance Road Race setup thread

steveespo said:
Just to be clear, middle hole is 1st hole down from stock location right? With lowering P springs it corrected LCA angle so the rear pivot (axle) is lower than the frame pivot at static ride height. This angle puts anti squat geometry into the rear.
Steve
Correct, at least that's my understanding.
 
6,363
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Re: Boss 302 Advance Road Race setup thread

OK time to bump this, has anyone besides Pufferfish been to the track and done their "homework" on tire temps and pressures?

also are there any questions along those lines on how to build your graphs?
 
6,363
8,187
Re: Boss 302 Advance Road Race setup thread

OK to start with...
log in what tire wheel combo you have , example 275x35x18 on a 10.5 wheel
1. get a tire/ wheel combo and set in someplace cool, (inside the house if the wife permits) put 25 psi in it and register the the temp of the tire.
2. do this again in the garage..
3. and outside, each time keeping track of the temp and pressure (be careful to check the pressure and NOT let any air out) the object is to get a pressure setting for each 10 degree of temps
4. at the track
5 after warm up
6 before each session
7. after each session. this is where the probe style temp gauge will come into play, which will be much more accurate than the infra-red units ( when you measure across the tire face, write down the AVERAGE temp as well, we'll use this temp as the actual measurement)

The objective is to get a psi reading for each 10 degree temp change (a .1 to .5 pressure gauge is recommended) all the way from the first ambient (indoor) all the way to 200 degrees in 10 degree increments , or at least enough so that you can fill in the gaps. If you miss one, don't worry the tire will cool off between sessions and you can sometime recover the lost temp at that time. If you are FORCED to add or subtract pressure, log it in on your paper so that is can be added or subtracted from your actual numbers.

Then we'll look at them together any questions?
So...who's in on this project?
 

Grant 302

basic and well known psychic
Re: Boss 302 Advance Road Race setup thread

Good assignment...wish I got it on Friday, *before* heading out to Laguna Seca! I'm in when I start going to the track locally. In the fall...after it cools down a bit. All the local tracks were in the high 90s low 100s this weekend.
 
Re: Boss 302 Advance Road Race setup thread

This is a great thread Steve. I'll try to chart some info this weekend with my new R6s. That said, after reading this, I'm really confused on optimal HOT temps. I know the goal is to get the COLD temp right, but at the end of the day it's the HOT temp we're driving on isn't it? I've tried low 30s hot on R6s but have found high 30s to 40 works better for me...probably because our cars are so heavy.

The ambient temps are projected to be in the mid 70s. I'm assuming if I start at 32 front and 31 rear I should end up around 40 HOT. Any suggestions? Also I do have a probe style temp gun, but is it relevant if you run a cool down lap, then drive through the paddock to your trailer? In other words, have the tires cooled too much to get good data?
 
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Re: Boss 302 Advance Road Race setup thread

cloud9 said:
This is a great thread Steve. I'll try to chart some info this weekend with my new R6s. That said, after reading this, I'm really confused on optimal HOT temps. I know the goal is to get the COLD temp right, but at the end of the day it's the HOT temp we're driving on isn't it? I've tried low 30s hot on R6s but have found high 30s to 40 works better for me...probably because our cars are so heavy.

The ambient temps are projected to be in the mid 70s. I'm assuming if I start at 32 front and 31 rear I should end up around 40 HOT. Any suggestions? Also I do have a probe style temp gun, but is it relevant if you run a cool down lap, then drive through the paddock to your trailer? In other words, have the tires cooled too much to get good data?

You are mostly correct, it would be much better if you came in on a hot lap and did the tires right there in the pits before going into the paddock, but you get what you get, when I did Yellow Boss at West Palm I did them as the car came off the track..no cool downs...better numbers. If you use timed sessions then come in a lap early.
I'm going to tie all of this together, it is hot pressures that are important, but what is "hot" 200 degree tread temp? or 220..170? and how do you get there from a "cold" setting.
Set the cold pressures (and measure the tamps) "cold" then as you run the car, if you have to make pressure changes to keep the car handling do it, but write them down so we can add or subtract them later..after that, let the car "normalize" over night, and measure the temps again...cold and see what they are (write down the temp). ALWAYS WRITE DOWN THE TEMP WITH THE PRESSURE OR IT"S USELESS!!!! :mad:

BTW those pressures sound too high to start with
 
Re: Boss 302 Advance Road Race setup thread

blacksheep-1 said:
You are mostly correct, it would be much better if you came in on a hot lap and did the tires right there in the pits before going into the paddock, but you get what you get, when I did Yellow Boss at West Palm I did them as the car came off the track..no cool downs...better numbers. If you use timed sessions then come in a lap early.
I'm going to tie all of this together, it is hot pressures that are important, but what is "hot" 200 degree tread temp? or 220..170? and how do you get there from a "cold" setting.
Set the cold pressures (and measure the tamps) "cold" then as you run the car, if you have to make pressure changes to keep the car handling do it, but write them down so we can add or subtract them later..after that, let the car "normalize" over night, and measure the temps again...cold and see what they are (write down the temp). ALWAYS WRITE DOWN THE TEMP WITH THE PRESSURE OR IT"S USELESS!!!! :mad:

BTW those pressures sound too high to start with
Thanks, will do. What are you recommending for starting cold pressures then? If I start cold at those pressures, I usually end up high 30s to 40 hot......
 
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8,187
Re: Boss 302 Advance Road Race setup thread

All tires are different, usually about 26-28psi @ 85 degrees relates to about 38-40 hot depending on the setup with the Contis. (had to check some notes).

Remember if you miss a pressure temp on the way "up" you can still get them on the way "down" in the cooling process.
 
Re: Boss 302 Advance Road Race setup thread

I must not be pushing my Conti's nearly hard enough. The greatest psi gain I have seen is 8 from cold to hot. Although as I type this, part of that could be they have cooled some before I measure them in the paddock.
 
Re: Boss 302 Advance Road Race setup thread

LS110 said:
I must not be pushing my Conti's nearly hard enough. The greatest psi gain I have seen is 8 degrees from cold to hot. Although as I type this, part of that could be they have cooled some before I measure them in the paddock.
That's about what I see too and why I'm having a hard time translating thesebcold pressures into the desired hot pressures. It could be due to the shorter sessions we typically run versus a longer race that blacksheep-1 is referencing?
 
Re: Boss 302 Advance Road Race setup thread

Probably no better information than right from the manufacturer. Here's the pressure and temp guide from Hoosier for R6s and A6s. For our cars they're recommending HOT 34-39+ and COLD 23-29. They also emphasize the following:

+Higher pressures will improve the performance capability but will require a more sensitive feel to take advantage of the
increase. One characteristic of the tires is the tendency to “skate” initially (when inflation pressures are correct). It is important to resist lowering the pressure to attempt to eliminate this feeling. Dropping the pressure too far may improve the “feel” of the tire however it will also lower the performance and increase the wear rate.


I don't think I can get 39+ starting at 29. I'll start 3-5 psi higher when heat cycling them on Friday afternoon, per their recommendation, and see how much increase I get from cold to hot. Then I'll use that for setting initial cold pressures in competition. I'll try to get someone to take tire temps in the hot pits if possible. They recommend 180*-200*.

[pdf]http://www.hoosiertire.com/pdfs/tctR6_A6.pdf[/pdf]
 
6,363
8,187
Re: Boss 302 Advance Road Race setup thread

I don't think I can get 39+ starting at 29. I'll start 3-5 psi higher when heat cycling them on Friday afternoon, per their recommendation, and see how much increase I get from cold to hot. Then I'll use that for setting initial cold pressures in competition. I'll try to get someone to take tire temps in the hot pits if possible. They recommend 180*-200*.

Then fill those tires at that pressure the day before when they are cold, and track them all the way up, we're trying to get enough data to fill out a graph. If you show up at..say Daytona in January and it's 35 degrees outside, you will need to figure out what tire pressures are at 35 degrees, as well as 110 degrees at Indy in whenever it was.
 
Re: Boss 302 Advance Road Race setup thread

This is a great thread. Lots of talk about tire temps, but seems like there are a lot of variable including camber, tire construction, track conditions etc. I'm pretty good about keeping records and always measure tire press before and after each run. The biggest variable is that I do check final temp in the paddock so cooling time is a variable.

I was told to set pressures hot and then I read them cold before the next session to set a baseline for 1st sessions on subsequent days. I always write down the air temp but don't have a way to measure tire temp [yet]. I've noticed as much as 1.5 psi difference just because 1 side of the car was getting sunlight and the other side was in the shade.

I guess the importance of getting the correct pressure depends on what your doing. Setting up for a race might be a lot different than running DE. In DE's, I never really run full out in my first session, so if I miss my hot temp by a bit, I can usually fix that by the next session.

Seems like getting a pyrometer is a good idea and I'll probably try and get one for next season. I also plan to get some camber plate for next season, so if I'm following this thread correctly, it seems that I should play with camber to try and get the temperature distribution between inside and outside edges even, then adjust pressure to match center tire temp to the edge temps. Does that sound about right? ???

Like blacksheep said, best idea might be to pull in mid or late session and measure temps and pressure in pit lane [just need to clear that with the group I'm running with, but don't think it would be a problem].

Another thing I heard was to adjust pressure until the tire rolls over onto the indicators. Is there anything to this approach? Or is this superseded by measuring temps with a pyrometer? Turns out that running 35 PSI front and 37 PSI rear [hot measured at the paddock] gets my Nitto NT-01 275F / 305R tires to roll right to the indicators, so this was my target hot pressure for my last event at VIR. Held very steady throughout weekend.
 

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