Couple of quick questions about HPDE

[johna]

I'm about to do my 2nd HPDE this year (and 3rd ever)......just a couple of quick questions - so I can get better at these track days.

1. How much do tires increase pressure when getting hot. It seems the tire should be at 41 psi at the track; so what should the tire be cold when starting? The tread on the tires look good - as they start to wear out - do they wear on the sides from cornering or just on the tread....

2. I changed the oil just before my last HPDE, 1 day event, and have driven an additional 300 miles (probably 500 total)...should I change the oil again before the next event?

3. I also put in new dot 4 brake fluid before the last HPDE; should I bleed the brakes...or is it usually fine?

I have about 6800 miles on car - are there any other oils or things I should flush or change before or after this event or after a track event.

I appreciate the help.

 

[TMSBOSS]

Johns

A good place to start is with the Boss owners manual supplement. Fluid changes and intervals are listed. If you still have the factory filled trans and diff fluids, a change is a good idea. I went with redline fluids.

Tires. Which tires are you running?

Brakes. I bleed brakes before each track event. If you go cheap on brakes be sure to have good track insurance. ;D

 

[F.D. Sako]

1. The only way to know what pressures to set your tire to, is to take cold and hot temperatures at the track. There's many different factors at play, so we won't be able to give you an exact answer. As Tracy mentioned, start with the recommended 35psi cold, and after you come in from a session, check the pressures and see how much theyve increased.

As you drive harder, tire temperatures and pressures will increase. I usually start at 27-28psi cold (depending on the track and tire location) and it usually ends up around 46-48psi hot.

2. Which oil do you currently use?
I think the motorcraft oil is known to break down pretty quickly, so it requires more frequent changes. I use Mobil1 5w50, and I just sent it in for oil analysis after 4 track weekends and 1500 mi (mixed track + street driving). Based on the report, the oil had plenty of life left.
To be safe, I'll be changing oil after every 5 track weekends, like some people here. Best way to find out how your oil is performing is by sending in a sample for analysis.

3. Again, which DOT4 did you use?
I use Castrol SRF and I bleed it after 3-5 track weekends.
Currently, I think you should be fine with yours, based in the info you've given (3 event driving experience + recent bleed).

As for the other fluids, I think diff fluid is recommended (302S/R manual) to be changed every 4hrs of track time. I go a little longer on this, maybe 8hrs of track time, using amsoil heavy duty 75w140.

Based on discussions with other members here, the transmission fluid also gets really hot, so I usually change the trans. fluid while doing the rear diff. I've been using BG synchroshift II in mine with good results.

 

[johna]

Thanks, great information, I appreciate the help.

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[johna]

I have never changed the transmission oil or different fluid...any links on how to do this...I will look on you tube also...like to do the work self

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[TMSBOSS]

Search right here.

Several good threads on each.

 

[Hermes]

[quoteI have never changed the transmission oil or different fluid...any links on how to do this...I will look on you tube also...like to do the work self

Sent from my SAMSUNG-SGH-I337 using Tapatalk][/quote]

I used to change my trans and diff fluid at the beginning of each season. I typically run about 8 days a year. Looking at the condition of the old fluids, I now change diff fluid every year [redline heavy shock proof] and trans fluid every other year. Since you haven't driven that many days yet, you may want to replace the factory fill at the start of the next season. I think the 2013 Boss came with a diff drain plug which makes this job pretty easy.

As far as you tire pressure question, there are a lot of factors that effect temps [track surface, track temp, your driving style, etc.] The best method I found is to set them as soon as you get off the track [41 PSI seems to work for the stock Pirelli's] then just check it before you go out on your next session. I always write down my out pressures to have a reference for next time, and what I've found it that ambient air temp effects the cold press as well as what side of the car the sun is shining on, so there is no hard & fast start pressure that will guarantee you'll end up where you want [41] you just have to gain some experience with them.