HOW TO SET your AIR PRESSURE for AUTOCROSS
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- เผยแพร่เมื่อ 12 ก.ย. 2024
- Adjusting air pressure is a free mod that can be made to any autocross car in any category and any class. It can shave seconds off your runs. But, determining the ideal air pressure for your Mustang can be confusing, especially when you’re first starting out.
This video covers the common methods for dialing in your ideal air pressure for autocross, and provides tips for setting and maintaining air pressure during events.
I’ll break down the basics of using chalk, pyrometers, and “reading” the tires to find the air pressure setting that allows you to get every last bit of grip.
The difference between winning and losing on an autocross course can come down to 1 PSI!
Who thumbs this video down? this is pure gold, thank you Warhorse Racing!
Thank you for checking out my video!
Had a guy in my live stream Friday night that said he just watches my channel and you channel. Pretty cool. Good info in your video as always
That is really cool! I hope we're inspiring people to restore and race their Mustangs!
good info. was surprised i knew a lot of it even though ive never auto crossed. Found your video while preping for starting auto crossing. thanks!
Thanks for checking out my video! I have several videos about autocross driving fundamentals on my channel that I use to help novices. If you drive a 79-04 Mustang, you'll find lots of helpful information about autocross mods too! I'm also happy to answer any questions you may have about autocross.
@@warhorseracing
Will be driving a mini cooper s 02 supercharger.
Throwing all but the kitchen sink at it. Upgrades I would do over time I’m doing all at once. I’d have to take the d## thing apart every time ! Easier all at once. Will be doing 15”c8 rims. Not sure on tire size yet. Will get a cheaper tire initially.
Trying to get a fox body from a dude. 4cyl. I really want to do a widebody.
I’ll be 65 next month , retired and motoring along.
Will check other Vinod yours. 😎
@@hipoman8087 The Mini Coopers are fun cars. Several people drive them at my local events. You're going to love autocrossing the Mini! Fox Body Mustangs are lots of fun too. The interesting debate about a widebody Fox (especially a 4-cylinder) is whether or not making the car wider will give you an advantage on an autocross course. A smaller car will fit through the cones easier. Happy Birthday, in advance! I hope you end up getting the Fox Body!
@@warhorseracing
Thanks bud. I’ll have a coyote in it. Have one in the drag fox body. Makes since on wide body being more difficult with cones. Probably kill quite a few cones early on ! LOL 😂
Don’t really care if I win or not. It’s the challenge against myself and the fun factor.
@@hipoman8087 A widebody coyote-swapped Fox would be a very cool car. One of the things I love about autocross is that I learn even when I lose. Win or lose, I always come away from events with the tools to make myself a better driver. And I have fun at every event.
Great info will try it out at the next Autocross . Keep the videos coming .
Thanks! Let me know how the event goes.
So many autocross videos on this channel I forget it's a mustang channel. Thank you I'll be applying these to my Subaru!
Thanks for checking out my channel! Autocross fundamentals apply to any car. It's great to hear that people in other cars find my videos helpful. I've had a lot of fun instructing in a lot of cool Subarus over the years!
@@warhorseracing yea that's what im saying a lot of you're concepts apply to other vehicles it's nice to hear!!! Thanks for your work
I really stuggled with my tire pressure the first 2 or 3 timed I auto crossed. The first couple of times I went the courses were very difficult to get around. I need a GPS lol. On top of that being new to auto cross, your learning to drive, and it is hard to make an adjustment to your tires when your learning to drive also. I now have 275's all around and 30 seemed to work good, but I am still dialing that in. I have a whole new suspension setup for my car that I have had for close to a year and it is still not on it. Once the new parts are on, my tire pressure will probably change.
It can be tough to start adjusting air pressure when you just start autocrossing. It's something to work into your routine as you progress. Improving your suspension and upgrading to better tires will usually create the need to adjust your air pressure. It's not a bad idea to go through the process of dialing in your air pressure once the new setup is on the car.
Your a gold mine of information. Thanks for doing this
Thanks for checking out my channel! It's great to hear that my videos are helping people.
The last autocross I went to, used the chalk method. It was a warm day in the low 90's. (I drove a FWD Focus ST) The rears started at 32 PSI and I eventually took them down to 29-30. The fronts however were a mystery to me. I started at 38 PSI (38-40/30-32 was recommended to me for my car online). After a couple runs, pressure in the front climbed to 42 PSI and chalk showed that I wasn't using the whole tire. I would bleed down to 39, but at the end of the next run I was back up to 42ish. I kept trying to bleed down and this repeated on the fronts 3 or 4 times before giving up. At the end of the day after the tired cooled, they were 24 PSI. Why could I not bring down the PSI at the end of each run, despite letting out so much air? Was the tire flexing so much under the front weight that it was just super heating back up? They were all seasons that were on their 60 to 70th runs (one reached the cords by the end of the day). I just could not figure out how to stabilize the pressure. I saw other drivers using spray bottle to wet their tires between runs. I watched your video looking for answers, but much of it I already know. I know you advise 1 PSI between runs, but it was rising 2 to 4 degrees. The process did seem to help, but I left wondering if I made a mistake or if the heavy front end of my car puts too much stress (in the form of heat) on the front tires. Advice is welcome.
Tire pressure increases on every run, sometimes 2-4 psi. So, if you set the pressure for 38 psi BEFORE your first run, it will probably be 40-42 psi AFTER the run. You would have to RESET to 38 psi, or, if you had chalk on the tread, ADJUST to 37 psi. That's the 1 psi change between runs I'm referring to. Repeat that process, going from 38 to 37 to 36, etc. on each run, until you find your ideal setting. I have to take air out after EVERY run. But, usually by my 5th run, it's only about 1 psi above my ideal setting. The tires on a FWD car are doing double-duty, putting power down and steering. On a hot day, it's not uncommon that the pressure will keep rising as the tires get hotter. Old all-season tires are probably spinning a bit, so that will add more heat. More heat increases pressure. If the tires are hot and greasy, you can spray them to cool them down. But you will probably still have to reset or adjust air pressure after each run.
Perfect video for the day of an important race for me.
I hope the video helps. And I hope you win!
Warhorse Racing thank you! I ended up dropping my pressures to 31 in the front and 28 in the rear (Yokohama 052)after stealing some course chalk lol. Had the lead in CAMC until run #7. ended up second in class and 3rd in pax overall
@@maartyrr That's awesome! It sounds like you had a lot of runs to dial in the pressures. I always like to see CAM cars high up in the PAX results!
Warhorse Racing I kept dropping the pressures throughout the runs, especially the rears. I’m shocked they you are able to run the rivals that low. And hell yeah #camnation - I’ll be doing my one and only national event at Toledo in about 2 weeks. I just don’t want to come in dead last lol.
@@maartyrr I would never have thought I could run my tires at 26 psi before switching to the Rivals. But, that seems to be the magic number for my cars. Have fun at the National Event! Focus on the course, not your competition.
Awesome information, i love all your videos as they are full of detailed information. Im not sure how much experience you have autoxing in wet or raining conditions but i have recently been faced with this challenge and would love to see some videos about how to change your driving and things to consider (tire pressures, suspension settings, alignment) for wet/raining conditions.
I looked through my footage from events, and I don’t currently have wet event clips to use for a video about autocrossing in the rain. If I go to a wet event in the future, I will put a video together. But, for now, here are some tips… There are many variables when it comes to autocrossing in the rain. TIRE CHOICE is important; some 200TW tires perform better in the rain than others. I can tell you from personal experience that the BFG Rival S is not very good in WET conditions. The Bridgestone Potenza RE-71r and Falken Azenis RT615K+ both seem to be better in the rain (based on my competition). In wet conditions, many people I know use their daily driving tires. If it’s DAMP, 200TW tires can still work well, but it will take longer to get heat in the tires. And, you will probably have to back up your braking zones, and wait a little longer to start rolling on the gas out of turns. You are essentially driving to a limit of traction that is further in than normal. For AIR PRESSURE, Tire Rack says to increase air pressure 6-8 psi from what you would normally run in dry conditions. That creates a smaller contact patch and keeps the grooves in the tread open to shed water. Personally, I haven’t found this to be helpful. The smaller contact patch with the Rivals makes traction worse. And, since I run my air pressure so low (26 psi), I wouldn’t go with less air pressure to increase the contact patch, either (the lowest I will go wet or dry is 25 psi). If you have some room between your ideal air pressure (dry) and the manufacturer’s minimum recommended air pressure, consider going a bit lower when it's wet. The most common and effective adjustment I have found when autocrossing in wet conditions is to use my adjustable shocks and struts to address understeer or oversteer. My V6 tends to understeer when the course is wet, so I soften the FRONT struts a little. My V8 tends to oversteer in the wet, so I soften the REAR shocks a little. On a Solid Rear Axle car, I would also consider adjusting the rear sway bar to reduce oversteer (if your rear sway bar is adjustable). The trickiest part of making those adjustments is to be sure the understeer/oversteer is being caused by the conditions, not how you are driving the car. If you’ve adjusted your inputs and aggression to compensate for the rain and haven’t seen an improvement, start adjusting the suspension to solve the issue. I hope this info helps. If you have any more questions, please ask.
@@warhorseracing great information! I compete in CP due to my weight and tire 100 TW rating. I never considered raising the tire pressure above reccomended, because like you said it reduces the contact patch and in the wet contact patch is more important than ever. I still ran my normal alignment -2.5° camber, +6°caster and 1/8 toe out. But i went full soft on koni yellows front and rear. Starting at 32psi and following your suggestion for reducing 1 psi at a time, I found 30psi in the rear and 29psi up front worked best for me. I went 29 all the way around but found the car picked up a slight oversteer, so i let heat build the rears back up to 30 and maintained 29 up front. (Solid axle new edge 4.6 2v @ 3005 lbs with driver). I ran toyo r888rs out back (its all i have for a rear tire) and re-71 up front. With rear sway bar disconnected. Overall i was very pleased with the way the car was performing, but after reviewing footage i feel like i left alot on the table at corner exit and through some sweeping corners. I appreciate your feedback and information, i am always overly impressed with your v6 cars handling and how it just goes right where you point it to go even when under heavy acceleration. Keep the videos and info coming. I appreciate you taking the time to share your experiences and knowledge. My father always told me, "the day you stop learning is the day you stop winning" cause there's always someone else driving, learning and improving and they are just waiting for you to slip up. I feel your videos give me that extra edge of knowledge over someone else and a chance to apply what I've learned at the next event.
@@Danky2448 Thank you for the kind words about my channel. I'm still learning more about autocrossing and building these cars every day. And, every season, my competition gets faster and faster. I'm glad to hear the videos are helping people. I've got more coming soon. Your alignment specs seem right for an SRA car. I run 1/16 toe out, but every car/driver is a bit different. Exiting corners and attacking sweepers can be tough in wet conditions. It's so hard to feel the level of grip, and to time when to get back on the gas. Are you running a square or staggered setup on your car? I've been really happy with the V6; it's proof that mass centralization really makes a difference. I'm looking forward to seeing how close I can get the V6 to 3,000 lbs. now that it's in CAM-T.
Thanks for posting this!
Thanks for checking out my video!
All factual content! And just when you think you have it figured out, you'll go and install adjustable shocks and struts and have to learn those settings in combination with your tire pressures. It's not uncommon to be chasing these items for most if not all of a season!
It definitely takes time and experimentation to find your ideal air pressure setting. And that setting can change based on the mods you make. The good news is, adjusting air pressure is free and easy!
Great info.
Thank you!
"And that will put the pressure on your competition" 💨🦾
Thank you very much for this video!
I hope the video was helpful. If you have any questions, please ask.
Great video!
Thank you!
I’m building an Autocrossing Chevy corvair. It’s not a Ford. But, concept is the same for setup. Can you recommend a tire pressure gauge?
I've seen several cool Corvair CAM cars over the years. I use the Longacre 52-52022 Liquid-Filled 2.5" Tire Gauge. It's held up well for 6 seasons.
Warhorse Racing thanks!! I purchased the 60psi version. Pressures will be 32-35 before a run.
Interesting that you run such low pressure. I run 36f30r on my 16 mustang gt performance pack with 305/30r19 rival 1.5s (bone stock beyond 19x11 s350 wheels and camber plates). I will be measuring with my infrared next event
How much negative camber do you have in the front and rear? Does the car still tend to understeer with your current settings?
All the camber (2.2ish front, 1 rear) it doesn't understeer with 36f. 32f gets understeer
@@PhilthyHorseRacing It's interesting that the car understeers at the lower pressure. You might benefit from a smaller front sway bar. My SN95 cars are different than your s550, but I run -2.2 F and -1.8 R (-2.0 R on my V6). Keeping the settings closer together is a "grip" alignment, as opposed to a "rotation" alignment. Depending on the rules of your class, you might want to make a mod that can add some more rear camber.
Is there any advantage to running nitrogen?
In my opinion, the minor benefits you will get using nitrogen in your tires at an autocross will be outweighed by the expense and inconvenience of maintaining only nitrogen in your tires.
@@warhorseracing I didn't consider the adding of nitrogen to the tire :(
I was able to get an adjustable rear sway bar, do you have a suggestion for the initial number of threads showing?
@@ToddDavey I usually start with 2 or 3 threads showing, then adjust from there. If you check out my "ThoroughbRED Part 4: How To Adjust Your Autocross Suspension" video, it details how to dial in the settings.
@@warhorseracing Thanks. I appreciate the info you put out. Had I found your channel earlier I'd have saved considerable time/money/effort!
@@ToddDavey I'm glad my channel is able to help people. If you have any more questions about setting up your suspension, please ask.
In the video you say that you start with more air pressure on your first run so that the tires will heat up faster. Don’t you actually mean less air pressure? It’s been my experience that starting with lower than ideal air pressure in a tire will make it squirm more and heat up faster. Thoughts?
When my cold 200TW tires are set at a higher than ideal air pressure, my cars slide around on course (front & rear tires). That helps them heat up. I do know some people who start lower than their ideal air pressure, but my ideal air pressure is 25 PSI and I can't go lower than that. My tires like a lot of heat, so I've found this method works best to get them happy.
@@warhorseracing Thanks! I’m guessing either way works well. 😊
@@mitchlewis535 It all comes down to what works best for your tires, your car and the conditions.