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Low traction tuning question

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Low traction tuning question

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Old 07-02-2019, 11:11 AM
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Default Low traction tuning question

For a low traction, or dusty medium traction track what (spring tension) steps should one change? What are expected results?

stiffen springs all around? Soften springs all around? Or change springs one side only?

this is assuming we can only use same tires and same prep for the tires... and using same body...
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Old 07-02-2019, 11:32 AM
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Kind of two sides to low grip regarding springs... if the track is clear of dust and debris going stiffer springs all the way around would help generate traction putting more pressure to the tires. If the track is wet or has terrible surface you have to combat then going with the softest springs would then probably be ideal just to get the car around the track. Typically going softer is when the traction comes way up but I would say start stiffer.

Here is a small list to prepare for low grip...

-Softer shock oil
-Stiffer springs
-Thinner rear diff fluid
-More rear toe
-Tire warmers if you are allowed
-More front droop (play with rear after adjusting front)
-Higher roll center (generate more mech traction)
-Thinner rear sway bar
-Moving the shock position further out on tower

I would never use different springs from side to side... If everyone is on the same tire then that's perfect.
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Old 07-02-2019, 11:59 AM
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Great reply!

If we are starting the day with a dusty track, is it safe to say stiffen the suspension till enough cars and laps have cleared the dust of the track?
And When track is sugared then soften the suspension for less responce and less edgy feeling...
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Old 07-02-2019, 12:44 PM
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agreed on that list DaSilva wrote.

-looser rear diff' always helps me a lot too. i'll go down to 1k in the rear if traction isn't great.
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Old 07-02-2019, 01:33 PM
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I always go to softer springs for low traction tracks.
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Old 07-03-2019, 05:55 AM
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Softer springs theoretically generate more mechanical grip. The reason for this is that stiffer springs cause more weight transfer on to the outside wheels when turning, which increases their lateral grip, but less than the amount of lateral grip that the inside wheels have lost due having weight transferred away from them. This is because the relationship between the weight on a tyre and the amount of lateral grip it produces is non-linear. If you put 1.5x the weight onto a tyre it does not generate 1.5x the lateral grip. The exact reason why heavy cars cannot handle as well as lighter cars even if you put appropriately stiffer springs in them.

Note that if you're swerving all over the road that's a dynamic load and soft springs may react too slowly to generate maximum traction all the time. Google 'suspension frequency'. If the car is wollowing around like a cadillac and is difficult to control, stiffer springs will help you. A smooth driver with soft springs will still be faster than an erratic driver with hard springs however. Shock/damper stiffness also comes in to play during dynamic conditions. The only other time you'd definitely want stiffer springs is if you had too much grip when turning - i.e. the car traction rolled, and no other change was able to prevent it traction rolling.

As a final note, a lot of people's intuition seems to be that body roll is the cause weight transfer. This is not the case. Body roll is simply the result of the suspension reacting to weight transfer. Even if you replaced the suspension with solid mounts, weight transfer would still occur while the car is turning a corner. Softer springs will change their length more than stiff ones when subject to the same change in weight, therefore soft springs will cause the car to roll more. Body roll needn't be a bad thing unless the suspension cannot maintain an appropriate alignment of the wheels/tyres to the road due to excessive body roll. If the chassis is rolling a lot, the amount that the wheels are cambered relative to the ground might change significantly. Therefore, using springs that are too soft may result in a loss of traction due to the wheel leaning over and therefore tyre contact patch becoming smaller during hard cornering. Ultimately weight transfer is largely unavoidable and hence why suspension geometries tend to favour maintaining good geometry on the outside wheels when the body rolls in a turn, at the expense of sub-optimal geometry of the inner wheels, due to the higher weight and therefore higher potential to generate lateral grip at the outer wheels.

Last edited by nbTMM; 07-03-2019 at 06:29 AM.
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Old 07-03-2019, 07:14 AM
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nbTMM, excellent post. However, note that softer springs just delays the weight transfer by a bit, the weight transfer still happens. Weight transfer is just a function of height of center of gravity and the track width of the car and it's the same amount no matter if you run stiff or soft springs.
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Old 07-03-2019, 07:22 AM
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Good info here!

what about when using tires that are not optimal for the track, like using harder tires in cooler than optimal temp for them. Should softer suspension help achieve mech grip or stiffer suspension to exert more pressure on the outside tire...??
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Old 07-03-2019, 08:48 AM
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Tires are 1/2 the battle when it comes to traction. You really want to run the right tires for the track.

I always run correct tires, yet guessing that even w a good setup the wrong tires will cause poor handling.
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Old 07-03-2019, 09:17 AM
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Originally Posted by eR1c View Post
Tires are 1/2 the battle when it comes to traction. You really want to run the right tires for the track.

I always run correct tires, yet guessing that even w a good setup the wrong tires will cause poor handling.
Thats true indeed! Id even say tires are 85% of the setup battle!

Ill rephrase, for practice and tire durability, i was thinking of using a harder tire for longer life save some bucks during unofficial practice races with friends, but want to use the tires as best as they can, so i wanted heads up what to expect, stiffer suspension for more pressure on outter tire, or softer suspension for taking a shot at more mechanical grip....
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Old 07-03-2019, 01:04 PM
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Originally Posted by b3master View Post
For a low traction, or dusty medium traction track what (spring tension) steps should one change? What are expected results?

stiffen springs all around? Soften springs all around? Or change springs one side only?

this is assuming we can only use same tires and same prep for the tires... and using same body...
try making the ESC smoother remove the punch/run a higher throttle frequency able to put the power down with less wheels spin is always a plus
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Old 07-03-2019, 07:11 PM
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I would suggest practicing with the tires you're going to race with. There's much more value in maximizing your track time on your race set-up and working to make gains there. You'll literally be causing yourself way too much work and anguish chasing multiple set-ups for multiple tire compounds...all in the name of saving a few bucks.
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Old 07-09-2019, 09:21 AM
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...not sure about the rest of you but I have a tire system.
When opening a new pack of tires (my fav's for asphalt are Sorex's) I will race them for about 4-5 full race days. I'll constantly check them after each race day and if they start showing small "banding" that is the rubber has tiny breaks in it like its pulling apart (usually at the outside edges) then i'll put them in a bag and label as "older" tires. I race at a few tracks, so if the traction is really high i may pull them back out and use for another race day, OR i'll just reserve them for "practice" sessions. Towards the end of the season I either give them away or throw them away, (there are a few guys I race w/ who don't have much $$ and don't invest in tires, they are always happy to take my older tires as they are still better than what they run w/). I'll open a new bag of tires once all my tires are in the "older" bags and/or if I am at a track where the traction is really low (new tires seem to help in this situation).

Then there is cleaning and saucing which I won't go into now.

I always use the same tire brand ..I've settled on Sorex's w/ Schumacher wheels ..its just my fav and seems to give me the best results (but each has their fav's I am sure).

At the start of each season I usually purchase:
1 set of 28* tire/wheels
1 set of 32* tire/wheels
2 sets of 36* tire/wheels
1 set of 40* tire/wheels

The 36's will get used most once we get into June, July and August and I may even pick up a 3rd and 4th set depending on how much I am racing.

The 28 and 40's get used the least but they are good to keep in my bag, in fact the 28's and 40's may last a few seasons as I don't use them as much.
I also switch tires throughout the race day as the track is usually cooler for the 1st heat (so i'll go w/ 28's or 32's) then again at the end of the day if the track has cooled again i'll go back down to 32's or something. So often a tire set may only get used 1x during a day ...in this way I am kind of using all my tires and I get a lot of race days out of them. I usually spend about $200-$250 on tires for the entire season. When I first got into this hobby I'd buy 1 set of tires and use them the entire season, problem is after about 3 or 4 race days they start breaking apart so by the end of the season your running w/ crappy tires. I'd also only use one temp' tire for all conditions, so the 1 set was kind of a waste of $$ as I didn't even use them properly. I've learned that tires are a really important part of car tuning.
I also store my tires in zip lock backs, after the race day, -clean then store them.
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Last edited by eR1c; 07-09-2019 at 09:33 AM.
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