Question. LSD/Tire Grades.

[IvanOffalich]

I used a posted tune for a car that was tuned for Racing Soft tires. The race that I was using it for was had a Racing Hard restriction. Due to this, the car felt "funny". It would not turn correctly.

I tried the same car with the RS tires in Practice Mode and it handles very well, but with the RH tires, it does not. This was all done offline and not online, just for clarity sake.

I remember coming across a tune that I used for one of the cars in my garage, but it has been awhile ago. On this particular tune, the instructions told to raise or lower the Acceleration Sensitivity in the LSD according to the tire grade.

In other words it said something along the lines of:
8/18/5 for Soft
8/16/5 for Medium
8/12/5 for Hard

I'm guessing at the numbers and just trying to give an example. I remember the middle number being changed by only a couple or a few, but the other numbers remained the same. I also could have the Hards and Softs backwards.

The question that I have is will this work for all cars and tunes? If I want to adapt a car to a different tire grade, will simply changing the Accel make it handle properly, or is it much more complicated than that?

 

[CyKosis1973]

The question that I have is will this work for all cars and tunes? If I want to adapt a car to a different tire grade, will simply changing the Accel make it handle properly, or is it much more complicated than that?

Yes and no. As per your example, the softer (gripier) the compound the more ACC you can add.

It might not be as simple as upping the ACC with better tyres though. I suspect if you are staying within one band of tyres, you won't need to make any other changes. But if a car was built on Sports tyres and you want to run it on Race tyres (or visa versa), you'll likely need to make changes to the suspension too.

You should find that the gripier the tyres, the harder you can make the suspension 👍

{Cy}

PS - I'm prepared to stand corrected, if I'm talking rollocks

 

[esoxhntr]

I agree with Cykosis.. only thing I will add is that you may find you need to increase the decel setting as the tires get harder on some cars if you notice the rear get squirrely on corner entry/braking

so accel - decrease, decel - increase when you go from softs to hard.

 

[IvanOffalich]

I'm going to summarize, since it will help me to make it sticky in my head:

If going from Soft to Medium or Hard (lowering the tire grade):

-Lower the LSD Accel until the car feels right.
-If car feels loose entering or exiting, increase the LSD Decel until it feels right.
-If lowering grade significantly, loosening the suspension will help.

Going to a higher grade tire:

-Raise the LSD Accel until the car feels right.
-If car feels stiff while entering or exiting, lower the LSD Decel until the car feels right.
-If raising grade significantly, tightening the suspension will help.

Thank you both. The car that I was using did feel better with the lower Accel setting. I think I dropped it by 4 going from RS to RH and it felt right. This will probably come in handy for me fairly often. It also helps me learn a little about how all of this works.

 

[esoxhntr]

I'm going to summarize, since it will help me to make it sticky in my head:

If going from Soft to Medium or Hard (lowering the tire grade):

-Lower the LSD Accel until the car feels right.
-If car feels loose entering, increase the LSD Decel until it feels right.
-If lowering grade significantly, loosening the suspension will help.

Going to a higher grade tire:

-Raise the LSD Accel until the car feels right.
-If car feels stiff while entering, lower the LSD Decel until the car feels right.
-If raising grade significantly, tightening the suspension will help.

Thank you both. The car that I was using did feel better with the lower Accel setting. I think I dropped it by 4 going from RS to RH and it felt right. This will probably come in handy for me fairly often. It also helps me learn a little about how all of this works.

fixed it for you, the decel setting only applies when you are decelarating.. ie. entering a corner. doesn't do anything when you are exiting (accel)

 

[Adrenaline]

As a general rule of thumb Ivan, in fact your OP might even be referring to me, I drop the accel 2-3 per tire grade. So, I'm going to say, that yes, in the most general of terms, you are correct.

Having said that, whether the Tune you're looking at, came equipped with a proper LSD build to begin with is a whole other story.

The following is very crude, but simple and easy to follow. Not designed as an end all.

I'd just start at a 9/15/5 on all cars.
Inside tire spin? Raise Accel
Outside tire spin? Lower Accel
Spin On entry? Raise DeAccel
Tight on Entry? Lower DeAccel (This is rare, and why I always start with 5)
Too stiff all around? Lower Initial
Too free all around? Raise Initial

 

[Johnnypenso]

As a general rule of thumb Ivan, in fact your OP might even be referring to me, I drop the accel 2-3 per tire grade. So, I'm going to say, that yes, in the most general of terms, you are correct.

Having said that, whether the Tune you're looking at, came equipped with a proper LSD build to begin with is a whole other story.

The following is very crude, but simple and easy to follow. Not designed as an end all.

I'd just start at a 9/15/5 on all cars.
Inside tire spin? Raise Accel
Outside tire spin? Lower Accel
Spin On entry? Raise DeAccel
Tight on Entry? Lower DeAccel (This is rare, and why I always start with 5)
Too stiff all around? Lower Initial
Too free all around? Raise Initial

This is pretty much what I do as well except I usually start at 5/15/5. I usually don't get to fine tuning the LSD until near the end of the tuning process as there's no point in fine tuning it until you have the car close to handling the way you want it to. For example, if the car is too loose on entry I'll make suspension adjustments to try and fix that before going to the LSD. If I can fix it with the suspension, I just leave the LSD Decel where I started.

Some guys might tune it first or in the middle, you have to find what works best for you, but Adrenalines take on it is spot on.👍👍

To answer your OP though, adjusting the LSD may not be enough of an alteration to make this car or any car. handle the way you want in going from RS to RH tires or any other tire downgrade. RS tires mask a lot of tuning deficiencies simply because the grip level so overpowers the car and smaller adjustments don't have as big of an effect. Often you will need to make suspension, ballast adjustments, etc. In this particular case, you might want to post the whole tune and then your driving impressions and ask for feedback.