Seeking advice to minimize over-steer

[Pnbnationsbest]

@MisterMac you know who drives slow on 696, HEMI DRIVERS! They get angry when their boats are made to look like anchors.

 

[MisterMac]

@Pnbnationsbest, I'll be taking my chances next month when we come back for a graduation party. We'll be driving a rental though. I won't be the fastest or the slowest, but I'll be cruising above the median I'm sure on both 696 and 94...If not, the wave of amateur speedsters can carry you away!

 

[YOWStinger]

Drive slower.

Seriously, you shouldn't be running into oversteer situations if you're just driving normally, unless normally for you is driving 8/10ths in the rain. My tires don't break free on the way to work.

 

[MisterMac]

Seriously, you shouldn't be running into oversteer situations if you're just driving normally, unless normally for you is driving 8/10ths in the rain. My tires don't break free on the way to work.

Yes, seriously I shouldn't be. For 17,000 miles I hadn't. Until I swapped out my 19x8 and 19x8.5 stock wheels for 19x9.5 (+25) wheels all around coupled with 255/35 FALKEN FK510 Summer tires all-around.

The extra width up front added 12% more tire-to-road than stock 19/8 with 225's. Also, my track width/stance, both front and rear, is 2.75 inches wider than stock. This further changed the steering dynamic to significantly more sensitive.

Even still, I didn't realize Discount Tire had inflated my fronts to 38 psi and the rears to 36 psi. This is exactly opposite of the door placard.

Lastly, my new front tires are 98Y, not 96Y like from the factory. The additional load rating equates to needing less pressure to plant the proper amount of tire on the pavement. So, last night, I used chalk (lengthy process or trial and error) to identify the ideal psi.

Final psi in front is 33 and the rear is 38. Perfect now! Ideal steering response and the ideal width of rubber on pavement.

 

[MerlintheMad]

So, last night, I used chalk (lengthy process or trial and error) to identify the ideal psi.

Could you please explain what this means?

 

[itguy61]

So you were able to adjust oversteer/understeer balance with tire pressure adjustments?

 

[Pnbnationsbest]

You're adjusting the proportion of cross-sectional contact of the tire by adjusting pressures, so yes.

 

[MisterMac]

So you were able to adjust oversteer/understeer balance with tire pressure adjustments?

Bingo!

 

[MerlintheMad]

So reducing psi in front increases understeer?

 

[Pnbnationsbest]

So reducing psi in front increases oversteer?

Inverse guy. The tie was overinflated so there was less tread on the ground.

 

[MerlintheMad]

Inverse guy. The tie was overinflated so there was less tread on the ground.

SMH. I meant to write understeer. I saw understeer in what I wrote and "now" it says oversteer. This thread has seriously messed with me. (I'm changing it now, now that it's too late. Heh.)

But you answered my question, which was the point of my asking. Thanks.

 

[WildBill]

Could you please explain what this means?

Video on tire chalking

Inverse guy. The tie was overinflated so there was less tread on the ground.

I'm sorry but I'm with Merlin on this. An over inflated tire that has less contact patch in my mind would allow the front end to push more, which is understeer. I have no doubt that changing pressures has solved Mac's problems, but it may be a bit more complicated where camber, caster, contact patch, and sidewall flex all have some part to play.

Edit: guess it is playing with my head as well Merlin

 

[MerlintheMad]

Edit: guess it is playing with my head as well Merlin

I'm so sorry! My edit isn't helping. But it makes me feel better.

 

[RLittle]

Increasing rear tire pressure increases oversteer.

Decreasing front pressure does the same.

Slight but noticeable

 

[SteveCo]

I'm so sorry! My edit isn't helping. But it makes me feel better.

You're Making it Worse!!!