Uneven steering assistance?

[koevasi]

Hi guys

Wasn't sure where to put this and I figured this page would get more attention than the maintenance page.

I am starting to experience irregular loss in power steering assistance mid corner. It happens when the steering is turned about half a turn in tighter second and third gear corners and when I go through quick transitions and I have to 'hurry' the wheel, just when I would appreciate the linearity of the steering. It has gotten gradually worse and it now happens almost all the time at speeds of 30mph or more.

It all makes driving the car very jerky since I cannot correct the line through the corner and I actually have to steer away from the turn to get assistance to come back in.

I am not sure if it is faulty sensors that cause this or I just need to reset the software. A local Toyota technician did a scan and tells me that there is nothing technically wrong with the car.

I hope I explained clearly enough!

Thanks in advance.

Steve

[Anthony]

Interested to see if someone knows about this.

[koevasi]

I know a fellow 86 owner who tracks his car often and he get this a lot as well.

[wparsons]

Does it happen right away, or does it take some time for it to start happening? It might be the motor overheating, which the manual states can happen in certain situations.

I'd be shocked if it was happening during lapping, but it's a possibility if the track has lots of low speed tight corners and you're running for extended periods.

[koevasi]

Originally Posted by wparsons

Does it happen right away, or does it take some time for it to start happening? It might be the motor overheating, which the manual states can happen in certain situations.

I'd be shocked if it was happening during lapping, but it's a possibility if the track has lots of low speed tight corners and you're running for extended periods.

I normally make sure the car is up to working temp before pushing it and might drive for 10 to 15 minute sessions at a time. Nothing that should overheat the motor to the extent that it affects steering, or so I would think? I don't drive on circuits either.

My friend who tracks it all the time DOES experience this a lot more severely than I do. He has the koyo radiator and an earls oil cooler and I am not sure you can 'overheat the motor' with these mods. He also drives on our F1 circuit as well so it's certainly not a heat soak issue?

[Norkoastal]

Originally Posted by koevasi

I normally make sure the car is up to working temp before pushing it and might drive for 10 to 15 sessions at a time. Nothing that should overheat the motor to the extent that it affects steering, or so I would think? I don't drive on circuits either.

My friend who tracks it all the time DOES experience this a lot more severely than I do. He has the koyo radiator and an earls oil cooler and I am not sure you can 'overheat the motor' with these mods. He also drives on our F1 circuit as well so it's certainly not a heat soak issue?

I think the posters above are referring to the electric power steering assist motor which may run hot when used in the manner you described. It would be nice to see this part of the car modded to allow custom assist pressure and/or larger motors for track duties.

[CSG Mike]

Originally Posted by koevasi

Hi guys

Wasn't sure where to put this and I figured this page would get more attention than the maintenance page.

I am starting to experience irregular loss in power steering assistance mid corner. It happens when the steering is turned about half a turn in tighter second and third gear corners and when I go through quick transitions and I have to 'hurry' the wheel, just when I would appreciate the linearity of the steering. It has gotten gradually worse and it now happens almost all the time at speeds of 30mph or more.

It all makes driving the car very jerky since I cannot correct the line through the corner and I actually have to steer away from the turn to get assistance to come back in.

I am not sure if it is faulty sensors that cause this or I just need to reset the software. A local Toyota technician did a scan and tells me that there is nothing technically wrong with the car.

I hope I explained clearly enough!

Thanks in advance.

Steve

Steve, what suspension are you on, and what's your alignment? How the car is set up will HEAVILY influence this.

[koevasi]

Originally Posted by CSG Mike

Steve, what suspension are you on, and what's your alignment? How the car is set up will HEAVILY influence this.

I am 'still' on tein flex now with 2.1 and 1.5 dg camber fr and rr respectively. zero toe both ends and no caster.
my friend who has the same problem (worse in fact) is on showa cup kit that is really mild in terms of spring rates and damping and hes also got similar alignment settings.

[CSG Mike]

Originally Posted by koevasi

I am 'still' on tein flex now with 2.1 and 1.5 dg camber fr and rr respectively. zero toe both ends and no caster.
my friend who has the same problem (worse in fact) is on showa cup kit that is really mild in terms of spring rates and damping and hes also got similar alignment settings.

It sounds like you may be cranking the steering too quickly. Slow down your input a little bit, and it shouldn't fight you as much, if at all.

Are you sure no change was made to caster? How is the camber plate aligned?

[koevasi]

Originally Posted by Norkoastal

I think the posters above are referring to the electric power steering assist motor which may run hot when used in the manner you described. It would be nice to see this part of the car modded to allow custom assist pressure and/or larger motors for track duties.

thats the thing. i dont think i drive the car THAT hard. 15 to 20 minutes of spirited driving at a time at best. i obviously wish i could drive harder but i am definitely not driving it as hard as CSG guys judging from their vids lol.
theres bound to be a lot more people experiencing this if it was to do with overheating of anything due to heavy track use??

[koevasi]

Originally Posted by CSG Mike

It sounds like you may be cranking the steering too quickly. Slow down your input a little bit, and it shouldn't fight you as much, if at all.

Are you sure no change was made to caster? How is the camber plate aligned?

Is there a way to know if the camber plate isnt aligned properly?? We dont drift and we arent tugging the wheel so hard to make a difference... I think!

[CSG Mike]

Originally Posted by koevasi

thats the thing. i dont think i drive the car THAT hard. 15 to 20 minutes of spirited driving at a time at best. i obviously wish i could drive harder but i am definitely not driving it as hard as CSG guys judging from their vids lol.
theres bound to be a lot more people experiencing this if it was to do with overheating of anything due to heavy track use??

There's a strong correlation between understeer and the steering getting very heavy. You can muscle past the steering "lockup", and it'll ease back up, but I don't recommend it. If it's feeling like it's not wanting you to turn more, then you don't have much front grip left.

Tein Flex gives the car an understeer bias, as do most off-the-shelf coilovers.

Is your camber plate horizontal (when you look at the car from the front) or angled?

[koevasi]

Originally Posted by CSG Mike

There's a strong correlation between understeer and the steering getting very heavy. You can muscle past the steering "lockup", and it'll ease back up, but I don't recommend it. If it's feeling like it's not wanting you to turn more, then you don't have much front grip left.

Tein Flex gives the car an understeer bias, as do most off-the-shelf coilovers.

Is your camber plate horizontal (when you look at the car from the front) or angled?

Hmm i dont think its understeer. The car isnt traveling all that fast to be honest. We are talking about the top end of second and third gears.. And in an frs thats like first and second in most cars! Sort of! In any event i can make the car oversteer at this point just by forcing the steering past this funny stage - in which case i would be giving it 30% more lock than necessary just to get past the lockup.

What is angled vs horizontal when it comes to camber plates? Maybe i need to take a picture...

[CSG Mike]

Originally Posted by koevasi

Hmm i dont think its understeer. The car isnt traveling all that fast to be honest. We are talking about the top end of second and third gears.. And in an frs thats like first and second in most cars! Sort of! In any event i can make the car oversteer at this point just by forcing the steering past this funny stage - in which case i would be giving it 30% more lock than necessary just to get past the lockup.

What is angled vs horizontal when it comes to camber plates? Maybe i need to take a picture...

Are you driving TCS/VSC off or with pedal dance?