Hello guysI have a 2015 with TVD .
Here is the issue.
Whenever i hit a pothole , small or deep, any anomaly over ,even on single wheel, the rear of the car moves abruptly to side. Small movement but you can tell that the car destabilise,or at least it gives that impression.
This is both when running straight or on a bend.Even on low speeds.

It is not confident inspiring to say the least.The behaviour reminds of a old generation live axle car.


Do you think there is some kind of misalignment on rear suspension? Bad shocks? Maybe tvd overreacting?

Anyone with experience on this?
Looking for help or some direction to troubleshoot.

Cheers

 

Did you get your alignment checked? What type of tires are using and how much tread do they have left? these are the key things to check.

In short, as I have a TVD RCF as well, there is a very tail happy behavior in order to make the car go faster through the turn and to inhibit understeer (as it is a high performance car). The car would tend to rotate the rear even on smooth roads as you trying to carry more and more speed, but that is make the car go faster through turn.

However, since you mentioned, it happens when you hit a pothole or a rough patch mid-corner, the car tends to follow the grooves or follows where the road leads it. That is either issue with tires tramlining or your alignment being out of spec.

 

Thanks for the reply
Tires are Goodyear Eagle F1 asymmetric, pretty healthy status on these.
Fully understand what you are saying but this is more nervous and abrupt than the usual twitchy sports car behaviour. Hitting a pot even at 30mph on bend gives you a small sidekick on rear.
Alignment is first to check,but i am asking if to start looking elsewhere as well...

 

Alignment is the first thing to check. I would not be surprised that it is your tire since Goodyear does not rank as one of the best brand for high performance tires. Looks like these tires could potentially be tramlining. Maybe, it could be made better with alignment. Michelin definitely does not exhibit this behavior.

 

Check tires as mentioned.

See if the shocks are leaking fluid.

Is the entire rear suspension stock? Any changes like lowering springs?

 

Stock suspension.
Maybe switch to Michelin and check alignment.
Any model that gets much preference with the RCF? We don't get snow and we have high temps most of the year.

Thanks for the help

 

Hey man, go with Pilot Sport 4S. Find the 100Y rear and 96Y front if you like stiff sidewalls (very flat cornering attitude). Otherwise, the OEM-Spec 2020+ RCF PS4S (92Y front and 96Y rear) are another option without the stiff sidewalls. I have the Extra Load ones (96Y front and 100Y rear) and they are absolutely amazing. Way better than the OEM Pilot Super Sport the 2015 - 2019 RCFs came with.

Alignment and shocks are a good thing to check as well.

 

Has the car ever been in an accident?

 

Not that i know of, and from inspection shows clear of accidents.

Hope it is alignment issue.I got the car a few months ago and have no trust that the previous owner made frequent alignment checks..
On a side note,maybe wrong,but the nervousness on hitting potholes is worse when TVD is on slalom mode.which i like to use often.makes the car feel like it has half the size.

 

I am running HRE 20'' (255+285), so OEM spec tyres are not option.
You think PS4s with high y is the route to go then?

 

Yeah, OEM spec RCF's PS4S are only in 19 inches 255 front and 275 back. For 20 inches, you will need to go off the shelf, which is fine as you can go 96Y front and 100Y rear like me.

p.s. Aftermarket wheels also some times cause a change in handling characteristics including if you have any springs etc.

 

This happens from suspension work and you stated you didn’t work on anything suspension wise?

 

Lots of potholes in my area. Used to have really bad all season tires with no grip. This would never happen when I simply ran into a pot hole.

Do you “twitch” under acceleration or regardless if you go over a pot hole or not? How many miles in your car? Accident?

 

No accident (that i am aware of)
No suspension job.
The twitch is on steady speed (no acceleration) and some times when hitting pot holes on straight line

 

Are you on the gas when you run to a pit hole or off the gas?

If you are off the gas then it maybe a suspension issue. How many miles on the car?

If you’re on the gas could it be that the momentary lack of traction going in the pot hole made one wheel spin faster than the other and there is some issue with traction control or TVD trying to adjust?

My car with really crappy all seasons would not get so unsettled by going over aggressive undulations on the road or potholes…and mine is an LSD no TVD magic to sort things (one of my biggest regrets).

I am guessing you are not the original owner?