ISF - Slight pulling to the left when driving over 100 mph

[Mantas88]

Hi there, so I have this problem when my ISF starts to pull to the left when I drive over 100 mph (private road, don't worry) and it gets progressively worse if driven faster. Good road surface, new tyres, no wind. 

I've took my car to Lexus and they checked my brake system (checked it for uneven wear, warping and etc), did the alignment and took it for a test drive. I've asked them about caster/camber, they said it's all green.

The issue still remains. 

Any ideas what could I check that could influence this behaviour? 

[LenT]

1 hour ago, Mantas88 said:

Any ideas what could I check that could influence this behaviour? 

Is there a camber on the road?

You say you have new tyres, but has anyone checked that the pressures are correct and identical?  Is the steering wheel perfectly aligned on the steering column?  Are the nearside discs generating more friction?

Are you left handed and/or have a dominant left eye?  Is the seat or the pedals slightly offset?

 

[Cactus]

The alloy itself? 

[Mantas88]

12 hours ago, LenT said:

Is there a camber on the road?

No, the road is perfect and flat, better than the Autobahn. I've took my wife's car an hour later day and I drove much faster with no issues. 
 

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You say you have new tyres, but has anyone checked that the pressures are correct and identical?  

Yes, first thing I did was check the pressure. It did the same with old ones as well... One of the main reasons I've changed tyres was that pull... 
 

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Is the steering wheel perfectly aligned on the steering column?  Are the nearside discs generating more friction?

I wouldn't be able to tell if wheel is perfectly aligned, but according to Lexus - it is...

Not sure about discs, braking is not affected at all. Both sides seem to be the same.

 

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Are you left handed and/or have a dominant left eye?  Is the seat or the pedals slightly offset?

My eyesight is left dominant, but my wife's is 20/20, and it still pulls when she was driving. She notices that even more than me. Seat position should be ok. 

I am just wonder what I am missing here. I've seen some Americans and Aussies having same issue and there was lad here with same problem, but they never came back how they sorted it. 

There was some talk about the lose subframe, but surely, Lexus should have picked it before an alignment? 

 

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The alloy itself? 

No mate, I have 2 sets of alloys at the moment, does the same on both. Exactly the same feel at exact same speed. 

 

[NemesisUK]

Were the new tyres a mirror pair? That is were the colour bands opposite on each tyre. Tyre run-out can cause drift if not cancelled out by selecting the pairs. Not too much of an issue at normal road speeds but still noticeable.

[LenT]

46 minutes ago, NemesisUK said:

Were the new tyres a mirror pair? That is were the colour bands opposite on each tyre. Tyre run-out can cause drift if not cancelled out by selecting the pairs. Not too much of an issue at normal road speeds but still noticeable.

Are you suggesting that these are asymmetric tyres, for example, that have been incorrectly fitted?

Can’t imagine any professional operation making that sort of error - but I suppose it could produce that ‘pulling’ effect!

 

[NemesisUK]

6 minutes ago, LenT said:

Are you suggesting that these are asymmetric tyres, for example, that have been incorrectly fitted?

Can’t imagine any professional operation making that sort of error - but I suppose it could produce that ‘pulling’ effect!

 

No, not at all...

All new tyre have radial colour bands signifying the degree of run-out and circularity. If an axle pair are fitted with the same direction of run-out the car will try to drift in that direction. A good fitter (with available stock) should choose a pair with opposing run-out to cancel the effect.

On a high performance car that will be driven at high speeds I would request that the tyre shop source appropriate tyres. Obviously this won't happen at the likes of Quickfit etc but those shops that often deal with performance cars should know.

[LenT]

1 hour ago, Mantas88 said:

There was some talk about the lose subframe, but surely, Lexus should have picked it before alignment.

 

Loose talk about a loose subframe!  That’s a bit worrying!

What happens if you accelerate hard from a slow speed?  Wear in the suspension or axle mounts might produce an excessive degree of ‘torque steer’.

I once had a big Alfa which - unbeknownst to myself - had an acute case of rust around the suspension mounts, allowing the rear axle to flex under acceleration and it produced just this effect.

You mention alignment.  Has the car been involved in a shunt that might have slightly distorted the axle locations?

Perhaps it might be worth an independent check?

[Barry14UK]

I am surprised that the pull does not occur until you reach such high speeds but if you have tried alternative Tyres/wheels on all 4 wheels, it seems likely that the problem is somewhere with rest of the car.  A very full check should be made to ensure that toe, cast and camber are all correct.  I don't know your model but some cars have some adjustments affecting rear wheels and wrong settings can affect pulling to one side. When on flat is the gap between the top of the tyre and the underside of the wing the same on both front pair and the back pair? As speed increases the car is having to work go harder through an air dam, therefore greater pressure exerted on suspension so any slight slack on nearside would mean that being pushed back more increasingly affecting steering.  Assume front wheels in particular freely rotate equally, in other words one side not causing slightly more drag. Possible misalignment due to accident damage also a possibility as previous post suggested might be the cause. 

 

[Mantas88]

5 hours ago, NemesisUK said:

Were the new tyres a mirror pair? That is were the colour bands opposite on each tyre. Tyre run-out can cause drift if not cancelled out by selecting the pairs. Not too much of an issue at normal road speeds but still noticeable.

Yes, I have another set of alloys and the car does basically the same.

[Twellsie]

have you ever had the lower control arm bushings replaced?

[Mantas88]

5 hours ago, Twellsie said:

have you ever had the lower control arm bushings replaced?

Not yet. I bought myself a set of Fig 90 LCA's after hearing that OEM bushings can cause similar issues during their life-cycle. (Only noticeable at higher speeds)

Not sure how true is that, but I've used it as excuse to improve the handling and reduce inner tyre war.

Today I've visually checked ball joints and a subframe and everything looks and sounds ok. Did another 5 OCD runs with two sets of alloys, swapping wheels and adjusting the pressure. Still. The. Same. 

I've booked in Hunter-Seeker alignment with a Kwik-fit (there are no other companies that do proper geometry checks here) as I lost a previous print-out. 

Now I am afraid I will have to work my way through all suspension elements until I will find the culprit. I've seen similar threads on US forums... Most of the times it was LCA on earlier models like mine...

[Malc]

sorry to read of your misfortunes arising here ........  sincerely hope you're going to get satisfied soon .....

 ............. lucky are us mere mortals with ordinary cars that can only dream to motor at 100mph these days on normal available roads 

I remember driving around your beautiful isle a few years back and wondrous new roads in the Republic benefitting from some huge EU funding schemes ........... many of which could possibly be good for regular 100mph jaunts too ...  is your Armagh speed limit still 70mph ?

Malc

[4969_LXS]

This was the state of my LCA bushes on my 2008 ISF with 70kish miles. Whilst they didn't move under MOT inspections, they did flex under load, allowing the control arm to move, I was also getting inner tyre wear, and used to squirm under spirited braking and follow ruts/grooves in the road. I swapped them for GSF bushes. It's made a world of a difference.

[Mantas88]

4 hours ago, Malc said:

sorry to read of your misfortunes arising here ........  sincerely hope you're going to get satisfied soon .....

 ............. lucky are us mere mortals with ordinary cars that can only dream to motor at 100mph these days on normal available roads 

I remember driving around your beautiful isle a few years back and wondrous new roads in the Republic benefitting from some huge EU funding schemes ........... many of which could possibly be good for regular 100mph jaunts too ...  is your Armagh speed limit still 70mph ?

Malc

Thank you, I wouldn't call it misfortune, but it fuels my OCD and it does ruin my experience with the car.  This and the brake fade, but at least I know what to do with brakes 😄 

Glad you liked it! EU funding schemes don't reflect much on the road quality, I would even argue that the asphalt they lay in South is worse during cold and wet conditions. It all depends on the season as well. They do have nicer tractors on the road. But nicer or not - they still make same big prostate splitting potholes like here in the Norn Iron. Even the the road layout is the same and you can fly off the road even without reaching national speed limit. That's the price you have to pay to have local farming produce on your table I guess.

In Armagh we are confined to 50 mph in the city and for the most part I've not noticed the issue with the pulling for more than a year. I didn't even notice it during 1/8 runs. On the motorway I thought it was just a wind or road imperfections and I don't have luxury to drive like McGregor and I didn't care much. 

Now as we have some good weather and restrictions are gone and I have ability to fully "send" it like Yukihiko Yaguchi intended. Both in Bishopscourt track and Enniskillen airport, not to mention industrial sites I have access due to my work. But venues where you can enjoy your car to the fullest are still limited and I bet in Kent alone has more race tracks. Bike is a king here. I can't complain much as I never done it in the past and I was surprised how cheap, unrestrictive and accessible it is. I keep hearing that drift scene is absolutely disgrace here, but I can't complain with my stock diff 😄 Might change my mind after OS Giken diff.

[Mantas88]

4 hours ago, 4969_LXS said:

This was the state of my LCA bushes on my 2008 ISF with 70kish miles. Whilst they didn't move under MOT inspections, they did flex under load, allowing the control arm to move, I was also getting inner tyre wear, and used to squirm under spirited braking and follow ruts/grooves in the road. I swapped them for GSF bushes. It's made a world of a difference.

Thank you mate, I think you hit the nail on me head.

By the way, how does GSF bushes feel? I bet it gives much softer ride, what about the roll?

[4969_LXS]

@Mantas88 From what I've read, the GSF bushes use a different compound/material than the ISF bushes and are slightly stiffer. The steering has become significantly more direct and I get no squirming, rut following and at the moment, much reduced inner tyre wear. It was definitely a worthy upgrade from my experience, handles like it should do 😈.

The reason I went for GSF bushes was to stay OEM, Lexus invest a lot of money in the design and the Japanese philosophy of constant improvement sits well with me. I didn't want Poly bushes and I didn't see the benefit in other companies offerings. If you want GSF bushes, get the 0mm offset ones. They come with a +/-20mm range. Lexus Parts Direct advised this and were great with the purchase.

Im surprised you've gotten brake fade. With the car being developed at Fuji and that hard brakiny zone after the straight, the brakes are pretty stoat. I've not come across any fade. I'm interested that's all 👀👀

[Steve]

only time i have pulled over to the left at 100 is when the police have pulled me over lol

[BTCC_ Racer]

21 hours ago, Mantas88 said:

Thank you mate, I think you hit the nail on me head.

By the way, how does GSF bushes feel? I bet it gives much softer ride, what about the roll?

Do you have the part numbers for these?

[4969_LXS]

Please see the part numbers in the attached image for the GSF bushes.

You want them With 0 offset.

It's easier to ring Lexus Parts Direct and they will help get the right ones.

They are plug and play. Any garage can fit them, they just slide on and off, takes 10 minutes. Just make sure they have the correct torque settings for all the bolts, 2 of which are for the subframe.

[Mantas88]

On 6/21/2022 at 11:40 PM, 4969_LXS said:

@Mantas88 From what I've read, the GSF bushes use a different compound/material than the ISF bushes and are slightly stiffer. The steering has become significantly more direct and I get no squirming, rut following and at the moment, much reduced inner tyre wear. It was definitely a worthy upgrade from my experience, handles like it should do 😈.

The reason I went for GSF bushes was to stay OEM, Lexus invest a lot of money in the design and the Japanese philosophy of constant improvement sits well with me. I didn't want Poly bushes and I didn't see the benefit in other companies offerings. If you want GSF bushes, get the 0mm offset ones. They come with a +/-20mm range. Lexus Parts Direct advised this and were great with the purchase.

Im surprised you've gotten brake fade. With the car being developed at Fuji and that hard brakiny zone after the straight, the brakes are pretty stoat. I've not come across any fade. I'm interested that's all 👀👀

That's something new I've learned. I feel stupid for buying poly Figs 90 without even considering OEM alternative. At least I will know what to get if I will hate the ride 🙂 Thank you so much for sharing this with us.

And about the brakes, well, I don't feel like I am getting sufficient bite and it really shows when warm. Or it could be just me as I don't believe that I've caused that much wear during few sends. To be honest, I decided to get new disks and pads and I will bed them in myself.  My pad choice is Ferodo DS2500 as I am familiar with then and I did loved how they performed on my BMW.

[BTCC_ Racer]

Thanks for this - just placed an order at the dealer.

Im gathering parts for a suspension refresh although was tempted with the poly type but the fact that this bush is firstly new, and better than the ISF it should be sufficient.

 

 

[Mantas88]

1 hour ago, BTCC_ Racer said:

Thanks for this - just placed an order at the dealer.

Im gathering parts for a suspension refresh although was tempted with the poly type but the fact that this bush is firstly new, and better than the ISF it should be sufficient.

 

 

Don't mind me asking, but what will you be upgrading suspension wise?

[BTCC_ Racer]

3 minutes ago, Mantas88 said:

Don't mind me asking, but what will you be upgrading suspension wise?

Im going for Bilstein B6 - o.e.m Shock replacement essentially i hear its 'slightly' more forgiving that the stock shocks, mines a 2008.

Also will be doing the rear diff bushes etc, once I decide what diff to get, although im hoping a o.e.m LSD assembly is sourced if not im thinking of a OS Giken LSD.

[Twellsie]

3 hours ago, BTCC_ Racer said:

Im going for Bilstein B6 - o.e.m Shock replacement essentially i hear its 'slightly' more forgiving that the stock shocks, mines a 2008.

Also will be doing the rear diff bushes etc, once I decide what diff to get, although im hoping a o.e.m LSD assembly is sourced if not im thinking of a OS Giken LSD.

I had the Bilsteins on mine before I swapped to the BC Racing coilovers, although they were on it when i got the car so not shure how they compare to standard, but seem alright