Finally Sorted The Suspension On My '08!

mrfunex · December 18, 2015

A few weeks after buying my 2008 ISF, after the honeymoon period, I began to realise how firm the standard suspension was. Actually, that's a total understatement - it was ridiculously firm to the point of pain; my wife hated it and I got weary of constantly weaving about on the road to find a smooth path through the potholes, bumps and other minuscule imperfections. Even small potholes sent huge bangs through the chassis, expansion joints made my teeth rattle and I had little confidence in the car around fast corners. The car is my daily driver, so a crashy, nervous drive becomes tiresome very quickly. This was one of the few complaints most journalists had with the car when it was released.

I tried lowering the tyre pressures a bit (quite high as standard), which made the ride softer, although gave the steering a heavier, "wading through treacle" feel - not a permanent solution.

I researched a few coilover options, specifically the KW V3s and the cheaper BC BR kit, but choosing my own spring rates for front and back presented a level of uncertainty I was uncomfortable with. I'm not an engineer/suspension guru and I'd hate to choose the wrong springs, change them, get it wrong, then have to buy more and have another go. I couldn't afford that kind of "wild stab in the dark" approach. As these cars are pretty rare, chances to have a ride in one with the suspension options I was interested in were almost nil. Even if I got the right combination by luck, I have no idea how to set bump, rebound, etc and wanted the ride height to remain standard.

I'd almost given up, when a great guy on here (PeterP18) put me in contact with a chap who'd fitted 2013 spec coilovers to his 2008 and found the ride much improved, but after 500ish miles, swapped again to an adjustable setup in order to lower the ride height. A few emails later, he seemed genuine and still had the old 2013 ones for sale, so I snapped them up!

My local main dealer fitted them and were extremely competitive on price too. The springs and shocks were a straight swap but unusually, the 2013 setup doesn't use rubber cups between the springs and the shocks. They're metal-on-metal.

So....

What a difference! The ride height is unchanged and bumps are now damped extremely effectively. Larger lumps are still evident (it'll always be a firm car), but the effect is much reduced without feeling detached from the road. The car seems more composed and flat around corners, and inside the cabin seems a bit quieter.

All in all, how the car should have been when it left the factory! I'm really happy and I'd recommend the change to anybody! If anyone's interested in the part numbers required, I can dig them out and pop them on here...

Stuno1 · December 18, 2015

That's great. The suspension on the earlier models is very firm. Getting in to my lotus evora is a pleasure! The isf was superb but as you say you really can feel every bump in the road. The lotus is pure magic.

Glad you got it sorted. Others will no doubt benefit from this post.

Arqum · December 18, 2015

hi mate. Glad its made a change on the feel. Please do put the part numbers up.

mrfunex · December 19, 2015

Stolen from srt4evah's post on Clublexus.com - the parts numbers people need...

Quote:

SPRING, FRONT COIL, LH (need 2)

part #4813153460

ABSORBER ASSY, SHOCK, FRONT LH MARK 48520-0W060

part #4852009Y90

ABSORBER ASSY, SHOCK, FRONT RH MARK 48510-0W080

part #485108Z072

SPRING, COIL, REAR LH (need 2)

part #4823153390

BUMPER, REAR SPRING, NO.1 LH (need 2)

part #4834130140

ABSORBER ASSY, SHOCK, REAR RH MARK 48530-0W070 (need 2)

part #4853009X70

Peter P18 · December 21, 2015

Glad to hear you got them Stuart. :)

Good deal for you, good deal for the guy that wanted to sell them as well. ;)

Everyone ended up happy! Lol.

Hope you enjoy many happy miles with the new setup mate.

Cheers.

Peter

Toothy · December 21, 2015

Just from the passenger seat it was obvious how much better the revised dampers are compared with the originals. Far more compliant and less crashy, especially over the rear. I think Japan forgets how bad the rest of the worlds roads are!

GibletPH · January 1, 2016

Does anyone have a ballpark figure for the cost of the parts above if purchased new from a main dealer? How does it compare to buying a set of aftermarket coilovers?

mrfunex · January 2, 2016

Unfortunately I have no idea how much these would cost from the dealer. I would imagine they'd be prohibitively expensive compared to aftermarket, most parts seem to be very pricy on these cars.

Common aftermarket options seem to be

BC BR coilovers - roughly £800ish

KW v3 coilovers - roughly £1400ish

(...at least they were when i checked...)

I've always found the main dealer to be very helpful - pop in and ask, and enjoy a free cuppa! Sorry I can't be more helpful.

GibletPH · January 3, 2016

Thanks for the info. I had a short test drive in an 08 ISF today and didn't find the ride too harsh. Saying that my current car has a set of coilovers fitted and set to the hardest dampening setting so maybe I'm just used to it?

Stuno1 · January 3, 2016

Thanks for the info. I had a short test drive in an 08 ISF today and didn't find the ride too harsh. Saying that my current car has a set of coilovers fitted and set to the hardest dampening setting so maybe I'm just used to it?

Fancy seeing you here

Suspension isn't that bad and is what anyone buying s performance saloon should realistically expect. What it doesn't have is adjustable suspension which a lot of people are now starting to expect so you can make it a soft barge when needed.

GibletPH · January 3, 2016

Yup, I get around :D

Thanks for the input, I'm set on buying one now!

Stuno1 · January 3, 2016

Happy days. Keep us updated. You won't regret it. There are so few about and this somehow makes the ownership experience that much more pleasurable.

Peter P18 · January 7, 2016

Hey Chaps,

Spotted a sales post on the US forum for some later spec suspension if anyone else is interested? The guy is in Germany I believe as opposed to the States, so shipping would be easier at least! ;)

If anyone is interested here's the thread: http://www.clublexus.com/forums/2gen-is250-is350-is-f-classifieds-06-13/808191-wtb-oem-isf-suspension.html

Look at the third post. Username is kauaian.

He wants $650 shipped, but that would be to the States. I'm sure he would take less for UK shipping?

The units are from a 2012 model with approx 50K miles on them.

I'd try for $550 shipped to the UK. That's around £377. :)

Magill · March 2, 2019

On 12/18/2015 at 11:46 AM, mrfunex said:

A few weeks after buying my 2008 ISF, after the honeymoon period, I began to realise how firm the standard suspension was. Actually, that's a total understatement - it was ridiculously firm to the point of pain; my wife hated it and I got weary of constantly weaving about on the road to find a smooth path through the potholes, bumps and other minuscule imperfections. Even small potholes sent huge bangs through the chassis, expansion joints made my teeth rattle and I had little confidence in the car around fast corners. The car is my daily driver, so a crashy, nervous drive becomes tiresome very quickly. This was one of the few complaints most journalists had with the car when it was released.

I tried lowering the tyre pressures a bit (quite high as standard), which made the ride softer, although gave the steering a heavier, "wading through treacle" feel - not a permanent solution.

I researched a few coilover options, specifically the KW V3s and the cheaper BC BR kit, but choosing my own spring rates for front and back presented a level of uncertainty I was uncomfortable with. I'm not an engineer/suspension guru and I'd hate to choose the wrong springs, change them, get it wrong, then have to buy more and have another go. I couldn't afford that kind of "wild stab in the dark" approach. As these cars are pretty rare, chances to have a ride in one with the suspension options I was interested in were almost nil. Even if I got the right combination by luck, I have no idea how to set bump, rebound, etc and wanted the ride height to remain standard.

I'd almost given up, when a great guy on here (PeterP18) put me in contact with a chap who'd fitted 2013 spec coilovers to his 2008 and found the ride much improved, but after 500ish miles, swapped again to an adjustable setup in order to lower the ride height. A few emails later, he seemed genuine and still had the old 2013 ones for sale, so I snapped them up!

My local main dealer fitted them and were extremely competitive on price too. The springs and shocks were a straight swap but unusually, the 2013 setup doesn't use rubber cups between the springs and the shocks. They're metal-on-metal.

So....

What a difference! The ride height is unchanged and bumps are now damped extremely effectively. Larger lumps are still evident (it'll always be a firm car), but the effect is much reduced without feeling detached from the road. The car seems more composed and flat around corners, and inside the cabin seems a bit quieter.

All in all, how the car should have been when it left the factory! I'm really happy and I'd recommend the change to anybody! If anyone's interested in the part numbers required, I can dig them out and pop them on here...

Magill · March 2, 2019

I am interested in making my 2008 Lexus ISF a much more comfortable riding car. I won't be taking it to the track so I am wanting a smoother ride as it is my Daily Driver. How did you resolve your issues with the harsh ride? Did you install the 2014 suspension on all 4 corners to soften the ride? I am interested in doing this and need as much info as you can give me. What do I need to swap out 08 Suspension to the updated 2014 suspension on my ISF? Do you have have the complete parts list with part numbers I will need to convert my car? I appreciate any help you can give me. I look forward to hearing back from you when you get time to respond. Thanks a lot buddy. And if you think I should go another route that is even better for a softer ride, just let me knoe or stear me in the right direction or leave me other contacts to contact. Thanks in advance!

Ryan Magill

812-660-0379

Rockport, IN 47635

Arqum · March 2, 2019

Pls. Would be interested

mrfunex · March 2, 2019

Err... It’s a while ago, but I installed 2013 suspension on my ISF - they were a straight swap. I have no idea if the 2014 suspension is the same.

The part numbers are in post #4 of this thread. You buy the parts and fit them (I was very lucky and sourced an almost unused set of everything secondhand - dealer prices are extremely high). It’s not really any more complicated than that!

The ride wasn’t as good as my GSF is, but I thought it was vastly improved over 2008 spec.

Arqum · March 2, 2019

Seeing if I can get my hands on a set, but may do dealer route.......

Twellsie · March 2, 2019

I have a full set of Bilsteins on eBay at the min which are also a good improvement over standard, only changed as I have gone down the coilover route

Arqum · March 2, 2019

Hmmm.... Now that is interesting. Would have 1st preference on OEM bits.

Arqum · March 2, 2019

39 minutes ago, Twellsie said:

I have a full set of Bilsteins on eBay at the min which are also a good improvement over standard, only changed as I have gone down the coilover route

You got a link?