Can an ISF ride like a Lexus ??

[Jon Dee]

Went for another longer test drive today and can confirm that the factory audio still cranks hard on classic LED Zep  

Ride is now comparable to my previous 2008 E92 that had new Bilstein B4's and factory springs all round. Compliance over small imperfections is excellent and larger imperfections are handled without passing any sharp impact to the chassis. There is still tyre thump but that is unavoidable with big wheels and short sidewall tyres. The stiffer springs on the HKS coils would possibly work a little better on the race track. But Bilstein's reputedly give better adhesion, so for a car that is not intended for the track the Bilstein's and factory springs are a clear winner for ride quality on the road. 

The car now has a "firm and sporty" ride as befits a high performance sedan. There are still a few very minor rattles and noises as can be expected with a well used car. But it is now a pleasure to drive... mission accomplished  

Now I just have to find out why I have coolant leaking at the front under the air filter box ?? Radiator ?? 

Cheers...

[RichGS11]

It's a cheap and easy fix replacing the radiator. Something I would reccomend with the type of radiators Lexus use on some models. The coolant line for the gearbox runs into the bottom of the radiator. These radiators can corrode from the inside and I don't need to tell you the damage coolant can do in the place of gearbox oil! It's around a £5k fix from Lexus for a new box.

I changed both my radiator on the GS, and the ISF (same style radiator), on the drive at home. It's a relatively cheap maintenance job when compared to the possible damage it will cause when faulty.

[Jon Dee]

11 hours ago, RichGS11 said:

It's a cheap and easy fix replacing the radiator.

I haven't been able to spot any telltale pink staining or leakage looking down from the top, but I can see coolant pooling on top of the bellypan. Getting underneath for a closer look will have to wait as I have just had a cataract operation, and crawling under cars is not on the list of approved post-op activities   There is a local business selling alloy radiators for NZ$500 which is lee than half the price of the OEM item with plastic tanks. I just have to check to make sure they have the heat exchanger for the trans in the bottom tank (and it looks like it does). If it has and I need a new radiator, I will most likely try the alloy version. 

Cheers...

[ubersonic]

Samiboost on YouTube uses that radiator, good reports if I recall.

 

[Jon Dee]

Car had been sitting for ten days with coolant on the full mark and nothing leaked out. So I got the belly pan off today... couldn't see any leaks. Let let the engine run until the thermostat opened and then I got a leak. Coolant sitting all the way along the top seam between the tank and the core, so I figure the top seal has let go. 

Ordered a new rad... had to settle for the OEM style as there just don't seem to be any all alloy units available on AU or NZ. Should be here in a couple of days and then the fun starts 

Cheers... 

[Jon Dee]

Changing the radiator is the kind of job that can probably be classified as "easy" or "straight forward" after you have it done it once or twice. But the first time verges on a nightmare as you fumble your way through the removal process finding out the hard way what needs to be removed (and in what order) to gain sufficient room to finally pull the radiator. The pièce de résistance is getting access to the two small bolts at the bottom front of the A/C condenser !!!!  

Never the less the new rad is in and sitting full of coolant until tomorrow when I will give the engine a run while the car is still up on blocks. If no leaks I'll button it up and go for a drive. Got the OEM wheels on now with OEM tyre sizes. I'll be setting the pressures to the factory recommended 36F/37R psi and evaluating the ride :) 

 

[RichGS11]

Well done! There are guides on YouTube for it. Compared to changing the headers on the ISF on your driveway, the radiator is an easy job 😆

At least you got it done and hopefully the car runs well.

[Jon Dee]

14 hours ago, RichGS11 said:

At least you got it done and hopefully the car runs well.

Ran it until the fan/s were at full speed and no leaks, so happy with that Had a bit of a panic attack when I went around to the drivers seat to check the temp gauge... the yellow triangle was lit up and the dash was telling me (in Japanese) that there was a problem in the front of the car !!!!! Turns out it didn't like the engine running for so long with the hood up... wheww   

Swapped the factory intake pipe back in (blue silicone one out) and will bin the K&N filter when the Japanese factory type air and cabin filters that I have ordered arrive. I was told that the car was serviced before I picked it up, so I will check the colour of the oil after I have been for a decent drive and decide if it needs changing.

Hoping to get to drive this car quite a bit over summer... I'm down in NZ so summer is not far away.

Cheers...

[EP80]

Did you guys keep track of how much coolant you put in the system once the radiator was changeed? 

The only reference I have found after a quick look is: https://www.clublexus.com/forums/is-f-2008-2014/939951-changing-antifreeze-for-isf.html#:~:text=If your system is empty,11.9 liters to refill it.

I plan to do a complete drain including the block, so I am trying to figure out how much to order. 11.9 litres sounds a lot and that post doesn't reference any source. Wondering what experience you guys had? Thanks

[Jon Dee]

7 hours ago, EP80 said:

Did you guys keep track of how much coolant you put in the system once the radiator was changed? 

I only drained the radiator (not the block) with the front of the car raised and the rear wheels on the ground. It took 5 litres to get the level between the marks once it was back on the ground. Probably no help, but it's a start 

Cheers...

[Jon Dee]

Well, the car is back on the ground and running. Happy with the more conservative look and sensible height. Set the tyre pressures and went for a short drive. Right now I would assess the ride as almost identical to my 2008 E92 mSport, firm and sporty. Tyre thump is still a little more intrusive than I would like but acceptable given the ride.

The E92 ran the same tyre size combination only in 18's rather than 19's. Not sure if that would make any noticeable difference. I will probably stay with the 19"s until the tyres need replacing and make a call at that time.

Here is how the car sits today...

Cheers..

.

[EP80]

2 hours ago, Jon Dee said:

I only drained the radiator (not the block) with the front of the car raised and the rear wheels on the ground. It took 5 litres to get the level between the marks once it was back on the ground. Probably no help, but it's a start 

Cheers...

Thanks, with that in mind, the 11.9 litre figure sounds like it might it might be possible. 

[Jon Dee]

When I was changing the air filter yesterday, as I wiped out a few dead insects from the fixed part of the air filter housing, I noticed that there was a flap arrangement at the back. This is operated by a vacuum servo mounted external to the box, and put me in mind of every young lad's performance mod of punching a few extra holes in the airbox to "help the engine breathe". And I admired the fact that there must be some hot-rodders in the Toyota design department  

Up until today I had been driving my car in much the same style as I drove my E92... ease into the gas and let the low end torque pull the car away smoothly, gliding through the gears in the lovely smooth transmission. But today, the sun was shining and I was feeling a bit frisky, so I accidentally (heh!!) hit the gas hard after I pulled onto the main road, and let the engine run up the revs. WoooOOOTTTTTT !!!!!! I wasn't watching the rev counter, but suddenly all hell broke loose Pretty sure the afterburner kicked in judging by the substantial boost in acceleration and the roar from the engine !!!!

NOW... I understand why people love this car... Jekyll & Hyde... you better believe it  

Cheers...

[GMB]

Try kickdown - you know, past the pressure point on the gas pedal - at 60/65mph in 8th. Mine goes down to 2nd and takes off like a scalded cat with the usual fanfare from the engine.   -  Lovely!😮

Be careful you'll be doing over a "ton" in a very short time.

[RichGS11]

Very fun and underrated vehicles. Making mine lighter and opening up the entire exhaust system from the block has made for an entertaining drive. Also moving the redline and tweeking the shifts makes manual mode a hoot.

Let it warm up and let it rip.

Amazing machines!

[Jon Dee]

On 11/8/2023 at 7:52 PM, Jon Dee said:

I only drained the radiator (not the block) with the front of the car raised and the rear wheels on the ground. It took 5 litres to get the level between the marks once it was back on the ground. 

It seems to take a while for air to work its way out of the cooling system as I have managed to squeeze another litre in to the overflow container since I have been driving the car. It has settled at just above the lower mark when cold now, 

Cheers...

[Jon Dee]

On 9/15/2023 at 8:45 AM, NothernDan said:

If you want a nice compliant ride.....Airlift all the way.

I have been doing a bit of reading to educate myself about AirLift suspension, and see that the usual procedure is to "build" a setup from a range of components. The better part of the cost is in the compressor and controls, which at the top end of the scale contain a lot of clever stuff that I don't think I would really need. Further down the scale are simple manually controlled setups that on the surface, would appear to meet my requirements i.e. no self-levelling, no Bluetooth, small compressor. 

If I was to go down the AirLift route all I would require would be adjustable damping on the shocks (as per the attached pictiure) and the ability to "set and forget" the ride height at a sensible level. 

If you have used an AirLift system on your car could you indicate if the type of simple system I have outlined would give the desired compliant ride ? Or would you recommend a different setup ? 

All comments appreciated 

Cheers... 

[Jon Dee]

Been driving around for a few months with the Bilstein + OEM springs setup on the car and a square setup of 18 x 8.5 ET38 wheels with 255/40-18 tyres all round. Works fine from a handling point of view but I still feel that the ride could be improved.

Had another look at Air Lift and I'm sure that bags would offer an improved ride, only the complexity of the install, cost of the hardware and the loss of boot space put me off. Reading the reviews and manufacturers blurb leads me to believe that most people install bags for show rather than go. And since I'm not interested in "laying frame" or adjusting the height on the fly, I started looking around to see what other options were available. Extensive research LED me to these....

TEIN Flex Z coilovers are the latest iteration of a product like that has been around for a long time and they are now focused on improving the ride on street driven cars without giving away much in the way of performance. TEIN have other performance coilovers for tracking or other sporting applications. Spring rates are comparable with the highly rated SWIFT springs and the Flex Z comes with improved damping adjustment.

Being a complete coilover assembly there is no need to be messing around spring compressors and swapping over OEM parts, so installation is pretty straightforward. Reviews and comment from jeffrosie6 in this forum indicate that these TIEN's should give me the ride improvement that I am looking for... so I'm hunting down a set at the moment 🙂 

Cheers...

[Jgtcracer]

14 hours ago, Jon Dee said:

Been driving around for a few months with the Bilstein + OEM springs setup on the car and a square setup of 18 x 8.5 ET38 wheels with 255/40-18 tyres all round. Works fine from a handling point of view but I still feel that the ride could be improved.

Had another look at Air Lift and I'm sure that bags would offer an improved ride, only the complexity of the install, cost of the hardware and the loss of boot space put me off. Reading the reviews and manufacturers blurb leads me to believe that most people install bags for show rather than go. And since I'm not interested in "laying frame" or adjusting the height on the fly, I started looking around to see what other options were available. Extensive research led me to these....

TEIN Flex Z coilovers are the latest iteration of a product like that has been around for a long time and they are now focused on improving the ride on street driven cars without giving away much in the way of performance. TEIN have other performance coilovers for tracking or other sporting applications. Spring rates are comparable with the highly rated SWIFT springs and the Flex Z comes with improved damping adjustment.

Being a complete coilover assembly there is no need to be messing around spring compressors and swapping over OEM parts, so installation is pretty straightforward. Reviews and comment from jeffrosie6 in this forum indicate that these TIEN's should give me the ride improvement that I am looking for... so I'm hunting down a set at the moment 🙂 

Cheers...

I currently run Swift springs on the RCF and the ride didn’t change much from OEM.  If you’re after a more compliant ride then I can imagine a lower spring rate then factory might suit….

[Jon Dee]

That's what I am hoping 🙂  jeffrosie6 changed from RS*R to TEIN Flex Z and noticed a big difference as the spring rate dropped a lot.  I'm running OEM springs and Bilstein B6 shocks valved to work with OEM springs. And they do... the handling is improved but the ride comfort level is much the same as the stock 2008 "sportscar" ride. Here are some spring rates I have found...

The Bilstein's emphasis is on performance, and they don't have any adjustment. TEIN's emphasis is on improved ride quality. So although the TEIN Flex spring rate is only a little lower than OEM in front, I am hoping that a factory tuned coilover with adjustment can achieve improved comfort without giving away too much performance.

The magic is always in matching the shock valving to the springs 😄 

[Jon Dee]

On 9/2/2024 at 7:01 PM, Jon Dee said:

Extensive research LED me to these....

Can you believe that when I wrote a post above with the word "led" in lower case, it has magically been changed to capitals, underlined, and linked to an amazon advertisement for LED headlights !!!!!! WTF ??

Then I look back a few more posts and find that when I wrote "bluetooth" the same thing has happened and it is now linked to an amazon advert !!!!

Oh yeah, and the cute thing is that these magical alterations are only visible if I view my posts without being logged in. Once I log in the alterations disappear and everything is normal.

Anyone else want to play this game of hide and seek 😀

[jeffrosie6]

Back on after a long absence. Ride quality is good but I now feel that the front rates of 8kg springs is far too low. I think the 8kg springs are meant for the lighter IS250 engine. The ISF will need the 10 or 12 kg springs in the front. I'll at some stage be buying the 12kg springs. 

I got mine from Tegiwa Imports for £630 which is a bargain really. I also bought coilover socks to keep them weather protected and had the sprayed with ACF50 for further protection.

[Jon Dee]

9 hours ago, jeffrosie6 said:

Back on after a long absence. Ride quality is good but I now feel that the front rates of 8kg springs is far too low. I think the 8kg springs are meant for the lighter IS250 engine. The ISF will need the 10 or 12 kg springs in the front. I'll at some stage be buying the 12kg springs.

It is a fact of life that everyone is different, and that opinions on a cars ride quality and handling is almost entirely subjective. If coilovers were subject to the same extensive comparative testing as tyres, then there would be some good data available... but unfortunately, that does not happen. So we rely on random opinions, where in most cases there are plenty of opposing views.

My objective is to get a more compliant and comfortable ride, and as you and a few others have reported that the Tein Flex Z improve the ride, I'm prepared to take a punt on them. I'm not any kind of suspension expert, but I do know that the springs and shocks have to be tuned to work with each other to get a great result. I'm hoping that Tien have done that, and the fact that they use twin tube shocks (a la Koni) is a good sign.

If I was looking to track the car then I would stay with the Bilsteins and stock springs as they are a performance B6 monotube design that emphasise performance rather than comfort. Should the Teins not work out I'll put the Bilsteins back in and call it a day 🙂

[B1RMA]

Hopefully the Teins will work out for you. I'm a big fan of Tein having had them on my track prepared RX7 and then on my highly modified Mini which had the wonderful Tein EDFC system fitted.

In fact I've decided that if another AVS shock absorber goes/leaks and needs replacing on my RCF I'm going to rip out the whole lot and replace it with a Tein EDFC coil-over system. I have no doubt from my personal experience it will be better than the already excellent AVS system on my RCF

[RichGS11]

Tein get good reviews from ISF owners. It all depends on your wants and needs. All I would reccomend is getting the car corner weighted and balanced on coilovers or don't bother with them. It costs, but it's the best way to marry up the suspension with the car. Mine is a completely different animal. My spring rates aren't for everyone, I get that, but balancing the car appropriately has the same effect as mapping the engine after big modifications.