is350wh

Well, I tried to use only the F-Sport Springs, while keeping the standard non-sport OEM shocks. Yes, that is a supported and warrantied option. At first, things went well. Later on, I started hearing all kinds of noises coming from the suspension, especially from the front (not the infamous "clunk"). I had the dealer check the integrity of the setup 2 or 3 times; they didn't find the issue.

With that setup, I also had quite a few issues with the integrity of the suspension's performance. It seemed that the F-Sport Springs + OEM Shocks setup just couldn't keep the car together and planted to the road properly. It was usually okay, but under stress, the car tended to bounce or wobble. The biggest problem with it was that it was unpredictable.

Problem Summary: That combination looked great and it was the cheaper way to go, but the result was:
>Unpredictable and inconsistent suspension performance
>Suspension noises that sounded unsafe (like something was loose)
>Very rough ride over "significant" bumps (seemed to get worse over time; probably the shocks wearing out)

Decision Making:

OPTION 1: I considered going back to the OEM Non-Sport Springs and using the F-Sport Shocks. I got confirmation that this is a supported option. However, after looking at some stock height IS350s, I just couldn't do it. The wheel gap is just - well, hideous. Lexus REALLY needs to fix that in the next IS generation. NO OTHER SPORTS CAR LOOKS SO AWFUL RIGHT OFF OF THE LOT! Of course, very few cars look SOOOO good after they're lowered. So, I guess it's a trade off, huh?

OPTION 2: I considered the OEM "SPORT Springs" and F-Sport Shocks. The OEM Sport Springs are .4" lower in the front. I think that option would have worked okay, as far as "looks" are concerned. However, I couldn't find a solid answer about how firm the OEM Sport Springs are. I couldn't find the spring rates. Not even the dealer knew. I did not want to get overly firm springs, because I hate the small bounces (jitter) when driving over very bumpy pavement. Plus, the OEM Sport Springs were pretty expensive - more than the F-Sports.

OPTION 3: Do what I should have done the first time - Install the F-Sport Shocks (Bilsteins) and F-Sport Springs. I am concerned about the "high speed float" issue that is well documented on this site. I am also concerned that this setup will be even harsher than my previous one. However, it seems to be the best available option. This is what I decided to do. I should have the car back in a few days, so I'll try to post a review of my experience of three configurations I've had (Non-sport Stock, F-Sport Springs+OEM Shocks, F-Sport Springs & Shocks).

Decision Summary: It's sad that I have to spend SO much money to get a decent suspension and also fix the IS's wheel gap. What is really annoying is that there isn't even an available configuration (from Lexus) that will provide what BMW and Infiniti provide right off the lot:
a) "Normal" wheel gap (something that doesn't look like a stinkin' 4x4!).
b) A sporty suspension that won't float/bounce, but still provides a comfortable, non-punishing ride.
c) A front lip that won't hit most parking blocks when the car is lowered slightly to eliminate the wheel gap.

True, I haven't tried the Stock Sport configuration. In fact, I don't think I have even seen one in person. They are hard to find. Maybe that was the magic configuration. But, even with that one, the pictures I have seen on this site indicate that there is still a lot of wheel gap. Maybe Lexus will listen to our complaints and get it right next time. Or, maybe they do this on purpose, because they probably make decent cash off the F-Sport accessories.

BTW - I bought NEW springs, too. Waste of money? Almost definitely. I just couldn't put the same ones back on - just in case there was something/anything wrong with them that was causing my noises. Plus, after spending so much on this installation, I wanted to make sure the whole setup was fresh (the springs were not much extra cash, compared to the shocks and installation). Also, the rears were the PTR07-53080s, which have the clunk noise. I bought the PTR07-53090s this time. I went ahead and put the TEIN silencers (mediums) on again, just to be sure there are no clunks.

It is worth noting that I was unable to get the dealer to replace the rears under the TSB. I was hoping they would cover the labor to replace my PTR07-53080s with the PTR07-53090s, but they said that that TSB only applied to F-Sport cars that came off the lot with the package and also had the specific, verifiable noise.

GSteg

iTrader: (15)

Option 3 is the best if you want to reduce the bounciness. When you go with stiffer springs, you want a shock to match it. If you're experiencing bounciness, then your suspension is under-damped. Seems like you are really concerned about looks, so Option 1 and 2 will probably be thrown out the window.

is350wh

Thanks for the feedback. That's the route I'm going, so I hope it provides the balance of performance, looks, and comfort that I am looking for.

IS350HKS

iTrader: (4)

Hope you find something that fits you

MiiK350

iTrader: (8)

If you got the PRE TSIB springs installed at the dealership, then they lied to you. They do have to cover it under the TSib.

I have a sport package IS350, but swapped out the springs with H&R's. I'm selling my springs if that is ever an option for you down the road.

quang

iTrader: (8)

F-Sport shock is much better than stock shock. I used to have stock spring/shock with F-Sport 19" wheels, ride was harsh and noisy. After switching to F-Sport spring/shock combo, ride is close to stock (except bumpy road) and quieter (except clunking noise as I have pre-TSIB spring).

is350wh

IS350HKS: Thanks.

MiiK350: Man, I believe you. I don't think they "lied," but I think they are mistaken. The thing is - I'm the one and only F-Sport customer that particular dealership has had, ever! Crazy. Makes it hard to get knowledgeable feedback about anything F-Sport. I'll keep the H&Rs in mind. If I make another change, it will probably be back to stock - or I may end up in another car maker's forum, if I go that direction.

quang: I forgot to mention that I considered that config for OPTION 4. That is, OEM Stock Springs with 19" wheels. There was a lot of convincing information on this forum that indicated the 19's wouldn't help the wheel gap. That's the main reason I didn't go that direction. Your feedback is interesting. Was your stock setup the "Sport" suspension or the standard soft suspension?

is350wh

I'm scheduled to get my car back next week. Then I'll test it. If the ride is too stiff, I may swap my Rear F-Sport Sway Bar back to the OEM. Only if it is necessary. I think that will soften the ride a little, because it will allow each of the back wheels to travel with more independence. I'm hoping it won't be necessary, because the sways really eliminated the stock body roll. Then again, the sways actually did more to make my ride harsh than the lowered springs did.

JDKane527

iTrader: (10)

Sways have minimal effect. Lowering springs have a harsh ride. My h&r rides harsher than your fsport. You just live with it haha or go coilovers.

is350wh

Major BUMMER. The dealer called and said they don't have the equipment needed to get my current F-Springs off and to install the new ones and the new shocks. I had to go pick up my car. Oh well. It'll give me more time to think about this.

The thing with the sways is that I installed them (front & back) before the lowering springs. The sways had a major affect on the feeling of suspension firmness. True, hitting big bumps straight on was still soft; forward dip while braking was still soft; rear squat during launch was still soft. But, hitting bumps that would normally only lift one wheel at a time was harder; hitting road irregularities was harder; cornering was harder.

Coilovers are the way I would go, IF I knew I was going to keep the car (which I don't) and if I was willing to possibly compromise the suspension parts of my warranty (which I am not willing to do).

What I really want to see - if anyone has one - is a picture of F-Sport 19"s on a stock non-sport IS350. Yes, I've searched almost all of the pictures on this forum, but I haven't found a picture that was definitely the non-sport version on F-Sport 19"s. I found a few pictures of 19"s on the sport package version, but that's slightly lower (even .4" makes a difference on this cowboy 4x4 car). BTW - The New Full Face F-Sports are awesome! I'd love to see more pictures of those, especially on a stock suspension.

Micaiah

I can't believe that they don't have the equipment to change out your set up. That's crazy! Is this a Lexus dealership? Don't they do shocks/springs? Amazing.

I have the 19 inch F Sport wheels with sport susp set up from the factory. I love the way that it feels right now and concerned about how close to stock the F sports springs/shocks are in terms of harshness. So many people say it's close to stock but then some say it's too harsh.

is350wh

Micaiah,

Yes, this is the same Lexus dealer where I bought the car and where I had all of the other F-Sport stuff installed. I had the springs installed at a different Lexus dealer - the one I'll have to go back to now.

Do you, by chance, have a picture showing the front and/or rear wheel gap? I really want to go back to the stock suspension. I just need to know what I'm getting into; it's a very big investment.

To answer your question, the F-Sport setup is DEFINITELY harsher than stock. But, people are partially correct when they say it is close to stock. Here's the deal: The "progressive" nature of the springs is VERY apparent. They feel great sometimes, soft other times, just right sometimes, awesome during performance SOMETIMES, and really harsh and unstable at other times. It's really wild.

The springs can be really bad when you hit a major bump at any decent speed. The car does not "bottom out," but it's like you just hit the limit of the springs and there's nothing left to cushion the blow except for your car's guts and your body. Something inside my dashboard (like a connector) literally snapped after I hit a large bump on the interstate, and now my dashboard has a loud and very annoying rattle.

Going over uneven roads at slow speeds is embarrassing, especially when I have passengers, because the car wobbles back and forth like a piece of junk would. It must look really silly to other people, too, because it looks so unstable. Hitting hard bumps is also embarrassing; my passengers, generally, hate it.

I've had the springs for well over a year, and I am very particular about this type of stuff, so I have analyzed this issue at length for a long period of time.

Keep in mind, though, that I have been running the F-Sport Springs with the standard OEM shocks. I am sure the experience is much different with other combinations, such as F-Sport Shocks and Springs or F-Sport Springs and Sport Shocks or other combos.

Thanks for your help, everyone.

is350wh

Just for reference, here are some pictures I took of a new stock IS350's wheels. Front and Rear. And, here is a picture of my current front and rear wheels with F-Sport Springs.

Micaiah

Wow. Just realized I have no head on decent shots of the gap. But here is what I DO have....sorry it's not that good. It's dark now and if I do it now pics won't come out well.

Sport package springs with 19 inch F sports wheels. Notice my tires are lower profile than yours so that widens my gap.







Yours looks much lower. I like the way yours sits. I love the handling of the set up I have though. None of what you describe in terms of wobbling or being unstable. This car sticks to the road like glue. Feels nice and heavy on the road and no harsh bump. You do feel the road, it's not a floaty feeling. But enough to know the car is sporty.

quang

iTrader: (8)

I had the stock none-sport suspension with 19" F-sport. I had the sway bar too before adding F-Sport spring/shock. The stiffness remains the same before and after. But the ride quality improved.