VikH

iTrader: (5)

With cars equipped with F-Sport Springs and/or F-Sport Shocks: Driving at high-speeds going over certain dips, the car is too floaty at times. It is to the point were you literally come out of your seat when you hit the end of the dip. It feels like the suspension is not connected properly and it is not hugging the road.

Motor Trend noted this problem as well:

http://www.motortrend.com/roadtests/...ort/index.html


Who else has this problem? Vote up!

JiggaWATT

I have the f-sport shocks and tein s-tech springs. I have only had them for 2 days but I have to agree. at times the car feels floaty, almost bouncy over roads with dips. i Am hoping this will get better as my car gets adjusted to the new suspension.

it seems that the shocks are stiff over smaller imperfections in the road, but roads with humps and dips, i almost felt like my head was about to hit the ceiling, and i was afraid i was going to bottom out (flashbacks of highschool) but the suspension tightened up on the way down. it just lets go too much as u come up out of a bounce.

pisaykotik

Yes I experience this too. Could it be due to the progressive nature of the springs? Would a move to a coilover setup eliminate this problem?

passnu2

iTrader: (33)

^^ I dont think that is the problem or I would have it with the Tein springs also. The only difference is that the F-Sport does not have the rubber around the springs as the Tein does. So its possible you are hearing the springs hitting each other? that is the only difference I can see from Vik's car and mine. I would get a wrap and try it to see if it takes care of it. I think the eibach springs have a similar set up where you can wrap the springs.

pisaykotik

I know about the noise and that is a separate issue. This thread is about the car being floaty at high speeds over dips and in fact when it happens I couldn't hear any noise from the springs.

passnu2

iTrader: (33)

^^ My mistake I thought this was the other thread with the noise Vik started.

after reading your reply I still dont think it has to do with the progessive springs as I didnt get this with my aftermarket springs. they are different but only to an extent. I have driven Vik's car but never over any large dips. My car feels floaty now as I have the rear OEM on it only now and I can tell a HUGE difference in how the car drives and feels over bumps. Some times you dont realize how much something has improved your car over time till you go back to OEM...lol. sorry for the mix up

VikH

iTrader: (5)

Guys when you vote, can you post up what suspension parts you are running? That way we can identify what is causing this issue. It seems like this is caused by the F-Sport Shocks since Jigga with just Shocks feels it and fluxx just has F Springs. Although ba-b4 voted no, I know he also voted no for not hearing the F-Sport clunk when he infact posted later that he hears it (PUNK!).

Has someone been drinking too much

LOL

ba-b4

Hey man I voted NO in the beginning of the clunk noise because in the beginning I really didn't hear it! Later I did hear it but I can't edit the polls anymore! The high speed float thing I vote no because I don't think it feels floaty but I know what you are referring to. I think it's pretty locked down and the car follows the bumps and dips more and as a side effect when there's a dip the car goes down real fast but you yourself float up out of the seat like a roller coaster sensation then when the car bounces back up you plop back down into the seat causing you to feel a sensation of float but actually the car itself might not be floaty. I don't know if that makes sense but but that's always how I've thought of it. I've sat in cars with really soft floaty suspensions and on high speeds on the freeway there is a definite difference between those cars and the f suspension IS.

passnu2

iTrader: (33)

i didnt see this as an option on your poll maybe you need to put the bottle down and you wont hear these so called noises you are hearing

VikH

iTrader: (5)

I think you are on to something. However, I don't think your specific theory applies. When you enter a dip you are forced downwards into the seat. Only when you hit the "hill" or end of the dip, will you be launched upwards while the car stays relatively hugged to the road. Think of the roller coaster situation. You are not out of your seat at the valley of the hill. You are out of your seat at the top, aka the end of the dip.

Here is what I think the situation is:

When a stock IS enters a dip at high speeds the suspension extends with the dip. There is a slight bump at the end of the dip, but not noticeable since the car did not fully go down with the dip.

When a F sport IS enters a dip the suspension does not extend since it is stiffer. Therefore, the car will travel down to the dip and it will be forced upward at the end. IMO, this is a function of the F-Sport Bilstein Shocks and not the springs.

passnu2

iTrader: (33)

man you complain a lot about your car? you should sell it for another car if you are not so happy with it. why did you buy a lexus if you didnt want that floaty drive/feel??

LMAO...just drive that other BLK car and get rid of the IS Then you have a car that is worth modding

PS I voted NO because I dont have these springs

Kurtz

iTrader: (1)

The motortrend article says it feels like the springs and shocks aren't working properly together.

That -is- a problem with progressive springs in general, it's impossible to match shocks perfectly to em... the shocks have a fixed dampening rate, the springs rate are variable. Dunno if that's what's going on here, but interesting that it's the observation MT made on their F-sport car.

chris07is

iTrader: (10)

hey vik and mike...whats going on fellows? you guys remember me? LOL.. hey so far my Stech seems pretty good to me...i dont feel any floaty on any dips...i mean... drive here in SO.CAL and our roads are miserable... sometimes, i kinda feel it though, but it depends how deep is dip on a high speed...seems fine to me...

ba-b4

Yeah I think with good coilovers you can adjust for that rebound and compression damping with F sport shocks there's no adjustments to be had so you're stuck with what we have. I had a thread complaining about the f sport setup not absorbing the irregularities in the road as well as before. Not sure why the shocks and springs aren't match up well? There's lots of folks with the f springs only and not the shocks together. Maybe it's so that people can buy them seperately and have them work ok with just the stock shocks. I think if they sold as just a matched set only far less people would get them.

VikH

iTrader: (5)

You should know a lot about the car being floaty since you lifted your IS

I have another thread the complains about a VALID F-Sport issue (clunk). This thread is more theoretical and I am not sure if it's an actual issue. I will take you on a top speed run in the car and you will know what I am talking about. When you go over a dip the car literally launches you up out your seat. However, this could be due to the car hugging the road and me feeling a roller coaster effect.

LOL. The black car isn't mine. Maybe when you get an M3 I'll get an M3 too.