ba-b4

So tonight I installed the F sport chassis brace and I can't really tell if it's doing something but of course I already had the f shocks, springs, and sways so the car was already pretty tight. I KNOW for sure that the brace does SOMETHING though because on turns that I normally take everyday fairly agressively I never got the traction control light to come on but now with the brace on the light turns on all the time. The stock brace is really really flimsy and about 5lbs. This F brace is like 15lbs and totally solid. There's no way the stock brace can prevent any kind of chassis flexing whatsoever. I'm thinking since it's a flexible springy brace it might act sort of like a shock absorber that assists the chassis if it ever flexes to bounce back or something. The f sport brace however prevents the chassis from flexing at all. I don't know if this is necessarily a good thing though.

One thing I can say about having the whole setup is that now the car is kind of scary now. It think that it's so tight that the car as a whole can't absorb road imperfections as much as the stock car can. At the same time the car feels flatter of course and will give the driver a false sense of security to take corners harder then before. If it was a smooth track that might be fine but on freeway ramps or regular roads where there's all sorts of imperfections this stiff of a setup might not be too good and will cause you to lose control if you're not careful. I'm going to keep my setup but if I could do it all again I think I'd just go with lowering springs and sways. Or stock springs and f shocks and sways as the best balance for the car's handling on real roads.

kevintq

iTrader: (5)

oh.. so are you saying that having the full f-sport suspension is someone not as safe as the stock suspension?

ba-b4

What I'm saying is I sense that by having a really braced up and firm locked down suspension it makes a person feel very confident.. The feeling of being very controlled and flat while cornering is cool but the problem is I feel the car now is not as able to cope with the irregularities on the road as well as stock. On the track a stiff setup might be great so that the driver can explore the limits of the tires and traction while the car stays flat but something like this on the street might not be as good because there are lots of bumps grooves and potholes. If you are over confident due to the flat tight feeling and take a corner really fast the combination of speed and braced up chassis and suspension will cause the tires and wheels to not soak up the rough road as well as if you left the car alone. Yesterday I took a local offramp pretty fast and the car got unsettled a bit and the rear stepped out when I went over this small bump in the ramp... This never happened before when I took the same offramp at the same speed when I was stock. Tried it before with my other car as well and I never had that happen before either. Even though when I was stock it felt sloppier in the turn the car soaked this bump up without any drama. My experience was further reinforced when I installed the chassis brace today. Even though I didn't feel much difference due to me having installed all of the other F suspension parts the vdim proved to me that the car was having trouble over rougher pavement in turns as the vdim light kept flashing on and off when it never did before.

darkdream

can you make any comparisons the set up in terms of stiffness to any popular cars? like a stock G35?

ba-b4

Well my sis has a stock G35 coupe.. It's hard to say which is firmer.. I would say they are pretty close but the G isn't lowered so I guess there's more suspension travel and it's stock sways aren't as large as my upgraded F sways so my IS is flatter in the turns. I haven't driven her G enough to get too detailed about it though. When it comes to the overall driving experience I think I would still would rather drive her car to tell the truth. The steering on the G is more direct and firm and I like the exhaust note of that car too and it doesn't get upset over the bumps as easily as my full f sport supsension IS. But as a complete package the IS is still better overall.

pisaykotik

So I take that you don't recommend the brace then? I got the springs and was thinking of adding just the sways for now (not both sways and brace together) and see how it goes.

lobuxracer

iTrader: (2)

Can you adjust the damping on the shocks or is it fixed? If you can adjust it a tad softer, you might get past the compliance issue.

I've never believed or observed stiff suspensions to work well on the street. They also do not work well on many racetracks because a racetrack builds up a washboard in braking zones. The first time I rode Sears Point on my bike, I couldn't believe how bad the washboard were in the braking zones - a stiff suspension would have put you off track in those days.

ba-b4

Yeah I would say forget about the chassis brace. If you don't drive regularly on a smoothly paved track it probably wont help you much. I only got it because I was on the fence about the brace and thought it might be cool to get all the F suspension parts put in. Then another member here had his for sale for cheaper than new because he needed some extra cash and so I couldn't resist and bought it off of him. Now I might even put it up for sale again myself later on.

ba-b4

Nope I don't think the F shocks are adjustable.

VikH

iTrader: (5)

Damn dude, your car is F'ed up

carchitect

iTrader: (1)

I think you are over exgerating a little.

The OEM 3-piece rear brace helps minimize fore-aft flexing. The f-sport brace takes it further by triangulating the brace points diagonally and being all 1-piece construction built with stronger materials takes a rigid chassis even further.

The fsport springs are progressive. I'm a linear rate spring kinda of guy. I prefer the suspension to perform consistently. For this reason I purchased the IS350 with the sport suspension. I'm planning on installing the f-sport sways and brace soon.

ba-b4

Honestly by the seat of the pants I can't feel any difference before the F brace and after but the car's traction light seems to be much more sensitive after the install yesterday. So I can exaggerate all I like but doesn't matter because the reality is the car's traction control has to work harder now that the brace is on. The only thing I can conclude from that is that the new brace makes the car's structure less able to absorb the rougher patches of road in cornering. I'm not sure how else to explain why the trac light comes on so easily now. How would you explain it?

blk250

iTrader: (3)

That is strange, I have installed springs, sway bars, and the brace, but not the F-Sport shocks. I am taking off/on ramp @ speed too... , but I have not seen the trac light nor hearing the beeping sound. Is the VDIM of both 250 & 350the same?

ba-b4

no I think they're different systems... 350's is more advanced???

darkdream

yup they are different