Getting Rid of understeer? Better handling?

J

jonv8944s

Member
I know the FX50 has an unfair fight against it, when I compare it to the GTR, but there has to be somethings that can tighten up the handling of the car a bit. Don't get me wrong, its not horrible, but I know the SRT8 we had could definitely out handle it, by a lot.

I realize for me, I should have gotten the Fx50s (does it really handle noticeably better?) but for my wife the technology package was must, and 2011 & 2012 cannot be ordered with both. They are mutually exclusive. (Go try to order one on line with both, you will see).

SO we preferred the tech package over the fx50s, so now I have to see what I can do to tighten up the handling. I was thinking the strut tower brace was a must, but how good is it really?

Is the main issue the tires? I have the 21s, which are all season, which I really want to stay with, but I wonder if they had been 'run flats' with the stiffer side walls, would it corner more 'flat'? I realize its unlikely I can get a better performing all season tire. Should I revert to 20s and get an all season with run flats?

I realize a nice set of coil-overs would likely be the fix, but with no good options right now, I need to look for alternate solutions.

What about stiffer sway bars? Is the fx50S's sway bar any different then the regular fx50 ?

I know there are also other chassis stiffening options for the rear, but I am thinking those are going to be hard pressed to do anymore for rigidity then the stiffness the OEM tow hitch adds to the car by locking in both frame rails in the rear together in a VERY solid manor. Looking at the GTSPEC stuff, I just wonder how much can all those parts really add for improved handling.

I'd even be willing to lower the car a bit (lower center of gravity), but having the camber issues is not something I would want to inherent from such a move.

Appreciate any insight and direction people have on CONFIRMED options. I want real world experience and insight, not some of the 'oh that might work' or 'this could maybe help, try it.' I'm looking to benefit from research already done by members. No reason to reinvent the wheel in this case.

Jon
 
I'm using the 21's as my rims and the all season tires ,and I have the sport package not sure if the 50 without sport ride different than mine does with the sport switch turned off ....but I think there's a big difference when its on. i have been looking into the gtspec stuff and I bought and installed the strut brace I really like how it feels the car feels more solid over bumps and really holds it self together in turns and am going to buy all the rest of the braces they have for my 50 because of that. Am also going to lower it on H&R's sometime soon.

Sent from my HTC Sensation 4G
 
Yeah, I can't answer if 'non sport' mode of the fx50s is the same as the fx50. I am guessing not though, since I believe the shocks are different manufactures. I would 'guess' that soft mode of the sport setup is softer then the 'normal' setup of the regular fx50. Again only someone who drove them back to back could provide insight.

Thanks for the insight of not blaming the tires!

Jon
 
the real answer to this is that it is what it is:) you're not going to change what it is unless you change things that really affect the ride characteristics and handling. no one or two simple bolt on things are going to have a dramatic effect unless it's altering the suspension itself. things like strut bars and other reinforcements can help a little but to really make a big difference would take bigger changes

lower center of gravity is a start, stiffer springs will decrease body roll. stiffening the rear suspension even more will aid in lossening up the rear end a bit relative to the front, which can really reduce the excessive understeer the FX suffers. it will handle better but it will ride worse in direct proportion. it's all a trade off. right now it is what Infiniti deemed to be appropriate balance between ride and handling. a set of good coilovers would be a good start if such a thing exists, if not then the more common cheaper sets are an option but will still bring challenges in the alignment areas as well as the amount of playing around with spring rates and adjustments and testing and analizing, it could get as complicated as you allow it, the question is just how complicated and deep do you want to get and how much comfort are you wiling to sacrifice... if your looking for a simple way then I don't think there's any out of the box total solution available.

as far as the 50S it's a totally different animal suspension wise. it uses a computer controlled variable dampening feed back system with 4 wheel steering, you can not retrofit this in any practical way.
 
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There are a few coilover companies that make them for the 09+, xyz racing and ksport. There is another one, I don't recall the name but it was bashed by other members to probably not even worth mentioning.

They run around $1,200+.
 
turbocad6 said:
the real answer to this is that it is what it is:) you're not going to change what it is unless you change things that really affect the ride characteristics and handling. no one or two simple bolt on things are going to have a dramatic effect unless it's altering the suspension itself. things like strut bars and other reinforcements can help a little but to really make a big difference would take bigger changes

lower center of gravity is a start, stiffer springs will decrease body roll. stiffening the rear suspension even more will aid in lossening up the rear end a bit relative to the front, which can really reduce the excessive understeer the FX suffers. it will handle better but it will ride worse in direct proportion. it's all a trade off. right now it is what Infiniti deemed to be appropriate balance between ride and handling. a set of good coilovers would be a good start if such a thing exists, if not then the more common cheaper sets are an option but will still bring challenges in the alignment areas as well as the amount of playing around with spring rates and adjustments and testing and analizing, it could get as complicated as you allow it, the question is just how complicated and deep do you want to get and how much comfort are you wiling to sacrifice... if your looking for a simple way then I don't think there's any out of the box total solution available.

as far as the 50S it's a totally different animal suspension wise. it uses a computer controlled variable dampening feed back system with 4 wheel steering, you can not retrofit this in any practical way.
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The 'it is what it is' thing is a bit of a cop out. Anyone could say that about the GTR also, saying its power level is what it is, and thats what nissan wanted, your right, it is what they wanted, but its not something that appeased all owners, so you saw significant development in power increases. I am not saying the fx50 needs significant increase in handling, It just needs to be tightened up. I explained I was not trying to compare it to the GTR, but instead another SUV, the SRT8 we owned. Even the GTR can benefit from some suspension related changes, like a square setup of the tires or the sport/track alignment vs the 'street alignment' These are relatively 'simple' fixes and I was looking to investigate similar 'simple' approaches to improving the handling. I am not looking to duplicate the fx50s, I was simply asking if there was a noticeable difference in handling between the two versions. i realize there is a significantly different approach to suspension on the two.

Thx,

Jon
 
just about everything and anything can fall under "is what it is" until you change it, sure even the GTR falls under this too :) didn't mean it as a cop out, just stating the obvious... to really change it you'll need to really change it. simple changes are going to give simple results. your talking about "getting rid of understeer"... that is no small achievement. I'm trying to point out that you are not going to "get rid" of understeer with any simple things, you will need to alter what it is. don't want to hear that?
 
I was asking for feedback on the options I had already pointed out. How is that not what I wanted to hear? Again on other cars, inducing more neutral balance or even over steer can be as simple as going with stiffer anti sway bars.

Again I ask, any feedback on the items I have already mentioned would be greatly appreciated. And if there are other options, please indicate such.

Its a SUV (or station wagon, w/e you subscribe to), I know it won't handle like a sports car, but I certainly can help move it up the ladder a bit and achieve better handling then it currently has. Those with insight into how to do this without telling me to give up, or spend a million dollars (exaggeration) on the project will be greatly appreciated.

Thanks,

Jon
 
CUSTOM: made front and rear sway bars; make em thicker. All suspension bushing must be changed, to alot stiffer ones. In the end you will be happy but not as much. Also check x5 m forums, how ppl want too make their x5 handle like the m one or 335 folks who changed all their suspension bushings, arms and stuff to stock M3...
 
Yeah, I am not going to have custom sway bars made, but if they already existed, I'd be in for a set. Yeah the bushings could be changed out, but unless there was a confirmed kit for them who would want to do all that work for what honestly will amount to marginal at best gains. (Did similar work on a Viper of mine, and the results weren't anything spectacular, so I wouldn't expect so on the FX50 either).

Thanks for the thoughts though!
 
Looks to me you want a part that you can bolt up ovrnight, and make ur Fx handle better than "any" other car you have owned.
 
from what i can tell you're expecting the fx to be far more mod-friendly than it really is. i don't think the outcome will be satisfactory given the time and money you're willing to invest.

suspension geometry is not friendly to lowering, sway bars are not a mainstream aftermarket offering,and the goals are really lofty on an suv that "is what it is."

i'm not saying nothing can be done, its just that the fx isn't all that easily tuned.
 
you can buy all fo the GTspec braces that they make for it, get coilovers/springs, wider wheels, better tires, lighter wheels, do weight reduction...
 
jonv8944s said:
I was asking for feedback on the options I had already pointed out. How is that not what I wanted to hear? Again on other cars, inducing more neutral balance or even over steer can be as simple as going with stiffer anti sway bars.

Again I ask, any feedback on the items I have already mentioned would be greatly appreciated. And if there are other options, please indicate such.

Its a SUV (or station wagon, w/e you subscribe to), I know it won't handle like a sports car, but I certainly can help move it up the ladder a bit and achieve better handling then it currently has. Those with insight into how to do this without telling me to give up, or spend a million dollars (exaggeration) on the project will be greatly appreciated.

Thanks,

Jon
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the only options I've seen you point out was that you don't want to do coilovers because of alignment issues, you ask if anything from a 50S can help which it cannot, and you ask about runflats helping performance but they of course will not, they would only make it worse, so really you haven't pointed out any viable options, more "feedback" on these options is not going to change anything... a strut bar will offer a subtle change in feel but will not really do much more than that, certainly not going to eliminate understeer.

you seem to be looking for some sort of unknown hidden out of the box solution but there is obviously none, as has also already been pointed out to you. you only want to hear CONFIRMED options by those who have done it?, but obviously no one has, so really there should be no replys at all in this thread, yet there still is, because people are still looking to help and give input.

I never said you should give up. I also never said you have to spend a million bucks, exagerated or not. but you WOULD have to actually DO something more than simply ask for what doesn't exist. I tried to give some insight as to what could actually be done and why, if you were really so inclined, but I now see that all I did was waste my time. there are SO many reasons why the FX handles the way it does, and there are without a doubt ways to change it, re engineer what it is into what you say you want it to be, but this would not be easy at all and would take more effort than it seems you're willing to put into it.

now I am NOT saying your wrong for not wanting to really get into modifying it, not at all, as most wouldn't, and as no one really has on the 2nd gen, but without really modifying it, it will remain "what it is", and it will continue to suffer from excessive oversteer at the limits and less than sports car handling, because it is what it is... that is not a cop out, it is the truth. I too was unhappy with what my fx was in the handling department, so I did change it and I did make it handle like a sports car. along with this I have also made it ride like a sports car too, and had to trade off some comfort for performance in doing so. this is possible on the second gen too, very possible, although a bit more difficult than a first gen, but it would take a lot of effort and dedication and yes, even some money to actually do it :) since were talking about doing something that hasn't been done, the ONLY way to do it is you would have to pioneer it and do some research and some development. there is a reason why no one else has done it yet... it's either that or just sit and wait to see if anything ever becomes available... it may someday,,, good luck with that :)
 
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Who said I wont do coil-overs? coilovers will not cause an alignment issue, unless you lower the car. You can get the benefits of stiffer suspension without lowering the car. I have no problem with a coilover option, if someone had a confirmed solution of which ones work, and what were appropriate springs, I'd buy a set. But apparently they do not.

Dont knock runflats, please to god do not tell me that you think a performance car cannot or should not have run flats because it hinders performance, please tell that to Viper, Corvette, Porsche and GTR owners. That is not true that they dont provide a performance benefit, they can. Its called side wall rigidity.

It seems that people prefer to live in the paradigm that there are no options out there, so just accept it. I am not a fan of that mentality.

I'll go it alone.

I appeciate the help people attempted to give (and some did) with relivant and helpful feedback.

Jon
 
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jonv8944s said:
Who said I wont do coil-overs?
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jonv8944s said:
I realize a nice set of coil-overs would likely be the fix, but with no good options right now, I need to look for alternate solutions.
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:)


The long and the short of it, is that is seems that there has not been much progress out there in terms of solutions to the handling problems you're looking to fix. Go out there and try out some of the solutions that have been discussed and report back with your findings so that the site can benefit the next guy. I hope you're able to figure something out to make it better.
 
Right, again, I'll do coilovers in a second if there is an confirmed solution/option for them. Its not that I 'wont' do them due to some perceived issue I have with them, its that from my searhes on this forum, I do not seen a confirmed option that works.

I do not think I am contradicting myself with those two quotes, unless someone tells me I am wrong, that the ARE confirmed good coil over solution, I am just stating its not an option so I'll have to look somewhere else. (until there becomes a confirmed solution).

---------- Post added at 04:10 PM ---------- Previous post was at 04:06 PM ----------

It seems as if I am upsetting the apple cart by asking about wanting more, or even knowing whats out there. Maybe I am used to enthusiast car forums where people and vendors are chomping at the bit to improve the current cars offerings. I know enough people/engineers/vendors from my past cars, that I can inquire as to what some of these folks are able to do, even if its a one off just for me. Its not the prefered method, but I can do it. Perhaps even something like revalving the stock shocks could help (I know a guy who can do that). Like I said, since my inquiries seems to cause angst amongst members here, I can work on the puzzle elsewhere.

Jon
 
I would buy coilovers with a high spring rate and make sure the shocks are valved to match the spring rate. In regards to the no rear camber alignment fix, I would simply lower the second generation FX to reach the lower limit of the factory specifications or maybe a hair out.

I have no experience with ANY of these manufacturer. I would point you to Kido, but they haven't designed them yet.

XYZ - no idea of spring rate:
http://www.ebay.com/itm/2009-11-10-...35&vxp=mtr&hash=item1c15f13d79#ht_2975wt_1185

KSport - F:16kg/R:14kg/mm spring rate.
http://www.ebay.com/itm/KSPORT-KONT...X35&vxp=mtr&hash=item43aa02ce46#ht_1089wt_952

D2 - no idea of spring rate:
http://www.ebay.com/itm/D2-RACING-R...35&vxp=mtr&hash=item336fda9878#ht_3092wt_1185

NEX - 12kg/10kg setup:
http://www.ebay.com/itm/NEX-FULL-SU...35&vxp=mtr&hash=item5ae5143727#ht_2749wt_1217
 
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