Correct.

Actually, they may be better with stiffer struts, but not with stock.

This is one area I have been testing. If I fit my 205/50/16 wheels and tires there is a lot more roll and sway than with 175 / 65 R15 stock tires.

So, I want to use my 205/50/16 wheels and tires for better road grip, what will counter balance this problem?

 

I understand from other forums that Roll Center Adjusters will solve the problem better than having reinforcement bars installed.

Based on J's Racing's website:-

The roll center of a fit was corrected and special parts that were able to be changed to ideal geometry were remade this time.

The effect of the roll center adjustment before succeeded in the improvement of a further effect to the geometry change by having changed the angle of action fulcrum as it was.


【 roll center adjuster 】

The [rowaa-mu] angle worsens and the position of the roll center has fallen on a fit that drops height too much.
The amount of the roll increases because the body center of gravity and the roll center part, and the cornering force is sacrificed.
Moreover, the suspension stroke decreases, too and the limit lowers.

The roll center that has fallen can be corrected to the ideal position by installing J 'S RACING roll center adjuster (The body center of gravity and the distance at the roll center are corrected to a short position), and ideal suspension geometry is achieved.


【 effect of installation 】

For instance, because it greatly influences a fit etc. that unite [daunsasu] etc. , a full effect is brought to all fits made [ro-daun] regardless of the genre.

- A decrease in amount of excessive roll by [ro-daun]
- Earth feeling of tire and improvement of steering wheel information
- The steering wheel (reception desk tire) : to a quick response so far.
- The cornering force (grip power) is greatly increased.

They are [ro-daunfitto] indispensable parts that can be used comfortably even on the street though they are special parts that appeared from super-endurance and the attack participation knowhow of time.

In the lower postion of Fit(Jazz) doesn't have good condition with the lower arms. It will give high speed cornering to your car. it cause from collection with geometory of lower arm angle.

Below are the link & pix:-
‰pŒê–|–ó ƒEƒFƒuƒy�[ƒW–|–ó - ƒGƒLƒTƒCƒg –|–ó





What's you guys' opinion of the RCA?

 

At present, I'm only lowered about 20mm with the full Mugen Suspension.

 

Roll center adjusters will definitely help as far as performance and stability goes, but they're not completely necessary if your GE8 is just a daily driver. But hey, if you're baller, then go for it. I'm planning on getting a set for my DB8. Anyway... The reason why the Tanabe NF210 allows the car to sway a bit is because of the spring rates. They're pretty soft due to the fact that the NF210 was designed with the focus on comfort more than performance. For example, if you were to take your GE8 to the track, it would be ideal to have a stiff suspension setup.

 

The wider tires seem to be the problem. I don't know the answer to this. There must be a simple cheap solution. Unless it's the rubber on the Good Year F1's I am using, but they are new.

 

Whose 205/50x16 tires are you using andthe wheel width?
And what air pressures?
Usually wider tires with 35-40 psi will be more stable and not prone as much as oem tires. And of course some tires have sidewalls that are flimsier than othrs. more air pressure is required.
Wider tires do tend to track the unevenness of unsmooth roads much more than narrow tires. Most describe it as darting back and forth over the rioad. Uncertainty if you will.

 

I am using Good Year Eagle F1 GS-D3 205/50z/r16" tires and I have tried various tire pressures. I think 40 psi does help a lot, but it is a very harsh ride. I like to keep my tire pressure within Honda specs.

Actually, we had the car up on the lift today to check the Mugen suspension along with everything else and all looks perfect.

On a good flat expressway the car feels good, but even then it's finding every little imperfection on the road. It's felt more at low speeds. Driving around the city it feels very floaty.

We had the same feeling with the coilovers and various spring rates and damper settings were tested by the supplier.

Everything comes back to the tires as stock tires feel fine.

 

Honda specs are for oem tires and 205/50x16 aren't oem. When you go to a wider tire there has to be higher tire pressure to have the tire take its proper cross-section. Less pressure mens more flexible sidewalls and hence more wallowing in the car when encountering wavy surfaces.
And if you are on narrower rim wheels, say 6", the wallowing is more pronouced. And a Mugen suspension, being stiffer, will increase the tendency for tires following imperfections because it is a suspension for performance not looks.

 

Honda recommends 205/15-16s with its Mugen Fit wheels. I'm sure they also recommend a new tire pressure. Figure out what that is to eliminate the guessing game.

 

There is slip and tip....

Bigger tires, stop the slip of the car... but not the tip. In fact around turns you'll go faster because you won't be slipping and will in turn "tip" more because your suspension is not tuned for that tire. Sway bars IMHO are band-aids for suspensions.

They want to have agressive spring rates, but don't want to have a stiff or harsh ride. While it works, it does tend to make the car have have too much spring rate in purportion to dampening rate.... that is why alot of cars feel too stiff. Less dampening of the spring rate during movement.

 

I am not sure if a rear stabilizer bar will help the front much in this case. They are mainly used for more stability when cornering.

I forgot to mention that my wheels are 16x7 JJ and on the inside of the wheel reads ET 4.0 and from what I have read they are perfect for 205/50z/r16" tires.

I must admit, I don't know much about wheels and tires, but I do know this has something to do with the wider tires.

 

I just fitted a 16mm rear stabilizer bar and it seems to have helped the rear a lot, but there is still a problem on the front driving over slightly uneven rod surfaces.

This has something to do with the Fit's body flexing a lot especially on the front after installing any stiffer suspension and wider tires. This is the strange part, with stock wheels the car feels fine, but not as much road grip

I am going to try installing these 2 front lower suspension braces, but I think the front lower control arm brace may do the job by helping the suspension do it's job correctly. Any ideas welcome.



I think these 2 lower front braces no 5 & 6 do the same job.

 

Just fitted the 2 point front lower brace as in no 5 in the post above that links the control arms.

Everything seems much better on the first test run on uneven roads and it seems like it's allowing the suspension to do a better job with less body flex.

Maybe, I'll install no 6 at the weekend. They're easy to install, straight bolt on. Only $70 for the 2 pieces.

 

Oooh, I need those, Lek.

So are those parts only available in Thailand? Hmmm...LOL :-)
Me needy. Can you get these? Wonder how shipping would be?

 

Actually, the Ultra Racing parts look stronger than these. I just bought them to test and if they solve the problem I will buy better quallity ones.

 

Hmm...are the UR bars thicker? better welds? Just curious. I can't afford the prices they have on the bars.

 

The 2 point front lower arm is the one that does the job. The car feels much firmer and the car doesn't roll so much on uneven roads. Just buy the 2 point lower bar to tie the control arms a bit.

Update:

When I first test drove the car with the front lower 2 point bar it felt much firmer straight away, but after driving over 200km today the car is bouncing a bit again.

This must be the result of poor quality hollow light weight aluminium. I know the fix, so all I need is a stronger better quality bar. The question is which brand? Maybe Summit Racing http://www.tsthailand.com/

 

I put in Tein Super Street a few days ago, which did a great drop lowering my ride and improving my handling. For the ride comfort sacrifice, I hit turns super well, though it's obvious that I'm going to start looking into these bars (chassis flex is still there).

I highly recommend Tein if you're down for putting down the bucks. They make great suspension kits.

 

I know I'm piss off a lot of bench racers here, but here goes...

For those who aren't really in-the-know with coilovers - they really aren't useful in spirited driving/DD driving. If you don't have the capacity to corner-weight your car and have your car professionally setup - then don't buy coilovers. Improperly setup coilovers can actually ruin a cars balance and handling. If you're building your Fit for track duty and hardcore Auto-X/street driving then its worth the money. But be prepared to spend a lot to do it right. I've seen numerous street driven cars with strut based suspension setups and good swaybars and good tires run very well on tracks and auto-x courses. I've also seen lots of Porsche owners go out and slap on megabuck coilovers only to promptly crash their cars on an on-ramp. A good coilover will give you adjustability, lots of tuning potential - but at a cost of ride quality and lots of money.

As from what I've seen a good strut/spring combo along with aftermarket sway bars and sticky tires are the best suspension combo for DD/canyon driving. Progress and Eibach, along with Sprint make awesome springs. For struts, Konis, KYBs or (if you were planning on buying coilovers and have some $$$) Showa Mugen dampers are where its at.

For starters, a rear sway and sticky tires will make a huge difference.

 

^^^ so what you're saying is not to get coilovers if you're just going to use your car for DD, right?

Damn, I wanted to get coils because of the adjustability of the ride height. That's my main reason for wanting to get coils and I have big friends that ride with me so when they go in the car, the car goes down considerably and with coilovers, the ride height won't be affected at all. Well that's what I heard. I was so close to getting the Tanabe DF210 springs but decided against it because I wanted the ride adjustment options of coilovers.

So, now I'm basically confused lol. What should I get?? I want to get coilovers, but as like you said, I don't want to sacrifice ride comfort since that was a big factor for me in buying the fit. Overall though, I still want to lower, but which way??

Sorry for thread jacking!!