bigpow

2008 Touring Roadster, recently went from stock wheels/tires/springs to the following:
18x9.5/10.5, 255/40/18-275/40/18 & Eibach lowering springs (stock suspensions)

I noticed significant changes in handling:
- high speed cruising at freeways is more stable, easier to center, less noise (probably due to the tires).
- But on the twisty roads, it feels sloppier. More understeers. It made me drive slower than before, just because I couldn't really feel the car that well anymore.

I'm just an average driver, not a racer or anything, but since I drive these roads a lot, I could feel the difference right away.

Is this expected with my new setup?
What can be done to improve this, at least to put it back to stock feeling?

I love the new look and all, but the loss of handling worries me a bit..


Thanks in advance!

MicVelo

First up, check tire pressures. If you are indeed understeering, I'd suspect that with the 255/275 combination, you may have more air in the rear tires. Re-set if needed. Run the fronts at 36, rears 34 as a baseline. Adjust as necessary.

And what specific tires did you put on? Construction varies by tire type and brand so that could also contribute to the uneasy feeling.

With all the new hardware, did you get the car aligned? Or at least have it checked?

Eibach ProKit springs lower the car "only" 15-19mm and with that amount of lowering, alignment might be OK but should be checked anyways. I run ProKits and did have to re-align - but my reason for doing so was to bring the tires back closer to the middle of the stock alignment range to give them a chance to live a little.

Note: adding adjustable alignment hardware (front UCA and/or rear toe and camber hardware) will be necessary to correct camber & caster up front and camber & toe at the rear.

Did you put the Eibachs on stock shocks? If so, that could also upset the balance of the car, possibly adding too much roll stiffness to the front (while creating insufficient damping to the rear).

Worst case scenario is to add new shocks and/or adjustable sway bars to tune the suspension to add a bit more roll stiffness.

But start with the tire pressure and see what that does.

rancor

What are the tires, they will have a big impact on the feeling. How many miles have you had the new tires on; are they even broken in yet?

HRMoneyPit

Should have went square

travlee

iTrader: (8)

my money is on he didnt get it aligned and toe/camber is off

mr. sparco

iTrader: (13)

Wider wheels and tires do numb up the steering feel from stock for daily grocery getting. It feels less nimble to me. I have multiple sets of wheels and tires (all different setups), every time I switch it up which is often, I can feel a difference. If the handling feels sloppy, you may want to get new performance shocks to complement the springs.

bigpow

I'm taking notes...
Will try them out and report back.

I'll check tire pressure and try 36 F and 34 R.
Also, scheduled for alignment check in 2 weeks.

I'm a bit concerned that I might have to pay again for the labor to transfer the Eibach springs on new shocks. I did bottom out twice already...

Much appreciated!

travlee

iTrader: (8)

you will.

Spike100

Hi bigpow… I went from stock springs, shocks, sway bars, and 18x8” wheels with square tire widths (245/40 front and 245/45 rear) to aftermarket spring and shocks (Tein springs and Bilstein shocks), larger Nismo sway bars, and 245/40 front and 275/40 rear tires.

I did experience some disappointment the first time I ran this setup for the same reason you mention. It felt “sloppy,” especially when comparing to the square width setup I had been running before the conversion.

I did what Mic mentions. I checked the tire pressures. The fronts were less than they should be and less than the rears. I increased the fronts to 36-37 psi and dropped the rears to < 35, and this helped a little.

Mic also mentions that tire selection can have a noticeable effect upon handling. I agree, and here is why. I was previously running Continental Extreme Contact DWS in a square width setup (245/40-18” F and 245/45-18” R). The handling with this was very good.

After installing new springs, shocks, sway bars and wheels, I went with Continental Extreme Contact DWS (245/40-18” F and 275/40-18” R). The handling was a little disappointing. It was a little better, but not what I hoped for, and it actually felt a little sloppy in certain situations.

I believe the disappointment in handling is based in sidewall rigidity. All-season tires (Continental Extreme Contact DWS being an example) have softer sidewalls than summer performance tires. That is one reason the AS tires provide a more comfortable and more quiet ride. The problem with AS tires is they are more “wiggly.” So if you mount more narrow fronts (my case is extreme with a 30 mm difference front to rear), the rears overpower the “too-flexible” fronts, and you experience wiggling and under-steer.

For a staggered setup (20 to 30 mm difference front to rear), I’m going to mount summer performance tires with a stiff sidewall. I’m guessing but believe that will make a noticeable improvement in handling.

bigpow

They're Hankook V12 Evos.

travlee

iTrader: (8)

to me those had alot of sidewall flex

mr. sparco

iTrader: (13)

Agree with Trav on that, those are fairly soft. Going from Advan a13s to V12s made my car feel more comfortable.

terrasmak

iTrader: (8)

How many miles are on the stock shocks ?

Did you get the car aligned ?

Understeer making you drive slower, do you know what understeer is?

VenomGT9

iTrader: (1)

Adjustable sways would be something to look into once you dial the right pressure.

bigpow

26k miles on stock shocks.

Perhaps I use the term understeer incorrectly, since I'm just a typical driver not a pro.
What I'm getting at is, I feel that the steering response is slower now compared to before.

Just made me realize, is it possible that I'm actually going faster than before?
And that's why it's making me scared now?
Too bad that I don't have 2 cars with 2 different setups to test back to back, that'd be ideal..

MicVelo

As someone (Mistuh Sparco, I believe) mentioned, often times going to a wider contact patch and overall size tire can create something of a numb-on-center feel to it. It's a tradeoff though.... lose a little feel, pick up more ultimate grip.

I feel the same way about my Bridgestone PP S-04s but have learned to just live with it. I hate trading off razor sharp response but to pick up the additional adhesion, it's one of those necessary evils sometimes.

Plus, as someone else mentioned, those tires you chose, while in the Max Perf category, do tend to be a little mushy and a tad less responsive according to surveys I've read on TR. Mitigate this a bit by running a higher pressure, maybe up around 40/38 for twisty driving.

bigpow

I went through the alignment check and it wasn't bad at all. Toes and cambers were adjusted to specs. The front camber are slightly off.

I've learned a bit more about the new characteristics of the car. I think it's a faster car, much better grip than stock.

I played around with tire pressure and it seems to help a bit.

I'm actually quite okay with it now, I guess I just got used to it.

Maybe later, I'll revisit the sway bars and shocks upgrade, but I'm gonna put to rest for now.

Thanks all.

If anything, I probably should have gotten the continental DWS tires over the Hankook. These V12 have great grip, but boy they're loud.

travlee

iTrader: (8)

Jwt, change fork and pivot ball also

MicVelo

Uhhhhhhhhhhh.......



Cross post???

travlee

iTrader: (8)

Oopsie.... it happens

You can delete them mic