I just purchased an '08 G35 (sedan) and everything is stock. I am considering to upgrade the suspension to either Tanabe or Eibach but I could use some help on making that decision. I prefer a ride that is smoother and less-rigid on the road (commuting and ****) but when I really push the car around a corner or windy roads, I want it to have a bit of a stiffer stance and not lean so much. Let me know what you think regarding the suspension.

As for another upgrade, I noticed that when I am decelerating from 70+ mph, the car begins to jiggle a bit towards the front, but according to the dealer, they completed a full inspection and I am pondering whether or not I need new brakes, or I should upgrade to something a little better.

I am new to this concept and Infiniti's as well so don't be an @ss, and let me know if you have any valuable input. Thank You!

 

SWIFT springs are the way to go if you will be using stock shocks.

 

Before you lower you sedan try Motordynes swaybars/endlinks, that will keep you car from leaning in the twistys!....Gary

 

If you want handling, then you want to mod your car so the tread of the tires stay on the road surface for better traction, so obviously the best mod you can add are a great set of tires. With that taken care of, because they keep your wheels to the ground, your struts and shocks are the next item you want to swap out. Once that is taken care of, sway bars should be next on that list to apply weight on the wheels evenly. All the strut bars, tie bars, cross braces, etc... technically do nothing for more traction but they will improve your steering feel. Just remember that the chassis can never be too stiff, but the suspension can. Another item I would add on the list for better steering feel is adjustable tie rods.

If you want looks, then just drop your G with springs or coilovers. Springs do not do much for handling, if anything they just stiffen your suspension making it feel like you have bigger sway bars while you are destroying your struts and shocks - the one part that is actually keeping those tires to the ground. Some argue that it lowers your center of gravity, but it actually shifts your center of gravity in a negative way. It also prevents a lot of sway, which while we want to eliminate most of it, we need a little sway for better handling (as you go into a turn, the outside tire needs to travel a further distance than the inside tire in the same amount of time, so the outside tire needs more traction which it gets with weight being shifted to that side)

 

If the comfort is a big factor I would either recommend staying stock or getting some fairly good quality coilovers like KW V2's etc. Despite what others say, all the lower end ones like BC, Stance, Function Form, etc. are even remotely as comfortable as stock and if you don't want a substantially harsher ride, they probably aren't what you're looking for.

That being said, if you just want your car to handle a bit better on spirited driving I would go for sways and as dofu said stickier tires first. Those alone will give you a much better feeling on the twisties. After that consider springs/struts or coilovers.

 

Eibach coils aren't bad either.

From my understanding they are just repainted KW V1's at a cheaper price point.

 

Swaybars are a waste of money if you know what you want to do with your car; you can easily achieve that with a good coilover setup. Call Odi at Feal Suspension and have him build you a custom set. The Feal 441 are made to order with custom spring rates and custom valving. If you are unsure what specs to get, call Odi and he will set you up. They are a "Budget" coilover, but he uses swift springs and hotbits shocks tailored to your vehicle. They are also rebuildable in the US for a very good price.

 

They are, but they don't have adjustable dampening

 

Maybe that's important for someone like you but we're talking about the OP's needs.

He just wants something to lower and not be too rigid but provide good handling against body roll.

For the price imo, your looking at Eibach (KW).

The preset dampening likely has drivability in mind as well as improved performance.

Idk about you but since I got my set... I haven't touched my dampening once.
For DD, I think its more than enough.

 

He wouldn't need the dampening for performance likely, but if he wants comfort having the ability to adjust may be helpful. Just a week or so ago someone posted who had a similar desire to maintain comfort and was not pleased with the comfort of the v1's. If he has the means to go for the v2 he will have that added safety net of dampening adjusting to keep it to his comfort level

 

Your right, it would be helpful.
Mind you the price difference is about $500 between the Eibachs and the V2's.

I think comfort on coils is largely subjective.
Coils will almost always be much stiffer than oem.
However, KW's are supposedly on the more comfortable side of the spectrum.
Now if someone who hasn't tried out any coilovers at all goes to the V1's, of course they will feel stiff. However in comparison to its competitors it will be much better.

I'm not trying to really argue with you here.
I believe your points are valid.
I just want to try and take this from another angle.
I hope the above wasn't too confusing. It's 1:35am... writing this before heading to bed lol.

I think it's really a matter of budget.
Mine was near the $2000 mark. After researching, my top picks were the Bilstein Pss10's and the KW V3's.

However, IF I were to go to a lower price point, my pick is Eibach.
Just me.

 

^ Totally agree. It's hard to advise people when thing such as comfort and handling are so subjective. Some think their slammed, stretched tires stance setup are comfortable, others find even slightly old oem struts uncomfortable so it's hard to know what people's comfort zones are. So when someone asks for comfort setup, if their budget allows it, I generally try to suggest them some good quality coils like Kw's with dampening so they have a higher chance of being happy with the comfort. I'd hate to advise someone to get the coils and then have it way too rough for their liking.

But I totally agree that v1's/Eibach's are great coils for the price even without dampening adjustability. Heck, if I didn't want to try out the fortune auto coils that I just got, I would have gone with either Eibach/v1 or kw V2's.

 

My biggest question is are you planning on tracking your car (at a road course) or autocrossing? I kind of assume from your post that you are not.

If that is the case, then you should be more interested in how your car feels through turns and not your real cornering ability. If you want to maintain a nice ride and have less body roll in a corner, the answer is obvious, anti-sway bars, as many people have said. You should get anti-sway bars that maintain the balance of your car; you want to increase the front and rear by the same amount.

The number one performance mod for your car is nice tires, but just as a warning, with nicer, stickier tires, because of the increased peak lateral forces, your car will end up rolling more in corners.

In terms of ride quality, your spring rate really is determined by your ride height. You generally want softer springs for ride quality (and traction!!). So the best is if you don't lower your car, and keep it at the stock ride height. If you really care about ride quality, if you keep your car at stock ride height, you can actually get softer springs if you never load up your car. The stock design has some extra bump travel in case you have 4 passengers and/or cargo. Similarly, if you are happy with the stock ride quality and don't plan on having passengers or luggage, you can lower your car a tiny bit with the stock spring rate, which will continue to work with the shocks. But this will INCREASE the amount of roll your car has.

If you are intent on replacing your suspension components just to say you have, then again it depends on what you want. In any case, if you change springs or coilovers, you first want to make sure the rear wheel rate is about 10% higher than the front wheel rate. Suprisingly not all suspension setups or coilovers maintain this, which will give you a terribly harsh ride for no good reason at all. This is because when you go over a bump in the road, your front wheels see it first. (http://www.optimumg.com/docs/Springs...Tech_Tip_1.pdf)

Cheap budget systems like the taiwanese/japanese crap usually will be overdamped and their spring rates are all over the place. That means that it might increase your steering response at the initiation of a turn, but then mid turn you will lose traction and your car balance will be off, and you will have less traction basically everywhere. They will also usually have a much harsher ride.
Good systems will give you better turn in, and better traction, but they will feel a lot looser and you will feel your car move more. Their ride quality is usually a lot better than the crap stuff.

In terms of the brake judder, try bedding in your brakes first to see if it goes away. It might be a lot of things.

Hey dofu, a lot of what you say is like half right. I recommend you start reading some real books and get some good basis of vehicle dynamics. I used to think random things I picked up over the years too, then I spent some time actually doing some learning and my concepts have completely changed. "Tune to win" by caroll smith is like a classic, and pretty awesome. the motoiq series on suspension is also a must-read (http://www.motoiq.com/tech/the_ultim..._handling.aspx). I managed to borrow "Fundamentals of Vehicle Dynamics" by gillespie, THE textbook from a friend, and it is pretty awesome, though pretty heavy on the math.

Weight transfer is basically a function of center of gravity height and wheel base. Decreasing weight transfer is good, because tires are non-linear in terms of normal-force to traction (why decreasing weight is good). Minimizing lateral weight transfer is good because it increase your total available traction for cornering. That is the main benefit in lowering your car, and one of the benefits in getting wider wheels.

Lowering the car will actually produce increased roll, which is not a good thing. Read the moto-iq article for other problems with over-lowering. You also need to run stiffer effective spring rate when you lower, which actually decreases traction.

Anti-sway bars mostly control peak roll angles, which decreases the time to get to peak roll. They also change the balance of weight shift (ie they can decrease the weight shift at one axle by increasing it at the other). There is some theoretical minus to them because you start tying your wheels together instead of having a truly independent suspension, but I've seen a lot of people (like caroll smith), claim that practically this doesn't come into play much. Though with stiff sway bars you do get decreased droop travel, and can get in-lift if you planned your suspension poorly, or ride over a bumper/zebra.

Anti-roll bars are a great compromise if you cannot sacrifice the ride height. If you are designing a track only car, then yes, first you want to lower your car, then choose springs stiff enough to support your lowered car without bottoming. Or you can go the opposite route, since years of experience have shown that a max spring rate of 2-2.5 is what most cars end up with, you can calculate your ride height backwards from there.

In any case, after that, if the driver is still unhappy with the amount of roll and the time it spends in transition, then your only real option is bigger anti-roll bars instead of stiffer springs. Similarly, if OP does not want to run stiffer springs

 

The reason I recommended sways/endlinks is because he still wants a comfortable ride and cut down on body lean, sways will do most of that. Coilovers/Springs will not give him a OE ride and will require a complete camber kit. (done right!) I suggested the sways as a beginning because that may be all he needs for his sedan to have fun. A set of Michelin Pilot Super Sports will give him more grip playing in the twisties....Gary

 

i love my tanabe nf210s