I already posted this in the Wheel forum, but I was hoping I might get a response here as well. Does anyone know the effects on lowering this particular vehicle (G35 coupe/sedan)? What I mean is, besides inducing more negative camber, how do we affect the rest of the geometry on the vehicle. Are we going to induce more wear on pivot points by lowering it as far as the Eibachs do? How do they affect our roll center/axis as well as roll migration? What about inducing more bump steer? I do not know how much room (in the geometry of the vehicle) there is for lowering the G, and I was wondering if anyone else has done the research with this. In many vehicles, lowering the car can induce unwanted effects, but the driver *thinks* that it feels better because he has increased the spring rates, and it feels stiffer. Mustangs are a perfect example. Lowering the car will put the front roll center through the ground, and this throws off the roll axis to a terrible angle. This in turn produces too much understeer, and the car plows through everything. How do the shocks/struts work with the eibachs? Are the Sport package shocks/struts more capable? Is there going to be enough dampening for the higher spring rates? How do they effect the VDC/yaw sensor? These are just a few of the many questions I was wondering before I decide to put them on my car. Thanks in advance, if anyone knows the answers.



'03.5 Brilliant Silver Sedan
Premium, Aero Kit/Package, Sport, Winter
Stillen Air Box, Clear Corners, Alum Pedals

 

Man, you ask some tough questions. Please let us
know the answers when you find them!

2003 Twilight Blue 5AT Sedan, sunroof,
Graphite Leather, splashguards,
GG/DB red 12 wire Hyper-grounding kit,
350Z intake duct, Stillen Hi-Flow Airbox

 

My thoughts are that I don't think I will lower my G. I bought the sport tuned suspension and it feels tight enough for me. I think lowered cars look killer. But I don't like their tradeofffs. Also you need to have some suspension travel to absorb the shock. This is especially true if your driving at a high rate of speed.

On my 94 SHO I replaced the stock suspension with eibach springs and tokico struts. It lowered it only slightly. It made a real difference in the handling. The one thing I don't like is I have to be super careful about going up ramps in to parking lots. I scrape the front facia when I back into my driveway. I don't want to deal with those issues with my G



Jim
'03 Sedan
Brilliant Silver/Graphite
6MT/ Premium package
Sport tuned suspension
Aerodynamic Body Kit
Navigation and Satellite Radio

 

This car should be fine with some sway bars if you want to stiffen the suspension. I don't plan on doing anything other than that and maybe a rtsb if one comes out.

as far as the wear point and bushings and such, an inch shouldn't hurt anything, This car has the same suspension as a Z and the R34 Skyline so I think you will be safe.

Only time will tell however and there is simply not enough data to tell

Better Life thru Chemistry

 

Khsonic03,

I lowered my G with Eibachs about 2,500 miles ago. The only issue I have is my splash guards scrape the the rial at the car wash I go to! That's it! I just got an alignment last weekend and that made a bit of difference. The rear camber was off a little and realigned to factory specs or within 0.01. The front toe was off a bit and that was put back to factory specs no problem! I think lowering looks great, it performs the same as I too have the sport package with the tigher suspension and I also believe turning has improved. I get out less further in tight turns than I used to and understeer seems to be reduced somewhat too.

Guys, don't be afraid to lower your G's! Dealer saw it and said nothing! Performance same as sport and if you didn't get sport, Eibachs will give you sport. Plus it looks unreal (see above!).

'03.5 G35 BS Sedan (I love that acronym!)
Stillen Intake, 350Z duct
Hyper-Ground Kit
Lowered!
Bulbs all around!
Splash Guards - Aero
Need Exhaust, Twin Turbo or NOS!

106554-DSCF0020s.jpg

 

I don't doubt that it looks good and feels better, the only thing is that you still don't know what the long term effects are. Obviously camber is going to be off, and you are going to get more toe-in, but that still doesn't show what else is going on in your suspension setup. I am concerned about roll center and axis, as well as more stress on critical pivot points that will not show itself for several thousand miles. Not to mention the possiblility of other suspension dynamics being thrown-off. What about VDC? Even if there are no warning lights being triggered, we still don't know hoe it is affecting the system.

'03.5 Brilliant Silver Sedan
Premium, Aero Kit/Package, Sport, Winter
Stillen Air Box, Clear Corners, Alum Pedals

 

Hey Chiphead,

Did you keep the original sport shocks (front and back) or did you go with a new set as well? I have the same setup as yours (eibach prokit) and i am planning to change out the shocks. If you change that out, which did you get?

-PratG35

 

pratG35 (Newbie)
09/20/03 11:35 PM

Hey Chiphead,

Did you keep the original sport shocks (front and back) or did you go with a new set as well? I have the same setup as yours (eibach prokit) and i am planning to change out the shocks. If you change that out, which did you get?
__________________________________________________ _

Curious, why? What is wrong with the way things are now? And what struts would you be reinstalling?

Ivry 6mt sed
Crawford Pleneum
Injen CAI
22" resonator
Cusco sway bars
350Z springs&struts
Enkei RPM2

 

My Eibach dropped 1.5 in the front and 1.3" in the back. The original shocks were meant to operate at a specific hight (travel) and dropping the car cause the optimum operating range of the shocks to deviate. So since we are now outside that optimum range, the shocks can bottom out more causing quick ware and tear.. I have heard others in the list suggesting changing the chocks also when lowering.. that's all.

-PratG35
-PratG35
<font color=blue>Silver 2003.5 G35 Sedan 5AT / Sports and premium <font color=blue>package</font color=blue>
<font color=blue>Stillen CAI </font color=blue>
<font color=blue>6 Wire grounding </font color=blue>
<font color=blue>Battery Quick Disconnect Switch </font color=blue>
<font color=blue>Eibach Pro Kit </font color=blue>
<font color=blue>350Z Intake Duct</font color=blue>
Stillen dual catback exhaust (when it comes out)
Crawford Performance Plenum (considering)

 

The stock struts are not equiped with progressive valving. They give out the same rebound and compression performance regardless of where the piston/rod is in relationship to the shock body. But their is a relationship between bottoming out the struts internally and quickened wear. However it is caused by the springs having less travel and part of that travel is done on spring rates that are lower than stock. Add in having less suspension travel and how the Eibach's final spring rates aren't really any different than stock, sometimes softer and you have the receipe for bottoming out more offten.

Your eibachs use a initial spring rates of 259 front 359rear and a final rate of 334 front 413 rear stock is
357 front 407 rear. Word to the wise, Eibach's developement car for the sedan springs, was a non sport sedan. So that was their baseline.

Ivry 6mt sed
Crawford Pleneum
Injen CAI
22" resonator
Cusco sway bars
350Z springs&struts
Enkei RPM2

 

That means that you need higher spring rates to reduce bottoming out on the stock shocks/struts. Otherwise you need to obtain more aggressive valving for the eibachs and/or more internal bump travel, although that might cause issues with other suspension components wearing quicker due to over-extended travel of those parts.

'03.5 Brilliant Silver Sedan
Premium, Aero Kit/Package, Sport, Winter
Stillen Air Box, Clear Corners, Alum Pedals

 

You got it. Running stiffer springs on stock struts is the main reason for premature strut wear, not to mention the control issue's and lowered performance from weak dampening to spring stiffness issues.. But with the Eibach's, their not stiffer than stock so that's not a factor.

Ivry 6mt sed
Crawford Pleneum
Injen CAI
22" resonator
Cusco sway bars
350Z springs&struts
Enkei RPM2

 

Gsedan35,

I guess I am a little thick up there. Let me conclude that since I originally have sports suspension with stiffer springs and shocks and now that I have eibach pro kit springs, that becaues the eibach is 'less' stiff than original springs so therefore my original sports shocks works with eibach well and I don't need to do anything... phew.. a long sentence..

Is my understanding correct?
Thanks much appreciate your input and insight. Thanks to you I just saved a few hundered bucks, enough for my Crawford Plenueum.. [img]/w3timages/icons/smile.gif[/img]

-PratG35

 

I have seen some Z guys over at my350z.com that have over 25K miles on their Eibachs with no problems. One guy, I think had 30K miles on his original tires with only slight wear due to camber issues. I really think that the prokit will work fine with the coupe with little to no adverse effects.