I am looking to upgrade my 2004 G35 sedan factory Sport Tuned Suspension for overall handling improvement in everyday driving. Right now I'm 100% stock riding on GSDs in 215/55/17.

I'm thinking of migrating to F1 GS-D3 in 225/50/17 (on the stock rim), lowering the car with Eibach springs, and adding adjustable swaybars. My goal is to have better gripping tires, better ride at slower speeds, and looks. Since this size is not as tall as my stock tires (and there already is a fender gap from the factory) the Eibach will improve looks as much as it will handling and comfort. My questions focus on the springs.


1) Once the Eibach springs are installed and the car is lowered an inch or so, will the installer be able to figure out and perform a four wheel alignment using the factory adjustments?
2) Are there any other considerations or components I'm missing?
3) When lowering, will my HKS exhaust lower along with the rear bumper, or will they hit eachother?

Thanks


2004 Sedan 5AT STS
Huper Optik Ceramic 50/Underbody Diffusers/Clear Corners/Brake Cover
GroundingGear 7 Wire/Z-Tube/Stillen High Flow Airbox/HKS Sport Exhaust/Technosquare F-Spec ECU

 

1. Yes, if they have an alignment machine. I hear that Hunter makes one of the best around. The front suspension is not adjustable but the rear toe and camber are a little (Despite the techs best efforts camber may be a little out of adjustment)
2. You can consider a rear camber kit to bring it back into spec. You may also want to consider that when you lower your car it puts added stress on the factory shocks, causing them to wear out faster. You will probably need to buy new shocks/struts in a year or so. Tokici D-Spec or Koni are very good.
3.NO!! (the will not hit) Lowering a car lowers the whole car together. Think of it as your car with about 10 people in it. The suspension is compressed at all four corners (uniform squat due to weight). Now when you lower your car, you are using shorter springs insted of added weight to get the car to squat.

Also there are many people in this forum that used factory 350z suspension '04 to lower their cars. You can pick one up used from my350z.com for about 150 to 250 (shocks/struts and springs)


04' Sedan 6MT Silver/Graphite/Premium/Aero/HuperOptik/XM
Z-Tube / Stillen- Sways, Airbox & Grounding Kit
19x8.5/9.5 Hiros / S-03s 245/40 & 275/35zr19
Coupe Suspension

 

Aviator,

Let me make sure I hear you right . . .

1) Lowering alone can take my car out of alignment, despite the best efforts of the tech.
2) In year or so my shocks will need to be replaced. I can choose aftermarket ones that will then last longer.

Is this right?

2004 Sedan 5AT STS
Huper Optik Ceramic 50/Underbody Diffusers/Clear Corners/Brake Cover
GroundingGear 7 Wire/Z-Tube/Stillen High Flow Airbox/HKS Sport Exhaust/Technosquare F-Spec ECU

 

1. It really depends on how much you lower your car. The rear camber may be slightly out of adjustment. That doesn't mean your car is all screwed up, it just means that it is a little out of factory specs. You can get a pair of camber arms for about 220 made by kinetix. However a lot of members run their cars with the camber slightly out with no problems. Your car will have increased negetive camber. This means that the top of the wheel will be angled in by a couple of degrees. This actually helps traction in cornering but lowers tire life as the inside of the tire wears faster. If you look at most racecars the have this negative camber. I see that you are planning on keeping your stock wheels which means the effect of the camber will not be as severe as someone running a wider tire. I'm pretty sure you should be ok.
2. I am not saying that they will definetly need replacement but I am saying that they will not last as long. Again many members are running lowered with their stock shocks with no problems......yet. Our cars are just too new to make a guestimate of the longevity of the shocks with a lowered setup.

Now with all that said, I am pulling my knowledge from info I have gleamed from this forum and past experiences with other cars. And not all cars are created equal. There are a few others on this site who have more knowledge or who might be able to explain it better. Hopefully they will chime in and give their two cents.

Check out these links for more info:
https://g35driver.com/forums/showfla...sed&sb=5&part=

https://g35driver.com/forums/showfla...sed&sb=5&part=

One more thing, I just ordered a set of Eibachs for my sedan but then decided to go more agressive. They should get here on tuesday and I will be looking to unload them. I paid $225 shipped. If you are interrested we can work a deal next week.

04' Sedan 6MT Silver/Graphite/Premium/Aero/HuperOptik/XM
Z-Tube / Stillen- Sways, Airbox & Grounding Kit
19x8.5/9.5 Hiros / S-03s 245/40 & 275/35zr19
Coupe Suspension

 

I have the Eibach kit with 225/50/17 Eagle F1's and it looks and handles great. The tires made the biggest difference in handling, IMHO.
I also have the Kinetix rear camber kit, now my rear camber is within spec...not so on the front. You will see increased wear on the inside of the tire, but honestly mine doesn't seem too bad at all after 8K miles or so. The negative camber does wear tires faster but also makes the car handle better...so it is a trade-off.
On your muffler issue it will be more of a problem dragging the ground than hitting the bumper....mine (stock)scrapes occasionally.

 

A couple of shots Eibach springs and Eagle F1 in 225/50.



332222-Cnv0016.jpg

 

Another.



332223-Cnv0015.jpg

 

Thanks Cook,

One question: is it me or does it look like your sedan sits lower than the Eibach advertised 1.1" drop?

Miami

2004 Sedan 5AT STS
Huper Optik Ceramic 50/Underbody Diffusers/Clear Corners/Brake Cover
GroundingGear 7 Wire/Z-Tube/Stillen High Flow Airbox/HKS Sport Exhaust/Technosquare F-Spec ECU

 

Until Cook replies, here is my 2cents. Different people have gotten different results. Some have reported about a 1.5in drop. You will just have to do a search to get more info.

I have sedan sport springs in my garage, coupe springs on my car, and eibachs and tein 350z H techs on the way. I am going to take measurements and pictures of all four side by side and post them next weekend.

04' Sedan 6MT Silver/Graphite/Premium/Aero/HuperOptik/XM
Z-Tube / Stillen- Sways, Airbox & Grounding Kit
19x8.5/9.5 Hiros / S-03s 245/40 & 275/35zr19
Coupe Suspension

 

I'm not sure as I never measured. Also keep in mind that the 1.1 advertised drop may be the initial measurement. The springs/shocks will tend to settle over time and indeed, I did feel they went slightly lower after the first few weeks. Also, the rear has a full tank of gas and 4 cases of water from Sam's, so it may appear a little lower.

 

Aviator and Cook,

Another question about negative camber. In your cases, I understand your cars to have more than factory spec negative camber due to your mods. From an aesthetic point of view, can you tell visually? In other words, if you stand in front of your car (or behind it), can you visually tell that the top of the tire is somewhat inward?


2004 Sedan 5AT STS
Huper Optik Ceramic 50/Underbody Diffusers/Clear Corners/Brake Cover
GroundingGear 7 Wire/Z-Tube/Stillen High Flow Airbox/HKS Sport Exhaust/Technosquare F-Spec ECU

 

If you stare hard enough you can see it, but a casual walk-by would reveal nothing. Remember I have the Kinetix camber arms so the rears are in spec. Hoenstly I think the front camber is now about the same as the rear, so they "match" so to speak. Keep in mind the stock specs call for a little neg. camber in the back.
I would at least get the rear camber arms, that way you can rotate front to back and get more total life out of your tires. They are not too expensive...$200 or so if I remember correctly and very easy to install.
Also if you are staggered you can still rotate side to side by dismounting/remounting. I used to do this with my 540 because the neg. camber was so bad in the rear, plus I had 265/35's which made it worse. The inside would wear much faster, but the wear would then shift to the outside after the rotation. I got almost double the life on the tires by doing this.

 

Thanks guys. Aviator, I would be VERY interested to get your feedback after your next suspension upgrade.

Regarding the Tokico D Specs, I called them yesterday and was told the shocks adjust from the top, and that they would not have to be removed every time I wanted to make an adjustment. I looked at my car, and while that's certainly true for the front shocks (top is accessed under the hood), I was unable to find the tops of the rears in the trunk, even after removing the lining. What's your take on this?

2004 Sedan 5AT STS
Huper Optik Ceramic 50/Underbody Diffusers/Clear Corners/Brake Cover
GroundingGear 7 Wire/Z-Tube/Stillen High Flow Airbox/HKS Sport Exhaust/Technosquare F-Spec ECU

 

Yeah, I'm not really sure. I had the same concern you did. If I have to remove the rears to adjust them, it will be a pain in the ****, but not as bad as the fronts at least. Also, once I get to a good setup, I probably won't touch them very much, if at all. I will post my findings later this weekend if the Hurricane doesn't hit Jacksonville. Right now I am taged to fly one of our jets to Dayton OH if it keeps its current track.

04' Sedan 6MT Silver/Graphite/Premium/Aero/HuperOptik/XM
Z-Tube / Stillen- Sways, Airbox & Grounding Kit
19x8.5/9.5 Hiros / S-03s 245/40 & 275/35zr19
Coupe Suspension

 

Aviator,

Well, the latest intellicast.com track shows it hitting north central florida, not JAX. On the other hand, I don't know how accurate the computer modeling really is . . . read Charley.

2004 Sedan 5AT STS
Huper Optik Ceramic 50/Underbody Diffusers/Clear Corners/Brake Cover
GroundingGear 7 Wire/Z-Tube/Stillen High Flow Airbox/HKS Sport Exhaust/Technosquare F-Spec ECU