That's why a lot of people change the full set up. Springs and shocks.

 

YES

No, spring rates are well documented.
https://g35driver.com/forums/brakes-...reference.html

the z has the same spring rate in front--314, so if you have the sport suspension(front stock G35 sport spring rate is 314) the only concern you have is alignment/tire wear issues.

The rear coupe springs from oem cpes with 17s/18s(3 red dots) have a spring rate of 342 which matches stock sport springs.

Numerous sedan owners like Daveb, jimmyc13, g35freak86, have done this. And to the extent that they changed shocks and struts from a z had more to do with the fact that they did not have a sport suspension and the spring rates were too high for the nonsport shocks/struts.

dave b has done numerous spring combinations and given detailed write ups on handling and the like...so its not like people just throw shiit on and hope it works.........

And if you go with eibach, they actually did all the R&D on a non-sport G35 and expect this to be a one size fits all for sport suspenions--looks like lazy cost cutting to me and so much for the big R&D dollars from major companies.....they didn't bother to do R&D on a sport susp.--guess it cost too much money and time.... so I would argue that zfront/gcpe rear is actually better for sport equipped cars

 

looks like i'm partially owned haha... but what about the dampening rates of a Z or G or even G sedan?? rebound and compression?? are they the same?

say someone does a mix and match combo.. im sure shocks would almost have to be done also to keep the car completely safe right?? or no?

 

Nismoboy... I agree to what you are saying to a certain extent by mixing matching springs/parts etc. However, I currently have the z suspension with z springs in the front and coupe in the rear. The only difference between z springs and coupe springs is the spring rate. By adding a higher spring rate in the rear (revised z springs) it enables the rear strut to work properly. I have been riding on it for over 3 months now and it rides/looks even better than stock. Sure looks aren't everything but I did look into this extensivly because going with such a Frankenstein setup was new to me. The G and Z and pretty much the same car on the inside. Sure they have differences, obviously. But they are designed by the same engineers and ideas.

In other words... if someone thought that putting z fronts and coupe rears in our g's was unsafe and wrong... no one would have done it. Think of it this way....cutting stock springs is cheap, easy, and effective..... but you don't see us g people cutting springs and taking the easy way out.. right?

 

yea i see what you're saying.. i guess in the end.. if you're happy with the end result no matter if you mix/match or buy something thats already made for the car.. thats all that really matters.. my only concern i guess was how safe it really was on a technical basis (with numbers and whatnot).. not just opinions, or hey it looks nice or hey it feels nice... but is it really safe?? you know what i mean lol..

and please people.. don't even think for one second about cutting your springs or even heating them up... if you do.. don't drive next to me.. i don't want you bouncing into my lane haha

 

lol yeah We understand what you're saying and appreciate your concern. There are proven numbers/stats, as Texan1 staed earlier. It shows the spring rates and everything you need to know

 

Thought I'd chime in and give you my experience with the Z/coupe with Sport shocks setup and puts some minds at ease.....maybe

First off, I'm highly critical of mods I do to my car which means I expect a lot from the mods and rarely will I accept a compromise for a mod. My G came with the Sports suspension and it's a pretty firm setup for OEM. My first drop came way of the coupe springs. That drop was good for about .6" in the front and about .8" out back. The rears looked perfect, but the front still looked too high. I was a bit concerned about camber issues with the 350Z springs, but I decided to take the plunge because I wanted the front to look better. By my calculations, the Z springs up front (a crack over a 1" drop) would closely match the rear gap of the coupe springs out back. I got the Z springs on upfront and I was right, the drop was very level (within a couple tenths). I believe I was the first one to run this setup as well. I really didn't change the spring rates over the OEM Sport spring setup so I figured I was good to go.

With this drop, I noticed no degradation in ride quality and impact harshness. The only compromise I saw was a little more pogoing at lower speeds (<35mph). I was willing to accept this compromise. I was able to get the car aligned to coupe specs, but keep in mind there is more camber, front and back, over the sedan spec. Last year, for any experiment, I put on the Z springs out back. They gave about a .4" slower drop (nearly tucked the rear tire). I really didn't like the ride or the feel. On undulating pavement, while in a turn, the car felt a bit loose. Wheel travel felt compromised on larger bumps as well. I put the coupe springs back on after a week.

I ran this setup for over a year on the OEM pos Bridgestone Turanza tires. I got about 41K miles out of the tires (bought the car with 22K) and didn't have any funky wear issues. An important note hear is the Turanza are asysmetical which means you can run them in any direction. When the Turanzas wore out, I bought a set of directional 215/55R17 Avon M550 tires. Buying directional, especially these tires, was a mistake. The tires were fine at first, but after 6K miles, the tires started to roar. Upon my typical 6K rotation, I noticed the inner edge of the front tires were feathered, a common problem on the 03/04 350Zs and some coupes. I rotated the tries, front to back and the noise went away until 6K miles later when the same damage was done to the swapped front tires. It turns out that even at coupe alignment specs, the damage was being done to the front tires because of excessive camber and the castor angle (neither of which is adjustable). It turns out this issue just wasn't a coupe/Z issue either. Q45s and 300ZXs suffered the same front tire fate. Lesson learned. Rotate more often and don't buy directional tires for these cars.

By now, I had 20K miles on my Avons and they roared badly, but still had 25% life left. After some research, I learned that you can run a direction tire backwards once the miles piled on because the water scavaging effect of the tire was pretty much gone. I ran the tires backwards for about 2K miles and knocked the feathering down a bit which quelled some noise. In March of this year, I got some 18X8 rims with 235/50R18 tires. The setup has a .6" wider contact patch so I knew I was in for tire wear issues. I bought asymetrical Pirelli PZeros so I could rotate the front tires, side to side. I rotate the tires every 2K miles and I really haven't had any tire feathering issues at all. I let the tires go 3800 miles last time and I did get some very slight feathering, but that's not bad seeing I let the tires go 1800miles longer. I rotate the rears, side to side, every 5 to 6K miles. The tires have no wear issues even thought there is a bit more camber out back. I've got about 8K miles on the tires and they should be good for about 20K miles or so which I good for a summer performance tire.

Eventually I may go with the Z shocks because they have a 1" shorter shock housing which means you'll gain nearly 1" of wheel travel back. That's never a bad thing.

Long winded ressponse so here are the Cliffs:

1) The ride quality with the Z/coupe/Sports shock combo is good and really no different than the Sports suspension setup.

2) The car should align to coupe specs, but keep in mind there can be tire feathering up front.

3) Make sure to use asymetrical tires

4) Rotate the front tires often, side to side (2K miles)

 

I was going to sell my 350z Htechs to a friend with a G35 coupe, in the tein book it says, .7 Front and .6 Rear for the 350z. About how much of a drop will it provide on a coupe and does anyone have any pictures of a coupe on 350z Htechs?

TIA

I aligned my car with Sedan specs and havent had a tire wear issue in over 30k miles of driving. If you align it properly, you shouldn't have problems with tire wear.

 

the drop you quoted is for 350z s-techs IIRC, the drop for a Z is .3"/.2" so on a coupe it should drop it .8"/.7". Your mileage will vary on that though, especially in the rear

 

Thanks for catching that bud, you are right... I will also align the car after we lower it....my sedan is in spec with no camber kits on it right now with those same springs... every car is different, so it may be possible to pull it off?

 

You can't align a 1" dropped sedan back to sedan specs without using adjustable camber arms, camber bolts, etc. It impossible.

 

+1, the ONLY adjustment is front "toe-in".

 

You freaking kidding me, this is one of those arguments I can win with proof. I own an alignment machine (http://www.hunter.com/pub/product/al...ems/index.htm), I can throw my car on the rack and print my cars specs and they are all within tolerance.

 

LMAO, you have rear toe and rear camber adjustments also, but nice try bud.

 

To the OP for what it's worth, I'm running 350Z H-Techs on my coupe, OEM shocks, without camber kit or align (since I don't have a camber kit the place told me they couldn't do anything for me). The front tires have a tiny bit of inside wear but not too noticeable, the rears have a noticeable amount of uneven wear.

I am getting SPC rear camber kit installed in the coming weeks, along with an alignment. I've had them sitting in my closet for half a year just never bothered to install them. So in my experience, with the 350Z H-Techs, rear camber kit is necessary, front not so much.

I also am not 100% happy with my drop because it is too conservative, however I would not be able to get out of my garage if it were any lower.

I can't imagine paying for springs, install, and dealing with potential camber issues on OEM Z springs that drop the car even less. It won't even be noticeable and definitely not worth your time, money, or headache.

If I could do it all over again, I'd have bought Tein Basics, front and rear cambers, and called it a day. In fact when my OEM shocks blow, that is exactly what I am going to do.