Ok guys so here goes - i know this thread is useless without pics, so i will get those up this weekend. In the meantime here are the results for some discussion:

2009 G37X with G37S coupe springs

The original height was about 4.5 - 5 fingers in the front and 4 fingers in the back (supergap) - with the springs installed it is now about 3.5 fingers in the front and 1.5 fingers in the back (so i got some of that droopy bum) I ordered some spring isolators to try and fix the rear a bit while i look for another solution for the springs that works perfect without any "fixes"

Took the car in for alignment - front is obviously within spec, the rear is sitting at -2.1 camber and thats as far as they can go...

When comparing the springs at the shop, both front and rear were exactly 1" lower than their X spring counterparts so it looks like the springrate in the rear springs is obviously not strong enough to keep up the rear (as the drop would have been even if they did)

I dont want to go with eibach's as i think they drop it too low for Chicago roads and I dont want to buy the front camber kit (im fine with purchasing just the rear tho) and i dont want to be at big negative camber.

Strangely it seems that even though the X's are supposedly heavier in the front, it negatively affects the rear (see Tanabe springs droopy bum on the X)

So thats about it.

And here are the pics!





Even though the drop is not that low in the back (compared to some other cars on here) you can see that the drop is uneven.

Front height:


Rear Height:


Here is the difference in the springs. These are the rear springs, the front ones were the exact same difference.
The right one is for the X and the left is the G37S coupe:



-IgS

 

For further research - has anyone tried to install regular sedan stock springs on the X? im just wondering if the rear would drop more than the front?

I was also looking on H&R's site (http://hrsprings.com/scripts/appguid...ind3&MakeID=15 ) and they came out with some new parts: G37 Sedan and G37x Coupe.

I know the H&R springs everyone was using before said they were for the gen2 sedans while they were the same parts as the 1st gen and dropped the car waaay too low - so looks like this might be addressed in the new springs. And the G37x coupe srpings give a more conservative drop than the Eibach Xcoupe springs.

My thought on this is technically the coupe springs should work on the sedan as long as the spring rates are fine. Since the X coupe is just a tiny bit heavier than the sedan (40lbs) im thinking maybe these would work???

thoughts?

 

Why not just go with the IMPULS if you want just a weak drop?

 

$700 for springs is a bit much...
if they were in the $400 area i would've picked them up right away.

 

How about 370z springs? Would that be an option?

 

No, unfortunately i dont think it would work. I believe a member on here tried to use just the fronts on his lighter 08 G35 and the front was low and i think he had some issues too.

 

370z springs work fine, I've been running them since Aug and have had ZERO issues. Ian had an issue that I think he figured out was something he had done himself.

 

Are you running both fronts + rears? What are your fender gaps measure at?
And looks like you have a regular sedan, not the X right?

 

mine looks just like Ian's in his thread

https://g35driver.com/forums/v36-bra...xperiment.html

 

Im dropping tomorrow using the stock Sedan non-AWD springs....

 

Awesome, good luck to ya, and let us know how it turns out, im very curious if the butt will sag (hopefully not!!!)

 

need to see pics!! and update on ride quality please lol

 

spring install is done (we didnt get to the GTSPEC braces unfortunately). Not going to hijack this thread but the rear was lowered the right amount for me. The front is hardly noticeable but hopefully that will change with settling.

im going to wait a week or so for the springs to settle, then ill post a review with pics.

 

^^ yes that would be great bat, im actually looking into getting just the back springs from the sedan, so looking forward to you review.
It would be good to know how much your front gap is. If its bigger than mine, might look into using the coupe fronts and sedan rears.

As far as the ride quality: I can say that I feel the back feels a bit too soft, just feels that the back is a bit more "loose" Its in no way bad, maybe i just expected more and its in my head as i keep thinking that these springs were not made for this... I had friends ride in my car and they said it feels the same, so it might be a placebo effect.

This might open up some experiments for mixing springs - but i feel that all 4 springs should be from the same model as they are "designed" to perform together - but i might be wrong on this as i dont have too much knowledge in suspension, just speaking from experience.

 

ill try and get some measurements and pics soon. i may try some coupe fronts if you are lower