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Discussion Starter · #1 ·
Hey Guys,

Call me old or a wimp but I have a degenerative back problem and the stock setup kills my back even in soft mode.

Some have mentioned that after installing lowering springs, changing the suspension mode ACTUALLY makes a difference.

Is there ANYTHING (coilover, lowering springs, sleeves, etc.) out there that will make it slighlty softer in the soft mode and at least as stiff as stock in the R mode? Maybe coilovers with softer than usual springs and reduce the compression and rebound?

BTW, it's for an 2009 w/ 28k mikes.

Thanks!
 

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Get non runflat tires and the ride will get a lot better. I suppose some non-RFTs are softer than others...
 

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My Blizzaks actually made my ride smoother and quieter...
 

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Get non runflat tires and the ride will get a lot better. I suppose some non-RFTs are softer than others...
Both of these will soften up your ride quite a bit. Keep in mind though, it will always be a bit stiff for a GTR
 

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Discussion Starter · #8 ·
Hey Guys,

Thanks for the replies!

So lowering springs will definately soften the ride a bit?

I've tried the Pirelli run-flats and hated them the minute I had them. Made the car swarm around too much on high speed bumpy corners...I believe due to the softer sidewall. Also lacked big time in overall grip, cornering and braking. Started with the Bridestone RF and now have the all season Dunlops which are way better than the Pirellis. I personally wouldn't recommend the Pirelli's...for ride or performance.

Thanks again!
 

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These are valuable info for me as well as a new GTR owner. Thanks.
 

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I have the 275/40/20 and 315/35/20 Nitto Invos and the ride is awesome compare to stock tires. Since I run oversized, the sidewall is more plus it is softer to start with. You will feel the difference immediately.

Perhaps some 2012 struts, and possibly springs...

Maybe some softer side wall tires (Nitto Invos come to mind).
 

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not to be a butt head, but maybe you should buy a Toyota or honda if you want a soft ride. NOT a sport oriented car like the GTR.
 

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Just get a good set of NON RUN FLAT tires, and it will make a world of difference. Or if you like straight line performance, get Drag radias as they have squishy side walls which make for great straight line comfort and power hook, but horrible in high speed turns.

Try some Michellin Pilost sport, non runflats. Used them on my vipers and loved them. (Viper came with run flats, hated the stiffness).

Jon
 

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Hey Guys,

Call me old or a wimp but I have a degenerative back problem and the stock setup kills my back even in soft mode.

Some have mentioned that after installing lowering springs, changing the suspension mode ACTUALLY makes a difference.

Is there ANYTHING (coilover, lowering springs, sleeves, etc.) out there that will make it slighlty softer in the soft mode and at least as stiff as stock in the R mode? Maybe coilovers with softer than usual springs and reduce the compression and rebound?

BTW, it's for an 2009 w/ 28k mikes.

Thanks!
Not any lowering springs will give you want you want- check with other owners. Go for a ride if you can.

Swift lowering springs are about the same rating as stock and are progressive. 1" drop helps handling and dash controls for R mode and comfort are enhanced.

Non runflat tires Michelin Pilot Super Sport 275/35-20 front and rear - fits both
http://www.nagtroc.org/forums/index.php?/topic/35902-swift-springs-finally-in-stock/page__st__80
$372 each 300 treadwear 27.6" tire diameter. If you don't have a contact already then try [email protected] Extention 294
The reason for not staggering the front and rear tires is that you want the same tire diameter front and rear and the sizes are not quite a good match.

You want a tire that will match the GTR's performance but ride smoother. Soft sidewalls help comfort but won't be up to par for handling if you drive aggressively.

One warning, non runflats means you might need a plan for a flat tire and tread wear will vary with your driving tendencies- I have heard from other owners that non runflats can wear fast too.
 

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The OEM Runflat side wall is stiff as bricks, and contributes to much of the firmness you speak of. I agree with a few of the other posters, simply switching to a non run flat makes a world of difference in overall smoothness.
 

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I switched over to non runflats and never looked back. Nitto NT555 275/35/20 r and 245/40/20 f. Huge difference in ride quality and much cheaper. Of course you sacrifice handling but I never track my car so I don't really care.
 

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The GT-R comes stock with progressive rate springs, meaning they are softer when extended and stiffer when compressed, by having the coils wound tighter at one end of the spring. So initial spring rate is low, moving up to a higher final rate at limit cornering or in bump. The Eibach springs were designed not to change the rate but simply to lower the ride height. I spoke directly to an engineer at Eibach about this. So they will not be softer than the OEM springs.

http://www.nagtroc.o...post__p__381960
"I spoke to David Cortez at Eibach today about their spring kit and about the stock GT-R spring rates. He was very helpful and here is what he told me.

Stock spring rates (Eibach's own measurements on a GT-R in Germany):

Front : 119 N/mm average rate (0, +- 20 mm deflection, +- 40 mm deflection). Max rate is 151 N/mm or 862 lbs/in. At static ride height, rate is 140 N/mm or 799 lb/in

Rear: 67 N/mm average rate (0, +- 20 mm deflection, +- 40 mm deflection). Max rate is 78 N/mm or 438 lbs/in. At static ride height, rate is about 68 N/mm or 382 lb/in.

Eibach spring set rates (product # 6389.140):
http://eibach.com/cgi-bin/htmlos.exe/08142...421399500022212

Front : average rate not given. Min rate is 399 lb/in. Max rate is 948 lbs/in. At static ride height, rate is 948 lb/in as soft coils are touching.
Drop is 0.8"

Rear: average rate not given. Min rate is 188 lb/in. Max rate is 485 lbs/in. At static ride height, rate is 485 lb/in as soft coils are touching.
Drop is 0.5"

They use progressive rate springs to essentially control the static ride height (saves using a second tender spring and spacer), and with their design, the static spring rate is the same as at full compression. Their goal was to increase front and rear spring rates by a modest 15-20% and to slightly drop the ride height. That way dampers can handle the new springs without requiring a change in valving."

So Eibach springs are stiffer than OEM.

http://www.nagtroc.o...post__p__382490
"Actually the progressive wind type is different on the OEM and Eibach springs. At static ride height, the Eibach springs are in the 15% stiffer range than OEM, but as the OEM spring compresses, it gets stiffer while the Eibach is already at maximum stiffness (starting before static ride height compression), and at that point the Eibach springs are only 10-11% stiffer than OEM. Most people would not feel much difference. Eibach springs mostly lower the car slightly, not requiring new damper settings."

The Swift springs are said to be progressive as well, and are designed to lower the ride height, essentially doing the same thing as the Eibach springs.

Swift/MCR's

Spring rate:
Front 5.4kg to 15kg, 302lbs - 840lbs
Rear: 2.4kg to 7.0kg, 134lbs - 392lbs

They provide a 1" drop"

So based on the Eibach measurements of the OEM springs in Germany, the Swift springs are virtually identical in maximum rate to the OEM springs, except in the rear where the Swift ones max out at 392 lbs/in versus the OEM rears at 438 lbs/in max. I doubt you could tell the difference as it is only a 10% change.

A large part of the stiffness is the run-flat tires as others have mentioned, and the damper valving. Even in comfort mode, the damper valving is very stiff. It is apparently better in the 2012's, but they have also made many other changes in the 2012's suspension, including changing the suspension arm geometry, caster, etc. So just changing to those 2012 dampers might not gain you as much in comfort as one might hope, but I don't know of anyone who has tried that. Another item is the stiffness of all the bushings, which is not something you can alter by going to softer bushings. I am not aware of any softer springs for the GT-R, or softer dampers. And when you go to race mode, it is just the damper that changes valving, so you cannot go to a softer comfort setting and maintain the same stiffness in Race mode.

I think pretty much the only option is tires with a softer sidewall, or custom springs, or a pillow.
 

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Claude, with all due respect I can catagorically state that the Eibach springs DO in fact increase compliance versus the OEM springs. I first placed Pirelli P-Zeros in the OEM sizing on my '09; ride was markedly improved. When I had the Eibachs installed, the ride improved again; (i.e. increased compliance), and there seemed to be much more of a difference in 'comfort' versus 'R' mode in the suspension settings versus the OEM spring. When I sold the car, I had the Eibachs replaced with the OEM springs but kept the P-Zeros on the car. The ride home from Dallas; (about 480 miles), showed me again that the OEM springs are 'stiffer' than the Eibachs, regardless of suspension setting. My first hand experience correlates with others who have replaced the OEM spring with the Eibachs; (and the Swifts also iirc).
Bish
 

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Bish, no replacement with first hand experience with the Eibachs. I got the info direct from Eibach above which says their springs are slightly stiffer than OEM, at static ride height. It would be normal since if they lower the car, you need to make the springs a little stiffer to avoid bottoming out. Perhaps their progressive wind makes them softer when they extend above the staitc ride height position than the OEM springs at the same position. He did not say what the minimum rate of the OEM springs were. That must be where the difference lies.But he read all the numbers to me from their actual test sheet made in Germany, and max front rate of the OEM is 862 lbs/in vs 948 lbs/in for the Eibachs. But those are just the numbers. Swift springs have a max front rate of 840 lbs/in vs 862 for the OEM, so essentially the same. Could be their min rate of 302 that makes them softer when the car lifts above static ride height. I guess that just tells you it is hard to know the specifics of progressive rate springs without seeing the deflection curve.
 
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