Hi, I am a new G37 owner, and I am looking into dropping my car for daily driving and occasional track driving.
I thought my researched info might help people here to choose a lowering springs for their needs.

Here is the info!

Stock
F 8.5kg
R 8.2kg

Eibach
F 9.8kg (+15%) -1.2"
R 9.5kg (+15%) -0.8"

H&R
F ?kg -1.5"
R ?kg -1.4"

Tein S tech
F 6.4kg (-25%) -2.1"
R 4.9kg (-40%) -1.9"

Tein H Tech
F 5.8kg (-32%) -1.5"
R 4.7kg (-43%) -1.1"

Tanabe NF210
F 7.6kg (-11%) -1.0"
R 7.2kg (-12%) -0.7"

As I finished my research, I noticed that tein & tanabe's spring rates are signeficantly softer than stock.

I can easily imagine that if you lower the car as much as it does with those softer spring rate, it will bottom out the shocks, and loose traction right there, so these wont work for people who wants to increase the handling performance.

It looks like the Eibach is the only choice for me to achieve both handling performance & looks.

 

Welcome to the forum and thanks for compiling the info. The softer springs you mentioned will NOT bottom out the shocks. I had the Tanabe NF210 before my coilovers as have many others and it's never been reported of them bottoming out. I can't speak from experience on the Teins, but I doubt they do either.

 

You know for only $700 more you can move to a full coilover set and get full height adjustment and a much much better ride. When you factor in install cost.. it's worth the extra to do this once and do it right. I've got a set of Eibach's already mounted on struts collecting spiderwebs in my garage....$700 pissed away.

Just to give you a few ideas.

 

Thanks a lot for your experienced opinion on Tanabe.
It is good to know that they dont bottom out.

But I read that there are people saying that the tires are rubbing against the fenders on springs other than Eibach. I dont think they are experiencing that simply becasue it is too low. I believe that spring rate is a big factor for that issue because you need greater force (spring rate) to support the vehicle's shift in weight through due to the smaller distance in between tire & fender.

Also, by lowering the vehicle, the roll center is farther a part from the center of gravity, which creates more body roll, which is another reason one would need to stiffen up the rate. I am sure that those softer springs will induce more nose dive too.

My goal is not so much to simply lower the car but I am looking for a performance increase in my vehicle. This car is not only a daily driver (so coilovers are out of the question) but it is also going to see occasional tracktime. So I want to keep my suspension setup simple but effective.

 

Me myself started as occasional track driver. However I soon found out that tracking is much more addictive than any other legal or illegal substances.

Here are several reasons I changed to Coilovers.

1. With springs my children at the back seat were like bobble heads. My daughter shouting "slow down".........

2. During street use I did not have any problem. However at the track rear seem to move, of course the tires will slip. But just that weary insecure feel from behind. You know when you have to go to the bathroom to relieve yourself...... something in that nature.

3. Adjust bump and rebound for specific use. My car is daily driver so when I dial stiffness on mid range during street use. Before I go to the track I dial them stiffer depending on the track, weather, and etc.

4. Even after springs have settled, I did not have had any problem with Tanabes rubbing. But I did encounter issues when I got wider rims and tires.

I just want to give you a honest advise. You will find yourself going to the track more often. You will want to change to coils. So instead of spending money on springs. Get coils, a little short cut will save you money in the future. I did regret spending my hard earned money on Springs.

 

Thanks a lot for a helpful opinion.

I DO understand that tracking the car is the addictive sports.

I currently have a car with an AST Coilover for the track event only, and I like it a lot. May be I should not even think to use my G37 for track event, but I miss RWD characteristic on the race track, since my track car is AWD.

Anyway, as I mentioned, this car will be used on the street more than 90% of the time, so I want to go with simple lowering spring for this car.
Also, I dont want to spend a lot of time to set up the suspension with coilover for this daily driving car. It took a lot of time and money to set up the coilover the way I really want on my track car.

I read your experience with lowering springs, but luckly I have had fewer issues with lowering springs than coilovers...The issues I had were acutually on Eibachs....All the Eibachs (all !!) I have had either made some noise or sugged badly in short period of time. So, I am not really a fun of Eibach, but as I read this forum, I dont see much issue for this vechcle application.

I am not 100% sure, but Tanabe might be riding on bump stop too much due to the soft spring rate. In fact even just driving on straight way, it might be riding on it.
As long as you study your car's suspension stroke, and trim the bump stops, it should not give you a bad ride as you mentioned.

Cars now a days uses the bump stop as a part of spring, so you should be careful on this when you set up your suspension. Even coilovers are used with long bump stop on real race scene now.

Again, I have not even seen G37 suspension, so I am not sure on this car though.

Once again, thanks for your advice!!

 

I would wait to see what swift is going to come out with. I would maybe look into doing the IPL shocks with the swift spec-R springs.

 

I just Eibach's second hand for 185 to my door. After I install them I get to test one side of the springs vs. coilovers argument for less than 200 dollars.

A quality set of coilovers you can trust not to make noise will run you 1500 to 2000. Then when you lower the G anymore than springs do you will need front and rear camber arms or you will destroy your tires with bad alignment. So that's another $500 bucks, not counting cost of install. As you can see, it snowballs pretty quickly.

That being said, if I had the dough I would have bought coilovers, just like I would have bought a Top Secret twin turbo kit

 

Really?
Will Swift release one for G37?
Let me call them just to make sure since Swift is my favorite brand.
I will update the info after I speak with them.
Thanks for your info.

 

slammed on....

 

just got the eibachs installed....the rides not drastically noticeable...you might notice it a little, but it's probably in your head. The drop is just right and no complaints. =)

 

Is there any additional information regarding Swift springs for the G37? Does anyone know if the Swift G35 springs will work for the G37/G25?

 

T&L, are the OE spring rates you list initially of 8.5F, 8.2R Kg for the G37 coupe or the G37 coupe "S" model? What model year?
I measured my 2010 G37 S sedan springs at 8.4F, 7.8R
Thanks, Thomas

 

I agree with BB I have the Tein S Springs and not one issue on Bottoming out... Soft ride...thats funny...Im stiff as a Corpse. Doesn't bounce very firm and corners are tight!

 

One your guessing on springs and Such...not really knowing if each spring or coil.
BB shared his experience on the Tanabe yet my own with Tein. My Coupe doesn't nose dive yet while gunning out from a dead stop handles great.

You speak about rubbing and such but if you'd look into it more its based on our wheel set up!

Things would change if one was to have different size Rims, Tires, offsets all to be considered in any factor..

Those lowering specs are not accurate, some are even lower or some not close... thats a base line spec... once it settles in or wheels come into play changes it all..

If your that concerned on this...key word "ASK" if you havent had a G ask around... till then IMO is just purely Speculation Dear Watson.... lol