Not sure how many of you are using these, i thought i would give them a shot. Supposedly the spring rates are based off of the 05+ Z's and they claim a 15% stiffer rate, sways are made by Hotchkis for COBB:



I will be putting on the sways this weekend, springs and struts are still waiting on additional suspension pieces before I put them on.

Using the calculator link below, I came up with this:

Front
wire diameter = .55-in
mean coil diameter = 3.95-in
free coils = 5
Using this it measures 436-lbs/in

Rear
wire diameter = .60-in
mean coil diameter = 4.465-in
free coils = 4
Using this it measures 535-lbs/

Might use the same calculator later on the extra set of stock springs I have just so I can compare apples to apples. The only weakness of that calculator is it doesnt take into account material tensil, which for OEM and Cobb I do not know exactly anyway and its not like I have a spring dyno sitting around.

 

Keep us updated on how they go. I was also looking at these. Cobb makes great products for subarus, we shall see.

This may be a stupid question, but what struts are you using? Stock?

 

right now im using oem suspension, i have my tokico d-specs ready to go but im waiting on additional suspension parts before i install them.

as for the sways, they're a nice fit (made by hotchkis) and provide a nice flat feel to the car. i feel i was lucky because i didnt have any issue with seized bolts during install which can always be a frustrating pain.

my one complaint about the cobb springs is they did not come with sping coil wrap on the first bottom coil. having one will cut down on any noise potential. stock comes with one and so did the previous teins i was going to use earlier. however i was able to peel off the oem pieces and put them on the cobb units.

compared to g35 springs, these are substantially shorter.

 

Interesting. Thanks for the update let me know how it goes. I'm looking for a decent suspension setup and I'm starting with hotchki sways.

 

Also, what would you think of cobb springs, hotchki sways, and stock struts?

 

Well i was able to go for a little drive in the car today and its an amazing improvement, the car is nice and flat. I have the rear at med-stiff and the front at second-stiff.

The cobb springs will be fine with the Hotchkis sways as the cobbs sways are the same. I would think that Cobb did do some comparison testing with the combo before releasing it as a package...as for stock struts, if they're not new you're going to overwork them fairly quick. I would try to get some D-specs new or used to fully utlize them.

 

front from the top:


front from wheel well:


rears:

 

Be prepared for the front end 'clunk' as your endlinks begin to go.. Depending on how you drive.. you may have a few months before you start looking. I got the Powergrid endlinks for the front - doing great so far.

 

I wonder why the end links keep failing on you guys the guy i race with (mpowers) has the stock end links on springs struts and shocks no problems even under race conditions.

 

maybe he has hearing problems?

 

Got any before/after pictures from the side???

 

COBB Bars

Front Bar Rates
Position 1 = 25% Stiffer over stock
Position 2 = 50% Stiffer over stock
Position 3 = 85% Stiffer over stock
Position 4 = 135% Stiffer over stock

Rear Bar Rates
Position 1 = 85% Stiffer over stock
Position 2 = 130% Stiffer over stock
Position 3 = 190% Stiffer over stock

Hotchkis Bars

Hole 1 = 1525 lbs/in (22% Stiffer than stock)
Hole 2 = 1845 lbs/in (48% Stiffer than stock)
Hole 3 = 2270 lbs/in (82% Stiffer than stock)
Hole 4 = 2855 lbs/in (129% Stiffer than stock)

3 Position Adjustable Rear 15/16"(24mm) Tubular Bar (5.5lbs)
Hole 1 = 520 lbs/in (80% Stiffer than stock)
Hole 2 = 655 lbs/in (125% Stiffer than stock)
Hole 3 = 840 lbs/in (185% Stiffer than stock)

Not exact copies, but very close. Sounds like Cobb has a great combination there. I jut bought a USED Hotchkis TVS1 kit. It will go on soon so I don't have any reviews. The Cobb kit sounds like it's about the same, but has stiffer springs and lowers more. I would have gotten it if I could find it used.

I'm a budget racer. My budget is small.

 

It is weird. I have talked to ppl that have end link failure and those that don't. Sorta like other Z problems...

 

I think a big portion of endlink failures depends on how hard you drive the car. If you don't stress the link, the failure never happens. Personally, I beat the snot out of my car on the backroads of North Carolina and at the race tracks.

 

Hi, do you know, or anybody know of anyone using Hotchkis 350z springs on both 350z and G35 coupe, I live in Australia and after market susp parts are in short supply for these cars, I own a 03 G35 coupe and wanting a moderate drop, Ive located a new set of Hotchkis 350z springs here in Aust, Ive also emailed Hotchkis in the US, and they quote that there specs are identicle on both 350z and G35 coupe, can anyone supply me with some info, actual drop hight, and ride quality, and spring rates, if possible! Sorry to bother you, but you seem to know a lot about these springs [Hotchkis and cobb]. Hope you can help with any info before I purchase. Thanks Geoff, from downunder!

 

You posted in my FAQ thread on G35driver the first page tell's you everything your asking here.

NOTE!: Any aftermarket 350Z spring will lower a coupe a additional ½” over and beyond the published drop amount for the 350Z.

Hotchkis 350Z Linear springs .6”/.8” drop on 350Z G35 drops will be higher
Spring rates in lbs 340/330

Oem linear springs
G35 coupes with oem 17’s & 18’s
G35 sedan’s with sport suspension
350Z’s 2003/2004
Front:314 Rear:342

So, your G35 coupe will have a 1.1"/1.3" drop on spring rates of 340/330 whereas your oem spring rates are 314/342.

 

i have aboslutely zero noise from my front end and I've already put around 10k miles on the sways...the Cobb/Tokico suspension isnt on yet still, probably going to stay stock ride height through winter.

I do have rear end clunking from my sways and endlinks, but im going to try the tip that suggest that the mounts might just be too tight.

Concept Z Performance (aka COZ) just came out with their Endlinks for $135 a pair, worse case scenario I'll get those if I need to.

Im still at medium on both front and rear (front is med-soft) and Im pretty happy with it for the spirited driving I do on a regular basis. I did a cruise over the past weekend with some of STI/WRX buds and they were amazed how flat and poised the car was. I was leading since it was my mapped route and they were worried I'd be slowing them down, that was far from the case.

I wonder if the slight stiffness difference was simply achieve with different hole placements between the cobbs and the hotchkis bars?

I have to change my oil next weekend so I'll check out the bars and links while im under there.

 

Thanks for the reply, Iv'e checked out this site a few times before thanks, I contacted Hotchkis by email, [Tech Dept] there reply was that there is no .5'' difference in there spring sets on a G35 coupe or very little, also if you check there web site they 'quote' the same part No's the same spring rates and the same drop hights on both 350z and G35 coupe This is why I'm doing some more reseach on these forums, got to have some luck soon! Someone out there must have used or tried these Hotchkis springs! Anyway thanks. Regards Geoff T. from downunder. PS PLEASE CAN ANYONE HELP!

 

Hotchkis is wrong. My oem baseline data comes from first hand measurements and from members that willingly lend me parts for verification.


Found this coupe owners post.