ADMAN

iTrader: (9)

BigZ88

iTrader: (2)

Here's the thing guys..Cobb, Hotchkis, stillen, whatever... the sways are all made independently to their own specs (or so I'd hope) as to what their development teams feel would be best for the Z. It is then your job, or your tuner's job to decide which system works best for you and your needs.

My biggest question goes towards the springs. Where are they manufactured? What type of materials and what are the material quality control specs? This is a much larger area of concern in my mind seeing as I find it difficult to beat a quality spring from the likes of Eibach, who is actually one of the few companies who manufacture springs in house and control every aspect of the construction.

Dave @ COBB

They are made in the US at a very reputable spring company that makes many OEM springs. As you stated, they are made to the specs I send them. We take random samples to test when they come in to make sure they are what we specified. Luckily, springs are a very inexpensive and low labor intensive item. So again, like you said, it comes down to what you and/or your tuner decide you want. We definitely do not provide the lowest drop, and we do not go crazy on spring rates. We try to best match the valving of the shocks and achieve the best possible balance on the car.

BigZ88

iTrader: (2)

I assume the shocks you mention are the OEM shocks? If this is the case, then for everyone's sake, he is doing you a favor by not dropping too much or going overboard with spring rates. Things certainly seem legit, and Cobb has certainly made a name for themselves as one of the very best import performance companies in the US. (at least in my opinion).

Go for it guys!

Dave @ COBB

Yes, that is the OEM shocks we designed them for. Most stock replacments would probably work fine as well provided they are made to work with similar to stock springs.

myZter

iTrader: (7)

well if theres a group buy or specials on these shoot me a pm. cant go wrong with cobb imo

blofeld9999

iTrader: (2)

These look good, I've been looking at the RSR since they have similar spring rates as the revised stock springs.

These offer similar rates (slightly stiffer - which is nice) but even more of a drop than the RSR. If they'll work fine with stock shocks, that's even better.

ADMAN

iTrader: (9)

on the Stage 2 Group Buy

Dave @ COBB

Hey guys, did you see this thread? There's a video.... https://my350z.com/forum/showthread....71#post4654171

Gsedan35

iTrader: (10)

Keep in mind that their are two rather different oem suspension's that the owners your trying to sell to may or may not have. Plus 15% vs a 2004.5-2007 car, means your springs have 361/491 rates (if anyone want's to lend me a single front/rear spring I'll be more then happy to confirm the rates and return the springs within 48hrs of receipt). The cars equipped with the same basic setup as your 2006 R&D car may have the shock valving range to cover what you've R&D to, however 03/04 oem shocks do not. They have vastly different valving rates with a lot more compression damping, plus the rear spring rate is 25% softer then 04.5+. So, 03/04 owners should be advised to purchase shocks that can effectively dampend 361/491 rates, D-specs, Koni sports or perhaps Bilstein make the most sense.

oem 2003/2004 314/342
oem 2004.5/2007 314/427

09-01-2004 06:34 AM

VandyZ
Human Consult-2
Nashville, TN
Report post | IP: Logged

Here is an email I got from John Whatley of Hotchkis:
quote:


There is no error on the spring ratings. The rear spring is in fact softer than the stock. The reasoning behind this is that: during testing we found that the rear end likes to bounce under hard cornering. By reducing the spring rate in the rear we were able to get more MPH in slalom testing and stopped the bouncing that occurred. These springs in conjunction with our swaybars will be matched with each other to provide a neutral feel under hard cornering.


{Theabove is Hotchkis responding to question's concerning their use of softer then oem springs in the rear (330lbs vs 342lbs) on 03/04 cars. }

Dave @ COBB

Very good info. I guess I will have to find an 03 or 04 car to do some testing on.

XIceDragonX

I always, always wondered what the point of going softer in the rear was!!! But my question is, I've already added quite a bit of weight to the back to try to make the stock suspension seem more neautral... done by making a custom sub box and how we set up the layout of everything to try to put somemore weight back there to try to even out that 53/47 ratio out some... I am still stuck between the Hotchkis and COBB. Although I am looking for better handling, but I have noticed in sweeping left hand corners, like my local rt 422 has, the rear feels like it is sliding slightly.

Gsedan35

iTrader: (10)

What you see in that email was a snap shot of why Hotchkis did what they did. Their R&D car of course had the same shocks and springs that your 2003 car has. Beyond how Hotchkis was working around dampning issues, due to the platform's built in anti dive and anti squit geometry, high rear spring rates are not alway's desired.

I don't see you ADDING weight to the rear so much in a attempt to improve the front/rear weight disturbution so much as I see you wishing the added weight of the sub box stuff has less impact because it's in the rear of the car vs the front. Not to take anthing away from wanting the car's sound system to sound like you want it to. The simple addition of weight is far to negitive performance wise then anything you could hope to gain.

Only run the Cobb springs if your going to replace your oem 2003 shocks, which merit replacement anyhow because of poor rebound control anyhow. 04.5+ owners will have to have faith that their different oem shock tuning works fine as Cobb's own R&D hopefully bore out. Getting bliss out of your car's behavior does differ from person to person depending on your whole car setup and what your doing imput wise.

XIceDragonX

well actually, I did add the weight to try to get more of a 50/50 weight distribution, because I even went as far as adding a second unneeded battery. But my car actually hugs turns a little since I put it in compared to before there was any weight in it at all... when there was no weight, i could floor it and the *** end would just want to rip around wildly... now i can get on it in turns and it just goes. I do not believe thou that adding only 100 lb's to a car can hamper it's performance too much... if so, I need to do some serious dieting. But are you saying that the COBB suspension is more aimed towards 04.5+ and the Hotchkis towards 03-04?

blofeld9999

iTrader: (2)

The Stage 2 kit looks good. I wish there was more than just one review though. I'm tempted to buy once I get my new wheels on.

ADMAN

iTrader: (9)

I have an 03 - looking for testing. Just needs COBB stickers...

XIceDragonX

See, I am still debating... so many people say hotchkis is top of the line, best of the best... but COBB has so freaking many good points too, plus that sweet video proof of how well it works.

Gsedan35

iTrader: (10)

Again, shock tuning on your car is not the same as their R&D car. I have run the same shocks and springs you have and I am telling you Hotchkis's statement is spot on the make. Your shocks CANNOT run spring rates that high and have proper control. The moment you get off smooth as glass pavement, game over. Replace your oem shocks with something better like Koni or D-spec, it's a totally different story.

XIceDragonX

so if i run the a good shock like that, i should go with the cobb, and oem shocks, go with hotchkis? As in, if i use the D-spec's, cobb's would respond better than the hotchkis?

ke0ki2k

iTrader: (2)

the Cobb sways can be tuned to bit quite a bit stiffer than the hotchkis bars though cant they?