catdaddy137

i think? , so then to use the cobalt springs on a hhr , and for the shock to match perfectly, i would have to call someone like Koni , and they would know what shock to use? or i may have to know what to ask for? and i don't ?they need what, cobalt spring rate , and hhr weight? i can find hhr weight. but i have no idea what the cobalt spring rate is or where to find it. and what i am aksing is , since you seem very knowledgeable , would it really make that much difference on a daily driver , and not a racing hhr?

rockone

The Cobalt SS springs lower the rear one inch over the stock HHR (non SS) springs, giving the car a level look. I have Cobalt SS front springs also but I don't think I will install them because of the snow we get in the Northeast.

IgottaWoody

Well..thats why I mentioned the "how long does a stock shock usually last with the stock springs".Alot of people would never notice in everyday driving.That is,untill they get replaced.Thats when you realise just how soft theyve gotten.The jury will be out for awhile on this one untill theres some real time data collected.Since there really isn't a whole lot(read that nothing) available aftermarket wise,we'll just have to do with what we have.I like a car that flat corners,so yeah, I'm biased.But not that hard core to drop $300 a corner to achieve it.I have GL's on the LS and it rides good, even with the 16's squishy tires.Though when I changed them I found the left rear shock leaking already,so when it warms up the WOODY will get a full set of SS dampers.I think they would fit the bill nicely.That way also I can compare it to my SS which only has an added rear bar installed.(The LS has one too,but only a 19mm).Then I may have a good idea which direction to go with the SS. Since they are relatively new,nobody has really experimented with them yet.And nobody really knows how well the stockers will hold up.Of course considering all the old farts that are driving them.........(they like the cushy ride..wink wink, better on the roids).
P.S. I was asking about spring rates months ago,,,I'd like to know too,but don't have a rate checker anymore since I stopped racing., and really hate breaking down front struts,such a PITA.Oh yeah, I fart dust too.

Justice Pete

Disclaimer -- I own a suspension company and am in the process of becoming a supporting vendor. Until we have the paperwork complete I will not post my company name out of respect for the rules.

Using SS coils from either the Cobalt or HHR will work. You should use the new low profile Cobalt SS front bump stop with the SS coils. The OE SS coils and struts are pretty good product and well matched, but you'll find your vehicle light on the critical damping scale with the late 2008 and on HHR SS coils and base or LT dampers. In late 2008 the spring rate spring rate was increased. The project manager did a really good job with his revisions. The car is now more neutral / balanced. We were working on a similar upgrade. We ended up with virtually the same coils rates with out any knowledge that the other was working along the same line. We met last year and had a good laugh about who copied the other guy's design. My guess is we would have had the same ride height if the OE was not restricted in his design.

I may have missed some of the details in this thread. If I did please excuse me for posting any duplicate information.

IgottaWoody

Your saying the SS coils were changed for the bettter in the late 08? But kept the same heigth? Interesting........Always thought it could use just a tad more coil, but didn't think the shocks would like them. I think the fronts are ,don't want to say soft, but not as tight as they should be....but thats me.Gm has done a good job,,but as with anything mass produced,it can be done over with better results...Main goal is to get it down about an inch,no less.So you gotta tell us what you used!!!!!And how it turned out!!!Did it get rid of that slight to heavy feel? Will the road critters have to duck?

ZTony8

Justice Pete,did your contact say that both the front and rear rates were increased?I can only find one part number for the SS rear springs and two part numbers for the front(the difference is trans usage) and they're listed for both the '08 and the '09 applications with no number supercession history.

Justice Pete

There is nothing in the rules that would prevent me from posting GM part numbers. Let me check on those part numbers and get them posted here.

ZTony8

The rear springs are #15938616,the fronts for a 5 speed are #25798126,for an automatic the part number is #25904874.These numbers all apply to 08 and 09 vehicles- no VIN break or supercession history is shown.

prod

I know there was a change in the cobalt SS springs with new part numbers, I have some of the older ones waiting to be added. I dont plan on racing, so the slightly softer and lower springs should do fine, along with the rear antisway bar.

ZTony8

Yeah,the Cobalt SS springs were changed for the 08-09 cars from the 05-07s but the HHR SS springs weren't changed from 08 to 09.