Hey all,

I am looking to buy new struts/springs in the near future, and I have been struggling to decide between coil-overs and lowering springs.

The car sees street driving as well as autox and maybe road racing eventually. Essentially anything but a drag car.

Initially I was looking into Spohn coilovers for all four corners, but after researching on the site there seems to be a lot of hostility about coilovers with the exception of low weight drag cars. Plenty of people bash them for other applications but I never really see a good explanation.

I would appreciate any guidance about which route would be best for me; I am prepared to buy koni yellows for the car, but I need to choose what setup to run them with.

Thanks,
Steven

 

Weight Jacks for adjustable height & easy replacement of spring weight changes as well as cornering weighting the car.

Rod Ends over poly or rubber. Rubber squishes & poly can bind in cornering creating snap oversteer when the poly is released from the binding.

 

Actually I should have asked first....What class so you want to tun in? That will determine what you can & can't do.

 

I have yet to determine what class I will be in- my car is a frankenstein of sorts so I am sure I will not be very competitive in the big picture. Racing is more of a hobby / weekend thing.

I'm looking for the best solution that will still be safe and fun on the street. I have tried to find info about weight jacks before but it seems to be another one of those subjects that people skirt around without explaining well. How many manufacturers still produce them?

thanks,
Steven

 

Ground Control still makes them:
http://www.ground-control-store.com/...gory.php/CA=86

I've had cut springs & Lowering Springs before & while weight jacks are more expensive, they allowed me to dial in my ride height for "free" (just by adjusting the jacks)

What are you trying to find out about them, that you haven't?

 

I just haven't seen many comments from people using them about how they drive. Obviously there are advantages with the easy height adjustments and spring changes- but how do they perform compared to lowering springs?

I guess I'm just trying to solicit some opinions before I pony up the money either way.

http://www.ground-control-store.com/...hp/II=20/CA=86
This is front and rear correct?
I read it but I just want to make sure I'm not missing something.

~Steven

 

That is the correct kit & the only way they'll sell it, unless you can prove that you already own front or rear. Like me....I had rears already & had to show them in order to get just fronts. This was about 2 years ago & it may be the same way now.

My car is 100% daily driver & I am perfectly happy with mine & the 17" wheels & the lower profile tires. 650lbs front, 150lbs rear. Thinking of stepping up the rears to some 180lbs if I lower the car a bit more. I have some 200s (or 210s, i forget which) but I think those combined with the 35 series tires might ride stiff for my daily driver. I even have all rod ended LCAs & PHB, so the harshness of the springs nor rod ends never bother me a bit.

 

Thanks for the help- I think that I will probably end up ordering that kit when I order my konis. I guess I will read more about spring rates to try and find a good starting point. I have an LT1 swapped car on C5 wagon wheels 17 front 18 rears, 245/40 and 275/35 tires I believe.

 

installing the adjuster from GC wont by itself make the car drive differently, thats impossible. What they allow is for you to use a variety of different rate springs, yet keep the car at a specific height without having to cut springs. they cost more than lowering springs, and FWIW, there are very few lowering springs out there that are for performance applications. They are mostly for looks and generally are too soft in the rear, or way to stiff in the front.

you dont "need" them either, you can just use universal springs of whatever rate you need and trim to fit. they can even look "stock", if thats what you need.

I have the GC jacks in my 86, been there for years, and i have a more typicaly weight jack setup in my 92. Both do the job quite well, and were well worth the cost/effort over messing with lowering springs.

 

Thank you- that makes this clearer. Sounds like the setup I am looking for. Just need to pick spring rates.

 

If you go with jacks, a good starting point would be a 5/1 ratio front to rear, in the realm of 750/150 or 850/175 ish for a v8 car. see what happens, and go from there.

However, there is no reason not to use what you have for now. Factory Iroc springs and ws6 springs are pretty good. You may end up messing with the sway bars too. For those just stick with factory pieces, there are plenty of different sizes, and they all go for pretty cheap.

Dont forget good shocks and struts, Look into Koni yellows, or there is a thread about cheap bilsteins that should work well to and save a few bux.

 

I found a full set of koni yellows online for under 700 so I think I am going with those no matter what.

Most of my suspension components are worn out so I will be ordering springs with it- 850-175 sounds like a good place to jump off from.

Thanks for the quick responses guys.

 

As far as coil overs, I don't think anyone is saying that it's an ineffective suspension system, but there are serious caveats when it comes to how wide of a tire/wheel you can fit with a coil over system. If you're trying to build an all-out handling car and spending money on something as drastic as coilovers, being limited to an 8.5 inch wide front wheel is like tying your shoes together. Beyond that I dont know how well the factory strut towers can handle the stress of coilovers long term, especially on a car that is thrown into the twisties really hard.

This is an interesting comment and from what I've seen it definitely seems accurate. Coming from you I'm even more inclined to take it as gospel. But I was wondering if you had any idea which sets were more performance oriented? I know the Eibach Sportlines are some of the worst offenders being more for looks than speed. I've got my factory springs cut a little front and rear to stay roughly balanced, (1/2 coil on the front, 1/4 coil on the rear) but to go lower and maintain a good springrate balance I'm thinking I need to go with an aftermarket spring setup.

 

IDK about gospel, just personal experience. I've given up on spring kits. I just use universal springs and weight jacks, since I'd rather not deal with trimming springs if i dont have to.

as for the coilovers, you can apparently use a 9.5 on the front with them, if you keep them out as far as possible, and they will still clear the fenders. Its just not the best for scrub, better to keep them more inboard if possible, unless of course the wheels are going to be as wide as possible, ie; 11 and wider

 

If you swapped in an LT1, then per SCCA auto-x rules, you are in C prepared.

~Matt

 

I would beg to differ on Sportlines. The Pro-Kit (and most progressives) is not appropriate for this application. I used the Sportlines however, with some success. My setup was:

Sportlines
Koni Yellows
Energy Suspension bushings
32mm (I think) front bar
24mm rear bar
Spohn rear LCAs and panhard
Stock torque arm
SFCs and front strut tower brace
Full welded-in SCCA legal "6 point" cage (main hoop, rear braces, full front)
Wonder bar

This was in my friend's 84 Camaro, powered by a B&M mini-blowered 358, making right around 500hp (was originally in my Formula, but sold it to him).

This setup was surprisingly neutral at our local hillclimb events (www.pahillclimb.net). Very nice turn-in, neutral in the corner, and completely throttle-steerable at exit at both low and high speeds. This was with 17" Hoosiers (275 front 305 rear I believe), and about -3 camber up front... I found the spring to be very predictable and consistent. I am actually putting that exact setup on the 84 Z28 that I'm purchasing in the next week.

That said, I'd personally go with Ground Control if I had the funds and this other setup wasn't easily available and a good price.

 

https://www.thirdgen.org/forums/post...03-post18.html

I've read that from a lot of people. The Sportlines have lighter spring rates than the Pro Kit. They rely on the bump stops to limit travel, not spring rate.

Your car handles well because you have the rest of those mods, especially the Konis, not because of the Sportlines.

 

Agreed, but I was simply saying that the Sportlines were the better choice of the two. That was also because I was under the (possibly false) impression that the Sportlines were NOT progressive. I certainly can't dispute that point since they are not in front of me at this time, but I'm pretty sure the set I got was constant rate. That was really my point of this whole thing- Don't use progressive rate springs in a performance application.


That said, Ground Control is really the way to go.

 

the sportlines i had years back were defiantly linear rate front and rear.

 

And the plot thickens...

Its frustrating how hard it is to get clear answers on things that should be so obvious. Manufacturers just tell you what you want to hear and shoo you on.

 

www.stranoparts.com
give a call and get straight answers.