Suspension Help

[Jiveslug]

Hey gang. Well, Im wondering what I can do with my suspension that will make the car handle relatively well without having to go the full-blown adjustable dampers/adjustable coil-overs route. I am sure once I get some seat time Ill go there, but for now I just want the car to corner well enough to give me a solid base upon which to learn how to drive. The stock components are trash, so they will have to go regardless. Thus, Im looking for any suggestions on how to do a decent suspension on a budget. I realize that this may not be possible, but I figure it never hurts to ask. As far as suspension design on my car, it’s a basic MacPherson strut front and 4-link live axle rear with coil springs. I would say that its weight balance is in the 55/45 area. Im venturing to guess that the whole thing is similar to a first gen RX-7, but dont quote me on that. Ive heard various figures for spring rates at 250lbs both front AND rear to 900/600lbs. I think the real sweet spot is probably somewhere in the middle. What do you all think? I appreciate the help, because this is an area where I am finding that Im clueless. Thanks.

[Marcus Miller]

Ryan,

The key to picking spring rates is motion ratio, so the mac struts wil lbe close toyhe smae, but where onthe rear axle are the rearsprings mounted?

I would find out your current spring rates, and post them up. I would guess double would be close, depending on the sway bar set up.
The other pieces you need to consider are your shocks, its easy to over power lower brand shocks.
The best example of this would be a first gen Rx7; the tokico front struts can only handle up to 350 lbs. springs. At least one version of the "fast" setup is significantly higher than that. Going stiffer thna 350 and wiht a tokico and you start to hurt yourself. (I believe that is specific to the first gen 7 valving, and may or may not be applicable to other setups.)

Marcus

[gran racing]

how to do a decent suspension on a budget.[/b]

Could you give us an approximate price range you're looking to spend for the struts and springs? This will help isolate some of the options for you.

With spring rates, if you go very firm it is a bit different to drive (usually less forgiving) than if using lower spring rates. And as Marcus said, you need to match your struts and springs (make sure the struts can handle the spring rates you decide to use).

I do not think you want to compare your car to the RX7s (actually, for many reasons! :o ). They are just too different.

My car is set-up more in the mid-range for spring rates at 400lbs front, 600lbs rear. I bought non-adjustable struts after speaking with the suspension rep. For me, it really made sense. They were less expensive than the multi-adjustable units; still built for my car, tracks racing at, spring rates, and driving style. For someone new to racing, it also made things easier for me. Many new people buy multi adjustable struts and do not know how to tune them properly. Once they get it close, they leave it alone anyways. With the non-adjustable struts that I got, there was no option to be tinkering with the various settings and it forced me to focus on other things (such as improving my driving abilities). Three years later and I am still very happy with the decision.

Yes, I know, there are advantages of multi-adjustable struts if a person knows what they're doing.

O.k. Back to my original question than we'll give you some more info.

[joeg]

Proper coil-over springs are not expensive and can be had used for even cheaper money.

As to struts--the key--I would not know what is available for your car, but adding a threaded sleeve to anything is possible.

If you can afford nothing, just cut your stock springs a coil and a half, reassemble and go get some track time.

Cheers.

[Z3_GoCar]

Have you looked at Koni single adjustable struts/shocks. I'm sure they either have an application for your toy or maybe the inserts. I think that Ground control up in Folsom may be able to set you up with a threaded body kit. If I remember right your rear is a dual leaf spring set up?? Have you looked at any books on suspension set up? With leaf's you can have custom springs cut, curved, and heat treated. A couple of advatages to coil-overs is weight balancing and quick change spring rates. I know where there's a coil over system for BMW's that's below $700 for the set, now the shocks aren't adjustable but it'll get you the corner balancing and the ability to change spring rates. You should be able to find a similar system, maybe for less yet. Oh, another option would be shox.com they had a good deal only beat by the fact that I didn't have to pay sales tax to tire rack.

James

[Jiveslug]

Hey guys, sorry for not responding, its been a bit of a hectic week. Anyway, Ground Control does make a set of coil-overs and they run about $200 for the fronts. They do not make a set for the rears. There is a small company in Florida who makes coils for the rear of my car for $450 a set. The prices are pretty good, but right now Im really just looking to get the car on the track. I would use the stock suspension, but it is totally shot. ANYway, I would like to avoid the cost of adjustable dampers for now. Are there any cost-effective (say, 300-400 bucks for the set of 4) that might work? What concerns me are the dampers and their ability to deal with a high spring rate. It seems to me right now, with my somewhat limited knowledge, that if I don’t go adjustable damper, I really cant go much higher than 350# spring rate (depending on damper maker). I was really hoping to go somewhere around or above 500# in the front, but Im not sure if that will be possible for such inexpensive dampers. So I guess my question boils down to: Are there any decent struts/inserts and shocks that I can get that will handle a relatively high spring rate for the $300-$400 price range (per set of 4)?

Oh, and as for the suspension design, I looked up more info on the RX-7 and youre right, its not that similar. I GUESS you could say it is somewhat like a 4cyl FOX bodied Mustang, just lighter and sans quad shocks in the rear (my Corolla uses a panhard bar). Thanks again all!

:cavallo:

[mowog]

The inexpensive but good alternative to multi-adjustable shocks for AH Sprites was Carerra. For the Nissan it was QA or Pro. Seems QA purchased Carerra. You may want to give QA a call and see if they can recommend something - if possible, go with rebound only adjustment for a compromise. Another possiblilty is Koni. There's a guy running Production that works for them, maybe he could come up with an inexpensive damper for your car. I can find his name if interested.

I've found the Carerra, now QA, springs are really bad. The ends aren't ground flat and they don't hold their original specifications (put 2 together and rotate, you'll see the sides don't touch from top to bottom, and if you spin any one you'll really see what I mean about the ends being ground wrong). I prefer Hypercoil springs, and they aren't much more money. However they didn't make a size we needed and AFCO did. Turns out the AFCO springs are ground correctly, and they are within a few percent of rated specs. The price is good too. :happy204: In my opinion, which isn't worth much I'm sure, Eibach is a poor 3rd choice (I've had some that didn't hold specs and took a set that wasn't straight - they were bent after less than a full season) Hope this helps....