280z budget suspension for autocross?

Over the winter I’d like to rebuild the suspension in my 280Z with the intentions of autocrossing it in the spring. This is also going to be a Challenge car so I’m trying to keep the cost down as much as possible. I’ve been thinking of using anything from stock replacement struts with used lowering springs, Tokico suspension kits, or sectioned struts housings with coil overs. I don’t plan on lowering the car too much and I think I’d be happy with a spring rate around 250 lbs since it won’t strictly be an autocross car. I just want to see what other options I have and find a direction for my build.

Stock struts won't be able to cope with autoX unless they put really good units in the 280Z, doubt it. A decent set of aftermarket struts and shocks will really help along with some mild aftermarket springs. Custom coilovers can be good but you'll be guessing at spring rates. A set of springs designed for the car would be a good easy start.

You'll want good rotors and pads too. A cheap set of rotors will likely warp with good pads. Look for Hawk HPS if you want mild street manors, or Hawk HP+ if you want awesome autoX behavior... or just get Duralast Gold...good enough for the XJ-R

For struts anything over stock I’m limited to Tokico’s unless I want to spend a bunch of money on Koni’s. I’ve read that the springs that come in the Tokico 280z suspension kit are around 180 lbs. The Tokico HP struts will handle up to a 200 lbs. spring while the Illumina’s are good till 225-250 lbs. and are adjustable.

For coilovers instead of custom I was thinking more along the lines of sections strut housings with coilover sleeves. This would allow me to open up my spring options and dial in ride height but I’m still limited on my strut inserts ( MR2, VW Rabbit, etc) unless I want to spent some more money. Cost wise it will be close to the suspension kits but more labor intensive.

I’ve already done Beck Arnley rotors and Stop Tech performance pads. Brakes feel ok but the OE rotors are non vented and I haven't been to hard on the car yet. There are a few bolt on upgrades but they would all be a budget hit. At least the performance pads were only a $9 hit (Amazon open box deal).

Go the shortened strut housing, cheapo coil over route. This is what we have been doing on the TR8s and believe it or not the suspension setups are similar. I have a shelf full of springs in the ball park you will need. Come on down and borrow whatever you need. The good thing about shortened coil overs is you can change springs in about 10 minutes a side. I just did a buddies TR8 front and rear with those $50 kits on ebay. Transformed the handling on the car. Spring rates in the 200s are good for street cars, but for competition you will want to go stiffer. Some of the road racing guys are in the 500 range. I've found that if you go way stiff on the front sway bar, you can run softer springs and achieve the same effect. Go with the illumunas, you will need the extra dampening for the stiffer springs. I thought they were good up to around 350# or so.

Why ask? You know you'll just end up autocrossing a Mazda 2

Do you have any fabrication ability/facility? If so, definitely sectioned struts. Bilsteins can be had for less than tokicos and are superior, you just have to make them fit.

Let me go over my suspension. P30-0032 bilstein struts from a mk1 rabbit 200F/225R stock sway bars .25" Toe out total front 0 camber poly bushing everywhere but the radius rods

This setup is tail happy, but even on 300tw street tires there's too much roll autoxing. If I were to do it again, I'd use R36-5022 bilsteins from a 3000gt with 375F/350R springs and I'd consider removing the rear sway bar if you have trouble with putting power down. You can go a little stiffer, but these rates with roughly normal corner weights put you right around the magical 65% of critical damping.

The P30-0032's have relatively little compression damping because they are valved linearly, the R36-5022 is valved digressively and has much more LS compression. For the P30 I'd recommend 275F/250R, and for the R36 I'd go for what I mentioned above. Don't worry too much about the ride, the bilsteins really ride well with higher rates.

Camber is going to be your friend, get as much as possible however possible, slot holes, fab some sort of camber plate, offset bushings, do it. Aim for 3degF/2.5degR.

This video should give you an idea what it looks like body lean wise on crappy street tires. http://www.youtube.com/watch?v=t5y_kPkUDUQ

Maybe keep an eye on the classifieds on Hybrid Z if you are wanting budget...

It looks like the R36-5022 might need to have the internal bump stop trimmed and i'm not sure what gland nut will work with my strut housings. Also will they need to be revalved?

If you're going to use the R36, I think you're going to have to modify a female gland nut and weld it to the end of the strut tube, that's what I did for the P30. The R36-5022 stock valving looks good for the springs I mentioned on a Z, but I'm no pro. I know others have used them on similar cars and been happy. If you put any faith in the "use 65% of critical damping, at least as a start" they are right there. If I was going to continue to develop my car for autox, I'd buy them. On the bump stop, not sure, depends.

I more or less did this, except I changed things. http://forums.hybridz.org/topic/98897-step-by-step-coilover-conversion/

This is another good thread, there is some discussion of gland nuts here. http://forums.hybridz.org/topic/69623-the-strut-thread-koni-illumina-tokico-carrera-bilstein-ground-control/page-19

Edit: Cutting down the bump stop is probably a good idea.