I have a 2004Z which I daily drive and autocross 4-5 times per year. Here is my current setup:

-Tokico D-Spec spring/shock kit (rates are 375/375 f/r)
-1st generation Hotchkis front and rear sway bars set to medium (3 adjustments)
- Enkei RPF1 9.5+15 front 10.5+15 rear
- 265/35/18 F 285/35/18 rear Michelin Pilot Super Sports
- SPC rear camber arm and toe bolt
- SPL front compression arm bushing (solid heim joint)
- Whiteline front control arm bushings

The car feels very stable during autocross runs, and handles fairly neutrally maybe with just a hint of understeer. Ride quality is not harsh for daily driving. I am looking to upgrade my shocks and springs to allow for ride-height adjustment. Here is what I am thinking:

- OTS Koni Yellows
- Koni spring perch and threaded body for fronts for ride-height adjustment
- SPL Mid-link for rear for ride-height adjustment (in addition to benefit of eliminating eccentric washer toe adjustment)
- 2.5" ID Swift springs (what spring size do the yellows need?). Thinking 7k/7k or 8k/7k to stay within the range the Konis are valved for (please comment on spring choice and rate)

Anyone with experience with a similar setup please comment. Thanks

 

I am also thinking of Ohlin's coilover setup if anyone has experience with those

 

Why do you want ride height adjustment if you already seem yo have the car dialed

 

So I can corner balance. In addition, this is the only setup I have ever raced on in my Z and it "feels" good to me, but I want to try something a little different with higher quality components to see if I can improve lap times. I have 3 years of autocross experience in addition to ~15 hours of road course time (in a corvette not my Z) much of which I received professional driving instruction, so I want to start upgrading components now that I feel I am getting the most out of the current setup.

 

Pretty reasonable response. I wonder if it will satisfy the coilover police Sorry I had to...

 

Hope I'm not getting a rep for being the "coilover police". But this situation is different: the OP has some experience with solo and track driving, plus professional instruction. At least he has some idea of what corner weighting is.

Having used Koni DA race shocks with Nissan comp T2 springs on my T2/T3 Z, I understand what this package is like. I think they'll be very hard to use as a DD, with very harsh ride and on-edge handling. They'll work well on smooth pavement, but will be hard to tune for anything less. And they'll also be a handful in the rain, unlike your current setup.

The Koni threaded perches use 2.5" springs, and the T2 springs were 10" long.

 

Well you mentioned Ohlins, what is your budget?

At that price point you have a selection of quality damper choices that you won't have to mess with and will be competent out of the box. Dont get me wrong OTS Konis are great I used them for a number of years but I think with all the trouble to convert them to ride height adjust youre better off stepping into something higher on the ladder.

To add on to what dkmura said, T2 springs are ~690/690lb (12.3k)...youre looking at between 392 and 448lb (7-8k).

 

Thanks for the responses. I am looking to spend $2.5-$3K. After doing some more research and based on feedback, the OTS Koni option probably isn't worth it considering what complete systems are available for just a bit more that are higher quality and ready to go out of the box.

That being said, I have narrowed it down to either the Ohlins road and track coilovers or Truechoice Koni Phase 2 or 3 solution. My buddy has the Truechoice phase 3s on his G35 and likes them, but I am hesitant to get a double adjustable shock since you could go crazy trying to get the "perfect" adjustments. I won't be tracking my Z (until I get a second car that is), just autocross, so double adjustable just seems overkill. I am leaning towards the Truechoice phase 2 setup (single adjustable) as they are upgradeable by Truechoice if needed, and I already have a friend that has and likes them.