03threefiftyz

iTrader: (25)

Swap them to aftermarket and you will get an inch or so back. That said, I would also do a 7" spring.

dizenman

iTrader: (7)

Thanks, I ordered a 7 inch spring so I will have that Tuesday according to Amazon. Right now I'm 1/4 inch above stock, so if that lowers me to 3/4 below stock I'll be perfect.

As it sits, I took it to 133 today and it felt super stable despite the front being taller than the rear. I expected lift but there was nothing.

Also, right now I'm running a 400lb rear spring. Since I'm swapping my front springs, I'll also have a 500lb spring available. Do you think I would be better off with the 500lb or 400lb rear? Some more info on my setup: I have Eibach front sway bar at full stiff, and oem bar at the rear. I also have the Eibach bar for the rear in my garage. Tires are 295/35/18 rear and 265/35/18 front.

Thanks

03threefiftyz

iTrader: (25)

I would leave the 400 out back and start to back off the front bar if it pushes.

dizenman

iTrader: (7)

Getting an alignment tomorrow, put the 7 inch springs on yesterday. currently ride height is about 27.25 inches fender to ground in the rear, and 26.25 in the front. This is closer to where I want to be. I would perhaps consider going to down to 27 rear 26 front. The problem I'm running into is that at full travel there is a gap between the spring and the perch, currently about a half of an inch. In order to combat this I am going to be ordering some helper springs.

Here is my recommendation to anyone considering this in the future: get 6 or 7 inch 2.5id coil springs for the front as well as helper springs. 7 inch springs at the lowest setting with helper springs should give you a ride height no more than an inch lower than stock. if you want to go much lower than this, I would probably recommend going with an OTS coilover setup, or for an extra $180 per shock + shipping (more if you want something crazy) send your shocks to truechoice to be shortened and revalved to your hearts content.

Another thing to mention for those that have not done the install before, Most of the guides I saw recommended detaching the UCA to remove the shocks. I did this the first go around for removal, but for reinstall and for my second go around when I swapped the 8 inch springs for the 7 inch springs that it is much easier to disconnect the LCA from the chassis instead. It is a bit a pain in the *** in that it requires the removal of the fender liner and under shrouds, but it is much simpler.


Once I get my helper springs in I think I will write a DIY for anyone else looking to do this, as I went through quite a bunch of trial and error figuring this setup out and it would have been super helpful to see some sort of DIY.

Z1NONLY

iTrader: (2)

If you intend to use a front sway bar, you won't get a gap on the front unless you fully extend both sides at the same time.

The sway bar is effectively the helper spring when driving.

dizenman

iTrader: (7)

Really? Didn't know that. It's only about $100 for helper springs, though. I'd kind of rather be safe than sorry.

Z1NONLY

iTrader: (2)

I just discovered this while installing my setup.

Heck, there's so much pressure that I had to lift both sides to adjust the height on one side. Just lifting one side still kept too much pressure on the place the spring meets the sleeve adjustment. (Because of the sway bar trying to compress it)

No harm in a helper spring though.

dizenman

iTrader: (7)

Yeah, It's more a result of me being paranoid rather than an actual need, perhaps. I think I am going to swap my endlinks while I'm down there as well. I think it would be a good idea to do that..

terrasmak

iTrader: (8)

You can easily top out suspension, especially the rear. I bet mine come close under braking at times. The street driving can easily do it.

Z1NONLY

iTrader: (2)

The kind of forces created during braking are much higher than those created under straight line acceleration. (We are talking NA Z's here) As soon as you start turning and trying to compress one of the fronts, the sway bar starts trying to compress the other.

As, I mentioned already, I can jack up one side of the car....nothing but air under one of the front tires....and the spring and related hardware are still making contact both top and bottom.

dizenman

iTrader: (7)

That might be true, I haven't tested it on my setup yet, but I have helper springs on the way just for piece of mind. Once those are in I will be installing those, new UCAS, endlinks, and control arm bushings all at the same time

hajwoj

Weight saving for STU:
Wheels
Brakes
Seats and rails
Battery
Entire exhaust
All the stuff in the trunk, spare wheel, tools, etc
Aero or decorative plastic stuff undercar and engine
My belly, I can miss a meal

Anything obvious I'm missing?

Also, to make sure, the Nismo diff cover is not allowed in STU? I worry about the heat the Cusco rs diff will generate, not so much in Autocross but longer runs.

Glenn350zHR

iTrader: (5)

Diff cover is allowed

hajwoj

I can't find that in the rules?? Says Nismo replacement parts are not allowed. A differential cover can be replaced on solid rear axle cars only. Section 14.8G6
Am I missing something? Would love to install the Nismo one.

Shane86

iTrader: (1)

diff cover exemptions are only for straight axle cars, who need mount points.

You could put up an argument that the Nismo diff cover is a "cooler" though, which are now permitted.

hajwoj

I didn't think I would get a reply from SCCA so quick. Confirmed straight axle cars for suspension needs only. I could submit request for clarification or rule change. However it would be unlikely to change. I'm putting the diff back together this weekend with the OEM cover.

Shane86

iTrader: (1)

Yeah, it's disappointing. I've talked to a few STAC members personally with the same request, and already had it confirmed as illegal. A full blown diff cooler setup is legal.. but hey, not this cover.

I actually already took a stab at a rule change request.. but i started with Street Prepared board. Can't go adding modifications in ST classes that won't work upwards to Street Prepared.. Unfortunately it didn't seem to get anywhere.

The one i've really pushed for though is to carry down the radiator allowance from SP. You can upgrade any cooler on the car, add just about any you want, but not the biggest one in the front of the car.

joshua350z6841

iTrader: (3)

wanted your input.
ok i have a 04 350z with a gtm turbo kit making 420 to 500 at rear. getting ready to build a Quaife Differential. so i can ether use the stock Manual 6 speed 3.538 diff or Auto 3.357 diff. i have both sitting in the garage. i use the car for auto x an a few track days. an i was thinking with auto x i find myself bouncing of the rev limiter more then i like too. so i could see where the auto could pick up a few mph with the different gears ratio. just not sure how the compromise at the lower speed if i would suffer.

03threefiftyz

iTrader: (25)

Definitely going to want a 3.3 at that power level IMO, especially if you are running something near the stock redline. You may also find yourself wanting a tall rear tire as well. By the end I was running the BSP car up to 7500rpm on the 3.5. That's way beyond the point of known explosion in a DE, but I didn't really care.

joshua350z6841

iTrader: (3)

thanks for the input an i feel you are right. after hours of reading last night i have decided to go with a Cusco LSD Type-RS 1.5-Way. an right now rev limiter is set at 7300. wish the a7 came in a 295 /35