tungstenfoot

Hi Folks, Its still snowing here in NY so why not document my little winter Z project…I’m doing what I would call a complete overhaul of my suspension setup this year along with a bunch of "while your there" items, plus some extras

I wanted to document my efforts, especially since I didn’t find much info on alignment w delrin bushings and some other parts I'll be installing. I figured I’d try and provide as much info and photos to help someone out someday.

Heres a sampling of what ill be doing:
Delrin bushings in control arms, by Van steel (Rec'd 3/17)
New BFG Rival S 275/35-18 fronts, 315/30-18 rear (Rec'd 2/17)
Camber Kit, by AMT Motorsport. (Install April '17)
DIY garage alignment: ride height & rake,toe camber caster, setting targets, review actuals
Corner Balance, monitor rake
Rear axle seal, diff vent mod & Diff fluid (complete 3-11-17)
Mighty Mouse Catch can (Complete 4/1/18)

About the car & suspension:
2003 Z06: Street driven 2k -4k per year, 64K miles on clock, no track days, 2-5 AutoX per year, occasional visit to drags, and considering attending SCCA Track nights

My goal is to sharpen turn in, improve steering feedback and reduce the car’s tendency to dart and tramline (especially bad under power). I want all this without completely killing my tires if I take a road trip from Buffalo to cars and coffee in Toronto or drive to Pittsburg. If I can reduce wheel hop while I’m at it, even better.
I know, It’s a tall order but I’m a gluten for punishment. It’s a hobby for me and I enjoy wrenching, especially on the Z06.

Suspension Mods & pertinent info: LG GT2 Coilovers, StranoParts Big Front Swaybar, Powergrid adjustable endlinks, NEW Vansteel Delrin bushing Control arms, NEW AMT motorsport Camber kit. I was running Rival S 295/35-18 front & rear ("square") when experiencing these ailments but I now have NEW Rival S 275/35-18 for front and will run NEW Rival S 315/30-18 for rear. I THINK reducing the front tire size will help my tramline issues (plus fresh bushes). I Still need to get the tires mounted

I will be doing my own alignment, I have smart strings, a DIY camber gage and will be corner balancing w scales. As soon as the AMT Camber kit arrives I’ll start re-assembly, hopefully early next week.
Thanks for checking in, and hope to show some decent progress soon.

Control Arms removed:

tungstenfoot

You can see how far the stock Upper Control Arm bushing has pushed out. Its 14 year old rubber, time to move on...don't you think!

tungstenfoot

Vansteel did an excellent job, all joints are nice and tight yet smooth, I’m super impressed. The UCA dog bones are beautifully machined, very high quality pieces...but, looks aren't everything will see how everything fits!

tungstenfoot

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tungstenfoot

My new tires are not as tall, so i'll need to raise ride height a bit. I was already scraping air dam on my driveway...
The smaller diameter 315/30 rear will also give slight benefit of "gearing" for AutoX, i feel it bogs 2nd gear on smaller courses. 295/35 was diameter 26.2" , the new tires are 25.4" - 25.5". The 315's are some wide *** tires!! Compare w 10.5" long tape across each tire:



So with .76" smaller diameter tires on deck, if i did nothing i'd be lower by 3/8"! Thats alot, and need to get back to my previous height (might actually raise slightly).
I will rough-in the shocks now and fine tune rake/corner balance later.
To rough in the LG GT2's i measured thread pitch of the shock body threads:


Metric 1.5 Pitch = Pitch of .059 inches or 16.93 threads per inch (tpi). Meaning if i need to raise 3/8", i need to turn each shock bottom out about 6.5 turns (.38/.059=6.44)

Ive turned out the rears 7 turns and will turn the fronts out 6. Will measure ride height and rake when i get everything buttoned up.

The AMT kit is really nice and thought out. The parts are laser etched and packaged w labels to further help your install. It comes with high quality hardware and excellent instructions too. AND they fit perfect! Ill get some more pics up soon

tungstenfoot

the rear end is back together, just need to fasten passenger parking brake and add new diff fluid...

The AMT camber kit is installed at rear too. The instructions are very good and easy to understand. The aft bushing of the rear control arm does not require a camber plate, only the fwd bushing has a slot in the cradle for adjustment. Its difficult to orient to these pics but here is the fwd side of the driver rear control arm (fwd bushing), i have it set to "S2" meaning the "street" hole 5 being least amount of camber for this hole, 1 being the max. "T" hole is for "Track" and gives more camber than S hole. The indicated position always faces outboard toward the wheel, here is S2:

Below is the aft side of the driver rear control arm (fwd bushing) also set to "S2"facing outboard toward the wheel, you can see how the spotfaces differ in the cradle, the plate geometry is such that they fit these different cutouts perfect. I sketched the adjustment slot so you can see how this position pushes the lower arm outboard for more camber.
This photo also clearly shows the other "T" hole (Track) and how IF i used that hole and positioned the plate and bolt outboard, it would be more aggressive (more neg camber).

For future reference on Moog lower ball joints, aka "problem solvers" there is little to no info on torque specs. I thought they could be different than OE because they use a castlenut and cotter pin...So I got a hold of Vansteel & Moog suspension and they confirm they are designed for OE torque specs.

Install tips for Moog problem solver: Don't install grease fittings until after the boot is pressed on to avoid damage to the zerk. Use a short section of 2" PVC pipe w a heavy inside chamfer to press or impact the boot on over the ball joint (it must have a press fit ring overmolded & integral to the boot). The chamfer on the pipe will avoid a sharp edge contact to the boot which could tear it, you dont want that. Also important: the boot has a channel for grease overflow, you want this oriented inboard. There is small lettering molded on the boot, its easy to miss. You want grease to purge AWAY from the brakes!

JETninja

I had this Pfadt Street/Track alignment done on my last Z and will do it to my new one sometime soon.

​Caster 7.5 degrees on both sides (C6 can take a bit more, C5 will smoke the PS pump and rack with 8 degrees or more)
Front Camber -1.3 to -1.6 on each side
Rear camber 0.2 degree less negative camber than the front (ie. if the front is -1.5 then set the rears at -1.3 degrees
Toe: in 0.05 degrees for each side front and rear

max
-1.3 8.5 0 (0°)
-0.9 -1/16" (0.17°)
Rear
Camber (deg) Caster (deg) Total Toe
Camber (deg) Total Toe

Think I went with Zero toe and my tires lasted a long time and it handled so much better.

tungstenfoot

Thanks for this reference, i did not know about the PS pump issue! Was your alignment with Delrin bushings? Since there is so much less compliance w Delrin (and less dynamic change) I'm wondering if there should be a fundamental difference in my alignment targets.

JETninja

Nope, it was a stock but lowered 2004 Z06.

Pic taken on 17m drive in Carmel, CA back in 2013...




And the 2002 Z I just got last Jan, has under 9k miles on it, Still need to do the same alignment to it.

nsogiba

Looks like a fun project, thanks for documenting. You ever head up to Toronto Motorsports Park for open lapping? I'm in Buffalo (Lancaster).

95wht6spd

Nice write up. So you sent your A arms in to Van Steel and they installed bushings, etc?

tungstenfoot

It is fun! Coming back together now... The AMT kit arrived, the rear is almost back together now. Ive not been to Toronto Motorsport park, is it still active? I'm in Hamburg. AutoX at all?

tungstenfoot

Yes, and its not cheap. I think all the arms were 70 ish pounds shipping, there and back (FL) ran me $180 (just shipping).

Front driver side coming together. The Vansteel upper "dog bones" are offset and slotted to provide more camber and caster. For my initial settings, ive installed one 1/16" shim per upper mount and slid it to the rearmost position within the dogbone slot (max caster). For the lowers, again im starting w position of AMT plate In the street "S2" position.

nsogiba

It is indeed active, last season I only got out there once on a Friday afternoon, but 100 bucks Canadian for unlimited lapping with almost zero traffic for 4 hours can't be beat. I used to autocross in 2009/2010, not so much anymore. I never really enjoyed standing in the parking lot for hours at a time just to run a couple times...

C5SCCA

Interested to get your feedback on the Delrin bushings for street use in terms of NVH!

tungstenfoot

Heck, you cant beat that! I'm in. A friend at work goes a few times a year too. Give me a heads up if you plan to go, maybe we could get a convoy...which can be fun too! I hear you on autoX, WNY region especially could use some improvements how they run things. MBR region (Erie PA) runs events at Erie Speedway w banked oval as part of course, i've run up to 10 runs there. Worth checking out.

All good reason im going through the car and checking everything now. All new fluids: rear diff, trans, brakes, and powersteering being done. Also replacing my original OE rear rotors and pads! Went w Centric rotor w Ferrodo DS2500 pads ($$). Wasnt happy w price of these pads but ive had them on fronts for ~4k miles and figured i should match the pad compound front-rear

6speedsteve

Excellent write up, I like the coilover adjustment trick, I will have to get some more info from you when I get mine installed. I found that installing coilovers that have a specific drop already designed in is tricky when you have drop spindles.

tungstenfoot

Thanks and let me know, you can borrow my pitch gages whenever you need

tungstenfoot

Tonight i was able to get 8, count them 8 tires!!! Plus 4, 18" speedline wheels in the back of a BMW 3GT, i still cant believe it. The SMALLEST tire among the bunch is a 275/35-18. Im impressed. Check this out


How can you not like hatch backs!

6speedsteve