ninerguru

After some extensive reading and searching, I decided to upgrade my suspension. The plan is to have Bilstein do a re-valve of the shocks and try to reuse as much hardware as possible.

Turns out that metric springs are available using the OE 60mm diameters for both front and rear. Plan to go with 600/800# springs. I already have the dog bones and rear toe links.

Because the rear OE spring is progressive, it has a bottom diameter of 60mm and a top diameter of 71mm. This created a problem... I found that Tarett Engineering has developed an adapter to allow use of a 60mm spring using their monoball rear mount. This was developed for the 997 GT3 and it looks like it will fit the 996. I will let you know how things work out...

I took my suspension apart yesterday and wanted to share some pictures of the dis-assembly process.

I will post additional pictures as the rebuild continues. I plan to ship out the shocks this week, I figure it will be a month before I get them back with shipping and such. Track season is over for the GT3...

Stay tuned!

DHI

Thank-you for documenting this.
I was thinking about doing this in the off season as well.

Crazy Canuck

I have the Tarrett upgrade as per Mooty's guidance along with 800/1000 springs and Moton Clubsports.

Suspension is very much worthwhile doing.

The stock shocks won't work with stiffer springs. Revalving will work but the Motons are pretty cool.

TurboCup87

Thanks for showing this. Please keep us updated.

BTW does your wife know that you're boogering up her rug?

FFaust

Nice DIY, keep us posted.

philooo

why did you take the wheel carrier out ?

v12man

I am in progress with this - car is having corner weights, right heigts and alignment done at the moment, 1000/800 H&R springs, and zero weighted tender springs to get some droop without the spring falling out of the hat.

The local tech who revalves the shocks just built a new hat set to solve the spring size issue - +-60USD.

When I dropped the shocks off. he was busy with a production run of shocks specifically made for the GT40's made by Superformance - automotive art

ninerguru

Philoo, As per the repair manual, the hub needs to come out. I do not know if you can actually swing the whole assembly from under the wheel arch and then remove the shock. Too many chances of damaging the paint.

Really easy to do with the right tool to pop the ball joints ($20 at Sears). Disassembly order is: brake caliper, unplug sensors, unclip brake lines/wires from hub holders, undo cross member diagonal, pop tie rod, pop ball joint, undo 3 nuts inside trunk and remove whole thing from below.

One nut holds shock to hub. Remove that and you can disassemble strut/spring. No tension on front strut, so it is relatively easy.

Rear is just loosening the lower bolt that holds shock to hub, undo 3 nuts inside cabin after removing "GT3" rear cover, hold strut up with hand, slide out bold and remove strut towards you. I had to use a spring compressor in the rear as the spring had tension on it.

It a real easy process... Shocks go out to Bilstein tomorrow. I was having an issue with my left rear tire being chewed up in the shoulder. Happened to my Toyo and now again on my other set. I think I had a bad shock. Will ask shop to check alignment once the whole thing is completed...

SH || NC

Very cool. So do you send the specs of your new springs to Bilstein so they know what to match? Do they dyno the shocks before shipping back to you?

ninerguru

Yes, you basically let them know what springs you are using, car weight and f/r weight distribution. I did this in the past with my 74 after upgrading the torsion bars...

BTW, does anyone have a relatively correct weight value for a GT3? I figure it is about 3250# Thanks!

philooo

I see, I wonder if it is because the gt3 suspensions are longer ?

Because I was able to remove my oem strut without removing any of the suspension links and rods.

see my update on this thread here:
https://rennlist.com/forums/996-foru...-included.html

and you can see here how the wheel carrier just tilt down and outward:


actually to tilt it down while taking the shocks past the fender, I push it down using a tire bar, it was quite easy, little force to be applied.

SH || NC

My current config puts me at 3182 but I have removed some stuff, and added some stuff.

AudiOn19s

GT3 stock suspension will come out the same way you did it, but it does put some stress on the outer ball joints to do things that way. Removing the upright is proper but not necessarily required.

TrackDays247.com

This is good. DIY...fantastic.

ninerguru

The only issue I see with not removing the hub, is how the top of the sway bar link fits on the hub. Manual specifies that bolt/shock bracket must be centered on hub to prevent it from touching hub as suspension moves L/R. See my first picture, where pinch bolt grasps shock. Perhaps it can be centered when hub is in the car.

From phillooo's second picture, it looks like the sway bar link is attached differently on his car. It was no real big deal to get it out. YMMV...