Finally had corner balancing & wheel alignment done

[GP20]

Well, I'm very embarassed to admit that it had been a year & 9 months (about 3,000 miles) that I had been driving my Z4M with screwed up wheel alignment. During this time I tried 5 sets of aftermarket suspension - TCK coilovers version 1 (with the strut clunks), H&R springs, Eibach springs, KW coilovers before finally going back to TCK coilovers - this time version 2 without the strut clunks. I finally got all the big & small issues worked out. This morning I had my Z4M corner balanced & wheels aligned at Cantrell Motorsports in Kirkland, WA, exit 20 I-405 for those who are local.

First of all, I'd have to say the owner Colin Cantrell is absolutely easy and awesome to work with. Cantrell is a very race oriented shop specializing in Porsches. They own/tune/race 5~6 Porsche race cars that they have in the shop. Also, when I was there this morning there were:

- 997 GT3
- 997 Turbo
- 996 GT3
- 996 Turbo-S [Edit: this was owned by Cantrell]
- Lotus Exige S
- Lotus Elise

All customers' cars. If those owners trust the shop enough, I think my lowly Z4M would be okay as well. I took pictures of the shop/cars with my cell phone and will post them up later.

The whole job took about 1.5 hours (for both corner balancing & wheel alignment). I went in with 5/8 tank of gas. I usually fill up when there's 1/4 (or 2/8) of a tank left. So I figured 5/8 is right down the middle between 2/8 and 8/8 (full tank). I weigh about 160lbs, and Colin put 160lbs of weight on the driver seat. I left the tool set, the M-mobility kit (air compressor & tire sealer), and another 3lbs~5lbs of crap in the trunk since I always drive around with them anyway.

I was surprised to learn that my ride height was set up nearly perfectly even before doing any adjustment. Only the driver rear needed to be raised about 1/8". The car's now absolutely perfect 50.0% front & 50.0% rear with the driver in the car. Even without corner balancing, my ride height set-up was probably okay, but it was nice to get it done anyway for the peace of mind.

Here's the alignment specs that Colin recommended and that I went with:

Front camber: -1.5
Front caster: 8.0
Front toe: 0.05

Rear camber: -1.8
Rear toe: 0.16


EDIT: Added 09.19.2008

Here's an update on the car weight.

Initially when I posted the thread I had written (or typed) the car's total weight, which I edited out because I didn't think the weight numbers were quite accurate. I had the stock exhaust put back onto the car today so I had Cantrell re-weigh the car again. I went in with 5/8 tank of gas like last time. Turns out that since they did corner balancing & alignment at the same time the first time, the car was weighed with the alginment bracket things attached to the wheels.

Here's basically what I initially wrote:

My Z4M weighs in at 3262lbs without the driver & with the following mods:
- Hardtop (57lbs according to Ron Stygar)
- TCK Koni shocks and springs (about 10lbs lighter than stock struts/shocks & springs)
- 19" BBS RGR's and 235/25/19 & 265/30/19 Goodyear Eagle F1 GS-D3's (about 20lbs lighter than stock wheels)
- heated seats / manual seats (I've read that for power seats, the motor adds 20lbs in each seat)
- 2lbs of closed cell foam from my sound proofing project
- OEM strut brace (about 4lbs)
- 5/8 tank of gas

So without the hardtop and without the 10lbs of crap in my trunk, the car would weigh in just a tad under 3200lbs.

The total weight I got today was 3237lbs. Every other condition stayed the same. So without the hardtop & 10bs of crap in my trunk, the weight would be 3170lbs. That's compared to the 3197lbs that BMW quoted for the Z4M-roadster. I'm not 100% sure what's BMW's process to measure curb weight and how much gas they put in their Z4M; I do know that they test the cars basically bare-bone without any option. I think my Z4M's weight now is certainly much more accurate and reflects the weight I've lost with the wheels & suspensions.

 

[Curtis]

It's nice to hear someone else take the setup of their car seriously. It's one of my pet hates when people fit lots of expensive parts and just expect the car to handle better without bothering to dial them in.

It will be interesting to hear how you get on with 50/50 distribution, I tried it and absolutely hated it. Not enough weight over the front for my liking but it all depends on driving style and personal preference I suppose.

 

[GP20]

Pictures were taken by my cellphone. Sorry about the poor quality.

Edit: the black 996 Turbo-S was owned by Cantrell as well.

997 Turbo



997 GT3


Lotus Exige S, 997 GT3, 997 Turbo



Lotus Elise


996 Turbo-S



996 GT3








My lowly Z4M on the rack.

 

[gannet]

some nice cars there - including yours

 

[ovrkll]

Very nice collection of cars! Give us an update on the settings once you have a chance to "play" a bit.

 

[GP20]

It's nice to hear someone else take the setup of their car seriously. It's one of my pet hates when people fit lots of expensive parts and just expect the car to handle better without bothering to dial them in.

It will be interesting to hear how you get on with 50/50 distribution, I tried it and absolutely hated it. Not enough weight over the front for my liking but it all depends on driving style and personal preference I suppose.

To be honest, I'm not sure how much my M will see tracks in its life-time given that all the local tracks either have already banned or have plans to ban convertibles. Probably too late to do auto-x'ings this year as well and will need to wait till next year. Nontheless, I'm just happy to be able to drive my M, to toss it around without worries. My goal was to find a street set-up that has better ride comfort than stock AND has better cornering performance than stock; I believe I've finally reached that goal with the TCK set-up. I know you've been a strong advocate of doing the bushings first and suspensions later. My stock bushings are still pretty new but aftermarket bushings will be my next suspension mod in another 10k miles or so.

I haven't driven the car very much after alignment (only 15~20 miles). So far my impression is that the car is simply so much easier to drive - tracks straight, ride feels much smoother & a lot less bumpy. I had no idea how much I was fighting the steering before the alignment. I slightly pushed the car on one of those clover-leaf on-ramps a couple of times and feel much more confident now. I still can't believe how I endured those 1 year and 9 months and how much fun I've missed out.

 

[pmeloche]

996 Turbo S. :drool: :heat: Did you say you drove your car 3K miles in 21 months?

 

[Curtis]

It's nice to hear someone else take the setup of their car seriously. It's one of my pet hates when people fit lots of expensive parts and just expect the car to handle better without bothering to dial them in.

It will be interesting to hear how you get on with 50/50 distribution, I tried it and absolutely hated it. Not enough weight over the front for my liking but it all depends on driving style and personal preference I suppose.

To be honest, I'm not sure how much my M will see tracks in its life-time given that all the local tracks either have already banned or have plans to ban convertibles. Probably too late to do auto-x'ings this year as well and will need to wait till next year. Nontheless, I'm just happy to be able to drive my M, to toss it around without worries. My goal was to find a street set-up that has better ride comfort than stock AND has better cornering performance than stock; I believe I've finally reached that goal with the TCK set-up. I know you've been a strong advocate of doing the bushings first and suspensions later. My stock bushings are still pretty new but aftermarket bushings will be my next suspension mod in another 10k miles or so.

I haven't driven the car very much after alignment (only 15~20 miles). So far my impression is that the car is simply so much easier to drive - tracks straight, ride feels much smoother & a lot less bumpy. I had no idea how much I was fighting the steering before the alignment. I slightly pushed the car on one of those clover-leaf on-ramps a couple of times and feel much more confident now. I still can't believe how I endured those 1 year and 9 months and how much fun I've missed out.

Glad to hear your getting on well with the new setup, it's amazing the difference a few adjustments make. I'm still surprised at the 50/50 distribution though. Maybe it just wasn't suitable for my mods and driving style. Also glad to hear your getting the bushes done! As you know thats another of my pet hates!!

 

[Wondermike]

:sweetheart: :sweetheart: :sweetheart: :sweetheart: :sweetheart: :sweetheart: :sweetheart: :sweetheart:

What a beast 8)

 

[wrh3]

Eric,

Your alignment settings are close to mine, definitely makes the car much easier to drive hard as I believe the factory settings are designed to err on the side of safety (aka understeer, among other things).

 

[GP20]

Eric,

Your alignment settings are close to mine, definitely makes the car much easier to drive hard as I believe the factory settings are designed to err on the side of safety (aka understeer, among other things).

Yeah I was pleasantly surprised by how much difference a wheel alignment makes. The car rides a lot less bumpy right afterwards. But then again my wheel alignment was VERY messed up before.

For sh!t & giggles here's what the specs were before:

Front camber left: -2.10
Front camber right: -1.50

Front caster left: 7.13
Front caster right: 7.51

Front toe left: 4.9mm
Front toe right: -7.0mm

Rear camber left: -2.02
Rear camber right: -2.58
Rear toe left: 1.8mm
Rear toe right 1.0mm

 

[GP20]

Here's an update on the car weight.

Initially when I posted the thread I had written (or typed) the car's total weight, which I edited out because I didn't think the weight numbers were quite accurate. I had the stock exhaust put back onto the car today so I had Cantrell re-weigh the car again. I went in with 5/8 tank of gas like last time. Turns out that since they did corner balancing & alignment at the same time the first time, the car was weighed with the alginment bracket things attached to the wheels.

Here's basically what I initially wrote:

My Z4M weighs in at 3262lbs without the driver & with the following mods:
- Hardtop (57lbs according to Ron Stygar)
- TCK Koni shocks and springs (about 10lbs lighter than stock struts/shocks & springs)
- 19" BBS RGR's and 235/25/19 & 265/30/19 Goodyear Eagle F1 GS-D3's (about 20lbs lighter than stock wheels)
- heated seats / manual seats (I've read that for power seats, the motor adds 20lbs in each seat)
- 2lbs of closed cell foam from my sound proofing project
- OEM strut brace (about 4lbs)
- 5/8 tank of gas

So without the hardtop and without the 10lbs of crap in my trunk, the car would weigh in just a tad under 3200lbs.

The total weight I got today was 3237lbs. Every other condition stayed the same. So without the hardtop & 10bs of crap in my trunk, the weight would be 3170lbs. That's compared to the 3197lbs that BMW quoted for the Z4M-roadster. I'm not 100% sure what's BMW's process to measure curb weight and how much gas they put in their Z4M; I do know that they test the cars basically bare-bone without any option. I think my Z4M's weight now is certainly much more accurate and reflects the weight I've lost with the wheels & suspensions.

 

[GP20]

By the way, stock mufflers and Eisenmann sport weigh basically exactly the same.

Stock - 9.7kg / 21.34lbs each side
Eisenmann Sport - 9.65kg / 21.23lbs each side

 

[GP20]

Did a search and found out how curb weight is measured.

http://www.pc.gov.bc.ca/cmg/newweb/GVW.htm
Base Curb Weight
Is the weight of the vehicle including a full tank of fuel and all standard equipment. It does not include passengers, cargo or any optional equipment.