Audi TT Suspension Arms

[LePatron]

I recently installed a set of Audi TT aluminum control arms on my car after reading about this mod on the UK boards. This mod provides for a number of enhancements over the stock set up and the results are nothing short of amazing. For me this is the single most significant chassis performance mod in terms of decernable handling improvements. Turn in response is incredable and the car feels as if it's on rails through fast sweeping curves.

Benefits of these arm include:
- Lighter (unsprung) weight; 5 lbs vs 9 lbs per arm.
- Higher center of roll as explained in the attachent below.
- Stiffer solid bushings which improves feel and reponse.
- Finally and most significantly, ajustable front camber.

Cost of parts isn't exactly cheap and you will need to make use of a hydraulic press to swap out the rear bracket bushings but the rest of the installation is simple and straight forward.
TT Aluminum Control Arms Parts List (pricing from genuineaudivwparts):
8J0 407 151 D (need 2 Same part # left and right) $216.00 X 2
Ball Joints
8J0 407 365 $92.16
8J0 407 366 $92.16
Ball Joint Nuts
N 103 320 02 $0.66 - need 6
N 909 429 01 $1.07 - need 2
Ball Joint Bolt Stud Brackets:
8J0 407 175 $11.88
8J0 407 176 $11.88
Bolt for Rear Bracket to sub-frame
N 105 797 01 $1.32 need 4
Bolt for Rear Bracket to frame
N 908 235 01 $1.87 need 2
Bolt for Front Bracket- horizontal
N 101 410 01 $2.82 need 2
12 Point Axel Bolts
WHT 002 795 $2.82 need 2
A couple recommended tools:
Ball Joint Tool: OTC 6297 ($47.34 - $43.47 Tool Discounter, Tooltopia)
Sub-Frame Locating Pins: T10096 ($34.84 http://tools.vw.com)

Finally a few images:

(Borrowed photo)

TT bushing on left, OEM GTI on right.

Also check out the information cut from an Audi technical Bulletin that is attached. (full document: Audi TT Suspension
The - 1.8 deg of camber is the most possitive we could get. I know some folks are running -2.0 to 2.5 deg with camber kits and the present setting is the balls for handling but I'll be keeping an eye on inner tire wear. If necessary I may just elongate the ball joint bolt slots to get it a little closer to the -1.5 that I was originally shooting for. You may want to do this off the bat especially if you are running really low.

I'll post additional information on the installation proceedure if anyone is interested.

 

[julito04]

Nice write up!

 

[ViRtUaLheretic]

Thats a great writeup but this seems a tad expensive.
I still subscribed or future reference though.
Thanks!

 

[g_berserk]

weight aside, wouldn't it be easier and cheaper to just get a set of camber plates?
are the 1/4 inch difference in height for the joint ball-wishbone enough to make such a drastic difference over the camber?

I want to improve my car's ability to turn and get rid of the understeering nature of the design, and so far my bet is set on anti-lift kit to improve caster and rigidity of the bushings and adjustable camber plates. But this TT arms mod caught my eye as well.

Also this thread comes to mind
http://www.golfmkv.com/forums/showthread.php?t=90005

If you scroll down to post #9, there's a cheap alternative to correct the suspension geometry.
No word on the sport spindles yet

 

[Bunnspeed]

Does the reduction in unsprung weight create any noticeable improvement in ride quality on the road or the ability to soak up midcorner bumps? Any increase in road noise with the harder bushings? Nice writeup!

 

[shortwave360]

i iz jealous... thanks for the write up! best list of parts and pics to date!

 

[maxgtiturbo]

seems like alot of work.

 

[shortwave360]

Does the reduction in unsprung weight create any noticeable improvement in ride quality on the road or the ability to soak up midcorner bumps? Any increase in road noise with the harder bushings? Nice writeup!

It's not going to feel "better" as far as comfort is concerned. The car is going to be more reactive and confident while giving a far more accurate feel for the road. The driver is going to have "extra time and awareness" while spirited driving is taking place. Thats my best description for wanting to lighten & improve unsprung wheel weight.

 

[LePatron]

Quick update:

The day after my original post I went out on a spirited run that included a brief high speed run at an indicated 140 mph and I have to say that the car seems absolutely transformed. The front end is absolutely glued and I will be bringing the rear sway bar out to full stiffness to get the handling on to be more neutral . The increased high speed stability suggests increased positive caster and as such I'm disappointed that the shop didn't record caster. The remaining concern has to do with inner front tire wear and I will be updating this post on that issue. :thumbsup:

 

[RRacerguy717]

Quick update:

The day after my original post I went out on a spirited run that included a brief high speed run at an indicated 140 mph and I have to say that the car seems absolutely transformed. The front end is absolutely glued and I will be bringing the rear sway bar out to full stiffness to get the handling on to be more neutral . The increased high speed stability suggests increased positive caster and as such I'm disappointed that the shop didn't record caster. The remaining concern has to do with inner front tire wear and I will be updating this post on that issue. :thumbsup:

To add some info the Audi s-3 spindles are also alot different .:thumbsup: Bob.G

Edit to add Below to compare STOCK cast MKV contol arms

 

[Gotsol]

great info, I've been day dreaming about adding these along with the aluminum spindles.

please post more info.

 

[GodSquadMandrake]

Thank you for that excellent and very informative post LePatron. I gather from what you say that the Audi TT control arms are slightly wider because you aren't able to get less than 1.8 degrees of camber. At first it sounded to me like the kingpin axis was changed, but I'm not sure that is possible. Maybe it's more about how the other geometry was changed. Regardless it all seems to add up to a great modification. I can't wait to do this on my car. Losing 8 pounds of unsprung weight is huge... Porsche uses aluminum lug bolts to save less than a pound per wheel, and we've all seen the super light weight 13g lug nuts for JDM rivals.

I noticed something interesting about the ball joints. This may sound screwy but hopefully someone else can follow my idea... Since the part number is the same for both left and right control arms that means that it's the same thing on both sides, just flipped over right? So that means that the ball joint could be bolted to either the top or the bottom. If you switched it to be on top of the control arm instead of on bottom how it is now you would lower your roll center another 1/4" or however thick that control arm is. Unless I am missing something there is even more potential in this modification than you first thought. But the only problem with lowering the roll center in the front so much is that the rear roll center remains unchanged. This might create a slight instability in the rear if it was lowered as far as the front so it might be best to have a slight reverse rake in this case.

Please keep us updated with your progress. I love to see these sorts of modifications.

One note on those spindles. The size of the knuckle for the brake caliper is different, IIRC the casting is thicker. So either some modification or different brakes are required.

 

[LePatron]

The Audi TT has 26 mm wider front track compared to the Golf/A3 which is achieved at the swivel bearings or spindles. The control arms are identical in length to the stock steel units. The difference affecting camber setting is in the ball joint bracket design. As I said it would be easy to elongate the mounting slots in order to achieve a more positive camber angle. I'll probably be dong this in the coming weeks as I hate the thought of wearing out my front tires prematurely.
The idea of adding aluminum swivel bearings is very intriguing I must say. Does anyone have the part numbers for these?

 

[stangg172006]

thats over $700... is it really worth it?

 

[shortwave360]

It's hard to judge whats worth it when it comes to these cars. It's a mod that comes way down the list on the mod path.

I am considering this now that someone did the math for me. I just ordered the WALK and am wondering if the a-arm is compatible with the kit?