MKI Audi TT to MKIV Jetta front suspension swap

ZiggyoftheNorth

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Joined
Dec 14, 2018
Location
Aliquippa PA
TDI
2005 Jetta TDI
I've read a bit on this swap and found a 2003 TT in a junkyard. I grabbed the struts, spindles, brakes, sway bar, Andy even the strut brace under the hood. It has the 12.3" rotors and red calipers. :D

Has anyone else done this swap out there? I'm wondering about a few things.

1. Should I use the TT springs or the ones on my Jetta?

2. I didn't get the rims. (Only one damaged one was left.) I need 17" rims to fit over the calipers and checking the specs, the TT offset is different than a Jetta. Which is a better choice for the swap?

3. I'd like to make the factory strut brace work. I want to go back and drill out the welds to get the parts with the studs on the strut towers and firewall. If I can't get them, I was considering rivnuts and bolts to mount it. Has anyone out there installed one and have any advice?

4. Will the TT struts affect my ride height?

Thanks
 

D-Cup

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Jul 22, 2017
Location
San Antonio TX
TDI
2010 Jetta TDI Cup Edition, 2003 Jetta GLS, 2000 Jetta GLS, 2012 JSW
1. Don’t know - depends on what your goals are. What are your goals for the car?

2. Offset probably won’t matter much unless you experience rubbing between wheel and caliper.

3. Sounds like a lot of work that can be avoided by buying sportier struts for your car.

4. No. Springs will effect ride height - not struts/shocks. But struts that are 16-17yrs old are probably shot. Better off buying some newer/less used ones.
 
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ZiggyoftheNorth

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Joined
Dec 14, 2018
Location
Aliquippa PA
TDI
2005 Jetta TDI
Bajan,
That would be wonderful. What I've read said you needed at least 17" rims. New Beetle 16" rims are much cheaper and easier to get.

D-Cup,

My car has 256k and needs some general TLC in the front end. I wanted the bigger bushings and generally heavier duty parts. I got this stuff for a steal at a U-Pull-It type yard on a day they had a half off sale. And better braking and better handling are always a plus when you can get them.

1. Daily driver and road trips. I assume the TT springs for a 1.8T are roughly the same as a Jetta TDI, but don't know. That's why I'm asking.

2. That's why I'm asking. I'm hoping someone who has done this might know if there is an issue. It seems like the factory probably made them different for a reason.

3. & 4. Strut brace stiffens the structure of the car regardless of the struts used. Cast TT control arms are not compatible with VW MKIV sway bars without modification. Mine don't even have the bosses to drill out. TT sway bars attach to the strut. If I buy new I still need TT struts. Being that though the struts bolt righ into a Jetta but are a slightly different design, it seems rational to ask about differences in ride height. After all the springs mount to the strut and the strut mounts to the car. A change in either one affects height.
 

red16vdub

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Aug 26, 2013
Location
(617) City of CHAMPIONS
TDI
03 JSW 5spd
Bajan,
That would be wonderful. What I've read said you needed at least 17" rims. New Beetle 16" rims are much cheaper and easier to get.

D-Cup,

.

Not sure where you read that but, I know 16” work because I have that setup on one of my tdi’s, and they fit my car without issues. Close but they do fit .



Bajan
 

ZiggyoftheNorth

Well-known member
Joined
Dec 14, 2018
Location
Aliquippa PA
TDI
2005 Jetta TDI
Thanks Bajan. I wish I knew that sooner because I passed up some nice ones thinking they wouldn't fit. Since you have this setup is there any other advice for putting it together?

Any idea if there is anything special about the rear suspension on aTT? It looked the same as a Jetta at a glance except for the calipers being red. Rotors are 9".
 

bobbiemartin

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Joined
Jul 16, 2012
Location
Jacksonville, FL
TDI
2010 Tiguan TDI 4Motion, Jeep Grand Cherokee 3.0 CRD
I grabbed the struts, spindles, brakes, sway bar, It has the 12.3" rotors and red calipers.
Has anyone else done this swap out there? I'm wondering about a few things.
I've done this on a Golf I had. Depending on what you are trying to achieve, it's a worthwhile swap. The benefit is slightly better front end geometry and the advantage of easily adding a bit of negative camber. You can see pictures of my Golf here. As said, you need the lower control arms if you don't have them.
Should I use the TT springs or the ones on my Jetta?
I would suggest neither. What are you trying to achieve? Boy racer slammed look? Handling? Raised? That will determine the springs.
I didn't get the rims. (Only one damaged one was left.) I need 17" rims to fit over the calipers and checking the specs, the TT offset is different than a Jetta.
You will need to swap calipers, at least the mounting brackets. The TDI brakes mount differently. I would suggest you reconsider the 312mm brake setup. It's very heavy and I doubt you really need brakes that big. 1.8T brakes are 288mm (just slightly larger than the TDI rotors) but use calipers that fit the TT hubs and have much bigger pads than the TDI brakes. Much lighter than the 321mm setup. I was very happy with this setup.
Will the TT struts affect my ride height?
No, but what shape are they in? I would consider replacements unless they are in very good shape. I would replace the mounts and bearings at the minimum. If you look around you can find uprated strut mounts. Seat Cupra rear bushings help as well.
I would also consider swapping the subframe. The TT uses firmer mounts than the TDIs do. The steering rack is a nice upgrade as well. It has a quicker ratio (less turn lock to lock). Not all TT's had the quick rack, so make sure before you buy.
You will like the TT swap. Once you get the suspension sorted (especially if you have a limited slip) and even a moderately grippy tire, it's a really fun car to drive. I've sold on my Golf, but I do miss it at times.
 

Yourbuddysatin

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Oct 28, 2016
Location
Pennsylvania
TDI
2013 Jetta tdi
If this help I’ll tell you what I have going on for my mk4 tdi golf. Audi TT front rotors with caliper and brackets. 1.8t/vr6 knuckles. Stock lower control arms with poly bushings. Stock sway bar with poly bushings. ECStuning coilovers poly upper strut mount. Rear are stock 1.8t/vr6 brake set up. I’ve been swapping parts from tt to golf since I bought my first gti back in 07 and learned they are almost the same cars. Hope that helps.

16” are the smallest wheels you can fit on the front with the larger TT front Brake set up.
 
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ZiggyoftheNorth

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Joined
Dec 14, 2018
Location
Aliquippa PA
TDI
2005 Jetta TDI
Thanks for the responses everybody.

Donor car is a 2003 Audi TT 1.8T FWD. I disconnected the brake lines and sway bar, unbolted the LCAs from the subframe, removed the nut from the top of the strut, and removed each side as an assembly. I also took the sway bar and the brace across the strut towers under the hood.

I'd like better handling. Lowering it would be rough though as roads are like mine fields here. The only VW with similar struts that attach to the sway bar is the R32, which sits lower than other MKIV models according to my Bentley Manual. I'm not sure if it is the springs or a different strut height that makes the difference, which is why I asked the questions about both affecting the height. The TT is smaller but seems to have more options so I was thinking the weight was in the same ball park. Are TT springs stiffer for handling though?

bobbiemartin,

Thanks for the tip on the subframe and steering. How would I be able to identify the better rack?

Thanks.
 

Yourbuddysatin

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Oct 28, 2016
Location
Pennsylvania
TDI
2013 Jetta tdi
A vr6 TT would have stiffer front springs to support the heavier 6 cylinder. Probably would make the car sit a little higher using them on a 4 cylinder car.
 

bobbiemartin

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Jul 16, 2012
Location
Jacksonville, FL
TDI
2010 Tiguan TDI 4Motion, Jeep Grand Cherokee 3.0 CRD
I'd like better handling. Lowering it would be rough though as roads are like mine fields here.
You might want to look at a Shine spring set. They raise the ride height slightly but ride very well and the handling is good as well. I was very happy with this setup. I used Bilstein TC struts/shocks. The yellow Bilsteins may have been a better choice, but budget prevailed on that one.
Thanks for the tip on the subframe and steering. How would I be able to identify the better rack?
Thanks.
By counting the turns lock to lock. I think the R32/TT rack is around 2.6 and the standard rack 3.1.
 

ZiggyoftheNorth

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Joined
Dec 14, 2018
Location
Aliquippa PA
TDI
2005 Jetta TDI
Yes the 3.2. Same as r32 engine. Think 03/04 they had some in the states.
I got a Bentley Manual for the TT off craigslist. According to it they had them 2003 - 06. They also list two versions of the 1.8T...a 180HP version and a 225 HP version. I haven't figured out what makes the difference in HP yet.
 

ZiggyoftheNorth

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Joined
Dec 14, 2018
Location
Aliquippa PA
TDI
2005 Jetta TDI
As far as I know the 225hp TT is a factory hopped up tune. Maybe differant turbo? I never really got much into the 1.8t.
As far as I got before falling asleep last night, the 180 HP looks about like the MKIV setup. The 225HP has dual side mount intercoolers connected in series. If the one in the boneyard is still there and has this, it may be interesting to grab and try to use. It was hit in the front though and some parts may be trash. I think I've seen A4 and A6 Audis with a similar set up though and may be able to cobble it together.

Perhaps I should just have my paychecks direct deposited straight to the junkyard. :D
 

ZiggyoftheNorth

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Joined
Dec 14, 2018
Location
Aliquippa PA
TDI
2005 Jetta TDI
TT are set up just like a mk4. a4/a6 are longitudeinal so keep that into account.
True, but I'm not sure ho that would affect the intercoolers and the piping between them in the front. Obviously the plumbing to the engine would be different though.

The TT seems like an R32 version of a New Beetle and seems more comparable with a NB in general than a Jetta, though they are all A4 platform vehicles. I haven't found an A3 in the boneyard yet, but assume they are more like a Golf or Jetta.
 
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