Hi all,

I have been looking at changing my subframe for the aluminium S3 variant and upgrading to either TT or Passat Wishbones. Has anybody else done this and if so any pointers please.

Thanks in advance

Interested too if it's possible and if anyone has done this, I was a bit disappointed to find our 2017 Octavia has a steel front subframe when the old 2009 one we had was alloy.....seems like a backward step but presumably a cheaper component?

I have looked about and apparently the S3 subframe fits as do the Passat wishbones but don't want to order it all unless I am sure it works such like the lighter hubs etc any advice welcomed if you have done the swap or not if it doesn't work

It does all fit - the alu subframe is standard on the A3 and S3. I'm not sure what you've already done, but it would make sense to get some droplinks and do the ARB and such while you've got it all apart.

You don't need alu arms, but something like the standard caster SuperPro LCAs are a nice upgrade for longevity with the polybushes. If you want to splash out, SuperPro, RL, 034 and others all make alu arms with nice bushings. I know the TT arms are alu, but not sure about the Passat. Either way, there are better options than OE - @travs went for... Delphi?

Perfect thank you so much this helps greatly, would alloy TT arms be an upgrade?

I haven't touched anything suspension wise yet, just remapped and an exhaust now my warranty has ended. So there will be lots more questions I am sure.

If there is anything you would recommend please say, you said about the ARB any ideas?

Ok so you probably have it a bit easier than the Superb guys.

The big thing with the LCAs is that the key variant is track width of the car - determined by how long the width-section of the arms are and depending on a number of things the main one being which version of the mqb chassis you have. Despite the whole MQB is MQB - it isn't. There's MQB A0 (eg polo/fabia), MQB A1 (Golf/Octy) and MQB-B (Superb/Passat). Bigger the chassis, generally the wider the track width but there are variations. For example, Audi RS3 is MQB-A1 but understandably has a wide track.

The front track width of the Golf is 1541mm. The Octavia is 1535mm so 6mm across the car which is nothing. Superb is 1584mm.

So the Superpro TRC1070 which is deemed as applicable to anything coming out of Germany is meant for MQB-A1. Fine for yours and will do well (don't bother with TRC1071 which gives increased caster - its a pub-quoting improvement rather than anything that's going to get you anywhere if you're not doing things like track days and corner balancing). But stick the TRC1070 on a Superb and it pulls the bottom of the wheels in giving you positive caster, unable to get a decent 4wa and putting strains on other components.

I have TT arms on mine. The Delphi version is TC4442/TC4443 but they weren't in stock so I went for KYB which are KSC4260/KSC4261. Its odd as the Delphi is quoted as being for the Passat but the KYB aren't. Tbh, they seem exactly the same.

It definitely feels nice and solid and I think that's because of the solid rear bush. The old ones didn't look bad coming off but there is definitely a more solid feel to it. Weight wise, 2% of SweetFA in the grand scheme of things but either marginal gains matter to you or they don't.

Alu arms were £75 each, but with £35 shipping from Spareto in Estonia so £180. It said DHL would handle shipping and duty but what that means, is they'll pay it so they can pass through customs and deliver and then hit you with the re-charge. That was an unforeseen extra £53 so c.£230 in all. You can avoid a lot of that by ordering from somewhere in the UK. In fact:

Link for Delphi Front Right on ebay

Link for Delphi Front Left on ebay

As for subframe, they all seem the same. In fact, they're right across the Passat range right down to the 1.4, so I was thinking about getting a pre-loved one from ebay, and as I have a redundant Racingline dogbone mount insert for a certain type of dogbone mount, I might as well go for one that has the same type (they differ by engine code - I found that out the hard way but I posted the list so you can enjoy).

So what do you get? The alu one is lighter naturally but stiffer as its more solid - the steel one is stamped steel sheeting so it has more flex in it. Will we notice? Probably not without telemetry.

As @OccyVRS says, if you're going to do it, you might as well save a load of hassle and get the front anti-roll bar done too as it sits above the subframe which needs to be dropped to change the arb. And this will absolutely throw out the alignment so queue up one of those for shortly after too.

Front droplinks don't need to be changed unless you switch to coilovers or shocks where the mounting point is in a lower position than standard parts. But your suspension is only as good as its weakest parts so...why not. They're straightforward to change (note you need an M6 triple square) and if they replacements are adjustable you can really dial out any pre-load on the anti-rollbar (if, as said before, the mounting point on the shock is lower and putting torsion on the arb).

I'd absolutely advise getting a balljoint splitter if you don't have one too. The lower balljoints are a bugger to get out with a mallet!

I think that's everything I can think of for now. Oh, and make sure the dogbone bolts go into the DSG casing straight - its a very bad day to realise you've crossed and it needs helicoiling.