Tubular Front Subframe

[b55240]

For the last few months I have been trying to source a front subframe for my car from VW and Audi and everything seems to be on international backorder with no availability. I tried to place 3 different orders and looked on Etka for cross part number availability and tried to order a few of those. I have been able to track down one part number which "may" work, but at this time, I am just frustrated with this entire thing and the stock subframe still has 3 issues that concern me.

1. Ground clearance. I am not driving that low, but I am tired of my subframe scraping over speed bumps.

2. Stock subframe suffers from poor welds and have several problems where they like to "shift" and cause a popping sound, especially in reverse. This can be addressed by seam welding, but this could lead to the subframe deforming since it is only stamped steel.

3. Stock subframe likes to rust. For me this isn't a huge issues since I live in Florida for the time being, but up north this is a major concern.

With all this in mind, I started researching and looking into the different options I had and the more I thought about it, the more I realized that a custom solution may be required. It would also work between platforms, so B5/6 A4, B5 S4, B5 and B5.5 Passat.

I have finally found a fabricator who is willing to make a tubular subframe for me. I dropped off the tubing for him this morning. He told me he is going to start fabricating the jig today and should be able to start bending all the piping this week. Stay tuned because there will be many more pictures to come!

In the meantime, this is the tubing I dropped off to him:



And if everything goes according to plans, this is what I will end up installing in the car:

Bottom:



Top:



I am actually going to set up the subframe to use the factory mounts just in case there is too much NHV with the 034 Motorsports solid inserts.

If you have any questions, please feel free to ask. I am bringing home the jig with me as well so if I would need to make a few more in the future, I can.

[christianb5s4]

That's really cool, another benefit to this tubular subframe is it would make access to parts of the engine while the motor is in the car much easier compared to stock.

[topquarkpc]

so the subframe pictured is for B5 platform?
whose is that one?

[milehighkid24]

I will definitely want one fi it turns out to be lighter and stronger than the stock subframe

[Wagonholic]

Pretty cool, looks like it has a lower profile where the tranny would sit.

Makes the inevitable 2.7T motor pull that much easier

[MetalMan]

so the subframe pictured is for B5 platform?
whose is that one?

The build of the pictured subframe is from tinytim, starts here:
http://www.audizine.com/forum/showth...=1#post9390402

[b55240]

The subframe pictured was made by another forum member (tinytim) here a few years ago. He ended up selling the project and he had an amazing build. I tried to contact him a few months ago, but never heard back. I am using that as a starting point, and changing a few little things.

[Ephry73]

Definitely interested. These will also be ideal for converted B6 cars with say a 2.7 motor


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[topquarkpc]

The build of the pictured subframe is from tinytim, starts here:
http://www.audizine.com/forum/showth...=1#post9390402

thank you for that info...I appreciate it

[vavJETTAw36]

That is badass. I'd probably want one too if the price is pretty good.


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[hibiscusS4]

This is awesome in for results and pricing


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[slowSfaux]

I like what I see! Only problem with that is the dealer will laugh at you if you ask them to do an alignment and they see that in place of the oem piece. They'll turn you away guaranteed. And I'm not sure anyone but the dealer knows how to properly align our cars.

[achb5]

^ I was wondering about that too

[2000s4_m]

Might be right about that alignment issue with dealer but i dont know about your area, in here and in nearby cities there is a lot of experienced techs outside the dealer that will properly align my S4, actually the dealer will turn you down with just lowering springs as it throws tires out of range for camber


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[2000s4_m]

In for pricing!!!


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[getslideways]

The build of the pictured subframe is from tinytim, starts here:
http://www.audizine.com/forum/showth...=1#post9390402

As soon as I saw this thread title, the first thing I thought was "wonder if the OP has seen tim's build" lol

[b55240]

All the mounting points would be the same as stock. That is why I have even considered using the factory mounts since they allow the subframe to be moved so that the front end can be aligned accordingly. The suspension pickup points are going to be in the same place as the OEM locations since the lca's would primarily affect track width. I have thought about doing something similar to the RS6 with the dual LCA mounting points and then having a spacer made for the front axles. If you want camber and caster adjustment, you should consider adjustable upper control arms. They are absolutely AWESOME!!! I have the Stern UCAs and added a ton of caster and can dial camber according to driving conditions. Check out my build thread in my signature to take a look at the rest of the project.

If anyone has any ideas, I would love to hear them! Someone mentioned clearance for the oil pan to be removed easily so that the pickup tube can be cleaned or replaced easily. So I will take that into consideration once I get this one back from the welder to check for clearance. At some point I may need a few measurements to ensure it will fit all the motors with the manual transmission. If not, the mounting tabs on the rear could be adjusted to accommodate the S4 Quattro transmission. There are a few things I need to think about before I consider getting a small batch made because I want to ensure all areas are covered and this is a bolt in solution for everyone.

[slowSfaux]

Yeah I hear you on the same as stock dimensions, but the dealer won't care. Non-oe means they won't touch it for liability concerns. If you have someone lined up who can do a loaded alignment (not the same as adjustable control arms) then you're golden!

[QuinnsterKID]

I would be down to get my hands on one of these. The stock subframe gets in the way for everything. I have a tubular k member on my mustang and the difference between stock is insane!

[Ephry73]

Yeah I hear you on the same as stock dimensions, but the dealer won't care. Non-oe means they won't touch it for liability concerns. If you have someone lined up who can do a loaded alignment (not the same as adjustable control arms) then you're golden!

Just go to a specialized shop.


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[getslideways]

looking forward to more info, and pricing.

Hope to see some pics of the progress or the test fit session

[Lanorg]

Interested to see where this goes!

[2000s4_m]

All the mounting points would be the same as stock. That is why I have even considered using the factory mounts since they allow the subframe to be moved so that the front end can be aligned accordingly. The suspension pickup points are going to be in the same place as the OEM locations since the lca's would primarily affect track width. I have thought about doing something similar to the RS6 with the dual LCA mounting points and then having a spacer made for the front axles. If you want camber and caster adjustment, you should consider adjustable upper control arms. They are absolutely AWESOME!!! I have the Stern UCAs and added a ton of caster and can dial camber according to driving conditions. Check out my build thread in my signature to take a look at the rest of the project.

If anyone has any ideas, I would love to hear them! Someone mentioned clearance for the oil pan to be removed easily so that the pickup tube can be cleaned or replaced easily. So I will take that into consideration once I get this one back from the welder to check for clearance. At some point I may need a few measurements to ensure it will fit all the motors with the manual transmission. If not, the mounting tabs on the rear could be adjusted to accommodate the S4 Quattro transmission. There are a few things I need to think about before I consider getting a small batch made because I want to ensure all areas are covered and this is a bolt in solution for everyone.

About the mounting points, would you be installing rubber/polyurethane bushings or is it going to be a solid one???


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[b55240]

I have the 034 motorsports billet subframe mounts, but the mounts are going to be the same size as OEM so anyone can use either OEM or aftermarket.

[Lanorg]

Only the downpipes and center diff touch the subframe on re/re. Its not complex, you jack it higher. If you're making a tubular subframe, focus on performance with stock mounts. Dont over complicate it.

[2000s4_m]

I have the 034 motorsports billet subframe mounts, but the mounts are going to be the same size as OEM so anyone can use either OEM or aftermarket.

Like that, i hope you can really make it happen


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[audacity]

I like what I see! Only problem with that is the dealer will laugh at you if you ask them to do an alignment and they see that in place of the oem piece. They'll turn you away guaranteed. And I'm not sure anyone but the dealer knows how to properly align our cars.

who goes to the dealership to get their 16 year old car aligned. they aren't mythical creatures, they have a toe in/out and a connected camber adjustment...which i really doubt at 16 years old they are touching. you'll need bushings anyway.


id be in for this. i have been meaning to get the solid bushings from 034 this would make it so much easier. i would definitely try to have the duel mounting options for track widening in the lower control arms

edit: would it be possible to add a bar across where say a DTS would mount up so its all one piece, not sure if it would be worth it or as strong as a regular DTS but id imagine having everything locked down to one piece has to have some advantage

[Mark00s4]

isn't there some kind of adjustment to wheel alignment done through moving the sub frame? and some kind of jig type tool?

[Mark00s4]

isn't there some kind of adjustment to wheel alignment done through moving the sub frame? and some kind of jig type tool?

[slowSfaux]

who goes to the dealership to get their 16 year old car aligned. they aren't mythical creatures, they have a toe in/out and a connected camber adjustment...which i really doubt at 16 years old they are touching. you'll need bushings anyway.


id be in for this. i have been meaning to get the solid bushings from 034 this would make it so much easier. i would definitely try to have the duel mounting options for track widening in the lower control arms

edit: would it be possible to add a bar across where say a DTS would mount up so its all one piece, not sure if it would be worth it or as strong as a regular DTS but id imagine having everything locked down to one piece has to have some advantage

Research what it takes to align our suspension. It's not as simple as you, or jiffy lube, will say it is. Can't simply "set the toe and let it go."

[slowSfaux]

isn't there some kind of adjustment to wheel alignment done through moving the sub frame? and some kind of jig type tool?

Yes Mark, when our suspension is compressed, the camber change has to be equalized via shifting the subframe. The dealer is where most people go to have this done properly. Your local tire shop will simply adjust your tie rod ends until the toe is in spec and send you on your way.

[Zba]

How many dealers do you think are actually doing the "raised toe" adjustment? Do you really think you can tell the difference?

[Ephry73]

Love the idea of this for the the front and rear for sure.


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[b55240]

The biggest problem I see at the moment is making sure this works across all platforms. Widening the track like the rs6 does would require an axle spacer in the equal amount that the lowers are moved out. I don't want to make the lower arms adjustable since the UCA I have already take care of that and there are multiple solutions for caster and camber. I have played around with the idea of adjusting the roll center since our cars don't like to be lowered and keep proper geometry in the suspension. But this again would complicate things extensively and there are better things I would rather address. Such as aluminum hubs from a later year A4 to reduce unsprung weight or make a bracket readily available to run Cayenne brakes front and rear for a reasonable amount of money. If you can't find a shop who will properly adjust your suspension, you probably shouldn't even be looking into this honestly. I have found a few different solutions for problems our chassis cars present, and not all of them are for everyone, but at the end of the day, I know there are certain people who value performance above all else. I am just trying to address a problem ours cars have and possibly provide a solution for other and not just keep this to myself.

[MarcRogers]

The biggest problem I see at the moment is making sure this works across all platforms. Widening the track like the rs6 does would require an axle spacer in the equal amount that the lowers are moved out. I don't want to make the lower arms adjustable since the UCA I have already take care of that and there are multiple solutions for caster and camber. I have played around with the idea of adjusting the roll center since our cars don't like to be lowered and keep proper geometry in the suspension. But this again would complicate things extensively and there are better things I would rather address. Such as aluminum hubs from a later year A4 to reduce unsprung weight or make a bracket readily available to run Cayenne brakes front and rear for a reasonable amount of money. If you can't find a shop who will properly adjust your suspension, you probably shouldn't even be looking into this honestly. I have found a few different solutions for problems our chassis cars present, and not all of them are for everyone, but at the end of the day, I know there are certain people who value performance above all else. I am just trying to address a problem ours cars have and possibly provide a solution for other and not just keep this to myself.

Could not have said this any better.

"If you can't find a shop who will properly adjust your suspension, you probably shouldn't even be looking into this honestly"

^Truth


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[slowSfaux]

The biggest problem I see at the moment is making sure this works across all platforms. Widening the track like the rs6 does would require an axle spacer in the equal amount that the lowers are moved out. I don't want to make the lower arms adjustable since the UCA I have already take care of that and there are multiple solutions for caster and camber. I have played around with the idea of adjusting the roll center since our cars don't like to be lowered and keep proper geometry in the suspension. But this again would complicate things extensively and there are better things I would rather address. Such as aluminum hubs from a later year A4 to reduce unsprung weight or make a bracket readily available to run Cayenne brakes front and rear for a reasonable amount of money. If you can't find a shop who will properly adjust your suspension, you probably shouldn't even be looking into this honestly. I have found a few different solutions for problems our chassis cars present, and not all of them are for everyone, but at the end of the day, I know there are certain people who value performance above all else. I am just trying to address a problem ours cars have and possibly provide a solution for other and not just keep this to myself.

This hits the nail on the head. I'm not sure why I was looking at this as a factory replacement rather than a performance upgrade. My apologies.

[audacity]

Research what it takes to align our suspension. It's not as simple as you, or jiffy lube, will say it is. Can't simply "set the toe and let it go."

if you are honestly that concerned with it, some adjustable control arms would probably be better investment than the 200 dollar factory alignment. atleast the arms will last longer.

[Ephry73]

Definitely interested in these frames


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[landfill]

LOL I'm surprised anyone still takes their b5 to the dealer.

[pee quu]

Does it really give you any extra ground clearance though? Don't get me wrong this idea is awesome but on the other hand, the tubular sub frame shown now has more areas where things could possibly snag it (on the front end of it) and as far as the rusting concern goes, if you get this powder coated and it rubs the floor it will scrape the powder away and eventually will rust too. I don't notice a rusting issue on my stock subframe besides the areas where it has bottomed out on something. Other than that theres no rust