# 225 IC Cross Pipe: Structural?



## ManOfManyGTs (Dec 11, 2007)

In the process of doing my build now. I will be installing a CTS FMIC. As I was taking everything apart, I noticed that the cross pipe that links the two stock intercoolers is pretty stout and connect to the two frame rails. 

Does it serve any stiffening or structural functions?

Thinking of three options:

1. take it off

2. leave it on and install the FMIC (if possible)

3. take it off and fab up some kind of connector piece that installs in its place.

Thoughts?


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## l88m22vette (Mar 2, 2006)

Search this, there have been several small ****storm threads on this on the forums, its mainly no, but some people still hold to keeping it in. At the worst, it just adds a bit of weight, at best it gives a small structure/crash improvement being kept it. You can do an oil change much more easily though...


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## ManOfManyGTs (Dec 11, 2007)

Thanks. I did search but didn't find anything. Maybe I didn't hit the right key word. What do you call this thing?


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## l88m22vette (Mar 2, 2006)

ManOfManyGTs said:


> Thanks. I did search but didn't find anything. Maybe I didn't hit the right key word. What do you call this thing?


Sorry, didn't mean to be harsh - just what you did, but since it bolts to the unibody there is the debate over benefits of keeping it when going to a FMIC. I ditched it, and couldn't imagine I'd ever feel anything until I built the rest of the suspension and seam-welded the whole damn car.


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## The_RoadWarrior (Nov 21, 2011)

I am part of the group that believe that it shouldn't be removed. After all the discussions we've had on the subject (here and other forums) nobody knows for sure if it was meant to be structural or not from Audi. 

What I can tell you is that it's placement, it's construction and the fact that it's not too heavy makes it a piece worth keeping even if it's no longer functional. Think of it as a free forward cross rail brace, if that's something that even matter to you!

If you have to remove it, option 3 would be cool if you can pull it off the right way!


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## ejg3855 (Sep 23, 2004)

*FV-QR*

I have one in one car and not in the other.

MY thought is the R doesn't have it and that's the VAG top performer for the A4 platform. 

Did Audi design it to be structural is the question, I dont think we will ever know that answer.


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## Late__Apex (Dec 2, 2007)

My car is currently resting with the front frame rails sitting on jackstands without the cross pipe on (engine, crash bar, lock carrier and radiator all installed). If I remember, when I take it down, I'll measure to see if there is any flex from rail to rail.


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## The_RoadWarrior (Nov 21, 2011)

Late__Apex said:


> My car is currently resting with the front frame rails sitting on jackstands without the cross pipe on (engine, crash bar, lock carrier and radiator all installed). If I remember, when I take it down, I'll measure to see if there is any flex from rail to rail.


At rest, maybe not! Loaded in a turn, definitely and it's a good little brace to have linking the front rails that far forward.


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## The_RoadWarrior (Nov 21, 2011)

ejg3855 said:


> MY thought is the R doesn't have it and that's the VAG top performer for the A4


I don't know if that is entirely true, the Sport Car Club of America (SCCA) does not see it that way because the R is classed as a "D"street prepared while the TT is classed in the faster "C" group with the miatas. I have yet to see an R32 do better than a TT with similar prep while racing. 

Was it considered the top dog? Maybe, but in practice that is not the norm.

BTW I got your email and will reply shortly ( I'm getting more than I can handle lol).


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## [email protected] (Jul 1, 2009)

Why not keep it _and_ use it? You can retain the under-hood piping that way. Although I suppose a FMIC with passenger-side inlet would allow that as well.


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## The_RoadWarrior (Nov 21, 2011)

[email protected] said:


> Why not keep it _and_ use it? You can retain the under-hood piping that way. Although I suppose a FMIC with passenger-side inlet would allow that as well.


Maybe the CTS FMIC he is trying to run won't allow it to be retained and his decision on that particular unit is set in stone.


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## Doooglasss (Aug 28, 2009)

[email protected] said:


> Why not keep it _and_ use it? You can retain the under-hood piping that way. Although I suppose a FMIC with passenger-side inlet would allow that as well.


How would you use it for a FMIC install? You would need to have an end tank with inlet/outlet on both sides and you would effectively double the length of the piping and complexity.

You can leave it there- the only reason mine has been removed is for easier access to the oil filter. I planned on one day fabricating a brace and using those mounting points, but like many other projects that has never happened.

Question: 180hp quattro & FWD guys: Did your cars come with a cross brace? I know the mk4 GTI didn't and we share the same chassis design.


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## warranty225cpe (Dec 3, 2008)

As much as we have all talked about this cross bar/pipe, someone should just go ahead and do a run of braces. I'm sure we could drop some weight by adding a nice billet replacement. In that case, regardless of its structural benefit, your dropping some weight by getting rid of it. Then there's not reason for debate..


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## 20v master (May 7, 2009)

DougLoBue said:


> Question: 180hp quattro & FWD guys: Did your cars come with a cross brace? I know the mk4 GTI didn't and we share the same chassis design.


Don't know about FWD, but my 180Q had one. It's only purpose is to be a place to bolt the super extra long unneccessary power steering line to. :screwy: It's now in the garage closet. :laugh: I can't imagine putting an oversize oil filter in there with it in the way.


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## cphillips (Dec 2, 2010)

20v master said:


> Don't know about FWD, but my 180Q had one.  It's only purpose is to be a place to bolt the super extra long unneccessary power steering line to. :screwy: It's now in the garage closet. :laugh: I can't imagine putting an oversize oil filter in there with it in the way.


180FWD checking in...I have the bar removed for easier oil changes. Always was curious if it was designed to be structural.


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## ManOfManyGTs (Dec 11, 2007)

cphillips said:


> 180FWD checking in...I have the bar removed for easier oil changes. Always was curious if it was designed to be structural.


Any pics of this 180hp version of the bar?


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## cphillips (Dec 2, 2010)

ManOfManyGTs said:


> Any pics of this 180hp version of the bar?


How about this?


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## ManOfManyGTs (Dec 11, 2007)

Hmmm. Is it functional on the 180s? I thought that only 225 would have them because of the dual intercoolers and driver's side TB.


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## cphillips (Dec 2, 2010)

ManOfManyGTs said:


> Hmmm. Is it functional on the 180s? I thought that only 225 would have them because of the dual intercoolers and driver's side TB.


No, it's not. Neither end of the tube is connected to anything.


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## ejg3855 (Sep 23, 2004)

The_RoadWarrior said:


> I don't know if that is entirely true, the Sport Car Club of America (SCCA) does not see it that way because the R is classed as a "D"street prepared while the TT is classed in the faster "C" group with the miatas. I have yet to see an R32 do better than a TT with similar prep while racing.
> 
> Was it considered the top dog? Maybe, but in practice that is not the norm.
> 
> BTW I got your email and will reply shortly ( I'm getting more than I can handle lol).


I cannot see why SCCA would rank the TT higher (not doubting just curious), less power same or similar weight.

The R was designed by the R division, but they really just recycled the TT which was just an elaborate Golf. SHeesh idk this is a circular reference excel would be confused.:beer:


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## l88m22vette (Mar 2, 2006)

The TT is turbo and about 150lbs lighter because of the smaller engine configuration, it is a fine line though...


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## The_RoadWarrior (Nov 21, 2011)

ejg3855 said:


> I cannot see why SCCA would rank the TT higher (not doubting just curious), less power same or similar weight.
> 
> The R was designed by the R division, but they really just recycled the TT which was just an elaborate Golf. SHeesh idk this is a circular reference excel would be confused.:beer:


Like Eric said, a turbo car gets much more power out of basic allowed mods. The TT also have a lower CG and much more fender room for rubber, helping it out-handle an R with similar preparation.


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## ejg3855 (Sep 23, 2004)

The_RoadWarrior said:


> Like Eric said, a turbo car gets much more power out of basic allowed mods. The TT also have a lower CG and much more fender room for rubber, helping it out-handle an R with similar preparation.


Wait there is too many Eric's here. 

What is allowable mods in either C or D spec. As I recall the most basic mod would be ECU modification and that moves you out of either of those classes. 

This isn't the place to discuss this, I don't know much of the rules just what I hear from my auto-x buddies.


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## WiKKiDTT (Aug 13, 2009)

Now there's another.


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## WiKKiDTT (Aug 13, 2009)

Remove the pipe it's not structural. Jus a pipe bolted to the frame. Audi always over engineers everything. 

Eric


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## The_RoadWarrior (Nov 21, 2011)

ejg3855 said:


> Wait there is too many Eric's here.
> 
> What is allowable mods in either C or D spec. As I recall the most basic mod would be ECU modification and that moves you out of either of those classes.
> 
> This isn't the place to discuss this, I don't know much of the rules just what I hear from my auto-x buddies.


As far as engine, the allowable mods in all the street preared classes including C and D:
-Intake is unrestricted ( TB, intercooler, TIP, DV and piping are all part of the intake)
-exhaust is open (the exhaust has to finish behind the driver and there is 95-100 decibel limit)
-ECU modifications are allowed
-fuel system is open ( pump, injectors, FPR, rail and fuel type is upgradable)
-Manifolds (intake and exhaust are unrestricted)
-water injection is allowed as long as water only is used (meth/alky are considered alternative fuel)

All these basic allowed mods, if taken advantage of properly, are in favor of a turbocharged car. I clear 400 AWTQ with my car easy, an R32 can only dream of making that kind of power within the same allowances. 

Forced induction and AWD are always at an unfair position in the world of racing. Look at the EVO, it cleaned house in E, got moved to B after the Bimmers and Camaros kept crying, now it's been re-classed again because the corvettes, S2000 and 350 Z stop showing ( it's suppose to go compete with GT3s, Gallardos and the likes because the AWD/turbo combo is so freaking lethal with the mods allowed)


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## Marcus_Aurelius (Mar 1, 2012)

Bumping this from the dead just to post the picture that finally put this highly debated subject to rest. With AWIC, I have no reason to keep this bar if it serves no purpose, so I decided to dig into it a bit more to find what Audi's intent was. I always believed it would be beneficial because of its location and construction, but now we know that Audi designed it to be one of the chassis structural reinforcements (not integral but one of the main tub reinforcements). Here is another thread where we also discussed the cross tube (I'm sure there are others):
http://forums.vwvortex.com/showthre...d-radiator-is-structural&highlight=structural


*Everything in red is integral to the tub (including the front crash bar), and the bits in green are additional structural reinforcements *


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## 20v master (May 7, 2009)

So your final answer is that it is an additional bracing. /thread? :laugh: I really don't want to reinstall mine, and don't think I will, even knowing this info.


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## Marcus_Aurelius (Mar 1, 2012)

20v master said:


> So your final answer is that it is an additional bracing. /thread? :laugh: I really don't want to reinstall mine, and don't think I will, even knowing this info.


It was definitely designed with the intent to provide structural and torsional rigidity when your German peers did design study. The percentage of the total stiffness that it accounts for is up for debate (the released literature of the design study doesn't give detailed numbers to the public like the Japs do). It's really up to you, but if you have no real reason to discard, I'd put it back in. Personally, because of the location, I believe it plays an important role against torsional deflection of the forward portion of the frame and worth the hassle of keeping. 

PS: Did you get my email reply?


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## hunTTsvegas (Aug 27, 2012)

Good information to know! So,.. who's up for designing a replacement?!?!


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## 20v master (May 7, 2009)

Marcus_Aurelius said:


> really up to you, but if you have no real reason to discard, I'd put it back in.
> 
> PS: Did you get my email reply?


The reason not to put it back is it's almost impossible to remove the larger OEM oil filters with it in place. I do all my own oil changes + Cross Pipe = :banghead:. I'd put it back on if it weren't for that fact. I got your email and decided to skip on the 3.2 aux radiator. :thumbup:


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## Boulderhead (Oct 21, 2012)

*Bigger oil filter necessary?*



20v master said:


> The reason not to put it back is it's almost impossible to remove the larger OEM oil filters with it in place. I do all my own oil changes + Cross Pipe = :banghead:. I'd put it back on if it weren't for that fact. I got your email and decided to skip on the 3.2 aux radiator. :thumbup:


Is the longer filter really a big deal with our vehicles? I also dump and replace my own oil, and the folks at my local VAG parts shop suggested the shorter one was sufficient. Should I switch to the longer one next refill.. or not worry about it?


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## Marcus_Aurelius (Mar 1, 2012)

20v master said:


> The reason not to put it back is it's almost impossible to remove the larger OEM oil filters with it in place. I do all my own oil changes + Cross Pipe = :banghead:. I'd put it back on if it weren't for that fact. I got your email and decided to skip on the 3.2 aux radiator. :thumbup:


Not a good enough reason IMO! I've always used the larger capacity filter myself and it's doable (I remove filter from the top but also don't have SAI and the all the crap attached to the manifold). Regular size filter and cross pipe back on seems like another good option too! :beer:


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## Marcus_Aurelius (Mar 1, 2012)

hunTTsvegas said:


> Good information to know! So,.. who's up for designing a replacement?!?!


I'm on it! I've had the project in limbo for quite some time, and if the interest is good enough I can make it happen quickly. Who's up for Madmax cross tube replacement that will allow easy filter replacements? opcorn:


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## 20v master (May 7, 2009)

Marcus_Aurelius said:


> Not a good enough reason IMO! I've always used the larger capacity filter myself and it's doable (I remove filter from the top but also don't have SAI and the all the crap attached to the manifold). Regular size filter and cross pipe back on seems like another good option too! :beer:


Lower oil volume capacity = higher oil temps in the name of a slight increase in chassis stiffness = no thanks.  



Marcus_Aurelius said:


> Who's up for Madmax cross tube replacement that will allow easy filter replacements? opcorn:


Oh oh oh, me me me!


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## 20v master (May 7, 2009)

Boulderhead said:


> Is the longer filter really a big deal with our vehicles? I also dump and replace my own oil, and the folks at my local VAG parts shop suggested the shorter one was sufficient. Should I switch to the longer one next refill.. or not worry about it?


It was a countermeasure for the longitudinal motors and their sludge problems. The longitudinal layout put the B5 Passat/A4 subframe right under the oil pan, so their pan has lower capacity than a transverse pan. 3.9 vs 4.6 quarts if my memory is correct. So adding the larger filter bumps them up to 4.4 quarts, where it makes a transverse capable of holding ~5 quarts. More capacity means the same amount of heat going into more oil means lower average oil temps. It's good, but not something that is required or that will cause you long term problems. It also means you can dump in 5 quart Mobil 1 jugs without measuring :thumbup: (but Max will tell you Mobil 1 isn't good enough :laugh: ).


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## D2O (May 12, 2012)

I realize I am a couple of months out of date here - but is this still alive? I am interested in seeing what Marcus has coming up with.


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