# RS6 engine swap into 4.2 C5



## pedrow (Jul 18, 2009)

Hi, 

Has anyone here installed an RS6 engine into a C5 widebody? 

Does anyone know exactly what it is that needs to be done to the firewall in a regular A6 4.2 in order to accomodate an RS6 transplant. I'll be using an O1E tranny, so I think I am fine with the tunnel without modification. 

I have all the parts, and have done research regarding most everything else regarding the swap. Therefore, I just really need to find out about the firewall modification. If you can share some insight on this, I will greatly appreciate it. If your response does not address the firewall issue, it will not be helpful to me. 

If I don't go with the RS6 engine, then I'll go with a 2.7tt engine, which I already have (along with the manual tranny setup). 

Thanks...


----------



## pedrow (Jul 18, 2009)

thanks...


----------



## pedrow (Jul 18, 2009)

that would just be wonderful. Does anyone know if the cowl cover on the RS6 has the same dimensions as the 4.2 C5? I am talking about the plastic cover that is mounted between the firewall and windshield, and which covers brake fluid reservoir, wipers, etc...


----------



## mithril (Feb 6, 2003)

The dimensions for the rain tray cover are the same. Hell the rain tray cover itself is the same, just the removable insert that covers the battery in the 4.2L and S6 is different to allow access to the coolant expansion bulb. Don't for that you also need to relocate the battery to the trunk since the expansion bulb sits where the battery used to. You'll probably also need different tray mount(s) to attach the power steering and coolant reservoirs into the the tray.

Honestly if you're going to buy a 4.2TT, it's transmission, the different underhood wiring/mounting brackets and the battery relocation kit then swap it into a C5 4.2L widebody sedan you might just as well save yourself a lot of time/money and buy an RS6. The only reason I could see that swap making sense is if you where doing it on C5 S6 to create franken C5 RS6 Avant.


----------



## pedrow (Jul 18, 2009)

*thanks for the info. I already have all the parts, so I might as well*

do the work. I will be swapping the engine bits to a regular 4.2 block, which bolts right on to the manual transmission.


----------

