2.8 head swap???

[laxman851]

I've heard rumors of a possible head/intake minifold swap from a 2.8 passat to our b5 s4. If anyone has any legitimate information that could help straighten this out I would appreciate it. Thanks

edit: I forgot to mention i've already searched for more information, if anyone know's of another thread that clears this up just post it.

[blmlozz]

I've only been lurking around trying to find info about an s4 to buy one but, I do know from reading other threads here that the 2.8 head conversion is possible and popular with Bt gt setups but will require slight modifications to use. Also, as far as I know, there's no difference in the 30v from a passat or a4

[laxman851]

Can you shoot me a link to the threads or if you can remember some of the key words so I can search for it myself.

[AudiA4_20T]

I guess the search won't let you put in 2.8 on here, but Guruman is running them as well as Deb38 and some others...

Yes they fit, what is your planned setup?

[laxman851]

Welll I just searched it on google and found an old response on the B5/A4 threads and it wasnt really that informative they did cite one shop that ran a twin turbo set-up on a passat which should help me reference in some cases. I've just run across some money recently and I literally just finished my k04 swap last week and I'm still breaking in my clutch, i'd like to keep those in and I figured that the next considerable gain would be going this path. I've heard that there is ~100 more cfm with that head rather than ours which caught my attention. Alright, i've read some of the commets made by Deb38 on other threads and he seems to know what he's talking about. Over all I'd like to keep a my S4 a DD and not a fking gt28 DD a real DD.

[Das General]

What are your plans for the motor? Keeping K04's or bigger?

If you go with the smaller end of the turbo spectrum, your best bet would be to keep the 2.7 heads, as the cam is less aggressive and you won't lose any low end tq. If you plan on going bigger, the larger cam and better flowing heads will help. However, it might be wise to seek out a larger throttle body. Another alternative is the RS4 heads, which could be described as an option in between the s4 and 2.8 heads. But, with the RS4 heads, you will be looking at more money overall. This is because you will most likely need the RS4 fuel rail, throttle body, etc.

I am not quite sure of the differences in the s4 and rs4 throttle body, though.

[Dr. Jekyll]

2.8L heads are almost the same size as RS4 heads. Although the exhaust port on the RS4 is smaller than both the 2.8 and the 2.7 heads.

APB (S4)
intake = 42.64 W X 26.85 H
exhaust = 36.06 dia

ATQ (2.8 N/A)
intake = 56.60 W X 26.72 H
exhaust = 35.87 dia

AZR (RS4)
intake = 55.52 W 26.75 H
exhaust = 32.28


IIRC the stock S4 throttle body is 65mm and the RS4 is 75mm.