2.9 to 2.8 manifold swap

[maff 10]

I'm after a polished manifold for my abv 2.9 corrado and instead of doing the labour myself i've seen one thats for sale but comes from a golf 2.8 aaa, it has the smaller diameter inside plenhum.

If i fit this to my 2.9 engine could the smaller plenhum lose me any flow/horsepower at all, or will i be ok?

[captainredeye 0]

Stick with the 2.9! said it your self "Smaller", all about the air flow.

[MarkFoster 0]

The other thing to watch is that a lot of 2.8 manifolds are for OBD2 which means your throttle body won't fit to it...

[maff 10]

I think ill stick then, cheers

[goozie 0]

i fitted a 2.8 polished manifold to my vr and found it to be a bit better than the orginal, my therory behind this is, the 2.8 has a smaller plenum in width, so i assumed that the air flow would be more direct to the to each cylinder! and not just circulating in the larger 2.9 plenum, i may be wrong and i'm sure a guru on here will be able to put us right?

[dumptyboy 0]

i fitted a 2.8 polished manifold to my vr and found it to be a bit better than the orginal, my therory behind this is, the 2.8 has a smaller plenum in width, so i assumed that the air flow would be more direct to the to each cylinder! and not just circulating in the larger 2.9 plenum, i may be wrong and i'm sure a guru on here will be able to put us right?

 

I've also heard that the 2.8 manifold on a corrado can give better performance, basically just like your saying! I have wondered for quite a while if this is true and I infact have a 2.8 manifold and throttle body, so would also like to know if this is true.

 

Who on here can shed any light?

[goozie 0]

like i said i feel that it the 2.8 is better, makes the car a little bit more responesive, but that is only my opinion without any actual figures to say which is the better i suppose we will never know!?

[robo22sri 10]

The 2.8 odb1 inlet will give a little more torque as it is more restrictive than the 2.9 and also why the rado 2.9 gets more horse power

[4DUST 0]

like i said i feel that it the 2.8 is better, makes the car a little bit more responesive, but that is only my opinion without any actual figures to say which is the better i suppose we will never know!?

 

I have run the 2.9 manifold a schreck! and the 2.8 I am selling on the forum that is being referred to in this post. The manifold is for OBD1 as I was running with my Corrado throttle body with no issue. I have already told Maff there is no problem with the fitment. I found the torque to be a bit better than the 2.9 manifold lower down. Reminded me of the Schreck with the flap closed. Snappier throttle response compared to the 2.8 manifold due to the smaller plenham. Up the top end I did not notice any restriction.

For sale on the forum if any one is interested! :-)

[maff 10]

I appreciate the info 4DUST, just learning my way around all the obd1/2 and tuning options, my other cars going friday so if i decide to go for the manifold i'll let you know as polishing mine is a bit of a job!