Reversed Inlet Manifold
 

A friend of mine is looking at doing this on his WRX, how easy is it to do? (On a 1993 WRX - his car not mine)

Not that straight forward, and for what you gain in most circumstances not probably not worth it and things have moved on.

On the early manifold you need to ideally have the TB welded to the front side and the existing blanked of leaning the manifold in the original position, finding a good alloy welder to do this won’t be cheap.

Then you have to deal with the relocation of the Air con etc.

As said it’s a lot to do for very little gain, if he is going the full hog then its worth considering once everything else is done.

Easy, get a plate welded on to the other side of the manifold, and blank the TB entry off.

Air con has to be removed if fitted as the alternator needs to go to the side that the air con was as standard. power steering stays where it is. hardest thing is to get the throttle cable position right.

Every little helps.

any pics of these once done guys ?

Cheers
Chris.

:notworthy At 500bhp maybe, if the car's under 400bhp there are far more important things to consider.

Its not that difficult. Apart from the welding of the wedge I did mine myself. Mine's a 99 model.
Here's a pic of mine. Its poor quality and I have some tidying up to do but you get the general idea.

http://www.scoob.co.uk/rebuild/enginebaynow.jpg

Daz

I saw this one on your thread while searching Daz, it's coming along well.

How easy was it to cut the new hole in the inlet manifold? or did you simply spin it around? can this be done ?

Cheers
Chris.

I just basically had a wedge made and welded on then spun the manifold round. It cost me £80 for the wedge and to have it all machined and welded.

Intercooler pipe work was used from the original FMIC pipework I had. I just cut it where I wanted it then got the same local engineering firm to weld together. All in its cost me around £120

Planning on doing this within the next year as part of a large upgrade project...

I think if you buy a phase 1.5 inlet manifold (like off a Sti V3) you can reverse it, and only have to grind off some dowels underneath it?

i take it they do not sit correctly if they are not the 1.5 version? or can other versions be done too with enough work ??

Chris.

phase 1.5 is easiest to rotate.. the throttle body gets near the bonnet on phase 1 and 2.

The only issue on the 1.5 is the idle valve clashing with power steering / inlet pipe depending on set up.

Simon