Hi everyone,
I was wondering if I could change the plastic intake manifold of my Jazz 1.4 graphite (idsi from italy) with that one of yours Vtec...
Is it only a way to avoid overheating?
Does anyone know which other differences there are between them except the fabric they are made of?
It seems to me that aluminium intake manifold has a different (bigger) diameter... as well as the headers 4-1 from american Vtec seems to be bigger than others!
What do you think?
If Honda's changed them there must be a reason!

 

yours isn't 4-1? if not what is it then?

 

what isn't metal? The US IM is AL...

 

This is what I mean...




Plastic vs aluminium!




Don't you see any difference?

 

I'd want to find out, first, if there is any heat dissipation difference between the plastic used, and an aluminum manifold. Also if there is any difference in the bore size.

 

The truth is that:

Honda Fit intake manifold isn't totally aluminium made....
I still don't know if there's any difference in size, but the solution of aluminium + plastic certainly reduces the difficulty to access to the engine...
Another difference, however, is the trhottle body diameter (50mm vs 55mm)

 

The plastic intakes are very good. They are smooth as glass on the inside. The AL intakes are rough inside because of the casting process.

 

aluminum also has issues w/ cracking at the welds if they're not perfect. been there, done that.