7afe JDM vs USDM, specifications Options

[playr158]

ok on the topend of the 7afe

the jdm/euro spec is different then the USDM

mostly in valve train but what exactly makes it different and more benificial

[FallenHero]

you think the lack of EGR is the defining factor in the added power? I would have figured the shorter runners on the JDM engine would add power... Plus the US7a intake manifold has all kinds of sharp shape changes that cause turbulence... I'd also like to see if the throttlebody is the same size...

[Kwanza26]

you think the lack of EGR is the defining factor in the added power?  I would have figured the shorter runners on the JDM engine would add power...  Plus the US7a intake manifold has all kinds of sharp shape changes that cause turbulence...  I'd also like to see if the throttlebody is the same size...
[right][snapback]312362[/snapback][/right]

Did I say that? ;] In fact... the EGR system doesn't even do anything at WOT... so it's a non-factor... IMO.

I do however say the USDM manifold looks a lot better for performance than the JDM one. The JDM one is considerably shorter, you are correct, but it's not always the length of the runners and such that determine which manifold is better than which. It's a matter of efficiency... gotta find the good balance between a short top-end manifold and a good mid-ranged manifold. I've only seen a couple of JDM 7A intake manifolds... so I can't make an outright comparison, but from the outside, the USDM manifold seemingly has larger sized runners and has greater volume. I can't comment on the throttle body either. As for the USDM's "sharp edges"... open that sucker up and clean it out. Can't do that with the JDM manifold...