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

[doGGy]

NO EGR at first place.

Second - camshafts

Third - Header (4-2-1 pipe)

and more will come as i will remeber.

[FallenHero]

better intake manifold also.

[Kwanza26]

better intake manifold also.
[right][snapback]312333[/snapback][/right]

I'd say worst...

I think it's more a myth that the Japanese 7AFE is better than the USDM version. So far, it's only guess work. From what I've seen of the JDM 7AFE intake manifold, I really don't think it's better than the USDM one. As far as the cams go, I doubt they're much better either. Maybe very slightly, but I can pretty much gurantee it's not as some think (1mm more lift)...

Sometimes uber leet JDM sh!t just isn't as good as the USDM stuff...

[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...

[playr158]

hey fallen see if you can find out how big the jdm throttle body is in comparision to the usdm
if its larger i might take it from you

[doGGy]

They are compleatly the same from Exterior... Even the TB are the same.....

As for Kwanza - you ever driven Euro spec ST?

As i - i did drivin USDM st, cuz lots of people bring USDM car over here (salvaged) and i was in search for a celica for my girl, and i do driven ST with 120K miles from US - and all i can say - it totaly sucks.... compared to Euro ST.

Yea, difference might be not huge, but all the Smog stuff on USDM engine do NOT add power, as all the Euro ST's do not have them.... Header is different, ECU is different (our ST's Ecu is programed to run on 95 octane fuel, as for USDM you guys run 92 (euro spec) octane fuel.... this is the difference...)

Cams - different FOR SURE, dunno how much (might be not the 1 mm) but this will be meaasured for sure then Edo gets his car back.

better intake manifold also.
[right][snapback]312333[/snapback][/right]

[Illyont]

NO EGR at first place.

Second - camshafts

Third - Header (4-2-1 pipe)

and more will come as i will remeber.
[right][snapback]312294[/snapback][/right]

So Euro do infact have a 4-2-1 exhaust header? While the USDM doesn't? I have been looking at my exhaust several times and thinking "hmm.. why switch this? it looks really good "

What about the "second" cat? or the first, it depends on from where you count.. Do USDM have a cat on the exhaust header, and not Euro/JDM, or was it the other way around? I can't see any on my car, but I haven't been looking that much.. And I probably wouldn't be able to tell even if looking at one

This post has been edited by Illyont: Jul 15, 2005 - 7:16 AM

[playr158]

illyont you don't have a cat on your header and neither do i
its a 94 & 95 ST thing

tb are the same cool
then i would like to know the difference on the cams......

[edo17982]

well just thinkin that an engine as 7AFE have in US market a 4-1 header which gives his better at high RPMS instead the use of a 4-2-1 which help in low-medium RPMS is a silly fact cuz of fuel cut at 6.2 and cuz of max power around 5k.
The intake cam difference, dear Kwanza, has been measured from a machine shop. well maybe the USDM one I got, since it is used, lost few cents of lift but the difference measured was 0.8 mm (asked yesterday) so don't say if u don't try in 1st person.
The ECU is different also in years: I mean: my 94ST has different maps than Doggy's ST which is 96 if I'm right.
Just think my fuel cut is 6300RPMs, his fuel cut is around 7K!!!!!
Than the EGR think maybe let USDM engine lose a little bit cuz of rejoon of non-burnable gas into combustion chamber=less efficiency.
That's it I think....

[playr158]

so the cam has a difference of .8mm
what would be the benefit of that?
and which side is it on intake or exhaust?

[edo17982]

so the cam has a difference of .8mm
what would be the benefit of that?
and which side is it on intake or exhaust?
[right][snapback]312650[/snapback][/right]

I wrote it Intake cam
And as I'll be able to get one I'll let u know feeling and numbers differences

[playr158]

thanks edo

[playr158]

edo what injectors are you using?

[edo17982]

while keeping NA I'm using stock. They can provide fuel needed with stock cams.

[Kwanza26]

Lol... true that I've never driven a a JDM or Euro spec Celica ST, but don't assume I'm just guessing. I'm not the type to base a lot of info on guesses. For one, 90% of the used engines in US are direct from Japan. I've done plenty of 7AFE swaps, majority of which are JDM implants. I have seen the different versions of the intake manifold (2 different USDM version, 1 of which is very similar to the JDM version), have examined the differences between the USDM and JDM accesories, and for all of you who want to believe in some faint hope that "JDM is the SH!T"... go ahead if it really makes you feel better. Physically speaking, they're the same engine.

And again I'll say, the JDM version does NOT have .8mm more lift than the USDM versions. If you think that, you know nothing about camshaft designs. .8 is a LOT of difference. Something believeable would be like 232 degrees duration with 7.1mm lift (4AGZE/4AGE smallport cams) versus 240 degrees duration with 7.56mm lift (bigport 4AGE cams). Considering these are for a more performance oriented engine that revs all the way to 7500 rpms... why would the 7AFE, only able to make power to 6000 some odd rpms, have camshafts somewhat equal to these? Simply based on the torque band, I would guess that 7AFE has no better than 230 degrees duration and 7mm lift on the intake side. Assuming the JDM version has some cool .8mm more lift, that cam is gonna be 7.8mm lift and will be able to make power in the 8000 rpm range... kinda redundant. Lift pushes the power band higher up in the rpm. It'll essentially work against the head design.

As for smog parts... I never said they added power. I simply said EGR does not even come on at WOT, so it doesn't affect the way the engine makes power. What does affect power, is the pre-cat in the exhaust manifold. Those are really the only major emission parts... and I've run without them already... so I'm gonna say although the cat does slightly hurt performance, but it's not a night/day difference. The main thing is, the engines have the same compression, same head, very similar intake manifolds, similar cams (assuming the JDM version has some additional lift), and essentially the same powerband and basically the same ratings.

To close... argument only brings pyrrhic victory. The air of resentment will only worsten. I'd much rather prove through actions than words... but as that seemingly is impossible, believe what you want to believe. I am Done. ;]

[doGGy]

Lol.....

Nothing more to add....

But still, i aint saw the JDM version 7AFE, im only comparing what i saw/felt - USDM 7AFE and Euro spec 94-95 / 96-99 7AFE engine... So

Lol... true that I've never driven a a JDM or Euro spec Celica ST, but don't assume I'm just guessing.  I'm not the type to base a lot of info on guesses.  For one, 90% of the used engines in US are direct from Japan.  I've done plenty of 7AFE swaps, majority of which are JDM implants.  I have seen the different versions of the intake manifold (2 different USDM version, 1 of which is very similar to the JDM version), have examined the differences between the USDM and JDM accesories, and for all of you who want to believe in some faint hope that "JDM is the SH!T"... go ahead if it really makes you feel better.  Physically speaking, they're the same engine. 

And again I'll say, the JDM version does NOT have .8mm more lift than the USDM versions.  If you think that, you know nothing about camshaft designs.  .8 is a LOT of difference.  Something believeable would be like 232 degrees duration with 7.1mm lift (4AGZE/4AGE smallport cams) versus 240 degrees duration with 7.56mm lift (bigport 4AGE cams).  Considering these are for a more performance oriented engine that revs all the way to 7500 rpms... why would the 7AFE, only able to make power to 6000 some odd rpms, have camshafts somewhat equal to these?  Simply based on the torque band, I would guess that 7AFE has no better than 230 degrees duration and 7mm lift on the intake side.  Assuming the JDM version has some cool .8mm more lift, that cam is gonna be 7.8mm lift and will be able to make power in the 8000 rpm range... kinda redundant.  Lift pushes the power band higher up in the rpm.  It'll essentially work against the head design.

As for smog parts... I never said they added power.  I simply said EGR does not even come on at WOT, so it doesn't affect the way the engine makes power.  What does affect power, is the pre-cat in the exhaust manifold.  Those are really the only major emission parts... and I've run without them already... so I'm gonna say although the cat does slightly hurt performance, but it's not a night/day difference.  The main thing is, the engines have the same compression, same head, very similar intake manifolds, similar cams (assuming the JDM version has some additional lift), and essentially the same powerband and basically the same ratings. 

To close... argument only brings pyrrhic victory.  The air of resentment will only worsten.  I'd much rather prove through actions than words... but as that seemingly is impossible, believe what you want to believe.  I am Done.  ;]
[right][snapback]312740[/snapback][/right]

[normality78]

i've bought a 7AFE engine alone. How do i tell its JDM or USDM?

[playr158]

you have USDM there really is no big difference