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Guest SXU29T

just wanted to know your opinions on weather a jap spec s15 and a aus s15 with very similar mods be making the same power on 98 octane aus fuel, i know that jap models do run more boost then aus models 10psi to 8psi standard but if both the jap and the aus s15 have identical mods say exausht, filter and run identical boost say 14psi do you think that the import will still blo the aus spec? or will it be line ball?

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Guest SXU29T

mine is an aus spec its just that my girlfriends friends boyfriend has a jap spec and wants to race me of the street that is! and i just want to know what im letting my self into. Ive also heard bout the different turbo thing but i think that all auto s15s lack the bbturbo and super helical lsd, ive also been told that aus spec r's and aus spec s's have diff turbos??? the former being bb? also heard that s2 s14's came with bbturbo std?

If you tune yours up SXU29T, you should be able to match a jap-spec one... the aussie one is just detuned.. replace a couple of small things and up the boost (you can go fair bit higher than 10) and it should be pretty equal.

Sneak in a PowerFC while you're at it to kick his butt :D

Guest Works Auto

Ive driven both aussy spec and jap spec and honestly on the road you can't feel any difference. there very similar.

The aussy spec still has a ball bearing turbo. I was also sure that the injectors were exactly the same and the power difference was in the more aggressive timing on the jap model.

I have been in both as well, and driven both, thou, one was a dealer car (the Aust. Spec)

The Jap Spec is much better car. The interior has nice extras, and there are a few differences.

ECU is suppose to be different for the jap higher spec fuel, the Aus Spec has 420cc inj. Jap Spec has 480cc inj. The exhaust is different I believe (evened out in mods, thou, I'd check the dump pipes on each if they haven't been changed.) Possible Gearbox, Diff and and standard clutch differneces. (gearbox and diff ratios i mean - esp diff.)

the 45 extra kilowats is noticable.

A bit.

Upgraded Carpet, factory boost gauge, TV optional, better stereo system, original "s" on the steering wheel, leather optional, climate control, a few other plasticy bits here and there.

  • 1 year later...

i think on the seats of the JDM s15 its say silvia on the seats

the main difference with the jap ones is they run a different fuel map and boost factory as weel, due to the higher 100 RON fuel in japan.

That would explain why a slightly moded jap spec will spank an aussie version with the same mods. however start changin the oz spec engine managment and u have the identical car!

also the jap spec ones lose value almost twice as fast due to being an *import*

but i don tknow personal opinon

im planing to buy one pretty soon

Jap spec has a rear wiper too, thats one of the main was to tell. I bought an Aus spec mainly because it was newer, had one owner, had FULL service history and because i knew the power difference would be slight but add an exhaust and a filter and you would make the same gains as the jap spec and be even(because Aus spec exhaust is more restrictive). Factory boost gauge on Jap spec doesnt look as good as a Greddy pillar and only holds one gauge, i didnt see much difference in interior between the two.

i think on the seats of the JDM s15 its say silvia on the seats

the main difference with the jap ones is they run a different fuel map and boost factory as weel, due to the higher 100 RON fuel in japan.  

That would explain why a slightly moded jap spec will spank an aussie version with the same mods. however start changin the oz spec engine managment and u have the identical car!  

also the jap spec ones lose value almost twice as fast due to being an *import*  

but i don tknow personal opinon

 

im planing to buy one pretty soon

I think you pretty much summed it up. So what you gona go for the aus or jdm?

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