Doing a little tinkering, found some interesting data:

USDM STi JDM v7 STi
free length: 1.860 1.730
installed height (1.417")pressure: 50 lbs 50 lbs
pressure @ 9.55 mm: 107 130

This is assuming you use a USDM STi camshaft with the JDM v7 valvetrain. When I measured these, it was evident that coil bind would not be an issue. Use this info for what ever you feel it's worth, I'm not suggesting you do anything with your EJ257 valvesprings. :devil:

im a newb. are you saying they are just as good?

I'm not suggesting you do anything with your EJ257 valvesprings. :devil:

At first glance, it seems the JDM springs would provide a higher rpm limit. How you would make power on a EJ257 without the supporting headwork and camshafts is "new science"....or lots of boost. ;)

Just wanted to provide the community with the data; what they derive from it is up to them. :)

Bump for move to "built engine forum" :)

S.

done :)