roreswrx

does anybody know the exh./int. lift and duration of the stock cams on a wrx late model. or any place i might be able to find it.
any help would be great. also the same info on the U.S. spec STI. thanks THOMAS

DeliciouSpeed

iTrader: (2)

An excellent topic.
The US STI will have AVCS as all current STI models do. So their cams won't work in WRX heads. The AVCS heads can be retrofitted though. Both JDM WRX and STI have the same AVCS heads. However, the cams, valves and other goodies are differant. Just an excuse to upgrade to Jun pieces I say.

http://www.junauto.co.jp/processing/ej20/index.html

I don't have the stock. But MRT has listings for 4 types of cams, check with them for specs.

http://www.mrtrally.com.au/shop/sear...LL&DESCRIPTION

I have heard that Webcam has made WRX cams. But have not looked into this. Their cams have worked well for me, but many of their cams are regrinds. Regrinds no good. Hardfacing, no good.

k2

jimr

Are the stock WRX cams adjustable with respect to their timing sprockets? If valve to valve and valve to piston clearance allowed, you could then tighten the separation (more overlap, means less low end, but more high rpm capability), or decrease overlap by spreading the separation and gain cylinder pressure, build boost faster, but maybe lose top end.

The beauty of DOHC engines.

It would be interesting to measure output changes on an engine dyno after changing up-pipe and down-pipe and then take full advantage of cam timing changes (if a change from stock even made an improvement) to facilitate freer flowing exhaust.

Has anybody looked at the factory workshop book on assembling and timing valvetrain?

DeliciouSpeed

iTrader: (2)

The stock gears aren't adjustable, you could play with valve clearences to do the same thing with less adjustability, there is only so far away from the stock settings you can go.
You can re-key the stock sprokets-this of course has it's limitations. Cam gears are available from Jun and Toda (prolly others).

roreswrx

Found the number for anyone who might want them:
intake lift .367 duration 223

exhaust lift .363 duration 217
THOMAS

DeliciouSpeed

iTrader: (2)

I saw that on NASIOC, sad figures indeed, lot to be gained from cams for sure in this set up. Jun has 254 and 264 duration cams, they don't publish the lift though. I havent seen figures on any other EJ cams.

k2