Cam Timing
 

Has any one on this forum ever experimented with cam overlap/timing, this includes standard cams with noticable gains, As mentioned in a my intro i was a mechanic for 15 years and spent my last few tuning for Kostecki engine centre, We played with two BA 5.4lt 4 cams, One had mild cams (the biggest we could go without upgrading valve springs) locked at 0c (std cam gears) and the other had adjustable gears fitted and stock cams, Off memory the BA with adjustabe gears (with -4deg on exhaust) pulled about 40hp more than the cammed BA, My knowlage with WRX's is vague and i only apply the info have on all engines, More fuel + more air = bang, So do the EJ's respond well with the cams dialed in with more overlap?
Before I get a belting about the search function, I did search with no real info.

I too am looking at this very same thing at the moment, but with AVCS. The short answer to your question though is yes. More overlap from what I have read so far + better top end #

The first lot of AVCS heads came out with inlet only variable cam timing, the latest offreing has inlet & exhaust. The AVCS is obviously computer controled, via the ECU, however the same results can be had with vernier cam wheels. The AVCS uses oil pressure driven by a solenoild to change the timing of the cam position.

Couple of links for you.

[URL="http://www.drivingsports.com/site/2008/11/modifying-the-subaru-sti-avcs/"]Modifying AVCS[/URL]

[URL="http://drive2.subaru.com/Win05_WhatsInside.htm"]Subaru AVCS[/URL]

[QUOTE=RoughStilin;673125]I too am looking at this very same thing at the moment, but with AVCS. The short answer to your question though is yes. More overlap from what I have read so far + better top end #

The first lot of AVCS heads came out with inlet only variable cam timing, the latest offreing has inlet & exhaust. The AVCS is obviously computer controled, via the ECU, however the same results can be had with vernier cam wheels. The AVCS uses oil pressure driven by a solenoild to change the timing of the cam position.

Couple of links for you.

[URL="http://www.drivingsports.com/site/2008/11/modifying-the-subaru-sti-avcs/"]Modifying AVCS[/URL]

[URL="http://drive2.subaru.com/Win05_WhatsInside.htm"]Subaru AVCS[/URL][/QUOTE]

Thanks for the links Simon, I couldn't see why gains couldn't be made even with the non AVCS donks, I've serched Rexnet & NASIOC with no real answers, only more to do with dialing A/M cams, I would like to see if some one has done it and come up with the goods,
Reason im asking is i'm about to change my timing belt and thinking of shoving a set of vernier gears in.

If you had access to an engine dyno I'm sure there would be gains to be made. In the car it would be difficult to experiment with different timing to find whether a setting is better or worse than what you had. What you gain in top end you lose in bottom end so it will be a compromise as to the characteristics you want.

Shaun, have you got STD cams fitted or after market ?

[QUOTE=seagull;673321]Shaun, have you got STD cams fitted or after market ?[/QUOTE]

Still stock mate.

I have just posted about KiDo tuning and one of the things that distinguish KiDO tunes from many others is that we do adjust the AVCS when we tune a car. There are benefits.

[url]http://www.perth-wrx.com/vb/kido-racing/48800-lets-talk-tuning-kido-tunes.html[/url]