Efini~FC3S

iTrader: (4)

Taken directly from those articles

"start moving both cams in opposite ways (ie retarding intake, advancing exhaust). This will have the effect of increasing or decreasing the lobe separation angles. Increasing the lobe separation angle will generally broaden your power band while reducing your peak torque and lowering your idle quality, but it's also a great solution to decrease detonation."

So it sounds like the goal would be to increase the lobe separation a little bit, but not too much.

JasonC SBB

Bottom end became more responsive and stronger. The very topend seemed to improve a tiny bit.

m2cupcar

iTrader: (5)

So I asked for advice and didn't follow the majority. I got swayed by one the of the shop guys on two of my runs. Then later realized his recommendations were based on factory turbo cams which would already have overlap dialed out. Both his suggestions rolled the cams towards each other and as expected lost power over stock timing. They did give me a free run, and would've done more I'm sure - but I was out of time myself.

What I eneded up doing was backing up what's been said here- remove the overlap, spread out the time between intake and exhaust valve action. Runs were made on a MBC which showed 15.5-16psi on the trip over in the morning, but logged at 13psi target rising 1+psi and falling with the cam adjustments during the dyno pulls. My gauge has also showed very close to logged boost.

Stock cam timing (pwr/tq are 2x line data)


Intake -2*, Exhaust +2* (crank degrees): note more power with less boost


Overlay of runs at 13psi+ (pink & light blue are with the cam timing changes)


Dynojet at 16psi+ showing the difference in curves vs. the mustang. The only differences between dynos were the new magnaflow muffler and a lower boost level. The curves are similar pre torque peak, then totally different after.


I also noticed that the mustang dyno's roller rpm calibration process was off by 300rpm at my 7k redline. The dyno ign pickup was apparently flaky.

jonny

Has anyone testet the original GTX camshafts from the original mazda turbo engine? IMO this camshafts would be a good possibility. Are there any experience?

bobsaget

iTrader: (2)

Jonny start your own thread.......the OP is looking for advice and information on ADJUSTABLE cams, not GTX cams.