Cam timing advance

[DYI01]

I have been lurking in the clubrsx.com ECU tuning forum and have been reading up on the Hondata K-Pro. It seems the k20a4 intake cam timing can advance up to 60 degrees or so. The K-Pro is very in depth and has 12 different fuel maps. 6 per each cam profile and 1 per each 10 degreees of cam advance. Instead of the one big Base map on the PFC. I believe it has the same setup for the ignition timing as well.

Along to my main question, How far can we advance our VVT intake cam timing? Ive been doing some digging up of some info, but Im not incredibly knowlegeable about ALL this engine stuff. http://www.pressroom.com.au/pressroom/sample/presskits/99celicakit.htm#17 That link says:

"Celica's VVTi system can vary inlet camshaft timing over a range of 43 degrees relative to crankshaft angle.

However, the variable lift system has the effect of increasing valve opening duration, so the full range of inlet timing variation is 68 degrees.

(Taken from the maximum retard intake valve opening in the low-medium engine speed range at minus 10 degrees BTDC to the maximum advance intake valve opening in high engine speed range at 58 degrees BTDC.)"

Does this mean that the VVT mechanism, when using the PFC can only advance the cam timing to a max of 43 or a max of 68 degrees?

[Smaay]

while in lift i believe its 63 degrees. I believe the #'s in the PFC VVT map dont actually mean degrees, its just a refrence number...from what im hearing about the K-pro is that its a great tool and better than the PFC. Hopefully AEM will have an EMS out for our car soon...if so, then by by PFC

[vvtlikick]

From this article (http://www.sae.org/automag/globalview_01-00/08.htm), the VVT-i system has 43° of variability. For both the GT and the GT-S, in and out of lift.

I don't know if that's the mechanical limit of the system. Also, I've heard the new, retuned Vibe/Matrix/Corolla 2ZZ has a different VVT-i tuning.

[DYI01]

hmmm...So what do the arbitrary numbers in the PFC mean and how are they interpreted?

[Boosted2.0]

43 degrees is a mechanical limit.

[mirconrice]

Originally posted by DYI01
hmmm...So what do the arbitrary numbers in the PFC mean and how are they interpreted?

i would like to know as well :)

[APEXiTypes]

Originally posted by DYI01
I have been lurking in the clubrsx.com ECU tuning forum and have been reading up on the Hondata K-Pro. It seems the k20a4 intake cam timing can advance up to 60 degrees or so. The K-Pro is very in depth and has 12 different fuel maps. 6 per each cam profile and 1 per each 10 degreees of cam advance. Instead of the one big Base map on the PFC. I believe it has the same setup for the ignition timing as well.

Along to my main question, How far can we advance our VVT intake cam timing? Ive been doing some digging up of some info, but Im not incredibly knowlegeable about ALL this engine stuff. http://www.pressroom.com.au/pressroom/sample/presskits/99celicakit.htm#17 That link says:

"Celica's VVTi system can vary inlet camshaft timing over a range of 43 degrees relative to crankshaft angle.

However, the variable lift system has the effect of increasing valve opening duration, so the full range of inlet timing variation is 68 degrees.

(Taken from the maximum retard intake valve opening in the low-medium engine speed range at minus 10 degrees BTDC to the maximum advance intake valve opening in high engine speed range at 58 degrees BTDC.)"

Does this mean that the VVT mechanism, when using the PFC can only advance the cam timing to a max of 43 or a max of 68 degrees?
Not that it matters, buts it K20A2...And it's 50 degrees.
Bottom line is, the more air your moving the more cam angle advance you want. For the rsx, we have the option of locking the cam at a certain degree. This allows us to run the dyno with the cam angle locked at 10, 20, 30, 40, and 50 degrees. After that, you simply see what cam angle made the most power and where, then put your cam angle map together.

[00silverGTS6spd]

Originally posted by DYI01
hmmm...So what do the arbitrary numbers in the PFC mean and how are they interpreted?

that would be the million dollar question. perhaps mwr can answer that??

ALL of the numbers in the PFC seem to be just arbitrary numbers. If we knew what the numbers were it would be a lot less guessing and make tuning much more efficient.