Re: Cam Advancing - the Full Monty

[Robert Houk - SMCC WorkGroup Server Firmware <Robert.Houk@East.Sun.COM>]

   Those that paruse the archives, or have been here some time, should delete
   this post.  The subject of Cam Advancing has been covered in depth here, but
   as usual, *today* the archives aren't common reference material.

   [...]

   That said, the benefits are as follows.  The turbo spools up sooner, the
   torque is seat of the pants noticeable, and really no other ill effects on
   longevity, knock or even gas mileage (insert right foot exceptions).  I did
   progressive-mod-testing on a late 89 10vtq (2.0bar) and found that the car
   didn't come alive until the cam advance.

   The downsides are as follows:  High end tapers off sooner.  

   [...]

I'll chip in with my own observation/experience to pretty much back up
all of the above.

Specifically, my experience with '83 UrQ was:

a)  stock turbo, stock cam -- nothing below 3000rpm, turbo and cam both
    come online about the same time (3000rpm), cam runs out around 4500
    to 5000rpm. Overall, rather disappointing (this is a supercar???
    people paid $35,000 [1983] for this??!!??)

b)  "S4" turbo installed -- boost comes fully online by 2500, cam still
    runs out 4500/5000. Enough low-end boost the ECU overboost trips
    at *2000* rpm with 3-4PSI of boost.

c)  Schrick cam installed -- [lack of] lowend pretty much unaffected
    (as per seat of pants), high-end extends to redline now ("Oh, so
    that's what the revlimiter is for!")

d)  4 or 5 degrees on the cam (adjustable cam gear) -- lowend noticeably
    extended downwards; ECU overboost trips *again* at *7*PSI at 2000RPM;
    high end tapers off a little (but still vastly superior to stock
    cam).

Overall, *much* more of a *streetable* engine/car.

My only concern (academic...) would be that a full cam gear tooth is too
coarse/too much, but YMMV, and all that...the concept is a proven winner,
as far as I am concerned.

Another $0.25's worth.

					-RDH