Hi Guys, another brand new GTT product for you.
The GTT adjustable sprocket replaces the OE 'non adjustable' part allowing optimisation of the cam timing to enable maximum performance to be achieved with ANY cam.
As this part is removed anyway when a new cam is fitted it makes sense to fit this at the same time.Here are some instances of when adjustment will be needed.
1) The cam makers full lift for the inlet & exhaust may be specified as (say)
116 degrees,it is quite possible for this not to achieve best power for your car.As a general
rule plus or minus 4 deg. of adjustment will often yield better power. Generally speaking
retarded cam timing gives a little more high end torque and advanced cam timing a little more mid range. It does vary though depending on cam and engine,hence the importance of adjustability.
2) Cam chain stretch. The cam timing will retard as the cam chain stretchs (wears),even
one millimeter of stretch retards cam timing about 2 degrees!
3) Your '116 deg @ full lift' spec cam may not actually be 116 degrees,at nominal settings
it may achieve 114 ATDC on the inlet and 118 BTDC on the exhaust. It is not uncommon.
How do I set it?
You can either set set it to a nominal ' mid point of adjustment' position or to the manufacturers spec (eliminating grind errors or chain stretch error). Or for the last word
in power, on the Rollers:-
Start at midway,then work from there,doing a run at each setting.
Remember there is no desperate rush to set it on the rollers,if you start on nominal
it can be run like that for as long as you like.
I will add a picture later.
Regards Roland GT Tuning