Thread: Gspec Crank Pulley Comparison

I'm starting this thread to let people know about my findings.
My intention is not to harm somebody's reputation but set things right.
I'm sure anybody who saw what I've seen would do the same.
So no hard feelings.


On the bottom it's a N1 stock Crank pulley. This pulley is by 2cm/0.7874" larger than the Gspec one towards the alternator belt size only. I've made the same measurement on a standard SR20VE pulley and same data occurred.

Lets have a closer look on the N1 pulley.





My guess is that N1 is only special about it's weight.
All the pulleys start from -5 degrees timing. True?

Now have a look on what happens when you compare the two pulleys between them.







The Gspec pulley is 5 degrees off! You got almost a perfect match in timing marks at 10 and 15 degrees.

Want to know how I discover that? I wanted to reset my timing and set it according to specs and using the right procedure.
Well I did but the car was damn sleepy than before. It could almost turn off on idle. We increased the timing a little bit but still the same.
Finally I got in my hands a new Gspec pulley and made the comparison by eye and camera.
I've set it to 17 in order to have 12 degrees of static timing.
Don't worry I'm perfectly safe and confirmed operation through Datascan.

I wonder how you people set your timing on the DE ecus where use large numbers and how come nobody noticed that before?
Am I not seeing something I should?

That seems like quite the problematic oversight.

isnt the diameter of gregs pulley smaller as u identified? maybe thats the reason why the timing marks dont exactly line up....

If ur comparing the pullies by the 1 st mark, then stock start with -5 degrees n the gspec starts with 0 degrees(its clearly marked on the pully). Now if u try to line up the gspec one with the stock ones @ the 2nd mark which is 0 degree then they'll line up. Of course the spacing well be closer because of the smaller diameter of the gspec pully. I'm pretty sure if u degree it from the center it's both the same.

^ right if you have say a 10''od circle and a 20''od circle, you cant expect the marking to be the same on the smaller OD circle as the one on the larger OD circle if that was the case and the markings were the same the degrees would be correct on the larger Diameter and WAY off on the smaller diameter

Yep as mentioned, if you were to draw straight lights from the mark to the center, the lines would get closer to each other towards the center.

Now whats the big deal with the Gspec Pulley? Why not just use UR?

The GSpec pulley is designed for the VVL motors.

i think he's reading the marks wrong on the pullies. The gspec starts w/ 0 degree n he's thinking that it's -5 so that y he's saying the gspec is off by 5 degrees.

vassilis, have you tried putting a normal 20ve pulley to compare?

I wonder if the n1 pulley has timing marks slightly different because of the factory milled head? Honestly i have no idea if this is possible or its just a very small difference.

Or was the gspec supposed to be designed off an n1 pulley?

Exactly, not only that but the diameters of the pulley are 2cm apart, so the marks will be off slightly as well. That's why they said if he draw a line form the center, they'd be the same.