Has Anyone Seen These Before?

[frozenwaffles]

http://cgi.ebay.com/ebaymotors/Greddy-Adju...sQ5fAccessories

you recon its a good thing?

[R31Nismoid]

You have VCT.

You do not need a cam gear on the intake.

[N I B]

RB25 VVT gear is adjustable standard. Look behind the gear next time you have one off.

[frozenwaffles]

well how about that, after i took the gear of, yes it is adjustable. i guess the only advantage of the greddy one is it has markings...

so i now pose the question:

on an RB25DET is there any advantage to advancing or retarding the intake cam???

[PM-R33]

On stock cams and stock turbo no. The amount of time spent on the dyno mucking around with it, is money you could spend on a boost controller and add a couple of psi and get 10 times better results.

[STATUS]

well how about that, after i took the gear of, yes it is adjustable. i guess the only advantage of the greddy one is it has markings...

so i now pose the question:

on an RB25DET is there any advantage to advancing or retarding the intake cam???

the factory inlet cam changes valve timing automatically, so no need to play with it.

[R31Nismoid]

well how about that, after i took the gear of, yes it is adjustable. i guess the only advantage of the greddy one is it has markings...

so i now pose the question:

on an RB25DET is there any advantage to advancing or retarding the intake cam???

did you not read the post about VCT?

Or do you even know what VCT does?

Variable Cam Timing - ie, variable. Why would you need a gear to set something variable?

[wolverine]

Why is there factory adjustment on the back? Where do Nissan set it from factory?

[STATUS]

Why is there factory adjustment on the back? Where do Nissan set it from factory?

to maintain zero when block or head gets machined, from factory it is generally in the middle.

[frozenwaffles]

ok so i think its important to understand a few things here:

from what we know the vtc is in an 'off' state or 'on' state. hence it would adjust from say 0deg to 15deg yes? (i think its advance yes?)

so based on that then by adjusting the cam gear your adjustment range is now say +4deg and +19deg when 'off' or 'on' respectively...

hence this all makes quite a bit of sense then...

clearly from what i have seen now, the greddy gear would be useful as it allows more adjustment range and also have the markings to assist.

i have advanced it a little now and i'll report back i dont have and EX gear at the moment.

when i pulled mine off it was a tiny bit retarded...

[paulr33]

i got one of these on my r33 but more of a DIY style one that bassjunky made

we gained zero by doing it, the factory setup was prefect

as the others have said, the stock ones are adjustable, but you have to pull it out to adjust it

pete's thing (like the greddy one) made it so you can adjust it while the gear is on the car

[MrStabby]

did you not read the post about VCT?

Or do you even know what VCT does?

Variable Cam Timing - ie, variable. Why would you need a gear to set something variable?

Variable timing and adjusted base timing are not the same thing, and produce different outcomes so the question is a fair one. However the answer appears to be that 0 is generally best, but its not inconceivable that something other than zero could be better for a particular setup.

[PM-R33]

Exactly. Hence why i said on a stock turbo and stock cams it is pointless. You aint going to adjust it to improve response since the stock turbo is as responsive as you are probably going to get. And top end power and midrange, the gains you could possibly get would be that minimal you wouldn't even notice.

On a big turbo with after market cams than yes no doubt it could be adjusted for improvements.

Edited December 20, 2009 by PM-R33