And how exactly can this be determined??? Basically meaning what method can be used besides swapping out the cams for stock cams. That seems like a very long method.

 

can i make a adjustment w/ the timming chain to make up for the increased 4degree overlap?

 

Ha no kidding. It is def a question i am not looking forward to addressing.

 

I thought that stock overlap for vq35 cams is 2 degree of overlap?

 

You could retard the intake cams one tooth but that would open up a whole other can of worms since the Cam position sensors signal would be slightly out of sync.

 

Well i was referring to stock DE-K cam timing. Are tilley and stephen max drilling the 3.5 cams so that there's 2 degrees of overlap? If so, top-end power is being limited with these 3.5 swaps.

 

this is according to sr20den

VQ30DE (1995-1999)

Intake__Lift: 8.55mm -- Intake__Duration: 232º
Exhaust_Lift: 8.55mm -- Exhaust_Duration: 232º

Overlap: 6º
-------------------------------------
VQ30DE-K (2000-2001)

Intake__Lift: 8.55mm -- Intake__Duration: 224º
Exhaust_Lift: 9.0mm --- Exhaust_Duration: 232º

Overlap: 6º
-------------------------------------
VQ35DE (2002-2005) FWD

Intake__Lift: 9.5mm -- Intake__Duration: 238º
Exhaust_Lift: 9.5mm -- Exhaust_Duration: 240º

Overlap: 2º
-------------------------------------


So that would mean i have 6 degrees of overlap with the nismo cams?

 

Not necessarily. It depends on what stephen max's target overlap amount was when he drilled your cams. If he was aiming for 6, it's 10. If he was aiming for 2, it's 6.

 

The way he put it to me is that they are drilling them in the medium between the advanced setting and the retarded setting. I am not sure what the specifics come out to.

 

Well the 2* of overlap in the 3.5 is with the VTC's off which im assuming is in the fully retarded position. If this is true, when they drill the stock 3.5 cams there is surely more than 2 degrees of overlap.

 

Anyone know what the range of the VTC sprockets are in degrees?

 

So say they drilled the hole to be in the middle. Say around 4 degrees, that would mean i have 8 degrees of overlap. Now with that said, if i ran the vq 30 cams in the 3.5 i would have 6 degrees of overlap correct? The nismo's would put me at 2 degrees more than the stock vq30's?


Sorry about asking all these questions, but you seem to know more about this than i do.

 

I think the middle is closer to six, since that's what the 3.0's came with from the factory...a good compromise. It might be even higher than 6 degrees, depending on what the range of the VTC sprockets are.

The 3.0 cams would put you at 6 degrees of overlap. From the link mforrest gave, the r-tune cams are 2 degrees more aggressive than the JWT/JWT knockoff cams. Those advance cam timing 2 degrees on their own. Which means you're looking at 4 or more degrees more overlap than stock, which is pretty significant especially if you don't have VTC.

 

god this sux. The reason i shelled out the extra 900 dollars was because these cams were supposed to suit the SC setup very well. I really hope there is a way to make these work.

 

Wouldn't guys with the 350z have the same problem if they were to get a set of the wild tomei cams? If so how is it that they are able to get away with. Maybe engine management and tunning?

 

They have VTC's. That's the advantage they have. Being able to run aggressive cams while maintaining good idle and drivability.

The idle issues are bad enough with the overlap you're running now, but the problem is two-fold since you don't want too much overlap at all with boosted motors.

 

Ok so say they get the tomei 268 cams and the stock overlap is 2 degrees w/ the vtc off. If the the tomei add say 6 degrees duration(just a random #) Wouldn't that put the overlap at 8 degrees w/ the vtc off?

 

Duration |= cam advance. Do you mean if it advanced the timing 6 degrees? If so, yes, the overlap would be at 8 degrees with the VTC off. Hypothetically speaking, of course.