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Whiteblock six intake VVT control

tomasss

tomasss

former PRVert
Joined
Oct 13, 2008
Location
Sydney, Australia
Topic that has been already discussed here, here and here, but without any real experiences.
Some people said it would be best to weld the VVT solenoid in the middle position, some said it will reduce the duration (as solid cams has larger duration against the variable).
Some people said the control of VVT could be done with simple open loop 555 PWM generator, some people said it needs to be a closed loop system similar as OEM, taking into account the camshaft position sensor and rpm sensor, because constant PWM doesn't mean constant VVT position.

My situation is, I have a 1994 960 with 2001 S80 3.0 engine, the ECU and all electrical stuff is original from 960.
There is a VVT valve on the intake camshaft. Currently I am not driving it, and the engine pulls nice on the high RPM side, but the low end torque is bad. I have no OBD codes stored (of course, the Motronic doesn't know about the VVT), and other than the lack of low end torque everything works fine.
It was mentioned the fully adapted VVT (= powered) results in nice idle, does it mean that for low RPM I should power it and for high rpm I should not? I think that is the correct setup, on volvospeed, there is a note "Advancing the intake cam will improve low-rpm VE, while retarding it will help high-rpm VE, so start out advanced and retard it as the engine speed picks up to shift the power band around as needed".

What solutions do I have?
Any solution to properly drive the VVT?
What effort is needed to adapt the non-VVT cams from 960 to the VVT head?

10457714_10152595898519683_2129245131790674332_o.jpg
 
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I have already contacted the Honda guy who is making the VVT standalone units, and he confirmed that the VVT in Hondas is controlled differently, so I cannot use his solution.
At first, I will just run a switch into the cabin and see what benefits will bring the simple manual VVT full on/full off in various RPMs, and if it will be significant, I will think about some more complex solution.
Anyway, the questions above are still valid...
 
a way to do it is using the egr output of the motronic to control it.. preferable using the motronic 4.4 from newer 960 .. i have done similar setup to control boost on my ride..

that will give you closed loop 16x16 and total control of it

most people using vvt on tuned cars simply have a rpm controlled toggle that is under 3000 and above using a simple switch
 
Could the fueling of the motor be altered in motronic based on the intke being advanced or not? or is that not necessary because the maf will "see" the changes in the ve of the motor? what about the spark table? can it be changed when the vvt is active or not? kind of like a bmw vanos setup with where you either retard the cam all the way or advance it all the way.
 
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DNAsEqUeNcE said:
VVTuner from DIY autotune!
Click to expand...
Yes, I already contacted them as well, waiting for reply...at least the schematic seems promising (using both the camshaft and crankshaft position sensor), but there is no info about how the VVT valve is controlled; and I doubt it will be directly compatible with the 250Hz PWM required by Volvo VVT. Anyone here used that?

wiring-extgnd.png
 
Turbosundance said:
Could the fueling of the motor be altered in motronic based on the intke being advanced or not? or is that not necessary because the maf will "see" the changes in the ve of the motor? what about the spark table? can it be changed when the vvt is active or not? kind of like a bmw vanos setup with where you either reard the all the way or not.
Click to expand...
Hm, that is an interesting question, how the VVT is supposed to work? Is this feature only for advancing/retard the intake valves (to improve the filling of cylinders and reduce the hydraulic pumping losses) or it also influences the timing of fuel injects and ignition sparks?
 
you could also use a piggyback system to control this.. for instance the smt6 ? that can control on / off based on rpm / throttle etc
 
I believe you can tune the frequency in vvtuner. You certainly can in megasquirt to whatever frequency you desire.( in multiplied steps of course)

You might want to start playing with motronic suite.
 
Willett control at 250hz? How do you specify the frequency?
Moon_walk said:
a way to do it is using the egr output of the motronic to control it.. preferable using the motronic 4.4 from newer 960 .. i have done similar setup to control boost on my ride..

that will give you closed loop 16x16 and total control of it

most people using vvt on tuned cars simply have a rpm controlled toggle that is under 3000 and above using a simple switch
Click to expand...
 
DNAsEqUeNcE said:
I believe you can tune the frequency in vvtuner. You certainly can in megasquirt to whatever frequency you desire.( in multiplied steps of course)

You might want to start playing with motronic suite.
Click to expand...

unfortunately motronicsuite does not have all info for the 960 series..

and even though they have lots of information i still have level 200 optimization from volvo to tune this system

vvt sure uses a frequency and i can double check at what frequency it operates
 
Moon_walk said:
unfortunately motronicsuite does not have all info for the 960 series..

and even though they have lots of information i still have level 200 optimization from volvo to tune this system

vvt sure uses a frequency and i can double check at what frequency it operates
Click to expand...

you're the man I want to talk to seeing as I have a 1.8motronic car and m4.4 and a t6 engine is suiting my fancy in the future. What do you mean by level 200 optimization?
 
...and all three VVT control system developers (DIYautotune with VVtuner, 949racing with VVTcontroller and motorsport-electronics with VVTPro) anwered me that it is not possible to use their systems in Volvo whiteblock. The problem is either the positioning of the solenoid and the feedback loop (because other systems works that way that constant input = constant position of the solenoid, but the system in whiteblock has to be continuously updated) or the PWM characteristic (whiteblock VVT requires solid frequency and variable duty cycle).
Today I will wireup the solenoid into the cabin switch and try what brings the full on/full off positions...
 
Hank Scorpio said:
I think I saw on VS its 55hz.

Google volvospeed vvt delete and there are a bunch about deleting and controlling the vvt
Click to expand...

No, it was 250Hz
http://volvospeed.com/vs_forum/topic/136687-vvt-disabled/
The deleting is pretty simple, but the VVT camshaft has small duration compared to non-VVT one, so if I will disable the VVT, I definitely want to replace the cam by the non-VVT from 960. And thats the question I already asked - did someone this already?
Currently I am more inclined to control the VVT than to remove it and swap a camshaft, maybe after the experiment with manual switch I will change my mind...
 
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I'm very curious about what results you get with a manual switch. I wonder is either extreme retarded or extreme advance would be too much.

Any one have an idea of the range of advance/retard that is covered by the whiteblock VVT? Maybe we can compare it to the BMW Vanos which just uses an on/off switch setup to run full retard or full advance.
 
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