MY CAR IS A 5AT WITH A STAGE 2 STILLEN WITH EXHAUST AND HEADERS. wILL IT MAKE MORE POWER WITH THIS MOD OR WILL IT MAKE LESS. (VALVE OVERLAP ) IS COSTING ME 7 HP BECAUSE OF THE HEADERS.

 

IceY2K1Max:

Does it mean that we will need to re-write the ECM to get the cam shaft operation changed as well? Or it is purely mechanical, so the VTC is a plug-and-play device with the larger angle cams? It says that VTC allows greater degree of freedom to operate... sounds like the normal ECM just does the normal thing while the larger VTC will operate the cams mechanically from there.... ????

cheers,

richie

 

They are not rumors anymore, here is part of a letter that I recieved from nissan corporate the other day. It was sent from Nissan to the members of the Z club of Houston by E Mail.......

The 35th Anniversary Z(r)'s engine has been modified using revised pistons
>>and camshaft and the addition of electronic exhaust valve timing control.
>>The same engine will also be available as standard equipment on the 2005
>>350Z Track model (6MT only), which also goes on sale in early 2005.


This my friends are what they are doing to get the extra 13 ponies on the 05' anniversary and track models.

 

All that for only 15 hp???

Either...

a) It is de-tuned.
or
b) They aren't running Crawford parts!!!

 

I am really thinking about getting this part instead of headers. I wonder how hard the install will be? Anyone have ideas on labor and where is this thing located?

 

meh go headers

 

I wonder how you get them to have +15 degrees of intake opening and not +15 degrees of intake valve closing? Is that right, it was on the last page. Whatev?

 

i asked about this piece on 2 other forums b4, and on one of them phoenix tells me that the vtc pulley will make up some of the lost power and torque at the low end but not nearly as much as stock when running more aggressive cams. however, it also robs top end hp which is the reason one would go with more aggressive cams. so its a pretty redundant mod. i dont know tho, i wanted it too, and im just as eager to see the results that Adam gets.

 

okay.... so do we need any ECU mod (other than A/F ratio) to go along with this VTC mod at all?

cheers,

richie

 

I doubt the ECU VTC control needs modified. However, the AFR should need some tuning and maybe a bit of ignition timing to fully benefit.

The ECU will activate the VTC solenoids as it normally does with the Nismo VTCs, ie XXXXrpm less advance and then XXXXrpm full advance or whatever the engine loading dictates.

The mechanical max/min rotation limits of the stock VTC pulley is all that is being changed here, so when the ECU commands rotating to the max 30-degree angle, the Nismo VTC actually rotates further to give 45-degrees.

 

IceY2K1Max:

Thanks mate..... I think it really makes sense now!

cheers,

richie

 

not true.

This would definitely require an ECU update. I've researched VTC quite a bit, and eventually discovered that the continuous VTC (CVTCS) employed by the NEO VQ35DE (in the Z33), uses a feedback mechanism to control the cams.

The Nismo VTC sprocket will increase the mechanical limits of rotation, but the ECU will still command them such that they match the VTC angle table in the ECU. The ECU reads the cam angle sensor to determine current cam angle, and then uses the VTC solenoid to advance or retard the cam until the target angle is reached. Adding the Nismo VTC sprockets to the engine without an ECU update will realize absolutely no gains whatsoever.

 

While I dont yet 100% know, I believe azrael might be correct. I'v been trying to get this information from NISMO Japan for sometime now....still digging though

 

I am not certain that a reflash is required to make use of the Nismo CVTC however new software to support it would make it more valuable. Seeing as how the ECU does know the position of the Intake cams in relation to the crankshaft. My guess is that once the ECU reaches it's maximum advance spot on it's table it may not care about a few more degrees of advance afterwards. The advance is conrtolled by oil flow through the VTC solenoids.

 

I think azrael is correct, otherwise you'd throw a P0011/P0021 IVT Control ECU code.

 

I'm absolutely sure of this.

The factory service manual has a diagram in the Engine Control section showing the routing of oil through the VTC solenoid. It shows the PWM signal the ECU sends to the solenoid to advance or retard the cam until the cam angle sensor reads the target angle in the ECU 's VTC table. Presumably, TechnoSquare could update this table with new values, but I guess you'd have to check with Tadashi.

Regardless, I don't really think the TS reflash is a good idea, personally, since it requires shipping the ECU off and doesn't allow the car to be tuned individually. As far as I can tell, Motec and Pectel are the only companies with an ECU that can control CVTCS. Even the F CON V Pro can't do it. I have no idea when I can get around to it, but I might look into building a box that can control the VTC system. The most difficult part is tricking the stock ECU into thinking it still has control over VTC. If the ECU tries to modulate the cam timing and the cam position sensor signal doesn't reflect the changes, it will throw the IVT Control code.

Ultimately, this modification would primarily benefit engines with aggressive cams. These cams usually dial in lots of overlap and result in a rough idle and poor low-end performance. The Nismo VTC sprockets allow you to retard the cam to zero overlap at idle and the ECU can advance the cam at mid to high RPM to allow the intended overlap for high-end performance. Those of you with stock cams (or even mild aftermarket cams) won't see a lot of benefit from this modification.

 

Any signs there is a difference in IVT control during open-loop vs. closed-loop?

I wouldn't be surprised if during closed-loop the CVTC system is adjusting per loadxRPM as you stated, however during WOT it could be purely RPMxMAF based without load/angle feedback.

 

The cam advance/retard is always an independent closed-loop operation regardless of the state of the engine, because the amount of advance/retard that happens when the valve is opened by the solenoid changes based on oil pressure. At higher oil pressure, the cam will advance or retard more quickly than when the engine is running lower oil pressure. As a result, there is no way to specifically command some degree of advance or retard without reading the angle back from the cam angle sensor. The ECU simply opens the valve until the target angle is reached, as read from the cam angle sensor.

 

Any new info on this????

 

As far as I know Z350Lover is installing it in his car and it's going to be controlled by Motec ECU. All I can say is that you should stay tunned.

https://my350z.com/forum/showthread....hreadid=103026