Apexi PFC and variable cam timing

[Peter Wilson]

Hi all,

I've just got a PFC running on my R33, and all is well after some tuning (196 rwkw at 12 psi). Does anybody know if the PFC controls the standard Nissan inlet cam solenoid or not? If so, when does it cut-in and can this be adjusted? I can find no menus that relate to this on the hand controller.

Also (unrelated), what plugs and gaps are guys using to get good spark and no missfires with standard coils at 12 psi?

Thanks in advance, Peter.

[Sydneykid]

Hi all,

I've just got a PFC running on my R33, and all is well after some tuning (196 rwkw at 12 psi). Does anybody know if the PFC controls the standard Nissan inlet cam solenoid or not? If so, when does it cut-in and can this be adjusted? I can find no menus that relate to this on the hand controller.

Also (unrelated), what plugs and gaps are guys using to get good spark and no missfires with standard coils at 12 psi?

Thanks in advance, Peter.

Hi Peter, there is quite a long thread on VVT, how it works and the RPM's it functions at, do a search. Even using Datalogit there is no provision for changing the VVT settings.

As for plugs, that's a very often discussed item, do search for detailed discussion on the various choices. Personally I use NGK BCPR6ES-8.

[Peter Wilson]

Thanks Sydney Kid,

I'll do some searching for VVT (didn't know what the correct acronym was...). Looks like I'm stuck with whatever Apexi have done in the PFC.

Thanks for the plug advice, that's what I'm using now. Maybe I need to reduce the gap further (from 0.8 to 0.7 or 0.6?) at this boost level.

Peter.

[Sydneykid]

Thanks Sydney Kid,

I'll do some searching for VVT (didn't know what the correct acronym was...). Looks like I'm stuck with whatever Apexi have done in the PFC.

Thanks for the plug advice, that's what I'm using now. Maybe I need to reduce the gap further (from 0.8 to 0.7 or 0.6?) at this boost level.

Peter.

Hi Peter, what plugs are you using? I have never had to go below 0.8mm with the NGK copper plugs.

Don't stress over the VVT change over point, I have tried an RB25DET with a simple switch to turn the VVT solenoid power on or off. Ran it up on the dyno in the "off" position, then ran it up in the "on" postion. Overlaid the 2 power graphs and guess what? Nissan got the change over points perfectly correct.

[SeriesIIGTST]

Sydneykid,

I am be completely wrong but I'm sure that while tuning my car, my tuner pushed back the NVCS changover point on my car which helped eliminate a drop in my curve when tuning my PFC. I'm sure that's what he did cause I was in the car with him when he did it and he told me that was what he was doing?? (Car is R33 GTS25t)

Are you sure they are not capable of changing the RPM where it switches over?

[Peter Wilson]

Hey guys, can you please provide a link to the VVT thread? I can't find it by any obvious searches...

Also, is NVCS the same thing?

Sydneykid - I am already using NGK BCPR6ES gapped at 0.8mm. The dyno guy suggested my missfire may be improved by reducing it further...

[Peter Wilson]

Thanks for your help with this earlier. Just want to make sure I got it right...

1) The PFC DOES control the VVT (aka NVCS) solenoid

2) The clever Apexi people have set the change-over point the same as Nissan (about 5000 rpm)

3) There is disagreement on whether this change-over point can be changed by Datallogit, but all seem to agree it cannot be changed by hand controller

Is that it in a nutshell?

Cheers, Peter.

[LUMPY]

The fc-datalogit package that I have lets me change the VTC point. It is a recent addition. The older version software didnt have it. Same feature is there for the S14/15.

If it's stock, or near as, the standard setting is close enough.

[Sydneykid]

The fc-datalogit package that I have lets me change the VTC point. It is a recent addition. The older version software didnt have it. Same feature is there for the S14/15.

If it's stock, or near as, the standard setting is close enough.

Hi Lumpy, is that for the R33 or R34 PFC? What is the version number?

[LUMPY]

Hi.

It is for the 33. Unfortunately we dont have the v4.35 required for the 34GTT as it requires a box upgrade, which means return to factory, and that's a pain in the butt!

I'll check the software version asap for you.

[Chris Wilson]

Got a 96 GTS-t R33 with a Power FC, slight complication is that the car was an auto, now converted to manual. As soon as the throttle is opened even a tiny amount off idle you can hear the cam variable valve timing solenoid click open, even at 1000 RPM in neutral. Definitely the cam advance solnoid, disconnect the plug to it and the click stops. This is also affecting idle speed stability. What signal(s) control this, and what could have gone amiss in the conversion to affect this please? Also have no PAS load up idle speed signal showing on the Commander, nor gearbox in gear signal, (the latter because I haven't yet fathomed out which wires in the gearbox loom should be conected to this switch). All PAS wiring is in place though, and seemingly correct though. Thanks.