Request For Help: No Vct On R33 Rb25

[paulr33]

hi gang,

as per: http://www.skylinesaustralia.com/forums/in...howtopic=161511

as some of you may or may not know i am trying to port and get the RB26 PFC working on the rb20 and rb25.

the main issue i can see with the rb25 is that VCT is not supported.

VCT is switched on aroudn 1800rpm and off at 4700rpm by the stock ECU and the RB25 PFC.

i have tried with my 25 PFC turning VCT off at 1900rpm (that is, only have it on for 100rpm) and the car was a pig to drive.

lag city and it felt like it was as flat as a tack to drive around.

so my known working solutions are as follows;

1) use jaycar controller / type of system

this involves a 3rd party device to be built and tested / setup

its manual and would involve some time, each customer would need to buy one and set it up to retain stock VCT control

2) dont do anything and leave as is

this would leave the car boggy / laggy and gutless. can we do something else to make it "normal" without VCT?

can we hard wire the solenoid on or something?

3) required part of the 26 hacked 25 FC is exhaust cam gear

how does this negate not having VCT, i know it replaces the physical cog but does it make it drive the same and take away the boggy/laggy feeling?

how does it achieve this, as far as i can see aftetrmarket exhaust cam gear just lets you dial in forward/backward, does that then negate VCT ?

any suggestions/ideas would be great

i wanted the ported FC to be plug and play, that is a customer buys or gets a 26 PFC

plugs in my custom loom, makes some changes on the hand controller and its ready to go

it idles normally, runs like factory 25 PFC and they can fang around or head to their tuner

if they have to use the jaycar box it requires them (or me) to build the box, set it up, test it etc

and they would have to instlal it onto their loom

my 26 FC is on the way from japan so it shouldnt be long (a few days before i test it)

good news is it looks like rb20 customers should have it easy as theres no VCT needed or other trickery

[Guilt-Toy]

Hey Paul

I heard that Apexi are working on a replacement chip for R33 Power FC's because the damand is so high so we may see them readily available again in the near future...

I heard that Power FC's are still available for RB25's brand new but are more expensive... If anyone wants one new they can call Turbotechnics on 0249565466 who orders them Directly and are still available just a little more expensive because they are buying these NEC chips from wherever they can and are paying a higher price for them.

The info i get from this guy is allways very reliable but you never know i guess... Maybe the Rb25 PFC is not in such a great shortage after all?? this hype may settle down shortly...

Edited May 8, 2007 by Guilt-Toy

[paulr33]

if it does, that would be awesome, saves me worrying about this crap

[Guilt-Toy]

yeah well doesnt anyone wonder where people are buying the brand new RB25 ecu's and putting them on ebay ?? where are they getting them from?

I dont think someone purchased 2000 of them because they knew this shit was going to go down.

There may be delays on orders because they come from Japan when they are made but they are still being exported.

[paulr33]

i dont know of any shops or sellers selling new 25 pfcs. only second hand ones

[Guilt-Toy]

they are all over ebay ?? well they were lol

[Guilt-Toy]

$1550 New. They have to come from somewhere!

http://cgi.ebay.com.au/Apex-Power-FC-Nissa...1QQcmdZViewItem

Edited May 9, 2007 by Guilt-Toy

[paulr33]

id say bogus

even apexi dropped the fc from their 2007 parts list

[Guilt-Toy]

Its worth looking into!

[STATUS]

Hey Paul

I heard that Apexi are working on a replacement chip for R33 Power FC's because the damand is so high so we may see them readily available again in the near future...

I heard that Power FC's are still available for RB25's brand new but are more expensive... If anyone wants one new they can call Turbotechnics on 0249565466 who orders them Directly and are still available just a little more expensive because they are buying these NEC chips from wherever they can and are paying a higher price for them.

The info i get from this guy is allways very reliable but you never know i guess... Maybe the Rb25 PFC is not in such a great shortage after all?? this hype may settle down shortly...

yeah its true, even the AP engineering stuff is available if the customer orders quantity. The gear is all there but due to production costs they will only make stock they are readily selling, they do no want to be producing stocks to sit on shelves. At the moment they are producing to fill orders and until the orders warrant production of significant quantities the "discontiued" ones will stay that way.

Edited May 9, 2007 by URAS

[Beer Baron]

the exhaust cam gear doesn't replace VCT. VCT is only active on the inlet cam. think of it like an adjustable cam gear with 2 settings (1. response, 2 top end), but it can switch between them. so it gives you the benefit of an adjustable cam gear (again inlet only here) without the compromise. the reason people may say that fitting an exhaust cam gear makes up for no VCT is that they both have a similar affect on performance. but ideally you want BOTH.

[NickR33]

it just seems weird that the 25 is a pig with the VCT turned off... you would think there would only be a very small seat-of-the-pants difference... barely noticeable... afterall the 26 seems fine and its usually got another 100-200kgs to lug around... weird

[Guilt-Toy]

Yeah.....

They got 10 in last week and had 15 on order so they are comming into the country directly from Apexi.

yeah its true, even the AP engineering stuff is available if the customer orders quantity. The gear is all there but due to production costs they will only make stock they are readily selling, they do no want to be producing stocks to sit on shelves. At the moment they are producing to fill orders and until the orders warrant production of significant quantities the "discontiued" ones will stay that way.

[Gav]

hi gang,

as per: http://www.skylinesaustralia.com/forums/in...howtopic=161511

as some of you may or may not know i am trying to port and get the RB26 PFC working on the rb20 and rb25.

the main issue i can see with the rb25 is that VCT is not supported.

VCT is switched on aroudn 1800rpm and off at 4700rpm by the stock ECU and the RB25 PFC.

i have tried with my 25 PFC turning VCT off at 1900rpm (that is, only have it on for 100rpm) and the car was a pig to drive.

lag city and it felt like it was as flat as a tack to drive around.

so my known working solutions are as follows;

1) use jaycar controller / type of system

this involves a 3rd party device to be built and tested / setup

its manual and would involve some time, each customer would need to buy one and set it up to retain stock VCT control

2) dont do anything and leave as is

this would leave the car boggy / laggy and gutless. can we do something else to make it "normal" without VCT?

can we hard wire the solenoid on or something?

3) required part of the 26 hacked 25 FC is exhaust cam gear

how does this negate not having VCT, i know it replaces the physical cog but does it make it drive the same and take away the boggy/laggy feeling?

how does it achieve this, as far as i can see aftetrmarket exhaust cam gear just lets you dial in forward/backward, does that then negate VCT ?

any suggestions/ideas would be great

i wanted the ported FC to be plug and play, that is a customer buys or gets a 26 PFC

plugs in my custom loom, makes some changes on the hand controller and its ready to go

it idles normally, runs like factory 25 PFC and they can fang around or head to their tuner

if they have to use the jaycar box it requires them (or me) to build the box, set it up, test it etc

and they would have to instlal it onto their loom

my 26 FC is on the way from japan so it shouldnt be long (a few days before i test it)

good news is it looks like rb20 customers should have it easy as theres no VCT needed or other trickery

Paul

GTS-t VSPEC has been running an RB26 D-Jetro PGC on his RB25 over here in WA for quite some time now. He has retained the VCT and also made it adjustable (i.e. rev dependent switch point) by adding a third party switch (i.e. your option 1). I believe the point at which it activates makes significant difference to the power/torque curve.

Drop him a PM for further details

[paulr33]

hey

ok things i know are that the 26 FC will work on the 25 and that we can make VCT work

its just how elegant is the solution for the customer. i wanted it to be plug and play for the end user

so they dont have to fiddle with external boxes etc. like for 1 dude its fine to have a jaycar/external box but for 100+ its a different story

[2gceffy]

are 300zx ecu's still on production? few months ago i was goin to do the conversion from 300zx to run my rb25 with stock ecu's as i could remap the new one..

could this be another option?

i really hope everything falls back into place !!

[SilverECR33]

Guilt-Toy your a legend !. Gave turbonetics a call, and they can get them new, like you said, they are using chips they can source and doing them by order in japan only. then sending them upon request. and if you get them thru turbonetics, u can get an australian warranty with them.

(oh yea, Quoted price was $1550. and a 4 week wait.

good work no rumor at all. problem solved for me.

- CHeers

dale.

Edited May 9, 2007 by silverbulletR33

[MBS206]

paulr33

Do a dyno power run with the VCT turnt on all the way to redline.

Then do a run all the way to redline with it turnt off.

Have a look at the huge difference. Where the two graphs cross, this is your switch over point.

Due to the amount of lag down low, this may well indicate, due to the cam movement, that it wants some more timing (And will most likely be able to be done without inducing ping due to the cam "profile" change)

You may want to leave it turnt off and attempt a change of the tune.

[paulr33]

yeah i know about the changeover test point

my question is, can u tune the 25t and get the same results if you just unplugged say the VCT solenoid

that is, standard PowerFC, unplugged stock VCT, stock cams, stock turbo etc

like same midrange, power, response, feeling etc...

cos when i did my testing it drove like a pig

ie: unacceptable

if it can be tuned with the thing completely off, then im not worried at all

[MBS206]

If the VCT is OFF when going for top end power, then you'll never get the same response (You've changed the VE characteristics of the engine down low)

So when unplugged you will never get the same low down response, BUT with a decent tune (More fuel/timing) it should see you getting back alot of your response.

When you change cam profiles, it adjusts the timing maps drastically, that is exactly what you've just done.

Most likely, down low, you might be running a touch leaner or so the o2 sensor might say.

Throw it on a dyno, and see what you can tune in.