Rb25det Neo Vct With Haltech E11v2 ?

[bubba]

Ok, so due to circumstances outside of my control, I still have the Haltech e11v2 in my Stagea. However, I am getting tired of the lack of VCT.. I have been through my Haltech setup and it is most definitely NOT set up.

After a bit of research I became rather confuzzled with people saying the VCT on Neo engines is constantly variable but after finding a copy of an R34 workshop manual, it says the VCT solenoid is ON/OFF in operation..

SO, what I am planning to do is cut the wire to ECU pin #117 (Haltech is wired in as a piggyback), and wire it to one of the Haltechs' auxillary outputs to switch it on at 1100rpm and off at 4500rpm.

What I am after here is any experienced input.. suggestions.. problems..

Another thing is, the stock ECU is still getting an RPM signal (according to datascan), is that enough for it to still control the VCT solenoid? if it is, and it should still be operational.. I will have to investigate the wiring a little and/or swap in a known working solenoid.

Cheers in advance!

[Simon-S14]

yes its a an on off operation.. i dont know how the variable vct rumour started....

if you run piggy back... then the stock ECu should be used to control the VCT.. how come it was disconnected in the first place?

[bubba]

yes its a an on off operation.. i dont know how the variable vct rumour started....

if you run piggy back... then the stock ECu should be used to control the VCT.. how come it was disconnected in the first place?

NFI why it's not connected (I didn't put the Haltech in) but it doesn't work, I need to narrow down WHY it doesn't work but it's not set up in the Haltech and unplugging the solenoid makes no difference (there is a wierd hesitation around 3500rpm that made me unsure if the VTC was working but set up wrong).

I'll dig the multimeter out and see if I'm getting any voltage at the solenoid when I rev it up.

Cheers!

[N I B]

Just find out what output the solenoid is on and if its not then its easy to wire. One Aux output from the Haltech and a 12v feed is all you need.

As a starting point switch it on at around 1500rpm and off at around 5500rpm then play with it on a Dyno till you get the best power curve.

[bubba]

Just find out what output the solenoid is on and if its not then its easy to wire. One Aux output from the Haltech and a 12v feed is all you need.

As a starting point switch it on at around 1500rpm and off at around 5500rpm then play with it on a Dyno till you get the best power curve.

Cheers for that NIB, my next question was going to be what voltage is required

How would I wire the solenoid up? 12v to pin 2 on solenoid plug then pin 1 to output on Haltech?

[Simon-S14]

the solenoid has constant 12 volts

the ecu provides the earth.

[bubba]

Sweet, thought so. Got the carpc in and working so now I have datascan to see what the stock ecu thinks is going on..

VCT isn't working in normal operation but I can turn it on in the self-test, it does enable and there is a noticable change at idle, I went for a lap but only took it to 4500ish and I did notice a difference.

So my next question is, what could the stock ECU possibly be missing (input wise) that VCT would require to operate??

Nothing appeared out of the ordinary other than afm hitting 5.12v (running 3bar map sensor) and inj duty 91% it doesn't appear to be lacking any inputs that I can see

Edit: although.. I am sceptical on the water temp.. the highest I saw was 66deg, I need to plug the laptop into the haltech and see what that thinks the water temp is, no idea if that affects the VCT logic.

Edited June 30, 2010 by bubba

[STATUS]

The std ecu requires more than rpm to operate the VCT

The ECU checks the status that:

- engine temperature is above "min temp";

- engine temperature is below "max temp";

- load exceeds "min TP";

- speed exceeds "speed"

If above conditions are true, then it turns on at "min RPM" and off after "max PRM".

If at least one of the above conditions is/becomes false, then RPM parameter is overridden and VTC solenoid remains/turns off respectively.

On @ 1100-2000 (depending on ser I or Ser II) and off @ 5400, the on point is worth having a play with too...

[bubba]

The std ecu requires more than rpm to operate the VCT

The ECU checks the status that:

- engine temperature is above "min temp";

- engine temperature is below "max temp";

- load exceeds "min TP";

- speed exceeds "speed"

If above conditions are true, then it turns on at "min RPM" and off after "max PRM".

If at least one of the above conditions is/becomes false, then RPM parameter is overridden and VTC solenoid remains/turns off respectively.

On @ 1100-2000 (depending on ser I or Ser II) and off @ 5400, the on point is worth having a play with too...

Excellent info! thank you very much!

Will probably be the weekend before I get another chance to play around but I shall cross reference with the Haltech and see what it thinks the water temp is and take it from there.

Very happy knowing that the VCT circuit and solenoid are working.

I'm pretty certain it's NOT running a low temp. thermostat as I vaguely recall seeing temps around 80deg last time I had the laptop plugged in.. maybe the Haltech is using a different (read: not stock) water temp. sensor.. I know when I tried to use an Rb25 sensor with an RB20 ECU it thought it was in cold start all the time

Thanks for bearing with me guys, this whole VCT thing is pretty new to me.. I'm used to the old RB20's and my non-VCT'd RB30DET

There is some wonderful information cropping up in this thread now so hopefully it helps others out in the future too!

[bubba]

WELLITY WELLITY WELLITY

Turns out it IS due to the temp sensor, the workshop the previous owner used to install the Haltech must have swapped the ECU water temp sensor out for something else.

When I use Datascan to force the ECU to see a particular temperature, VCT actually WORKS!! (70deg seems to be what it needs to see to be enabled with the Neo engine). The difference is about 20deg between the stock ECU and the Haltech.

It's a completely different car with VCT working, no longer a laggy piece of shit! lol

Really doesn't like reving over 4500rpm, accidentally got there a couple of times because it spins up much more nicely now but it pops and farts (probably leanout misfire ) need to get it tuned with VCT now.

A question for the tuning gurus.. is it possible to throw a stock water temp sensor back in and "recalibrate" the Haltech somehow? don't really want to cut the VCT wire and make the Haltech to control it as it will be coming out in favour of a Nistune eventually.