Vct Controller For Rb20 And Non Vct Enabled Ecus On Rb25s, Anyone Interested?

[Rolls]

I'm a computer systems engineer so myself and a friend are going to create a module for my rb20 ecu + nistune that runs an rb25det to switch on the VCT solenoid.

We will work on an experimental design over the next few months (not difficult but need to find time) that will switch the VCT solenoid on from 1500-5000rpm (stock range).

The board will tap into the tacho pin out on the ECU and then via a little PCB turn on the VCT at the appropriate range. We will implement two pots to allow changing the upper and lower ranges of the VCT so you can turn it on from say 2000-4000rpm or whatever, allowing you to experiment on the dyno to find what works best for you. So basically it will turn on when you have some throttle open (eg tps is measuring something, don't need to advance the cam when you are idling or backing off throttle) and when the tacho pin is in range.

Now I am going to do this for myself no matter what as I want to see how useful it is, but if there is interest we would probably sell a proper PCB in a box for ~$50-60 with instructions. I've spoken to Shaun at boostworx and he thinks the VCT is good for 5-10kw in the mid range when enabled.

Now this is purely an idea at the moment, I will work on some schematics tonight and see how easily it can be done, and how the RPM out pin works on the RB20 ECUs to see how hard it will be to do.

So people, anyone interested in one if we make it?

Edited October 7, 2009 by Rolls

[CEF11E]

rolls, great idea.

I have been playing with VCT for a while and have experimented with tps switching and afm voltage switching. (using load insted of RPM) to switch. but had to many variables in driving conditions to see if it made any real world difference. I even played with cam timing in the intake cam. and what I found was that switching via rpm and leaving the range stock was the best option, atleast for a 30det.

I am sure there will be a few interested in this

[XRATED]

I have a rb25 in a 32 using the rb20 loom and computer.

+1 For meee!

[Rolls]

Think there is already some products out there that can do this but they arent cheap. I will keep this thread updated. I wrote the code to do it last night, but need to design the hardware and get my actual ECU so I can meter out the waveforms on an oscilloscope before I can really make something. Should have an update in a week or two.

Interesting to hear you have already played with it. I think I will aim for a basic model at first that just has static timing the same as stock, eg 30% throttle and 1500-5000 rpm it is switched on, however I should be able to easily make a model that you can vary the upper and lower rpm, along with the throttle percentage, just that it probably won't be that useful if we find that the stock variables work best everytime.

Edited October 8, 2009 by Rolls

[Rolls]

I'm open to volunteers that have equipment already running that I can test with. Basically be nice to have an already wired up VCT so that I can measure voltages and waveforms etc, hell if anyone has electronics/programming experience we can make this a group project.

I'm in Adelaide so PM me if you think you could help out.

[Crans]

Use an atmega processor I'll write the code for you already using one as an ecu for a 2 stroke quad bike very easily done

[Rolls]

Use an atmega processor I'll write the code for you already using one as an ecu for a 2 stroke quad bike very easily done

Its ok I've got 100s of projects written for PICs. I coded up a solution in an hour last night, this is the easy part, just need to figure out the input waveforms and whether I need op amps to transform them into a useful range, this is more where i need help, the electronics side. Ill post up a schematic soon with some source code so people can see what I'm trying to do with the data.

[STATUS]

we use a kit from jaycar pretty sure its 25-35 bucks so best check it out before you bust your nuts doing the same thing.

Edited October 8, 2009 by URAS

[Crans]

This one here should do it: http://www.jaycar.com.au/productView.asp?I...mp;SUBCATID=347

[Rolls]

Either way I can still build one for under $10 so I will probably do it myself as I do stuff like this everyday for my job (I find it fun), but it wouldn't be worth selling it for less than $50. So maybe look into this if you guys want something now.

Edited October 9, 2009 by Rolls

[Simon-S14]

ive got a product which i bought a few years back for a customers car for a different purpose. We used it to switch LPG on and off at a specified RPM windown for a turbo diesel patrol.

i'll grab a photo if you want.

[Rolls]

Thats cool, I'm more after the voltage ranges and waveforms of the tacho signal and the TPS signal. So basically I can translate volts or hz to rpm and volts to throttle percentage. I can meter this out myself once I get my stock ecu + nistune installed but I have a wolf in there atm so it's a bit more difficult.

Anyway looks like theres already stuff on the market if people want this now. I will still make my design and maybe put the design on the net so people can DIY on the cheap for ~$15. See how we go anyway.

[Simon-S14]

when i was looking, there was nothing lol. seems to be a few around now.

If you make something, and its easy to use, people will buy it! even if its more then the jaycar ones.

The one i have has dip switches for setting various hertz ranges for either rpm or voltage imputs. its complex to set up.

[Rolls]

Initially I will hard code it in software what throttle percentage and rpm range to turn it on/off at. Eg stock as stock. Then will add features to adjust lower,upper ranges and tps setting.

Edited October 9, 2009 by Rolls

[battery]

if you had your car tuned without VCT would you need a remap to get the full benefit after adding one of these controllers?

[Kwyjibo]

Even if you can't sell it any information posted would be great. Just built an RB20 with an RB20 PowerFC but looking at going RB25 as soon as I kill this. I want to keep the computer as the FC's are rare and its much easier to keep the RB20 ECU than rewire in a RB25 one.

[paulr33]

given the complexity i dont get why you would reinvent the wheel

if jaycar make a off the shelf thing, and from memory they do

then this would be perfect

[Rolls]

given the complexity i dont get why you would reinvent the wheel

if jaycar make a off the shelf thing, and from memory they do

then this would be perfect

With the work I do this is a piece of piss. I do it for a hobby, I get satisfaction out of making something myself. Same reason some people build cars instead of buying one already completed for half the price.

The jaycar item does not work exactly for this purpose either, it will be more complicated to use.

Edited October 10, 2009 by Rolls

[Crans]

Any news on this?

[Rolls]

Ive designed a PCB and its working but I had a set back with my car and money so I haven't actually been able to test it.

The stock ECU and nistune only got fitted a few days ago to it so once I have it on the road I will be able to wire it up and start testing. Not sure of a timeline, basically whenever I get free time off uni I will work on it.

Will let everyone know once I get something useful working.

edit: I can post up the schematic if anyone here can program PICs and wants to have a play themselves.

Edited March 16, 2010 by Rolls