CA18DET Secondary Butterflies Control System

Discuss topics related to the CA18DE and CA18DET series engines.
User avatar
louiswun
Posts: 119
Joined: Sun Jan 27, 2008 5:33 am

Post

roast wrote:Great video's and simple detective work, under no load the butterflies are opening around 5200rpm?

Did you do a similar test with load?

I don't remember anyone mapping the butterfly actuation table for the JDM ECU's...
Under no load it open at around 4,500rpm
I did drive on the road like that, but i not pay attention what rev it activate.


180sx_vc
Posts: 17
Joined: Mon May 30, 2011 9:29 pm
Car: 180sx

Post

Just wanted to know if anyone has tried using the volvo vacuum pump method? im asking cuz i might go this route....

User avatar
cbh148
Posts: 340
Joined: Tue Dec 01, 2009 6:53 am
Car: 2000 Civic Si, 1993 240sx Hatch CA18
Location: Huntsville, AL

Post

I'm also curious about the volvo cruise control pump method. Is it that much simpler?

User avatar
float_6969
Moderator
Posts: 19853
Joined: Mon Aug 26, 2002 1:55 pm
Car: CA18DET swapped 1995 Nissan 240sx (too many mods to list)
2015 SV Leaf w/QC & Bose (daily)
Location: Topeka, Kansas
Contact:

Post

The guy that did the writeup for the volvo method used it, and if you read the thread, said it works very well.

User avatar
cbh148
Posts: 340
Joined: Tue Dec 01, 2009 6:53 am
Car: 2000 Civic Si, 1993 240sx Hatch CA18
Location: Huntsville, AL

Post

It's performance wasn't debated, but whether or not it's actually simpler than the OEM setup is up for question.

Someone get Dee in here to convince me I don't need the whole thing some more lol.

User avatar
biosehnsucht
Posts: 1839
Joined: Thu Feb 26, 2004 10:20 pm
Contact:

Post

In my opinion it's simpler - a little bit of wiring, a very small amount of hoses, much better than the rats nest of vacuum tubes and check valves and so on.

User avatar
D_Stirls
Posts: 246
Joined: Mon Sep 01, 2008 4:04 am
Car: Nissan 180sx 1990 Ca18det
Location: Adelaide,South Australia

Post

cbh148 wrote:It's performance wasn't debated, but whether or not it's actually simpler than the OEM setup is up for question.

Someone get Dee in here to convince me I don't need the whole thing some more lol.
Street car or track car?

If it's a track car then it's 50-50 whether you use it or not as you'll spend most of your time above 4000rpm, though it does help bring the turbo on boost earlier so if your running a reasonable sized turbo it's still an advantage coming out of slow corners.
If it's a street car then it's worth 50% more torque below 3500rpm (like graphed in my linked thread if you read it) which is where you will be spending most of your time on the street, so in that case definitely keep it.
Last edited by D_Stirls on Thu Jul 21, 2011 2:34 am, edited 1 time in total.

User avatar
biosehnsucht
Posts: 1839
Joined: Thu Feb 26, 2004 10:20 pm
Contact:

Post

Like D_Stirls discovered by dynoing the various scenarios (as per his earlier link), if you're under 300kw / 400hp, then butterflies are where it's at.

User avatar
louiswun
Posts: 119
Joined: Sun Jan 27, 2008 5:33 am

Post

float_6969 wrote:The guy that did the writeup for the volvo method used it, and if you read the thread, said it works very well.
I'm doubt that the volvo method is the best, let say when the engine is at 3,000rpm, the tubro is making positive pressure, but the accuator still need vaccume to keep the butterfly close, that is why it need the vaccume tank and the check valve.

User avatar
D_Stirls
Posts: 246
Joined: Mon Sep 01, 2008 4:04 am
Car: Nissan 180sx 1990 Ca18det
Location: Adelaide,South Australia

Post

from what i understand about the volvo method (only skim read it)is it's actually a vacuum pump so there is no need for the tank as it creates it's own vacuum i.e. it doesn't matter what the manifold pressure is.

TheMAN
Posts: 272
Joined: Wed Jul 20, 2011 10:36 pm

Post

correct, the volvo pump is an electric vacuum pump.... it will ALWAYS work regardless of manifold pressure... in fact, it'll be ideal for diesel engines (since they lack vacuum)

User avatar
biosehnsucht
Posts: 1839
Joined: Thu Feb 26, 2004 10:20 pm
Contact:

Post

Not only does the Volvo vacuum pump method provide its own vacuum, it also provides its own vacuum release solenoid.

Original OEM method:
1x Solenoid
2x Delay valve
1x Vacuum tank
+ Lots of vacuum hoses

Volvo method:
1x Volvo vacuum pump
1x SPDT Relay
+ A single vacuum hose

Much simpler, works regardless of manifold vacuum, and much snappier switchover. Add in the delay valve between pump and butterfly actuator if you want it to transition more smoothly like OEM, though.

User avatar
louiswun
Posts: 119
Joined: Sun Jan 27, 2008 5:33 am

Post

biosehnsucht wrote:Not only does the Volvo vacuum pump method provide its own vacuum, it also provides its own vacuum release solenoid.

Original OEM method:
1x Solenoid
2x Delay valve
1x Vacuum tank
+ Lots of vacuum hoses

Volvo method:
1x Volvo vacuum pump
1x SPDT Relay
+ A single vacuum hose

Much simpler, works regardless of manifold vacuum, and much snappier switchover. Add in the delay valve between pump and butterfly actuator if you want it to transition more smoothly like OEM, though.

Oh, sorry, I didn't read the whole thread, I thought the volvo method is just using a solenoid from volvo.

180sx_vc
Posts: 17
Joined: Mon May 30, 2011 9:29 pm
Car: 180sx

Post

WOW... good info guys thanks.....wat wires(pin) do i need from the ecu to connect? sorry for asking this question but i just want to be sure and not F*** up the ecu or anything..

User avatar
louiswun
Posts: 119
Joined: Sun Jan 27, 2008 5:33 am

Post

180sx_vc wrote:WOW... good info guys thanks.....wat wires(pin) do i need from the ecu to connect? sorry for asking this question but i just want to be sure and not F*** up the ecu or anything..
JDM ECU pin 8 to ground the solenoid valve.

Red_CA_Silvia
Posts: 35
Joined: Sun Jul 24, 2011 1:16 am
Car: CA18DE(T) S13 Coupe

Post

So, after much reading of this thread and a few others, my initial thought that I had a EDM CA seem to be wrong. At least I know for a fact I have a JDM ECU with a NIStune chip in it. The problem comes in here: I have NONE of the parts for the butterflies. Not even the vacuum actuator on the back of the intake. Is there anyway to even put one on without pulling the engine? Or COULD I have a EDM intake? Anyway to tell for sure and certain? It's currently my DD, but will soon become just my toy/project. Street and some track.

TheMAN
Posts: 272
Joined: Wed Jul 20, 2011 10:36 pm

Post

you can't use the EDM intake because the heads are different... 4 ports instead of 8 ports

you can try pulsar nx parts, might work

User avatar
float_6969
Moderator
Posts: 19853
Joined: Mon Aug 26, 2002 1:55 pm
Car: CA18DET swapped 1995 Nissan 240sx (too many mods to list)
2015 SV Leaf w/QC & Bose (daily)
Location: Topeka, Kansas
Contact:

Post

Make a new thread and post pics. Somebody may have removed the valves and welded the lower up. If so, you're SOL unless you buy another lower.

180sx_vc
Posts: 17
Joined: Mon May 30, 2011 9:29 pm
Car: 180sx

Post

Sorry to bring up this old thread but i finally got around in trying to hook up the butterflies with a volvo pump. i hooked up the wires just like the way biosehnsucht showed. For some reason its not working, i can hear a clicking sound inside the pump but thats it. So i assumed the pump i got is bad but a friend of mind hooked up the pump directly to a battery and BAM!! its pumping. is it possible the pump i got is different from biosehnsucht? or something else is wrong?

User avatar
float_6969
Moderator
Posts: 19853
Joined: Mon Aug 26, 2002 1:55 pm
Car: CA18DET swapped 1995 Nissan 240sx (too many mods to list)
2015 SV Leaf w/QC & Bose (daily)
Location: Topeka, Kansas
Contact:

Post

removed this post due to me mis-reading the original post and providing mis-information

180sx_vc
Posts: 17
Joined: Mon May 30, 2011 9:29 pm
Car: 180sx

Post

OK. So is biosehnsucht's diagram wrong then? I pretty much copied hez diagram on point. On biosehnsucht diagram the plug from the volvo pump has 3 wires and from left to right he's got Pump/Solenoid/12v. But since that doesn't work, my friend suggested it should be 12v/pump/solenoid.....wat do u think?

User avatar
biosehnsucht
Posts: 1839
Joined: Thu Feb 26, 2004 10:20 pm
Contact:

Post

Sorry for the images going poof. TL;DR I derped when moving to a different VPS. Long version: I put the old IPs instead of new, then I put the gateway instead of new (copied wrong address) into my DNS, and then discovered after fixing that facepalm that apparently I never set httpd to start on boot and when my VPS was upgraded via reboot it never started again... DERP!

Your pump may be different, I'm pretty sure the wiring I show is right, because I was very particular about documenting what I did back then. I'd check but it is kind of difficult since the car is wrecked and there's no battery in it. I could hook up a battery, but then I have to find the alarm fob to make the alarm shut up, and ...

The way to test the wiring is to connect 12V to the 12V connector, and then connect either of the other wires to ground and it should either turn on the pump or release the vacuum depending on which one you hooked ground to. You should be able to feel it pull a vacuum if you put your finger over the vacuum side port (the natural colored plastic in my image). If that doesn't work, try 12V on one of the others and ground on the other two, etc.

User avatar
float_6969
Moderator
Posts: 19853
Joined: Mon Aug 26, 2002 1:55 pm
Car: CA18DET swapped 1995 Nissan 240sx (too many mods to list)
2015 SV Leaf w/QC & Bose (daily)
Location: Topeka, Kansas
Contact:

Post

180sx_vc wrote:OK. So is biosehnsucht's diagram wrong then? I pretty much copied hez diagram on point. On biosehnsucht diagram the plug from the volvo pump has 3 wires and from left to right he's got Pump/Solenoid/12v. But since that doesn't work, my friend suggested it should be 12v/pump/solenoid.....wat do u think?
Ignore my post (I removed it). The pictures were gone and I was going off of what I was reading and I mis-read it.

If you wired things up EXACTLY like he has pictured, it should work, UNLESS the wiring is different on your particular pump.

Buddyworm
Posts: 416
Joined: Tue Jan 09, 2007 2:55 pm

Post

Well I managed to get over to the local pick n pull this weekend to snag myself one of the Volvo actuators and I can confirm they work as described. I checked the movement of the butterfly actuator with my head in the engine bay and by the seat of my pants on a test drive. I neglected to use any of the factory delay valves so the changeover is quite noticeable.


HOWEVER the diagrams provided here were not appropriate for my unit. First, the ports of my unit are the reverse of the description. The black nipple is the vacuum port and the white nipple is the pump outlet.

Second, I had to wire mine up differently. If the other units people have are at all the same internally then wiring it up according to Method 3 will not work. Here's a shot of the guts of my unit (you can pop the lid off by hand, it just snaps into place):

Image

The numbers 1 to 3 on the above image correspond to the pins on underside of the unit, where the harness plugs in.

Pin 1 is connected to the positive (+) lead of the electric motor as well as one lead for the solenoid coil.
Pin 2 is connected to the ground (-) lead of the electric motor
Pin 3 is connected to the ground (-) lead for the solenoid

The short rubber vacuum line coming off the side of the black (vacuum) port connects to a nipple on the underside of the solenoid. The solenoid itself actuates a small trap door with a rubber plug on its underside. When energized, the solenoid snaps the trap door closed, sealing the end of the vacuum line and forcing the pump to pull vacuum solely through the main port. When the solenoid is de-energized it releases the trap door and "vents" the vacuum.

When wiring the unit according to this thread (12 volt power applied to pin 3) the electric motor does not engage, only the solenoid will actuate when you ground the appropriate pin.

Here's what I did:

Attention: The below quote block describes my first attempt at wiring the pump up: This method will NOT work.
You can mostly use the original diagram for wiring up your relay, but ignore Pin 87a.
Switched 12-volt power should be connected to Pin 1 on the pump.
Pins 2 and 3 on the pump are grounded through Pin 87 on the relay (the Normally Open circuit).

Now, when you turn your key to Run your ECU grounds the butterfly control circuit with your switched power, this energizes the relay, grounding the pump and solenoid through the normally open circuit (87). The pump engages and the solenoid snaps closed, applying vacuum to your butterfly actuator, closing the butterflies. Then, when the ECU opens the butterfly control circuit your relay flips back over to the normally closed (87a) circuit, the electric motor shuts off and the solenoid releases, venting the vacuum and allowing the butterflies to open.

That's it! Took me a while to figure out why my pump wasn't turning on, hopefully I can save others the same headache. This retrofit is well worth it in my opinion. I love that I've been able to get rid of that nest of 20-year old vacuum lines. Thanks to the original poster for making us aware of this option!
Now, the CORRECT method can be even simpler than the above:

Switched 12-volt power is still connected to Pin 1 on the pump.
Constant ground is connected to Pin 2 on the pump.
The ECU butterfly control wire (Grey wire from the OEM butterfly solenoid plug) is connected to Pin 3 on the pump.

So, when you start the car your switched 12-volt power kicks the pump on. When wired this way, as long as the key is in Run position, the pump motor will function.

Now for the fun part: Your ECU controls the amount of vacuum "seen" by the butterfly actuator by changing the solenoid's duty cycle. It does this by rapidly closing and opening it's ground circuit (grey wire) to achieve a specified pressure at the butterfly actuator by opening and closing the trap door inside the vacuum pump, much like an electronic boost controller controls how much pressure your wastegate sees. Essentially, they "vent" pressure in short bursts to control the actuator diaphragms.

Anyway, sorry for the confusion everybody. I was so eager to share my knowledge with the internets that I posted my method without properly testing first. My downfall was that my first test drive was on a warm engine; this morning on my drive to work the engine was a complete dog until it was up to temp, which was my first clue (apparently the butterflies are extremely important for proper combustion on a cold engine). Then this afternoon I remembered the below image, B02-1000, and it hit me:

Image

My Katakana isn't very good, but one of those words is "Shiorenoido," which means the vertical axis MUST represent Duty Cycle. (I later confirmed visually that the solenoid in the vacuum pump is energized 100% of the time at idle, for what it's worth.)

I have tested this setup thoroughly tonight, even going so far as to change the opening point through Nistune. The above image has an analogous table in the ECU ROM, making the butterflies extremely tuneable. I shifted the dropoff point from 2000rpm to ~4500rpm and it works spectacularly! I have yet to experiment with this fully but it appears to me that, without the factory delay valve in place, you should be able to precisely control the "ramp" of the butterfly opening action by changing the shape of the graph above in the ECU. Exciting stuff for me and my TD06!


Here's a pic of the unit for part# reference:
Image

**Edited for bungled wiring logic.
Last edited by Buddyworm on Mon Sep 09, 2013 10:40 pm, edited 3 times in total.

User avatar
float_6969
Moderator
Posts: 19853
Joined: Mon Aug 26, 2002 1:55 pm
Car: CA18DET swapped 1995 Nissan 240sx (too many mods to list)
2015 SV Leaf w/QC & Bose (daily)
Location: Topeka, Kansas
Contact:

Post

AWESOME! Thanks for the update. I'm going to edit the first post to reference this post so ppl know to look through the thread to find this. I'm also wondering if bio had a slightly different unit? Regardless, you've got it working, which is the important part.

Buddyworm
Posts: 416
Joined: Tue Jan 09, 2007 2:55 pm

Post

Hey everybody, please note my previous method for wiring this puppy up was a dud. I've edited my post to reflect the proper way.

User avatar
float_6969
Moderator
Posts: 19853
Joined: Mon Aug 26, 2002 1:55 pm
Car: CA18DET swapped 1995 Nissan 240sx (too many mods to list)
2015 SV Leaf w/QC & Bose (daily)
Location: Topeka, Kansas
Contact:

Post

Holy crap! I think that's new info! I was always under the assumption that the valve just had a simple switch over point and wasn't actually on a duty cycle in factory form.

Buddyworm
Posts: 416
Joined: Tue Jan 09, 2007 2:55 pm

Post

Indeed! I bet we can confirm this by wiring a small LED or lamp in parallel with the pump solenoid to create a visual indicator...

User avatar
float_6969
Moderator
Posts: 19853
Joined: Mon Aug 26, 2002 1:55 pm
Car: CA18DET swapped 1995 Nissan 240sx (too many mods to list)
2015 SV Leaf w/QC & Bose (daily)
Location: Topeka, Kansas
Contact:

Post

The fact that you found the map in the ROM is enough to convince me. I assume it's a duty cycle referenced to RPM? Or maybe load from the MAFS?

Buddyworm
Posts: 416
Joined: Tue Jan 09, 2007 2:55 pm

Post

Oh, I can't take credit for figuring this stuff out.

Here's an extremely informative thread on butterflies: http://www.nissansilvia.com/forums/inde ... pic=365186 Thanks to Niscort for sharing the butterfly control graphic.

As for the Butterfly control table in the ECU, the addresses for it have been floating around on the internet for a while but are considerably harder to find now for some reason. At least for me... Anyway, I had to do a bit of sleuthing in some old forum posts to dig it up. Anybody who wants to fiddle with the table in their ROM just needs to add the following to their ROMeditor or Nistune .adr files.

Code: Select all

#Add.map 1 
ADD_MAP1,&H3990,32,1,32,1,Variable air close (JDM)
I think the butterfly control is primarily RPM referenced, but I also think load factors into it as well as it seems to me that I can rev the engine under low load past the dropoff point without feeling them open. I'll be experimenting with the butterflies for the next little while so I'll post any cool stuff I learn!


Return to “CA18DE / CA18DET Forum”