Controlling the butterflies with boost

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curtisvr4

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Thought I would share this info to the masses. Always like the SHO's but finding a descent one when I was looking was impossible. So I ended up with a Galant VR4 and she stays on jackstands most of the time.

I'm a moderator over in GalantVR4 land and a self employed engineer the rest of the time. I just build one off custom parts, gauge panels with logos and pieces and parts in my garage, I play with the cnc mill I have and make a living, never going to get rich but I help with home work see my daughter all summer and after school everyday so feel really blessed.

On to subject matter. I built a butterfly controller for the Japanese dual runner intake manifold years ago. Recently I ended up with a couple SHO intakes and since then have fully ported, cnc the butterflies to 40mm etc. on one and put it on ebay and dependent on how it sells may do the other and a few my buddy says he can pick up for me and ship. Mainly since I have the code in the mill already to to the butterflies and the mounting fixture already done. Had a SHO owner contact me wanting to know how I did the controller so here it is, winner of the manifold on sunday will get this info as well.

Now for the controller.
The Japanese intake is like the sho intake one long runner one short, from the factory in Japan they were ecu controlled like yours but after mods on the car the range and when you need it to come in needs to be modified plus the us cars never we're supplied with these intakes so something had to be done. The US intakes are only 4 single runners and after lots of flowbench tests only flow 2 more cfm over the cyclone but the cyclone dependent on turbo size and mods has seen 50 ft lbs of torque increases but can't flow to 9K like a sheetmetal.

<<<<<<<<<Things you need>>>>>>>
wire (black and red)
hobbs switch adjustable 0 to whatever 1-10 is enough (Napa has these as well as some turbo subarus and saab out of the junkyard)
two vacuum solenoids (can be found on just about any mitsubishi in a junkyard on the fire wall)
-one normally open
-one normally closed

Picture here
http://i74.photobucket.com/albums/i251/bruceholder/L400/Odds/Ebay092.jpg

vacuum canister with internal check valve
-(mitsubishi can get these from the 3rd gen eclipse's and the montero's) if yours is bad but the sho one should work as fine as the mitsubishi and be fine.

vacuum hose
t fittings
zip ties electrical tape etc.

Now to start you wire up the solenoids through the hobbs
The ground leaves the chassis into the hobbs pressure switch and out to the two solenoids. 12Volt power comes from the battery /relay/ etc just don't have it hooked up all the time have it on a circuit that is on when the ignition is on. Power from the factory controller want work because it will come on to late.

Now for the vacuum line

From the butterfly actuators run two lines and tie them together and the remaining port run to the factory vacuum canister. Then a hose from the canister to the normally open switch. Now go back to the hose coming from the vacuum canister and the actuator install a t fitting and run the extra leg to the normally closed solenoid. Now the other sides of the solenoids need to be hooked up. Run a line from the manifold plenum and up to the hobbs and both solenoids and t all three together or drill and tap the plenum and install the hobbs in the plenum up to you.


How it works.... under vacuum just cruising the normally open solenoid is open going through the canister and is passing by the internal check valve and pulling a vacuum on the actuator and closing the butterflies.
Now when you throttle it boost pressure goes up and the hobbs opens making a circuit this opens the closed solenoid and closes the open solenoid. This redirects air and now the pressure passes through the normally closed solenoid and goes to the actuators and is stopped from circling to the other solenoid with the one way check before the canister, the butterflies are now open. The reason for the adjustible hobbs pressure switch is for tuning.

I found with a Garrett TO4b my 2.0 liked about 6 psi on the hobbs then when I went to the larger s362 which flows past a GT35R it liked 3psi that way they were open faster and the engine was eating air faster, but on these engines it maybe 10 or maybe 2 all dependent on which turbo /supercharger your running but easy and fun to go play and tune on a backroads. I'll probably be building a new sheetmetal intake for mine because Ive gone to a large frame VGT Holset and hoping for 650 to 700 hp.


Hope this thread is helpful to some of you guys just info I had floating around in my head.


I'll check the thread a few times this afternoon and do some research on here as the day goes by so if any of you have any questions post away. Curtis
 

randy'sho

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I am sooo confused right now! I am a visual person! Pics would be way better to help me understand what you are talking about! :thankyou:
 

yamahaSHO

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This is intereseting, however, most people here with boost are already running some type of engine management (TwEECer) which already allows you to control when the butterflies open (if I'm reading this right).
 

sho_sc

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Let me help a little here ...

Most of us boosted guys are running centrifugal superchargers, there are a handful of turbo guys, but not many.

The computer management program that we have, TwEECer, allows us to adjust the opening point of the butterflies. Opening point is based on RPM and throttle position which is adjustable because it is based on when the EEC sees WOT.

I'm running a T-trim Vortech and boosting on the high side. My race SHO sees 2 psi of boost at 2K RPM and 20 psi of boost at 7500 (limit of the impeller). I've found that when you run really high levels of boost, the butterflies become a restriction so mine are removed as well as all of the hardware associated. Yes, it runs like poo below 3500 RPM, but really wakes up above 5K RPM (and if you shift a 7500, you stay at or above 5500 RPM). (and poo is a relative term)

I really don't know what the advantage would be with opening the butterflies based on boost; maybe just maybe on a turbo, but not a blower.
 

curtisvr4

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Try it again
5 minutes to draw 30 trying to make it into a jpeg. So I printed it and took a picture. Now as for the tweeker some have tried a rpm/throttle position based controller on the cyclone some like it some don't but for 5 bucks worth of junkyard parts really easy thing to build.
 

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