electric exhaust cutout in intake????

[dohcfiend]

would an electric exhaust cutout function correctly under intake vacuum?? i.e. not get sucked open by vacuum?

i was thinking of doing a proto dual runner intake and that cutout would be the easiest to setup by far.

way i wanted to do it is all the factory intake piping would be there but an intake log would Y into the stock runners as low as possible and the end of it would sit that cutout. essentially it would function like a tb but would only have 2 positions open and closed, it would be hooked up using a WOT and a rpm switch.

i.e. it would only open under WOT and at 4000+ as an example.

at 1st i thought about using one of those fly-by-wire tb's but wiring data seems to be non-existent and unlike regular linkage tb's there is no IAC and it seems to be partially open instead of closed like older linkage tb's.

[pwmin]

i have no idea, but i hope it works out...sounds awesome

[silvergtjrad]

i dont think the cutouts open very fast.

[dohcfiend]

crap, has anybody seen one work to verify this? i really do not want to buy one to find out, they can be pricey.

[silvergtjrad]

The only ones ive seen are a gate style where there is a plate that slides in and out of the exhaust path. I would imagine a butterfly style, if they exist, would open quicker.

[Superdave]

you could modify a 3500 TB with a fast motor to open up.. that and some plumbing parts could work.

[IsaacHayes]

I've seen the butterfly type, but they are sloooow. Not something you'd want for instant switching of intake paths.

The electric TB I would imagine could snap open the fastest. I have a 3500 TB but don't know how to hook it up. I have thought about using it for an exhaust cut out or putting it on my air box to have that cone filter sound with a push of a button. haha

[z34phoenix]

ive been toying with the idea as well for about a year now... one issue you need to address is you really need the butterflys at the runers themselves....

cause if you just block the new second plenum/log one runer would try to breath not only thru its orignal runer, but will draw extra air thru the new holle you drilled... and just because the Cutout/TB/actuator is closed doesnt mean it cant draw air from other runners!

basicly if you cant block the holes at the runer you might as well just make a short runner intake.

fyi (im sure you knew this) this is pretty much for 96-97 upper intakes... the older intakes will have more issues trying to get the space.

[Schurkey]

Trying to replicate the Yamaha V-Max motorcycle dual-tuned intake system? What did they call it--V-Boost???

Interesting idea to use exhaust cut-outs. First Guess: You'll need to seal the pivots of the "throttle blade" as they're probably not sealed and would allow air to be drawn in by manifold vacuum.

[z34phoenix]

good point schurkey...

[dohcfiend]

alright exhaust cutouts are out and i still have to work with this 3500 tb. then it hit me, it is still a motor at it's heart and if bad comes to work i can hardwire the motor and rig up a new cover.

finally got the ballz to pop the cover off of my 3500 tb and i was met with a couple pleasant surprises.

also took a few days to find those damned torx with the middles missing to properly get the screws off btw.

1st i'll go over the cover. from the looks of it i could just use an ohm meter to find the pin on the front that corresponds with the ones on the back. wrong they must be used in some kind of combination to get voltage to the motor.

but the location of the pins is next to the edge of the cover so i think with a drill, some solder and some silicone sealant i can cover this just fine.

next is what i was referring to earlier about having to apply reverse voltage to close it all the way and foward voltage to open the tb. inside the tb there are 2 throws and 2 sets of springs, i figure all i have to do is cut away that one throw that the black plastic lays on and it will close the tb all the way until the bronze gear hits the other throw and it will stay closed all the time until i juice it to open.

so i learned alot by getting off my butt...lol.

that leaves me with one singular question, any1 know how much voltage this tb motor operates off of? i would say it is a 12v motor but it is just a guess.


with all that out of the way i can answer and ask a question or 2. z34 pheonix, yes i plan on using the 96-97 intake setup for this. next you are completely right on that. damn it. i'll have to ponder on this but i got everything else figured out.

next the question: there are no individual runner butterflies on the stock plenum so how would not having them on the second log make any difference?

p.s. yes there is an additional gear that goes between the motor and the throw but i removed it for the pic.

[Superdave]

keep in mind, that's a stepper motor not a regular one...


BTW, i have an extra 3500 TB if you want it.. just pay shipping

[dohcfiend]

it's also a gear reduction motor, it opens super fast.

[z34phoenix]

Ok here is a pic of what im talking about... on the left is the simplified air flow on a normal 96-97 intake... air comes from the TB down the arm and into the runer to get to the port.

in the dual runer.... if you dont have butterflys at the runers, the port will not only suck air from its runer and thru the arm, but it will pull air from the nieboring runners thru the hole even if the second TB/or cutoff is open or closed. this effect will supply the port with more air flow and be as if you had a much larger runner.... this will hurt Tq.

The SHO and all the variable runer intake manifolds i know of have the butterfly at the runner to stop flow from jumping to other runners.

[dohcfiend]

sweet thanx. i suppose i will have to ponder on it for a while.