URLACHER54
SHO Member
has anyone done this, i was talking to a guy today and he said this is agood idea. anyone, pros and cons of doing this.
removing the butterflies?
- Thread starter URLACHER54
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SASHO91
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Do not do it... end of story. No questions asked... if you do have a question search, its been beat countless times... 
BlackonBlack89
SHO Member
unless you are boosting keep em
if you take them out and you are N/A you will just lose a lot of low end power.
but after 4k there will be a gain obvisouly. (not streetable)
if you take them out and you are N/A you will just lose a lot of low end power.
but after 4k there will be a gain obvisouly. (not streetable)
SASHO91
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BlackonBlack89 said:
please enlighten us.....
BlackonBlack89
SHO Member
beat me too it LOL
SASHO91
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unless the motor is tuned, that tiny gain wont even be felt.
BlackonBlack89
SHO Member
so it not that tiny but the loss of low end is not worth it.
but if you are on a road track event it would be
never really below 4k
but if you are on a road track event it would be
never really below 4k
SASHO91 said:Do not do it... end of story. No questions asked... if you do have a question search, its been beat countless times...
Lies.
I did it on my old 94 ATX along with some porting to the heads and intake and boy did it pull from mid rpms all the way to redline. Below 3000 rpms lacked the torque though. I would definitly do it again on a ATX or MTX N/A SHO. The car now belongs to 38SHO and a few FSHOC members can tell you how impressive some porting and butterfly removal worked.
SASHO91
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any dyno proof???? 
SASHO91 said:any dyno proof????
No, I sold it shortly after I did it because Todd just wrecked his old Taurus and wanted a SHO. Never got it on a dyno and I doubt he will in its current chassis. Todd has not been on here in the last month and last I heard he might pull that engine and use it in a RWD configuration. Sorry, you'd have to take my word for it...I think my cars speak for themselves
SASHO91
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I stand corrected.... 
guess i need to double check whom i get my info from...... 
still though, unless this setup is tuned, there will be a tq loss... especially on the MTX.
guess i need to double check whom i get my info from...... still though, unless this setup is tuned, there will be a tq loss... especially on the MTX.
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jedhead
New Member
Easy way for you to find out. Disconnect the vacumn lines to the butterfly actuators so they stay open all the time. I am sure your friend has far more automotive knowledge than the engineers at Yamaha who designed the engine and messed up with the intake design.
Bob
Bob
SASHO91
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jedhead said:
well thats one thing Bob, we are talking about removing them completly from the intake...
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91_SHOster
Member
i've unplugged the secondaries before, and other than my loss of low end and the different sounds my intake made, nothing else happend. this is preety much what jedhead's saying, if you do this it's preety much showing you what it will be like removing it all together
SASHO91
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91_SHOster said:
that is incorrect....
when you simply unplug the secondaries, yes, they are open all the time. However, they are still IN the intake track.
I have a spare set laying around that i'll port, and seal up... see what it does..
If you lost low end power with just opening the butterflies, what makes you think removing them and increasing the opening is going to do anything but make you loose more low end power? This is a tuned intake designed to optimize torque in the low rev range and high rev range. By removing the butterfly plates you negate that effect. People who have track cars can get away with it because they don’t need low end torque and need as much top end as possible. I also believe that gas mileage will suffer, as this is a common symptom that your butterflies are stuck open, usually found in the help I have a problem section of this forum. But if your going to try it, get a dyno done before and after so that there is some proof.
Edit:
If you use the calculator on this page:
http://www.rbracing-rsr.com/runnertorquecalc.html
you will see that by increasing the runner area your peak torque moves up giving you less low end power.
Edit:
If you use the calculator on this page:
http://www.rbracing-rsr.com/runnertorquecalc.html
you will see that by increasing the runner area your peak torque moves up giving you less low end power.
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Shoaz
Studly dood
NJSHO said:
Exactly. It's a pretty simple, fast experiment, and it will save the time of removing and modifying the butterflies, only to find that we all know what'll happen, anyway.
When the plates are open they're not much of a restriction. The rods are probably more of a restriction than the plates, and it's pretty tough to remove those without causing some pretty major leaks. Not that they're much of a restriction, anyway.
The long runners are to improve low-end torque, period. As has been mentioned, for forced induction motors or motors that are never or rarely applied below 4krpm (e.g., track cars, race cars), they don't necessarily help (although IIRC Josh posted some stuff long ago that the runners still helped a bit even with a blower in some cases). For those of you familiar with it, the engine in Todd Cook's hillclimb car has a custom intake, no long runners at all, and he's been making a lot of power and winning events with it for a long time. This isn't anything new at all.
FWIW, the motor in the Pumpkin is 100% bone stock. It's pretty rare to be below 4krpm on a road course, but once in a while it helps to have that low-end torque.
SASHO91 said:that is incorrect....
when you simply unplug the secondaries, yes, they are open all the time. However, they are still IN the intake track.
I have a spare set laying around that i'll port, and seal up... see what it does..
Yes, yes, port the housings to about the BBB opening size. Gasket match the heads to runners and the tanks and you will be in for a suprise. I left in the shafts but grinded them down a lot. I believe that Kelvin (K-dawg on here) ran my old SHO in his VERY healthy MTX and from what I was told it about kept up.
NJSHO said:
You are correct. Loss end loss will occur. I used this car to suprise people on the highway where I was at optimal rpms for roll ons.
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