mechanical secondaries questoins
I would like to see a good write up and some sort of demonstration to prove that it is better than having vacuum secondaries. I am just not seeing as to why you would do it. Realistically you dont need the secondaries until they actually open with the vacuum setup. Otherwise its sort of like spinning your wheels in my opinion. You are wasting all that fuel and I see no reason you would be any quicker than before. Just my $0.02.... And if I am completely off base, Please educate me.
Hunting Skylines
Joined: Apr 2001
Posts: 3,431
Likes: 4
From: Brisbane, Queensland, Australia.
Originally Posted by dufourmike
And the wire. What is the point of doing it, unless you have a turbo, in which case the vacuum wouldn't open the secondaries.
Lets look at the ghetto parts of it in detail.
1) press the throttle, the wire has slack, so it might not open the secondaries right away, unless you wound the wire really tight (mad type yo),or it doesn't open at all( as such in nick1's case).
2) if the secondaries DO open, they open when the slack in the wire is gone, and the secondary plates now move with the pirmary, at a rate of...... hhmmmm...well, you would have to measure the radius of the linkage to find out the ratio between the primary and secondary linkages.
3)Assuming you've got this far, your pirmary plates are now open. but, there was slack to start of with, so where do the secondary plates go to? Doubt they would open all the way, or by everyones math, they would be 1/3 unopened, impeeding airflow, and losing power.
4) As your shifting mad quik yo, you snap the wire which you ghetto'd on, and you lose your street cred. damn, should have bought the civic.
Lets look at the ghetto parts of it in detail.
1) press the throttle, the wire has slack, so it might not open the secondaries right away, unless you wound the wire really tight (mad type yo),or it doesn't open at all( as such in nick1's case).
2) if the secondaries DO open, they open when the slack in the wire is gone, and the secondary plates now move with the pirmary, at a rate of...... hhmmmm...well, you would have to measure the radius of the linkage to find out the ratio between the primary and secondary linkages.
3)Assuming you've got this far, your pirmary plates are now open. but, there was slack to start of with, so where do the secondary plates go to? Doubt they would open all the way, or by everyones math, they would be 1/3 unopened, impeeding airflow, and losing power.
4) As your shifting mad quik yo, you snap the wire which you ghetto'd on, and you lose your street cred. damn, should have bought the civic.
The way the linkages are set up from the factory, the secondaries aren't able to open until the primaries are about 1/3 of the way open. You simply tie them together at that point and if done properly there is no slack and they are both fully open at WOT. I agree cable ties probably aren't the best method.
It takes about 5 minutes to do once you have the carb off.
Lives on the Forum
Joined: Jun 2004
Posts: 11,359
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From: Grand Rapids Michigan
Hey, I did it and I love it. Secondaries now open a bit earlier than they did before, which results in earlier horsepower for me. 
Economy can also go up, because like Sterling said you can feel when you are up against the secondaries. If you don't push past that point, your economy will be great. Otherwise, the power is there when you decide that you want it, rather than being loosely controlled by engine vacuum. No regrets here...
Economy can also go up, because like Sterling said you can feel when you are up against the secondaries. If you don't push past that point, your economy will be great. Otherwise, the power is there when you decide that you want it, rather than being loosely controlled by engine vacuum. No regrets here...
Joined: May 2002
Posts: 5,972
Likes: 37
From: Ottawa, Soviet Canuckistan
Yeah, if you pick up a carb whose mech secs have been properly done, all butterflies are fully closed at no throttle, and fully open at WOT. And they don't start opening at the same time. I don't know how it works, I just know it does.
Jon
Edit: And mike, you won't snap the wire "when you're shifting mad quick yo" because
a) you get smart and use tough enough wire and
b) you learn to have much more finness on the pedal than "DUH I SLAM IT TO THE FLOOR TO MAKE THE CAR MOVE!!!" . Now bugger off.
Jon
Edit: And mike, you won't snap the wire "when you're shifting mad quick yo" because
a) you get smart and use tough enough wire and
b) you learn to have much more finness on the pedal than "DUH I SLAM IT TO THE FLOOR TO MAKE THE CAR MOVE!!!" . Now bugger off.
Last edited by vipernicus42; Mar 8, 2006 at 10:04 AM.
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