Explain vacuum (already read the gauge/vacuum thread)
Explain vacuum (already read the gauge/vacuum thread) Help me wrap my head around this, as I'm new to the boosted world.
On a turbo car, is there a primary source for accessing vacuum for things that require it? What all requires it? I'm going with Victor Jr intake, 6061 Elbow which I believe has Vacuum access on it, and I'm told to run a vacuum block so I am ordering the Fore one that has 6 ports on it.
I know this is amateur ****, but that other stickie'd thread didn't explain some of the total NewB questions I had.
On a turbo car, is there a primary source for accessing vacuum for things that require it? What all requires it? I'm going with Victor Jr intake, 6061 Elbow which I believe has Vacuum access on it, and I'm told to run a vacuum block so I am ordering the Fore one that has 6 ports on it.
I know this is amateur ****, but that other stickie'd thread didn't explain some of the total NewB questions I had.
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Joined: Mar 2014
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From: Ohio
Brake booster, fuel pressure regulator, boost gauge, should get vacuum.
Just run everything that needs to see either vacuum or boost to a vacuum block. There isnt really anything thats going to get damaged from vacuum. If youre worried about anything, thats what check valves are for.
Just run everything that needs to see either vacuum or boost to a vacuum block. There isnt really anything thats going to get damaged from vacuum. If youre worried about anything, thats what check valves are for.
I think your asking about WHERE to get the vacuum from? If so, the port on the intake is the correct location. Your only going to pull vacuum in the intake. There is no other place to get it.
And Joe answered your other question.
And Joe answered your other question.
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
Help me wrap my head around this, as I'm new to the boosted world.
On a turbo car, is there a primary source for accessing vacuum for things that require it? What all requires it? I'm going with Victor Jr intake, 6061 Elbow which I believe has Vacuum access on it, and I'm told to run a vacuum block so I am ordering the Fore one that has 6 ports on it.
I know this is amateur ****, but that other stickie'd thread didn't explain some of the total NewB questions I had.
On a turbo car, is there a primary source for accessing vacuum for things that require it? What all requires it? I'm going with Victor Jr intake, 6061 Elbow which I believe has Vacuum access on it, and I'm told to run a vacuum block so I am ordering the Fore one that has 6 ports on it.
I know this is amateur ****, but that other stickie'd thread didn't explain some of the total NewB questions I had.
To me there is a difference in the brake booster needing vacuum to operate and the FPR being connected to a vacuum port.
The brake booster gets evac'd as good as possible any time you are off the gas, then it has a check valve to store that evac state as long as possible. This gives you some brake help even if you are not in a vacuum state in the intake manifold. It seems obvious, but when I was new I did not even think that we don't tend to use the brakes when under boost. Generally we are off the gas and then on the brakes which provides vacuum to help with braking.
Like the other guy said, there are many ways to view this, but it helps my understanding to think about the FPR as viewing manifold absolute pressure instead of thinking vacuum/boost. The FPR needs to know the absolute pressure to ensure the fuel flow remains constant through the injector as the pressure is changing only on one side of the injector. If fuel rail pressure held steady, but intake air pressure at the injector pintle changed, the flow rate would change.
I think it gets more confusing when thinking about the several different ways a BOV can be connected with vacuum above the diaphragm, vacuum below it, boost controller, pressure source, intake pressure on the valve, etc.
Sorry if this wasn't what you are asking.
The brake booster gets evac'd as good as possible any time you are off the gas, then it has a check valve to store that evac state as long as possible. This gives you some brake help even if you are not in a vacuum state in the intake manifold. It seems obvious, but when I was new I did not even think that we don't tend to use the brakes when under boost. Generally we are off the gas and then on the brakes which provides vacuum to help with braking.
Like the other guy said, there are many ways to view this, but it helps my understanding to think about the FPR as viewing manifold absolute pressure instead of thinking vacuum/boost. The FPR needs to know the absolute pressure to ensure the fuel flow remains constant through the injector as the pressure is changing only on one side of the injector. If fuel rail pressure held steady, but intake air pressure at the injector pintle changed, the flow rate would change.
I think it gets more confusing when thinking about the several different ways a BOV can be connected with vacuum above the diaphragm, vacuum below it, boost controller, pressure source, intake pressure on the valve, etc.
Sorry if this wasn't what you are asking.
Anything behind the throttle body sees vac/boost (depending on cruise/power)
Before the throttle body from the boost source, boost only-I prefer boost only to the fuel pressure reg
Before the throttle body from the boost source, boost only-I prefer boost only to the fuel pressure reg
