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Question about Wastgate

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95'RS-T

10+ Year Contributor
440
1
Mar 10, 2009
Germansville, Pennsylvania
I was wondering if i could hook up my boost gauge from my wastgate. I have the 2 ports. The side one is where my MBC is for the actuator and i the top port is just open. Now my gauge is a vac/boost and I just wanna see boost instead of vac, is this possible or should i just keep it teed off from my intake manifold?
 
I was wondering if i could hook up my boost gauge from my wastgate. I have the 2 ports. The side one is where my MBC is for the actuator and i the top port is just open. Now my gauge is a vac/boost and I just wanna see boost instead of vac, is this possible or should i just keep it teed off from my intake manifold?

Its a compound gauge, meaning that its going to read both reguardless of where you put the source. Only way you can get just boost, is if you buy a boost only gauge and not a boost&vac. For the record its always good to have a vac reading because thats what helps you with troubleshooting issues like boost leaks. Oh and that top port on your WG i'm guessing its a tial, is for ebc or a pressurized source like some of the pro guys that use co2 to control their wg's.
 
alright so i'll just keep it teed off at the manifold then i have one more question where is a good place to drill threw the firewall? right now i have the hose running threw the door and it gets pinched and i get a vac reading of about 12 and when i accelerate it goes to 0 and no boos reading. im thinking its because its pinched.
 
Its a compound gauge, meaning that its going to read both reguardless of where you put the source. Only way you can get just boost, is if you buy a boost only gauge and not a boost&vac. For the record its always good to have a vac reading because thats what helps you with troubleshooting issues like boost leaks. Oh and that top port on your WG i'm guessing its a tial, is for ebc or a pressurized source like some of the pro guys that use co2 to control their wg's.

If it is hooked up before the throttle plate it will only see boost. The vacuum reading from the manifold will only show leaks after the throttle plate, still helpful for finding manifold leaks and injector seal leaks. But, not for finding boost leaks in the piping. When i blow ic pipes off my vac reading is the same, i just can't build boost.
 
Its a compound gauge, meaning that its going to read both reguardless of where you put the source. Only way you can get just boost, is if you buy a boost only gauge and not a boost&vac. For the record its always good to have a vac reading because thats what helps you with troubleshooting issues like boost leaks. Oh and that top port on your WG i'm guessing its a tial, is for ebc or a pressurized source like some of the pro guys that use co2 to control their wg's.


That's totally wrong^^^

You aren't going to see any vacuum at your wastegate hose, because there isn't any vacuum at your j-pipe. It's a boost only source. You could hook up there, but it won't give you accurate manifold pressure, only the pressure coming out of your turbo. It won't reflect the boost drop across your IC or the throttle body.

The only way your boost/vac gauge is going to read vacuum, is if you put it after the TB.
 
That's totally wrong^^^

You aren't going to see any vacuum at your wastegate hose, because there isn't any vacuum at your j-pipe. It's a boost only source. You could hook up there, but it won't give you accurate manifold pressure, only the pressure coming out of your turbo. It won't reflect the boost drop across your IC or the throttle body.

The only way your boost/vac gauge is going to read vacuum, is if you put it after the TB.

OK.. So lets see.. you rather him just get an inacurate reading vs just selling his gauge and buying a boost only gauge? Yea that makes sense. And as for vac leaks, when my ic piping popped off I only had 10in of vac, when me at the time not knowing any better used cheap couplings and they ripped through at my intake my vac changed which was reflected on the gauge. The vac gauge comes in handy. And the wastegate stuff is correct as stated its directly off the tial site.
 
OK.. So lets see.. you rather him just get an inacurate reading vs just selling his gauge and buying a boost only gauge? Yea that makes sense. And as for vac leaks, when my ic piping popped off I only had 10in of vac, when me at the time not knowing any better used cheap couplings and they ripped through at my intake my vac changed which was reflected on the gauge. The vac gauge comes in handy. And the wastegate stuff is correct as stated its directly off the tial site.

I'm not saying he should get an inacurate reading, I'm just saying he's not going to see vacuum at the wastgate hose, because typically they tap into the j-pipe at the compressor outlet.

I guess I mis-worded that. I meant that's totally wrong to the part:
its going to read both reguardless of where you put the source.
It's not going to read any vacuum there.

I suppose all the rest of what you said was right. and I didn't intend for him to read boost at the wastegate. I was just stating, that if he did read the boost there, it wouldn't nesesarily give the reading that he wants. For all we know he has two boost gauges and likes to be able to measure boost drop across the IC.

I have a boost/vac gauge, and I have it hooked up to the manifold. Personally, I don't mind that it reads vacuum too, in fact I think it's cool.

I realize now, that you didn't mean you expected to see any vacuum there, just that if there were vacuum, it would read it.

The OP wanted to hook a boost/vac gauge up to the wastegate. In my opinion that's wrong, most of us want to read the boost in the manifold. If I were him I would just suffer through letting the needle swing both ways. But sure, if it's that important, go buy a different gauge, so you can't tell if there's normal vacuum.

Anyways, I have no idea why anyone wouldn't want their vacuum gauge to work, or why the hell people ask half the WTF questions on this forum for that matter.
 
I'm not saying he should get an inacurate reading, I'm just saying he's not going to see vacuum at the wastgate hose, because typically they tap into the j-pipe at the compressor outlet.

I guess I mis-worded that. I meant that's totally wrong to the part:
It's not going to read any vacuum there.

I suppose all the rest of what you said was right. and I didn't intend for him to read boost at the wastegate. I was just stating, that if he did read the boost there, it wouldn't nesesarily give the reading that he wants. For all we know he has two boost gauges and likes to be able to measure boost drop across the IC.

I have a boost/vac gauge, and I have it hooked up to the manifold. Personally, I don't mind that it reads vacuum too, in fact I think it's cool.

I realize now, that you didn't mean you expected to see any vacuum there, just that if there were vacuum, it would read it.

The OP wanted to hook a boost/vac gauge up to the wastegate. In my opinion that's wrong, most of us want to read the boost in the manifold. If I were him I would just suffer through letting the needle swing both ways. But sure, if it's that important, go buy a different gauge, so you can't tell if there's normal vacuum.

Anyways, I have no idea why anyone wouldn't want their vacuum gauge to work, or why the hell people ask half the WTF questions on this forum for that matter.
Being able to read VAC is always a +in my book. :hellyeah:
 
ok thanks guys i ran it through the steering boot and now i see that im running 7-8psi do any of you know what the correct vac should read on the gauge because right now im reading about 10-12 i dont know if it should be more or less.
 
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