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85_600
12-24-2005, 08:33 PM
Just wondering if anyone has any pics of where you tapped into the vacuum source for your gauge. I've got mine tapped into a "free" source coming from the manifold but either my gauge is off or the source is wrong or my line setup is bad. My vacuum reading "seem" to be fine ( cruising = 10 vac ), at idle in PARK = 18 - 19 vac. The psi is my big concern. At WOT I only get up to 5 psi. This is on a 1985 Dodge 600 A-413 stock T1. It should be what, 9 or 10 psi right?

I just want to see where everyone else has tapped OR, if you good with descriptions, write out where you tapped in for it. I heard someone had used the line coming from the master cylnder ( brake booster line ). Wouldn't that give screwing readings?

Thanks!
Paul

boost geek
12-25-2005, 02:31 AM
I also come off the intake, t1 in an 87 s.c. and also push only 5, sometimes spike to 6 psi. When I had my other 86 s.c., off the intake I was pushing 15-17 psi with t2, stock turbo, with 2 washers as waistgate spacers. The intake is the only place I would connect my boost guage to, thats where "whats happenin' counts" in my opinion. :)

85_600
12-25-2005, 03:09 AM
I probably should have specified that "free" source better, my bad :o

What I mean by the source being free is, I have one vacuum line that ends right before it "would" have gone into the vacuum block on the passenger fender. It was just sitting there blocked off. So I tapped into it.

My initial line setup was: Gauge - nylon - small rubber hose - nylon - small rubber hose - source. The first "rubber hose" was due to me crimping the nylon to the point of me having to cut the crimp out. The 2nd "rubber hose" is where the line attaches to the source.

Is there any truth to using the brake booster line? I've been told by a TD member that he used that and everything was fine. BUT, I was reading about where to and not to hook it up and someone said that if the needle moves when you brake - find another source.

Right now, my line is setup like: Gauge - 3-4" nylon - rubber hose - source. I just changed it to this Friday night and I have had no change in my readings.

Could this be due to the distance from the gauge to the source? I am getting the source from the passenger side, front fender area.

boost geek
12-25-2005, 03:38 AM
You could try straight rubber hose right to the guage, but your stock t1 would never go past 7 psi, in my opinion. This at least is what I seen from my 86-87 t1 log cars. They were supposed to spike around 8 psi for about 10 seconds when new, but I havent even seen that. The knock sensor might be holding it back.

GLHSKEN
12-25-2005, 11:36 AM
+1^^^^^ early TI's had a max of 7psi.. Computer controlled. That "capped" vac line was there for the boost guage originally if it is the one I am thinking of...

85lebaront2
12-25-2005, 03:17 PM
That's what I was thinking. On my T2 conversion, I tapped the "extra" line coming off the multiple "tree" on the intake. I am not reading Vacuum, just boost. Mine will "spike" to about 14.5 psi, then drop to a steady 14 psi. I am using a Mopar Performance program in the LM. According to my information, T1 setups run 7 psi. stock.

85_600
12-25-2005, 05:18 PM
I was reading up the psi at MiniMopar. 7 psi with a max of 9. However, I'm not even getting to 5 most of the time, even on a WOT run. It "might" go to 6 but mostly just right before the 5 psi mark. That's where I'm at a loss on why it's not reading right.
My vacuum readings do seem to be right on though, unless these are way off as well:

Idle, in park = 18 - 19
Cruising on the highway = 10

As soon as I hear the turbo spooling up the needle doesn't get to the 0 box. I have to really lay into it and then it goes past the 0 box.

I just wanted to see where everyone has tapped into the vacuum source(s) so I have an idea for another source, just to trouble shoot my gauge setup. If, after I try another source or two, my readings stay the same then I'm going to try another gauge to see if that's the problem.

85_600
12-25-2005, 09:20 PM
I just thought of something here. Maybe I'm barking up the wrong tree.

What types of problems would limit my boost to just 5 psi? I started thinking maybe it's not my line setup or gauge but possibly something else. If so I could start looking in this direction as well. With Winter here I do have some time to spend on this. I would like to find out if something is not right though by Spring. I have some mods planned and I'd like to know my real psi readings. :)

Thanks!
Paul

85_600
12-25-2005, 09:28 PM
+1^^^^^ early TI's had a max of 7psi.. Computer controlled. That "capped" vac line was there for the boost guage originally if it is the one I am thinking of...

This is the source I tapped into:

http://www.xwarlordx.com/red97sc2/Pics/600%20Pics/Vacuum%20Source.JPG

What about the brake booster line? Would that be a good one to start with? I'm looking for something relatively easy to work with. Even though I said Winter is here and I have time to spend on this problem, it is cold out. :o I do have enough vacuum caps and Tee's and adapters to work with.

GLHSKEN
12-26-2005, 10:59 AM
If you are spooling and you do not see "0"... your issue sounds like the guage itself. Hook a different guage to it and test.

85_600
12-26-2005, 11:41 AM
If you are spooling and you do not see "0"... your issue sounds like the guage itself. Hook a different guage to it and test.

Should the gauge read or get to 0 as soon as I hear it spool? The ever familar whine that I'm loving? Because if so, then I know it's the gauge. I have to accelerate at least half the pedal before the gauge will read 0, then it goes into the psi readings after that, but never gets over 5 psi, even going up a hill while doing a WOT run:confused:

GLHSKEN
12-26-2005, 11:52 AM
When it spools it should be at 0... If you hear it whistling, it's working hard enough to build pressure

Tony Hanna
12-26-2005, 06:53 PM
One thing I ran into recently was connecting the boost gauge to the same source that the PCV valve was connected to. With the setup I was running at the time, I should have been seeing at least 26 psi, but would only see an initial spike to 26 psi then it would quickly fall off to 18-20. I know the boost was there because it was still kicking the second stage pressure switch for the alky injection, I just wasn't seeing it in the gauge. After moving the gauge to a different source, it would read 26 psi constantly as it should.
I don't know if PCV valve leaking under boost is a common thing, but it'd definately be something to consider if your boost gauge is connected to the same source and is acting flakey.

TylerEss
12-26-2005, 07:33 PM
For what it's worth, when I installed a boost gauge in my 1985 T1 Log car, it never read more than 5 PSI... until I installed a Gus Valve. Now it reads 12 most of the time. :evil:

I hooked it up to exactly the place you're hooking yours to.

85_600
12-26-2005, 11:27 PM
For what it's worth, when I installed a boost gauge in my 1985 T1 Log car, it never read more than 5 PSI... until I installed a Gus Valve. Now it reads 12 most of the time. :evil:

I hooked it up to exactly the place you're hooking yours to.

You've got to be kidding me right? Same place and nothing changed until a G valve? Did you try other sources? I'd like to try some other places before trying to mess with the boost. I kind of wanted an accurate reading before doing so.

Really, if that's the case then I think $25 is a rather low cost for fixing the boost mis-reading.:thumb:

Lee'sdaytona
12-28-2005, 09:00 PM
yeah it sure sounds like your gauge is screwed up. I've had a few stock ones in my daytona along with my MOPAR PERFORMACE boost/vac gauge. When you lightly press the gas maybe a 1/2 inch down on the highway, the needle should be at 0 if not reading close to 0 on the vac side. If your hearing your turbo and its not even at 0 you have some gauge issues.
-Lee

85_600
12-30-2005, 01:00 AM
Just something else I have been thinking of, for testing purposes. If the TD didn't come with a factory boost gauge, would the hook up for one still be where it should be? The source that is. I've heard that the stock gauge is hooked up to a nipple close to where the MAP sensor is hooked up. I have not looked yet so I was just asking ahead of time, to save me some headaches of looking for something that may not be there.

Oh, I've also heard about popping the cover off of the gauge and re-positioning the needle to be accurate. I have an Autometer "Auto" gauge, one of the black and white basic gauges. If anyone knows, is this possible on these? I don't want to hack into mine knowing that it would probably void the warranty in doing so.

Thanks!
Paul

P.S. If I have some extra time Saturday, after replacing my SDS, I'm going to be messing with the gauge / line setup to see if I can get this thing to read right. I'll post up what I find or don't find later that night.

GLHSKEN
12-30-2005, 09:08 AM
the majority of the cars had that line capped off in the group of lines going to the solenoids.

Your best bet is to get another guage you know is accurate. Just by blowing into the line you should be able to get the guage to at least 0.

Tony Hanna
12-31-2005, 12:45 AM
An easy way to test your gauge is to use a regulated air supply. set the regulator on the compressor at 5 psi to start and connect your gauge. Compare the reading on the gauge at the regulator to your boost gauge at different pressures. This should give you a pretty good idea of how close your gauge is providing the gauge on your compressor is accurate.
I also use this method to preset pressure switches for alcohol injection or extra injectors.
HTH,

85_600
12-31-2005, 06:05 PM
An easy way to test your gauge is to use a regulated air supply.

Well, just tested it today. The regulator on my fathers compressor wasn't too good BUT, I did run it to 60 psi, then started to let some air out. When it got to 25 psi I "started" to hook up the gauge hose and by the time I actually got it on the barb I was at 20 psi on the compressor. So, looking at the gauge in the car at the same time looking at the gauge on the compressor this is what I found out.

Compressor = 20 psi, Gauge = 16 psi.

That's "about" what I've been off on the gauge readings. When I got WOT the gauge only reads 5.5 psi, which it should be 9 psi for 10 sec ( according to Mini Mopar ) for an 85 T1 auto.

I called Summit and they are going to send me a copy of my receipt. When I get it I will be sending the gauge to Autometer for analysis to see if the gauge is defective or not. A person on another forum had the same type of problem. He found out that Autometer either will replace a "defective" gauge or, if it's been damaged during installation then they can fix it and send the owner a bill for the repair.

I'll post up when I get some more info....

Tony Hanna
12-31-2005, 06:33 PM
Glad it worked out for you.:thumb:
Hopefully Autometer will do right by you.