defi d-gauge reading correctly
Sep 4, 2005, 02:51 PM
#1
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defi d-gauge reading correctly
when the car is off my boost gauge is reading 1" vac. i have my mbc set at 20psi. does this mean that i am only running 19psi instead of 20psi?
Sep 5, 2005, 03:02 PM
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this is just a guess... but if the car is off there is no reading on the gauge, the needle just drops back kinda like the rest of your gauges.... I just ordered the same gauge so when I install it I'll see how mine reads. How does it read when you have the car on at idle?
Sep 5, 2005, 03:37 PM
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When your car is off it should read ZERO.
No vacuum or boost at all.
At idle it should be anywhere between 15-20"hg.
If your needle isn't zero'ed when your car is off or even before you put the boost gauge on the car, send it back for a properly calibrated gauge.
In fact, take a picture of your boost gauge when your car is off & post it here.
I had a bad D-Series boost gauge sent to me once, it was off by 5psi
No vacuum or boost at all.
At idle it should be anywhere between 15-20"hg.
If your needle isn't zero'ed when your car is off or even before you put the boost gauge on the car, send it back for a properly calibrated gauge.
In fact, take a picture of your boost gauge when your car is off & post it here.
I had a bad D-Series boost gauge sent to me once, it was off by 5psi
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Sep 8, 2005, 10:41 AM
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Hey I installed my DEFI gauge last night, it reads 0 when its off, and about 20 in-hg vac at idle... Under full acceleration it spikes up to like 22 PSI and drops to like 17-18...
Sep 8, 2005, 01:21 PM
#11
Defi gauges are VERY accurate. One of the best gauges on the market. IMO
Also people reading the specs of 20hg-15hg remember cams will reduce the amount vaccum you car has so. people with cams could see 15-10hg. If it goes any lower that normally means that your motor is not doing very well.
dan628 - what you are experiencing is very normal. The reason the gauge is reading the boost is falling off is because it is.
Ben
Also people reading the specs of 20hg-15hg remember cams will reduce the amount vaccum you car has so. people with cams could see 15-10hg. If it goes any lower that normally means that your motor is not doing very well.
dan628 - what you are experiencing is very normal. The reason the gauge is reading the boost is falling off is because it is.
Ben
Sep 8, 2005, 01:30 PM
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Originally Posted by RallySport Direct
Also people reading the specs of 20hg-15hg remember cams will reduce the amount vaccum you car has so. people with cams could see 15-10hg. If it goes any lower that normally means that your motor is not doing very well.
Ben
Ben
Ben,
Ive noticed that with the cams I used to idle around 15hg, recently thats moved up to around 17hg. Would you mind giving a brief explanation of what could cause this?
Sep 8, 2005, 01:38 PM
#13
That is very rare for it to do.
Most aftermarket cams have a greater overlap in duration(which gives the cool lug lug at idle)
This causes the vaccum reading to go down.
I have no clue why your went up. What cams did you use? Anything else changed at the time? Cam Gears?
Ben
Most aftermarket cams have a greater overlap in duration(which gives the cool lug lug at idle)
This causes the vaccum reading to go down.
I have no clue why your went up. What cams did you use? Anything else changed at the time? Cam Gears?
Ben
Sep 8, 2005, 01:46 PM
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Originally Posted by RallySport Direct
That is very rare for it to do.
Most aftermarket cams have a greater overlap in duration(which gives the cool lug lug at idle)
This causes the vaccum reading to go down.
I have no clue why your went up. What cams did you use? Anything else changed at the time? Cam Gears?
Ben
Most aftermarket cams have a greater overlap in duration(which gives the cool lug lug at idle)
This causes the vaccum reading to go down.
I have no clue why your went up. What cams did you use? Anything else changed at the time? Cam Gears?
Ben
GSC 272/264. Ive only had them for about 3 weeks now or 1k miles. Head studs were also installed at the same time. I had a very pronounced lope after install which has decreased slightly as well.
