How accurate is the factory boost gauge?
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i think those factory idiot lights suck 
i dont think i have even seen the red one come on before, i wonder if its burnt out
if you get an aftermarket boost guage, it helps tune it and if you tie your boost guage into the same line that the Map sensor uses you will be able to see and what pound of boost your idiot lights come on with. it worked for me
if your light flickers maybe the map sensor is shot or you could have a crack in the hose that connects the sensor to the back of the intake. If its the original rubber hoses, they could be dry rotted or leaking, like mine was. The sensor is sort of a vacuum switch or sensor of some type
its on the inner passenger side fender,its a lil pod with a vacuum line on 1 side and wire plug in on the other side, its the 1 closest towards the battery.
if your curious or can't find it , you can go to www.gnttype.org and look up 84/85 sensors, and look up MAP sensor
Check me out ! i been reading so much on here, that i can actually give some1 a lil advice
talk to ya later
i dont think i have even seen the red one come on before, i wonder if its burnt out
if you get an aftermarket boost guage, it helps tune it and if you tie your boost guage into the same line that the Map sensor uses you will be able to see and what pound of boost your idiot lights come on with. it worked for me
if your light flickers maybe the map sensor is shot or you could have a crack in the hose that connects the sensor to the back of the intake. If its the original rubber hoses, they could be dry rotted or leaking, like mine was. The sensor is sort of a vacuum switch or sensor of some type
its on the inner passenger side fender,its a lil pod with a vacuum line on 1 side and wire plug in on the other side, its the 1 closest towards the battery.
if your curious or can't find it , you can go to www.gnttype.org and look up 84/85 sensors, and look up MAP sensor
Check me out ! i been reading so much on here, that i can actually give some1 a lil advice
talk to ya later
turbowrenchhead
Drive like you stole it!
- Joined
- May 25, 2001
- Messages
- 854
Mine is actually pretty accurate. The car was well taking car of. I thought that once I got a boost gauge on it that the factory would be way off because everyone says there junk, low and behold it worked fine. But I usally run more the 15 pds so I needed it anyways.
Suprisingly enough, my factory guage is pretty accurate. Mine also does the same thing. It only goes half way usually when pinned. But i found out that I had a leak at the adapter seal. When I hooked a boost gusge up to it, it was quite accurate. Only like 1 or 2 psi off. But ive seen lots of them totally outta whack. Even thr RPM guage I use seems to be retty accurate, but never checked out that one for myself 
-Todders
-Todders
Caspers fixed me up
Mine was so far out I would trun the key on and get 5 lbs of boost without having the car running. At idle it was seven and when I got on the gas nothing. Let's not even talk about the pegged out tach that never moved but, all the lights worked. Thanks to Caspers electronics I have a working and almost dead on (maybe a pound or two off) tach and boost. I got one while at the GS Nats this year. If any of you guys with bad ones want one that's close to correct John at Caspers is the man to get with.
Mine was so far out I would trun the key on and get 5 lbs of boost without having the car running. At idle it was seven and when I got on the gas nothing. Let's not even talk about the pegged out tach that never moved but, all the lights worked. Thanks to Caspers electronics I have a working and almost dead on (maybe a pound or two off) tach and boost. I got one while at the GS Nats this year. If any of you guys with bad ones want one that's close to correct John at Caspers is the man to get with.
When I was running the org. turbo the gauge was pretty close and came up a little sooner than my POS VDO does. When I switched to a 49 ( modded to fit our intakes...man did that thing spool slow) it read about 3-4 psi higher.
Now it reads 15 psi when the VDO reads 10. Is it because of more air with the bigger turbo, or is the VDO getting lazy?
I don't really care and just tune to less than 15% of knock.
Anyway...........you really need an accurate boost gauge.
Autometer?
Now it reads 15 psi when the VDO reads 10. Is it because of more air with the bigger turbo, or is the VDO getting lazy?
I don't really care and just tune to less than 15% of knock.
Anyway...........you really need an accurate boost gauge.
Autometer?
H
HotAirPrime85
Guest
a little off topic...but i just put an autometer boost gauge on the car, and i T'd off the line going to the sensor on the side of the passenger fender well like gnttype.org said....but i only get a vac reading, it doesnt move to the pressure side...just goes back to zero when im boosting. am i on the right line?
There is a pipe plug on the front of the intake behind where the coil pack is...Pull the pipe plug fitting out and screw in a new fitting with a vacuum line nipple on it and hook your boost gauge straight to the intake itself...
Twins, as far as having a bigger turbo that flows more air throwing your boost gauge off...Come on!!! The boost gauge measures pressure, NOT VOLUME!!!! Doesn't matter how much volume you throw at it, it will still only measure pressure...
Twins, as far as having a bigger turbo that flows more air throwing your boost gauge off...Come on!!! The boost gauge measures pressure, NOT VOLUME!!!! Doesn't matter how much volume you throw at it, it will still only measure pressure...
H
HotAirPrime85
Guest
i know about the pressure port but the bolt has been stripped...i guess ill have to drill the old bolt out or something....
Hey FJM ease up killer.....just like I posted that is my experience with my gauges on my car.
Maybe the VDO got lazier and the factory got a little more excited...either way thats what has happened over the six years I've had my GN.
Relax I'm just posting what has happened to me not trying to give directions on brain surgury.
I still stick by the jist of my post, get a good gauge.
Later,
Christian.
Maybe the VDO got lazier and the factory got a little more excited...either way thats what has happened over the six years I've had my GN.
Relax I'm just posting what has happened to me not trying to give directions on brain surgury.
I still stick by the jist of my post, get a good gauge.
Later,
Christian.
My factory guage reads about 4psi high at 17psi and is more accurate at lower boost. Once I started turning the boost up ~25psi it would be at 0 vacuum with the engine idling for a couple days and then go back almost to normal. I don't know why, maybe the diaphram stretches.
Not a problem TWINS...Kind of hard to put intonation in type... Looking back, my comments came across sounding a little harsh...It was meant to be kind of sarcastic, but not flamatory...
And yes, by all means, I do agree with your comment on getting a good gauge...Even if the factory one is accurate(if your car has one), it still only reads to 15#, which IMO, is WAAAYYY toooo low...
Later, and Happy Boosting!!!
Looking back, my comments came across sounding a little harsh...It was meant to be kind of sarcastic, but not flamatory...And yes, by all means, I do agree with your comment on getting a good gauge...Even if the factory one is accurate(if your car has one), it still only reads to 15#, which IMO, is WAAAYYY toooo low...
Later, and Happy Boosting!!!
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