Boost gauge not working correctly after upgrades
07-05-2016, 07:49 PM
#1
Le Mans Master
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Boost gauge not working correctly after upgrades
Just recently had my car installed with LG headers, DeWitt oil, Supercharger and radiator upgrade. I already had a Halltech intake on the car. They also tuned it.....
The boost gauge for the supercharger now reads about -14 or so at idle and will barely crawl above 0 if at all. I need to take it back in on Wednesday. The shop is going to look through the various connections etc.
Anyone have some ideas of where to look? The gauge does respond, it is just way off.......thoughts?
The boost gauge for the supercharger now reads about -14 or so at idle and will barely crawl above 0 if at all. I need to take it back in on Wednesday. The shop is going to look through the various connections etc.
Anyone have some ideas of where to look? The gauge does respond, it is just way off.......thoughts?
07-05-2016, 08:27 PM
#2
Le Mans Master
The boost gauge is driven (through the ECM electronics, of course) by a reading it takes from the MAP sensor. If the connector were off it wouldn't work at all, but it's worth looking to see if it loose or something.
More likely would be a change in the tune that changed it to an incorrect multiple (like 4 bar instead of 3, or however it's set up).
If you have a way to look at your tune, the stock MAP parameters are:
Sensor Config: SC-SCIAP-TIAP
MAP Sensor Linear: 425 kPa
MAP Sensor Offset: -32.50 kPa
If they messed those up, that'd throw the gauge off.
More likely would be a change in the tune that changed it to an incorrect multiple (like 4 bar instead of 3, or however it's set up).
If you have a way to look at your tune, the stock MAP parameters are:
Sensor Config: SC-SCIAP-TIAP
MAP Sensor Linear: 425 kPa
MAP Sensor Offset: -32.50 kPa
If they messed those up, that'd throw the gauge off.
07-05-2016, 08:42 PM
#3
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Throttle is probably closing to limit boost, there is an issue with the tune.
07-05-2016, 09:54 PM
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It happens all the time and is the most common way for the ECM to limit boost, with the throttle blade. Yes, it does feel slower but it's still a lot faster than other cars out there.....
If the MAP sensor calibration was off you would have other driveability issues and probably even CEL.
07-05-2016, 10:01 PM
#6
Le Mans Master
I think what Higgs is talking about is when the motor has been upgraded and now makes more power at a particular RPM than was accounted for in the original config. You get into a situation where actual power exceeds commanded power, so the ECU closes the throttle to bring power "back down" to the commanded amount. So I roughly understand it, anyway.
That would limit boost but you'd still make lots of power (not as much as if it were open all the way, of course).
I can't think of a -why-, but you could just change the linear 425 to 750, for example, and it'd still run reasonably well, but you'd never get far into boost on the gauge. I can see no reason they'd ever monkey with the MAP config though, so it's almost certainly not it.
That would limit boost but you'd still make lots of power (not as much as if it were open all the way, of course).
If the MAP sensor calibration was off you would have other driveability issues and probably even CEL.
07-05-2016, 10:02 PM
#7
Melting Slicks
Your boost gauge is not going to work if you put a different supercharger on. Mine doesn't work with my ProCharger. Tell us your build and numbers man..
Last edited by 2019 ZR1; 07-05-2016 at 10:11 PM.
07-05-2016, 10:05 PM
#8
Le Mans Master
If your boost gauge isn't working with your Procharger, something is broken somewhere methinks....
07-05-2016, 10:06 PM
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07-05-2016, 10:08 PM
#10
Melting Slicks
My shop (Race Proven Motorsports) told me that it will not work when you put a different supercharger in. They did tell me why but I honestly can't remember.. I will find out though..
07-05-2016, 10:20 PM
#13
Melting Slicks
Higgs Boson Are you telling me you have put a aftermarket supercharger on a Z7 Z06 and the boost gauge is working fine?? Again, I just want to make sure exactly what you are saying before I put another video up. I love this ****..
07-05-2016, 10:30 PM
#14
Le Mans Master
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612 rwhp, 635 rwtq
He also changed the upper RPM limit from 6500 to 6800.....thats it....
my graphs from the tune... https://www.corvetteforum.com/forums...no-charts.html
Last edited by firstgear; 07-05-2016 at 10:36 PM.
07-05-2016, 10:30 PM
#15
Le Mans Master
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I will try to get a video of it.....will make more sense what I am talking about....will do that tomorrow.
Last edited by firstgear; 07-05-2016 at 10:33 PM.
07-05-2016, 10:39 PM
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07-05-2016, 10:41 PM
#19
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that is what I am talking about....and its not a matter of it not working at all....it does move.....but when I first start out it is reading close to -10 to -15 on the gauge.....when I give it hell, then I might get a few points, say +1 to +2...give or take.....
I will try to get a video of it.....will make more sense what I am talking about....will do that tomorrow.
I will try to get a video of it.....will make more sense what I am talking about....will do that tomorrow.
You could even just go to autozone and have them scan it and see. clear it if needed and try again. if that doesn't improve the situation then you need to revisit your tuner/installer.