I have been reading a few posts on the board here about accuracy of the stock digital boost gauge when mods have been done. I have a couple of questions hopefully some person or persons can answer correctly. First off how much is 1 bar?, is that 14.5 pounds of boost? Also when is the boost gauge obsolete or should I say what causes it to loose its accuracy? When and why? Thanks

 

well the stock digital boost gauge from what i have read , isnt that greatest !! and 1 bar , is 14.5 lbs.

 

I run the Greddy EBC with digital readout along side the stock gauge, so that I can see both at approximately the same time. In lower boost situations, where the peak is instantaneous, the gauges can be off .2-.3 points, but once the throttle is pinned, they read about the same. The Greddy is more precise and reads to hundredths. For instance, a typical scenario would be the Greddy reads 1.16 bar at steady WOT and the OEM gauge reads 1.2 - From what I have observed, they seem pretty close at the high end. The OEM seems to round upward.

 

I have a giac tune that prototech did a few years ago, with exhaust and I noticed it hits 1 bar at about 40 to 45 hdrd rpms and at about 55 to 6k on up it goes to 1.1 and its steady and reliable according to the gauge as there is no falloff of the boost. One thing I noticed though is sometimes in between shifts I will notice a boost spike of 1.2 or even 1.3 when I am really rowing it! It immediatly goes back to the corresponding boost to rpm reading I was getting before the shift after the shift, meaning if it falls back to 5000 after the shift it will be 1 bar. I notice if I grab a couple of gears and I see spike during the shift and I ease off it after the shift it will go back to the corressponding boost to rpm that I am running. That is what made me start this thread in the first place.
thanks for the info!

 

The stock boost gauge has slow response time. Get one with a sweep dial and even memory/peak function so you can see exactly was is going on.

 

John, not to hi-jack the thread...but where did you mount your boost sensor?
Thanks..

 

Zuma,

The EBC w/ sensor and readout is mounted in the front center console where the CD storage unit was originally. Here are a couple of pictures:

Before install -


Installed -

 

Actually 1 bar is 14.7.

 

John I was looking at your video and noticed you had different rear wheels on your car at the strip, so I assume you had tires on it as well? What tires did you use and are you still all wheel drive?

 

Jamie,

Yes, still AWD. I used BFG R-1 R compound road track slicks. They resulted in worse 60' times than my Michelin Pilot Sports last year! Not good for drag racing :-) I am going to try to get to the track one more time this year with the MPS tires to see if I can crack 10's on street tires. Next season, I plan to try drag radials...and shoot for a best time.

BTW-If anyone would like to buy the BFG R-Compounds, I will sell them cheap. I have no use for them and they are brand new...used for a couple hundred miles.

 

John D,
Thanks for the pix....very nice...for some reason I was expecting a analog dial...but I like your digital!! I am still trying to figure out where to best mount the phyical boost sensor, are you tapping into the existing boost sensor connector or did you drill and tap a new hole and mount a sensor. I didn't see the sensor on the end of the pigtail lead in your photo...Thanks again....very nice.

 

There is a Greddy valve in the engine compartment that replaces the factory valve. A small air line is run from the valve up to the main unit pictured above. I believe the main unit in the cabin measures and displays the boost pressure. Based on what it reads..it tells the valve what to do.

I think the Greddy could also be used as a stand alone boost gauge, without the controller features if plumbed accordingly. It flashes high boost on every pull for 5 seconds and retains the highest boost achieved in memory until cleared. I reset mine every day, sometimes several times a day and then check it periodcally to see what I am hitting for high boost. Here is a picture of the valve...it has the red wire ties on each hose.

 

John D,

Thanks for all the info...your contribution's to this board are greatly appreciated!!

 

I am looking for a gauge that does the functions you mentioned here. sweep dial and memory/peak function. I have not been able to find a gauge like this with a black face.

Does anyone have any ideas of a gauge that would meet these needs?

 

You mean like this...