Boost guage compared to enginuity
Posted: Sun Nov 18, 2007 7:32 pm
So my boost guage hit about 24 PSI and enginuity read a max of 22.20 PSI, which is right? The parameter in enginuity I logged was manifold pressure, corrected.
Guage is tapped on the BOV, I assume the ECU gets it from the Manifold tap. I will check both next time, corrected vs uncorrected. Thanks for the response.zaxrex wrote:Where did you tap for the pressure guage? Where is the engine receiving pressure information from? If they are in different locations, then there can be some differences.
You say your software is showing "corrected" pressure, what parameters and calculations is the ECU using to "correct" the pressure?
Try switching the mode to uncorrected and see if it then matches your gauge. If it jumps up by ~14 PSI, then all it is doing is subtracting "atmospheric" pressure from the total pressure. This will give you a reading of the pressure above atmospheric withing the manifold.
Nice hanging out with you for sure, next time you can come visit us in VA.Forevapmp wrote:in for pics........
well I've seen them in person......
It was nice hangin out with ya'll...
Bryan, I still think it's a boost leak somewhere.....
-20, Vacuum. The sensors are reading from different places so that could account for it. But 3 PSI is about what it would be off... hmmgsx-lex wrote:I've seen mechanical gauges that have been of by as much as 3 psi! I'm not very familiar with enginuity stuff, but I will always trust a map sensor over a mechanical gauge. What does your enginuity gauge read when the car is off (log it with ignition on but car turned off).
Oops I'll check next time I go out there. Currently trying to hook up thisSabre wrote:Alex meant when the car isn't running at all. -20 mmHg is definitely with the engine on at idle
FYI, my hydra reads about 3PSI below my mechanical guage tells me.
aka
Mechnical = 21PSI
Hydra = 18PSI
and they are T'ed off of the same connection!
Yep, it will be off, but by a constantPhibs wrote:With a CAT in my DP I know the reading will be off, but will it be off by some reliable constant?
Sweet. I have the unit powered and calibrated. If anyone wants to help tomorrow @ the meet we can take it for a logging runSabre wrote:Yep, it will be off, but by a constantPhibs wrote:With a CAT in my DP I know the reading will be off, but will it be off by some reliable constant?Easy way to fix that:
At idle, you'll probably see 14.7AFR's in Enginuity and 15.7AFR's (for instance) at the wideband. You can then just subtract 1 from the WB and you'll get your actuals. There is the problem that as the gas velocity increases, the cat will not be as efficent and will vary a little. I don't think that little bit is much to be worried about though.