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Old 09-13-2013, 01:40 PM   #1
sc00ter
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Default Boost gauge that reads directly from ECU?

I've tried running a couple electronic boost gauges but even after maxing out the altitude calibration (which is around 5200ft elevation) the electronic gauges read 2-4psi low, especially when I'm up near 8000-9000ft, which happens often.

To remedy this I've been using a mechanical boost gauge instead. However, the issue is that I have quite a bit of wastegate flutter with the VF48 pro tuned at 19psi. This fluttering causes my mechanical gauge to fluctuate rapidly from about 15psi - 19psi making it damn near impossible to get an accurate reading at WOT. The datalogs from my Accessport show that everything is fine. I'm hitting target boost of 19psi and steadily dropping to about 16.5psi at red line with absolutely no hesitation or stuttering.

In an effort to get a more accurate and consistent boost gauge reading, I had someone tell me there are gauges that read directly from the ECU. I think in my case this would be the best solution. Does anyone have any recommendations on one? Or possibly other suggestions to remedy my problem.
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Old 09-13-2013, 02:33 PM   #2
jthatch12
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Rom Raider or Cobb AP
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Old 09-13-2013, 03:05 PM   #3
sc00ter
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Quote:
Originally Posted by jthatch12 View Post
Rom Raider or Cobb AP
Yeah, I've got the COBB Accessport already and don't really make use of it. Maybe I should just use that as my constant boost gauge. I just hate having to bring it out to the car and plug it in every time I need to drive.
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Old 09-13-2013, 03:57 PM   #4
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Quote:
Originally Posted by sc00ter View Post

Yeah, I've got the COBB Accessport already and don't really make use of it. Maybe I should just use that as my constant boost gauge. I just hate having to bring it out to the car and plug it in every time I need to drive.
The access port v3 has a nice mount and on off feature so you can just leave it in the car
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Old 09-13-2013, 04:01 PM   #5
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Quote:
Originally Posted by Razgeiz View Post
The access port v3 has a nice mount and on off feature so you can just leave it in the car
Dammit! I was hoping I wouldn't be able to find a reason to justify upgrading to the v3 but you just ruined that for me.

Looks like I'll be ordering one this weekend and selling my AP v2, boost gauge, and SMY gauge mount.
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Old 09-13-2013, 04:16 PM   #6
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Why not just make your own mount for the v2? You can even relocate your OBD-II port so it will be super clean. Should be a fun, cheap project.
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Old 09-13-2013, 04:17 PM   #7
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Quote:
Originally Posted by sc00ter View Post
I've tried running a couple electronic boost gauges but even after maxing out the altitude calibration (which is around 5200ft elevation) the electronic gauges read 2-4psi low, especially when I'm up near 8000-9000ft, which happens often.

To remedy this I've been using a mechanical boost gauge instead. However, the issue is that I have quite a bit of wastegate flutter with the VF48 pro tuned at 19psi. This fluttering causes my mechanical gauge to fluctuate rapidly from about 15psi - 19psi making it damn near impossible to get an accurate reading at WOT. The datalogs from my Accessport show that everything is fine. I'm hitting target boost of 19psi and steadily dropping to about 16.5psi at red line with absolutely no hesitation or stuttering.

In an effort to get a more accurate and consistent boost gauge reading, I had someone tell me there are gauges that read directly from the ECU. I think in my case this would be the best solution. Does anyone have any recommendations on one? Or possibly other suggestions to remedy my problem.
What are you using for the boost source?
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Old 09-15-2013, 11:26 AM   #8
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You can also use a liquid filled gauge to help lessen the oscillations. If that's not enough try a pulsation damper too.
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Old 09-15-2013, 11:51 AM   #9
teiva-boy
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Any obd logging system should work fine, very very simple to find on the web. Most people dont want to use the ecu as they fear its inaccurate or slow to react. The AP is a good solution, but probably not my preffered "permanent," solution.
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Old 09-15-2013, 11:59 AM   #10
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Quote:
Originally Posted by Psychoreo View Post

What are you using for the boost source?
This

If the ecu is reading stable boost but the gauge isn't its probably more about where you have the gauge tapped into
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Old 09-15-2013, 12:05 PM   #11
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Quote:
Originally Posted by cowboy_Rob View Post

This

If the ecu is reading stable boost but the gauge isn't its probably more about where you have the gauge tapped into
I'd bet dollars to donuts he's using something on/near the wastegate circuit as a boost source, hence the massive oscillations.
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Old 09-16-2013, 01:33 PM   #12
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Do you have a Garmin GPS? (thats EcoRoute HD capable)

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Old 09-16-2013, 05:14 PM   #13
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I' am scared to leave my AP in the car. When i use it i plug it in and pug it out and take it with me inside. If someone got into your car and stole that it will be a messy situation. You will have a married ecu to a device you no longer have. There are ways to reverse it but it is a hassle with an expense.. My food for thought..

Edit: A few Coloradans in here hope you guys made it through the flooding OK. My mechanical boost gauge sits below zero when off but when it is running it is accurate with the cobb ap. I used to live in steamboat and it was the same story. Maybe try a different company? I guess i don't have flutter to deal with so my response might be irrelevant..

Last edited by 02rex11; 09-16-2013 at 09:15 PM.
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Old 09-16-2013, 09:23 PM   #14
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If you have a mechanical boost gauge hooked up properly and it's bouncing from 15-19psi you are either going over bumps, listening to music really loud or there is something wrong. The mechanical gauge has a much higher sampling rate than the sensors available to the ecu, what you see on it is actually happening.
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Old 09-16-2013, 09:39 PM   #15
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I use the Android Torque app and a cheap bluetooth OBD2 scanner
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Old 09-16-2013, 10:06 PM   #16
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Quote:
Originally Posted by point78 View Post
Do you have a Garmin GPS? (thats EcoRoute HD capable)
That is cool, how does it work?
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Old 09-17-2013, 12:53 PM   #17
point78
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Quote:
That is cool, how does it work?
Garmin sells a bluetooth thing that plugs into the OBD2 port. It links up with the GPS, and you can set it to display a few different things, read/reset engine codes, etc.

It will calculate/track your MPG's pretty close too.
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Old 10-08-2013, 04:48 AM   #18
evil03mustang
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Quote:
Originally Posted by sc00ter View Post
I've been using a mechanical boost gauge instead. However, the issue is that I have quite a bit of wastegate flutter with the VF48 pro tuned at 19psi. This fluttering causes my mechanical gauge to fluctuate rapidly from about 15psi - 19psi making it damn near impossible to get an accurate reading at WOT.
Have you tried installing an orifice [boost pill] into your sensing line? If you've got any old turbos lying around, you should have a handful of those orifices. I've read many places that sticking a restrictor orifice in the line smooths out the needle bounce.
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Old 10-08-2013, 02:50 PM   #19
nmlittlebigman
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^^^ This^^^ without one your needle will oscillate. Also like Psychoreo and cowboy_Rob reference the ideal place to tap into is the bpv actuator hose.
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