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Discussion Starter · #1 ·
I installed my new Dash Hawk today. I love it. I am trying to figure out the meening of BOOST? At idle, the DH reads -4.5, is this right? What does this mean and why do we need to whatch it?
 

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I don't know,but you have my truck...
 

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Discussion Starter · #3 ·

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Your boost is a reading in pounds per square inch of fuel pressure. I don't know if -4.5 is normal, but obviously the more you lay into the gas peddle, the higher your boost increases.
 

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Discussion Starter · #5 ·
Your boost is a reading in pounds per square inch of fuel pressure. I don't know if -4.5 is normal, but obviously the more you lay into the gas peddle, the higher your boost increases.
Well,,,I am getting some low #'s. -4.5 at idle, and the # doesn't increase very fast. I don't think it got over 8 when I got on it. I will play a little tomorrow.
 

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8 sounds normal, getting on it some. You want to see around 5-7 during normal operation.
 

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Discussion Starter · #7 ·
8 sounds normal, getting on it some. You want to see around 5-7 during normal operation.
Yeah, I will, tomorrow we will see what it does.


I do have a pretty good lag from a standing start. I wounder if its related?
Any one think -4.5 at idle is something to worry about?
 

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I have the edge insight and it reads .4 lbs at idle and goes into the 20's when I hammer on it.
 

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Your boost is a reading in pounds per square inch of fuel pressure. I don't know if -4.5 is normal, but obviously the more you lay into the gas peddle, the higher your boost increases.

Not fuel pressure but air pressure. The gauge should read 0 at idle because no boost is required or needed. Then when you slam on it it will go up into the 20s on a stock motor and into the 30s on a modded tuner motor. When you get up to a steady speed, it should read 0 again.
 

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What version of the firmware are you running? You should be running 2.3 or higher on the DH firmware. My boost sits around 0.1-0.3 when idle. I've seen that sucker up in the 20's when I put the hammer down. Negative numbers don't sound right.
 

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I installed my new Dash Hawk today. I love it. I am trying to figure out the meening of BOOST? At idle, the DH reads -4.5, is this right? What does this mean and why do we need to whatch it?
Reading -4.5 psi at idle isn't normal. Actually any negative number isn't normal. Should be zero boost at idle then goes positive numbers (pressure) as the turbo winds up. A turbo can't produce negative numbers or it would be a vacuum pump. It could be the Dash Hawk is defective or the sensor is bad. I would suspect the DH is no good. If the boost pressure sensor is bad it will set a CEL code.
 

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Discussion Starter · #12 ·
Thanks guys for the replies.

Just got home and this is what I have. Yes, the DH does read 0 at idle or there abouts. Yes it does go well into the 20's when I romp on it, (stock right not). So all is fine.

My DH is the newest version I downloaded yesterday me thinks 2.3 something. This thing monitors a lot of data.

Other then boost and a few other things what are some of you guys monitoring?

Also, any info on the probe yet?

Again thanks for the replies.
 

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Discussion Starter · #13 ·
Reading -4.5 psi at idle isn't normal. Actually any negative number isn't normal. Should be zero boost at idle then goes positive numbers (pressure) as the turbo winds up. A turbo can't produce negative numbers or it would be a vacuum pump. It could be the Dash Hawk is defective or the sensor is bad. I would suspect the DH is no good. If the boost pressure sensor is bad it will set a CEL code.

Ya, I didn't think so. Today it did not run neg nunbers. It might bounce neg just for a second, but for the most part it was around 0. I will watch this and see what happens. I only drove to and from work so I will give it more time. Trying to figure out why I saw -4.5 yesterday. I will keep you posted.
 

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Thanks guys for the replies.

Just got home and this is what I have. Yes, the DH does read 0 at idle or there abouts. Yes it does go well into the 20's when I romp on it, (stock right not). So all is fine.

My DH is the newest version I downloaded yesterday me thinks 2.3 something. This thing monitors a lot of data.

Other then boost and a few other things what are some of you guys monitoring?

Also, any info on the probe yet?

Again thanks for the replies.
I'm still waiting on the probe also. I configured all 11 displays but the most I monitor is RPM, EGT1, Boost, and Fuel pressure. My other displays show EGT1, EGT2, Soot mass, and Regen Status. I have another display configured with RPM, GPH, MPG, and MPH, but since the GPH and MPG aren't showing correct readings, yet, I don't monitor that screen much. I have another screen configured with temps, another one configured with pressures, etc...I'm still tweaking my configs.
Hopefully they'll have the GPH and MPG stuff corrected in the next release. I find the DH useful with the DPF/Regen stuff. I can tell, with certainty, when it's in Regen. I can use the soot mass readings to guesstimate when it's about to regen. Well, anyways, I find it useful. :D

-Ronnie
 

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Discussion Starter · #15 ·
I'm still waiting on the probe also. I configured all 11 displays but the most I monitor is RPM, EGT1, Boost, and Fuel pressure. My other displays show EGT1, EGT2, Soot mass, and Regen Status. I have another display configured with RPM, GPH, MPG, and MPH, but since the GPH and MPG aren't showing correct readings, yet, I don't monitor that screen much. I have another screen configured with temps, another one configured with pressures, etc...I'm still tweaking my configs.
Hopefully they'll have the GPH and MPG stuff corrected in the next release. I find the DH useful with the DPF/Regen stuff. I can tell, with certainty, when it's in Regen. I can use the soot mass readings to guesstimate when it's about to regen. Well, anyways, I find it useful. :D

-Ronnie
Ya, I still have a few things to figure out also. I have things set up the same way as you. Temps, fuel related, pressures, ect, ect.

Also looking forward to the next release. :D
 

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I don't have a dpf anymore so don't use any of the egt readings from pre and aft dpf. I am sure you guys know that these readings are no good for using as a tool for safe engine operation. In order to have useful egt readings will need to wait for the add on thermocoupler which will need to be drilled into the exhaust manifold. I talked to xtreme diesel, who I ordered my Insight from, and they were expecting to get the theromocoupler on the 28th and then ship them out. Anyway, love the Insights look and features. I was never a fan of the look of pillar mounted gauges.
Later,
****
 

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Discussion Starter · #17 ·
FYI
Here is what I did wrong!!!!!

I set the DH to display Vac/Boost. This is the wrong parameter. Last night I set it up to display both - Boost (Under "GM specific - Sensors - Boost") and Boost/Vac (Under "air").

Boost ==== 0.1 at idle.
Boost / Vac ==== neg 0.1 to neg 4.6.

I did not know these where different. Now I do!
 

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glad to hear you figured out

0 at idle , 20 on it stock floored , about 5 - 8 cruising speed and 32 max on most hot tunes out there floored.

Any more psi than 32 psi on stock turbo is inefficient. The vanes close so much they become restrictive and reduce flow. Actually 29 - 31 psi max is what showed to be best on dyno for stock turbo. On my hot tunes Im at 32 psi. The boost is built into tuner now. Before I used ppe's boost controller and loved it . Set it at 29-31 max.

Gasuout
 

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Negative numbers don't sound right.
I've been running turbos in gassers for over 20 years... In a gasser, the negative boost is simply reflecting the engine's intake vacuum while at idle, and then as accurately stated above, boost pressure should be right around 0 at cruise and of course higher according to your right foot.

It was always my understanding, though, that diesels don't actually create intake vacuum, which is why our brake boosters are hydroboost instead of vacuum operated booster. So, I don't understand why a diesel boost gauge would show negative..

Any thoughts?
 
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