busa

Well after doing some reading(mostly on DTR) I have learned that the Edge Juice with Attitude and your factory MAP sensor does not give you accurate boost readings, well atleast in my case. I was worried about my max boost reading of 40 psi, I cranked my adjustable waste-gate rod all the way and it did not change. I was concerned that actual boost might be higher(and I was right) because I still have factory headbolts. I deciced to get a mechanical Autometer Boost gauge. Installed it today and the Edge is a consistent 5-7psi low above 10 psi!!! So the Edge would read 10 psi but I was actually at 15 psi. No big deal right,,,,,,,,,,, but when the Edge was at 40psi I was really at a scary 46-48psi So if your running stock head bolts and your Edge is reading 40psi you may want to invest in a real gauge

Bjans

After reading the post form the other day it got me wondering. I think the adrenaline reads boost off the map sensor like the edge does and it goes up to 57 that ive seen so its not the map sensor that cant read that high.

busa

Some people say that the MAP only reads to 40psi and others say 60psi, so who nows,,,,,,,,,,, I must have the 40psi one

dropped2500

But you also have to realize that any mechanical gauge is better than a electronic one.

busa

Thats why I did it. Hey, I've got an 88 'Stang and it runs mid 12's too! A little spray and my best is 11.5@ 127mph

dropped2500

Yea if i can ever quit messing with this darn diesel i could build the rear end in mine and put a driveshaft loop in and spray it on slicks. Should go 11's easy! Ive got a 3/4 full bottle sitting here in my room going to waste. Darn trucks why do diesels have to be so much fun?

CamperAndy

Not even close to true. Any device can have error but there is no reason to believe the mechanical gauge over the MAP without test against a calibrated source.

dropped2500

yes but mechanical has less margin for error as it is moved by whatever the gauge is for, ie. boost gauge is ran from air pressure coming out if the intake. Oil pressure is ran by oil being shot threw a line into the gauge. And so on... But electrical gauge runs off ohms 9 times out of ten and ohms all depend on wire size, wires not being broken from inside the sensor to the wire to the gauge..

dropped2500

And yes everything does have a down side but electrical has more of a down side

qzilla

That is so far from true it is not funny.

Yes, there are some antique, 100% mechanical gauges out there. The problem is that the parts (sweeper motors) have huge margins of error built into them.

For that reason most of the "analog" gauges you see end up being electrical because they are more accurate. I am not talking about digital as that imply refers to what the user sees, not how the product is working.

Most of the newer boost gauges use an electronic pressure sensor that basically senses the pressure via a diaphram and then submits and electronic signal. This is both considerably more responsive and more accurate than a true 100% mechanical gauge.

Now, it is not the idea but, the parts that are available that make the mechanical gauges less accurate. Just like a resistor, you can buy in 1% tolerance or 10% tolerance. The problem is that the mechanical stuff is typically only available in one tolerance and it is just not that good.

The difference in an electric "analog" gauge and a "digital" gauge is the response time and margin of error the sweeper motors have, versus printing it on a display. You can literally print info on a digital display 100 times a second if you want to. No one could read it but, it can be updated that fast. With the analog you are stuck with response time and tolerane of a stepper motor.

Now, like anything else a manufacturer can make stuff as accurate as they want, or they can get it close and call it good.

To say that electronic stuff is not good or safe is sort of silly since you entire engine is dependant upon these types of sensors. I don't care what your boost gauge says, if your map sensor was truly a piece of junk then you have real problems. Just because you see "real" data with your gauge does not mean the engine is going to respond to anything but, the junky old electronic sensor. If they are faulty they are going to break something.

All of the Bosch MAP sensors we have ever looked at are 100 times more accurate and hold tighter tolerances than ANY analog gauge on the market. They are not some junky little sensor.

busa

Good info qzilla(maybe a little biased though), but I will look to the side of caution and be trusting the higher readings of the two, the mechanical gauge. Especially beacause I am walking the fine line of trying to make a stock head gasket live.

stuckey200224

my head must have been welded on. i still have stock head bolts on the original stock head gasket and have never even retorqued it. and i can peg a 60lb guage.

busa

Arn't you the least bit woried about making a huge oily mess under you hood if that gasket fails?? I know I am so I'm going to adjust the waste-gate for around 45psi, but it seems most people have better luck with just about everything then me

busa

I know what you mean, you know you have issues when your 7000# everyday driver truck has more HP then your hotrod

qzilla

No, I agree with you. I am not saying ALL electronic gauges are accurate. I was not referring to specific manufacturers or specific gauges, I was talking about how they work from a manufacturing standpoint.

A lot of people think if it has a needle it is 100% mechanical and that is just not true.

Now, why your Edge only reads 40psi is a little beyond me, although I have a good idea as I went through this in beta testing with the Adrenaline. I never really had any complaints about it reading only 40psi but, I knew it was wrong so I fixed it.

My guess is that is slipped through the cracks or they figured for 99% of the people a 40psi gauge was plenty??