Here's a strange observation

[rlinbatonrouge]

When I dyno'd I used a Tech 2 for data. I found that boost only hits 12 psi and bleeds off to 10 near redline on the Tech 2 even with the 2.8 and the ported s/c. However, when I hooked up my interceptor, I hit way more boost than that consistently. I'll hit 16-18 psi easily. Anybody know why this is? Both tools are using the same sensor and plug into the OBDII connector. Any guesses?

[NoRemorse]

That is really odd. really really odd. Sorry, no answer for that.

[John]

I believe the tech 2 has the 12 psi max limit programed in bud, it wont show over 12 psi because it was told thats the most your car should be putting out.

[NoRemorse]

Originally Posted by John

I believe the tech 2 has the 12 psi max limit programed in bud, it wont show over 12 psi because it was told thats the most your car should be putting out.

But why would it sink down to 10 then?

[vandy0419]

Originally Posted by John

I believe the tech 2 has the 12 psi max limit programed in bud, it wont show over 12 psi because it was told thats the most your car should be putting out.

First, it reads from the same sensor point...he doesn't type in what kind of car it is and for it to pull up the specs. Second, if it was limited to read only 12psi, then why does it read that it bleeds off to 10psi.

[John]

Originally Posted by vandy0419

First, it reads from the same sensor point...he doesn't type in what kind of car it is and for it to pull up the specs. Second, if it was limited to read only 12psi, then why does it read that it bleeds off to 10psi.

When you use the tech 2 you have to put in the car type year and engine that tells the tech 2 what its working with. The max programed in the tech 2 from gm is 12 psi. the reason it bleeds to 10 is the tech 2 shows a boost decline being that it maxed at 12 it lost 2 psi so it reads 10. Ive already experienced this with a tech 2 and the boost gauge on my car not matching, and doing the same thing he described. the tech 2 does not have open sensor readings It only reads certain values it is programed with.

[rlinbatonrouge]

Originally Posted by John

When you use the tech 2 you have to put in the car type year and engine that tells the tech 2 what its working with. The max programed in the tech 2 from gm is 12 psi. the reason it bleeds to 10 is the tech 2 shows a boost decline being that it maxed at 12 it lost 2 psi so it reads 10. Ive already experienced this with a tech 2 and the boost gauge on my car not matching, and doing the same thing he described. the tech 2 does not have open sensor readings It only reads certain values it is programed with.

That's sort of what I was leaning towards. Are you sure that the max reading on the Tech 2 is 12psi? That just seems odd to me that they would limit a number like that. What if the sensor was out? Seems a good way to diagnose that would be by suddenly seeign 1000000 lbs of boost on the Tech 2. They normally don't limit numbers. I'm not saying that you are wrong but how do you know that they did in this case?

[sheek360]

ill ask supersport4, he has a tech 2 at his shop. Ill ask em around lunch.

[rlinbatonrouge]

Just thinking a little bit more about limiting parameters on the Tech 2 and why that wouldn't be a good idea. Let's say GM limited the reading on an O2 sensor to 800 mV. You could never tell that there was anything wrong with it unless it was reading really really low, and the chk engine light would never go off. I really don't think that they would limit any parameters for that exact reason.

[rlinbatonrouge]

I was told something along the lines of how the interceptor reads the parameters from the OBDII port that the Tech 2 knows how to convert it and the interceptor does not. But that doesn't really make sense because HP Tuners reads correctly. Anyone every use a true mechanical gauge for boost readings and checked it aganist a Tech 2.