Bosch 0281002845 3-bar MAP/IAT specifications

[steelmesh]

I swapped in a 3-bar MAP/IAT on the E67. I took the MAF IAT input and wired this to this new MAP sensor. The IAT calibration in HPT for the E67 shows resistance vs. temperature.

I found conflicting information on the IAT scaling, the vendor source says it is resistance and MoTeC says it's voltage based. The vendor spec also mentions something about a 1k ohm resistor in series. Any ideas here?

Vendor source: https://www.bmotorsports.com/shop/pr...oducts_id/1721

MoTeC source: https://www.motec.com.au/filedownload.php/?docid=5134

[Slowbalt2000]

I never changed my IAT calibration when I started using the LNF 3 bar sensor. It seems to be reading pretty accurately.

[steelmesh]

I never changed my IAT calibration when I started using the LNF 3 bar sensor. It seems to be reading pretty accurately.

Thanks for the input! I was questioning it because the E67 IAT scale was quite a bit different than the vendor provided IAT. When I manually entered the new IAT scale that was provided it wasn't working right. When I went back to the E67 scale it "seemed" to be working but I am not completely convinced of it yet just being cautious here about my assumptions.

[Slowbalt2000]

You could create your own scaling if you really wanted to. Ive done it before at work. We froze some ATF down to -35 and stuck the sensor in, then recorded the voltage/resistance as the temperature increased. Then we used a hot plate to heat the fluid to make the process quicker and get the higher end of the scale.

[steelmesh]

You could create your own scaling if you really wanted to. Ive done it before at work. We froze some ATF down to -35 and stuck the sensor in, then recorded the voltage/resistance as the temperature increased. Then we used a hot plate to heat the fluid to make the process quicker and get the higher end of the scale.

Kinda along the lines of what I was thinking, basically pull the sensor and take points compared to an external TC (figured water would be close enough and sensor safe). If my scaling happens to be incorrect or offset, that could explain the [Same Boost with Less Airflow] characteristic of the Twincharger setup.

[Slowbalt2000]

I could send you the values I use for MAP scaling. I dont think the IAT scaling is causing your lack of airflow. It seems that you lowered the turbocharger pressure ratio and thats what is causing it.

[steelmesh]

I could send you the values I use for MAP scaling. I dont think the IAT scaling is causing your lack of airflow. It seems that you lowered the turbocharger pressure ratio and thats what is causing it.

Send It!

I didn't explicitly say IAT caused low air flow ahaha, I implied if the IAT reading is incorrect (as in reading low) it could explain a lower airflow at a given boost level. My current understanding is that 1 cubic ft of 20C air at 25 psi is much more dense then 1 cubic ft of 70C air at 25 psi.