Wiring Harness for 3.5 / 5 Bar Map sensor

[2slowvw]

I had a hard time getting my hands on a wiring harness to run the Aem 5 bar map sensor so I can push boost over 30 psi. So I decided to make my own.

If anyone else wants one let me know, I have heard people paying $60 shipped for this, I will make them for $37 and include free Continental US shipping.

Why would you run the 5 bar instead of the 4 bar some people are running? I think Ed does a good job explaining the problem and symptoms.

Now on to the problem with the Bosch 4 bar... I think its the the pressure range rather than the resolution. The little data I've found on it, says it only reads down .5bar (-7.25psi relative vacuum at sea level). This is not enough for a gasoline engine as they tend to idle and operate at low throttle in the -9psi to -12psi range. So this sensor won't work properly when used on the manifold for load/fuel calculation. It'll work fine as a TIP sensor since it doesn't need to measure vacuum there. The AEM 5 bar, for example reads down to 0 bar (-14.7psi relative).

So this explains why some of you are having idle and low throttle drivability issues with the Bosch 4 bar in the intake manifold. There could be software tricks around this by calculating low load based on baro pressure, temperature, and throttle angle, but that's far from ideal. So until we can find a better a P&P 4 bar solution, it seems that the AEM sensor is the best bet.

..........


So I’ve been testing out the 4 bar sensor and there is definitely an issue at very low throttle angles right at the transition to decel. The sensor can’t read the high vacuum properly and results in -34% fuel trims and unstable a/f in that area. The result is a bit of a dead spot in the throttle in that transition as well as slightly jerky on/off throttle transition. This is most noticeable around 2000rpm in the 0-10% throttle range. I could see a lot of people not noticing or being bothered by the resulting drivability issue, but its not correct regardless. I’ve been able to smooth out the transition some with some tuning tricks, but at the end of the day, it’s just masking a real deficiency. For those talking about UM cars, I’ve only had one such car on my dyno, but that car also had a hard stutter at that spot, so I don’t think there’s anything too different going on.

FWIW, we’re at sea level and this issue would likely be much less prevalent or even cured at higher elevations. Maybe the folks reporting no issues are just at high enough elevations to get back into range of this sensor.

Thanks
— Ed

Includes:
All 3 connectors
Pinned and waterproofed
Length is 12inches long.

*A TUNE IS REQUIRED BY YOUR TUNER TO RUN A 5BAR MAP SENSOR*

 

[iTsLiKeAnEgG]

Good stuff, I may be reaching out for these.

 

[2slowvw]

Good stuff, I may be reaching out for these.

Awesome. Pm is the best way to reach me. I have 10 total ready now. If I get more orders I'll make more.

 

[nate704]

Subscribed!!
I will be reaching out to you when I'm ready to go!

 

[2slowvw]

All orders should have a tracking number sent to your email now except if you are a UK based Turbo company, you will get a tracking number this afternoon.



Thanks everyone!

 

[2slowvw]

Here are some snippets by ED @ EQT as to why the 4 bar is not ideal and i will update the first post also.

Now on to the problem with the Bosch 4 bar... I think its the the pressure range rather than the resolution. The little data I've found on it, says it only reads down .5bar (-7.25psi relative vacuum at sea level). This is not enough for a gasoline engine as they tend to idle and operate at low throttle in the -9psi to -12psi range. So this sensor won't work properly when used on the manifold for load/fuel calculation. It'll work fine as a TIP sensor since it doesn't need to measure vacuum there. The AEM 5 bar, for example reads down to 0 bar (-14.7psi relative).

So this explains why some of you are having idle and low throttle drivability issues with the Bosch 4 bar in the intake manifold. There could be software tricks around this by calculating low load based on baro pressure, temperature, and throttle angle, but that's far from ideal. So until we can find a better a P&P 4 bar solution, it seems that the AEM sensor is the best bet.

..........


So I’ve been testing out the 4 bar sensor and there is definitely an issue at very low throttle angles right at the transition to decel. The sensor can’t read the high vacuum properly and results in -34% fuel trims and unstable a/f in that area. The result is a bit of a dead spot in the throttle in that transition as well as slightly jerky on/off throttle transition. This is most noticeable around 2000rpm in the 0-10% throttle range. I could see a lot of people not noticing or being bothered by the resulting drivability issue, but its not correct regardless. I’ve been able to smooth out the transition some with some tuning tricks, but at the end of the day, it’s just masking a real deficiency. For those talking about UM cars, I’ve only had one such car on my dyno, but that car also had a hard stutter at that spot, so I don’t think there’s anything too different going on.

FWIW, we’re at sea level and this issue would likely be much less prevalent or even cured at higher elevations. Maybe the folks reporting no issues are just at high enough elevations to get back into range of this sensor.

Thanks
— Ed

 

[2slowvw]

Since Cobb Mpi has been rolling out I have received an influx of orders and requests on showing how I have mine installed. Below is a picture to give everyone an idea of how to install their setup.

 

[iTsLiKeAnEgG]

Received mine to prep for the E85 tune on built engine, feels well made

 

[2slowvw]

Just an update everyone. I changed out some of the material at the top so it is no longer automotive electrical tape to being all thick heat shrink at the connectors. It is a cleaner look. This coupled with supplies being harder to come by, I have to unfortunately raise the price to $37. Anyone who has messaged me over the past month when I was out of stock, message me back if I didn't hit you up already.



Thanks!

 

[Slowr16]

Can I get one plz I’m and how do I pay