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MAP sensor upgrade

Klrider44

Go Kart Champion
Location
Bucks county PA
So I understand that to run more than 29lbs of boost you need to upgrade the MAP sensor. When searching for the sensor I see a few aftermarket kits that have 2 sensors and a harness. I have also seen a genuine Bosch 4 bar MAP sensor. Do I need 2 MAP sensors and a harness? Looking for some advice.
 

Klrider44

Go Kart Champion
Location
Bucks county PA
Right now stratified, but I will most likely be switching to EQT once I get the vortex turbo. Just trying to get all my supporting mods together before the turbo goes in and I can just have it pro tuned once. I’ll be limited to 93 octane. So I am looking to upgrade the HPFP and the MAP sensors.
 

rammer80

Passed Driver's Ed
Location
Dallas,TX
Bosch 4 bar in the PUT location, AEM 5 bar with boost tap and harness for the MAP location.

No other solution works properly.

GREAT NEWS! I just bought the PR 4bar map kit. It better work!
 

PacDawg

Drag Race Newbie
Location
Gilroy, CA

PacDawg

Drag Race Newbie
Location
Gilroy, CA
GREAT NEWS! I just bought the PR 4bar map kit. It better work!

Yeah that is not the best solution. Its best to get an AEM 3.5 or 5 Bar for top MAP location.
 

Hoon

Autocross Champion
Location
Rhode Island
GREAT NEWS! I just bought the PR 4bar map kit. It better work!
If the Bosch sensor they use has the standard Bosch 4 bar range it's a half assed solution.

The Bosch 4 bar was intended for diesel applications, it doesn't read low enough vacuum to accurately calculate fueling at idle and very low throttle input, which causes drivability issues. It's fine in the PUT location because no vacuum exists there, but should not be used in the MAP location.

If they're using a different Bosch sensor than the standard VW one (which it appears they are because of the adapter harness) it might read low enough to capture the full range.
 

Hoon

Autocross Champion
Location
Rhode Island
Reason I asked is because Ed doesn't care for just the low PUT sensor being 4 bar due to drivability issues. So don't complain about that if you don't like it or get the 3.5/5bar combo which he will probably point you to.

This is a long explanation, but the short answer is there is no drivability issue with just the 4 bar PUT.

PUT is used for boost control and MAP is fueling. It's fine to have them on different scales, but above 29psi you're depending on the lambda controller to add fuel in because the sensor can't see the actual boost. Above 31-32 psi it can be a problem and the ECU can freak out.
 

PacDawg

Drag Race Newbie
Location
Gilroy, CA
Reason I asked is because Ed doesn't care for just the low PUT sensor being 4 bar due to drivability issues. So don't complain about that if you don't like it or get the 3.5/5bar combo which he will probably point you to.

EQT tuned SugarMouth's setup with just the 4 bar PUT and I haven't heard of issues with it.
 

rammer80

Passed Driver's Ed
Location
Dallas,TX
Well my tuner Sneekytuned recommended the PR4bar kit, so I guess he’s had success with it. i guess I will find out.
 

Diggs24

Autocross Champion
Location
de plains! de plains!
Car(s)
2015 GTI
This is a long explanation, but the short answer is there is no drivability issue with just the 4 bar PUT.

PUT is used for boost control and MAP is fueling. It's fine to have them on different scales, but above 29psi you're depending on the lambda controller to add fuel in because the sensor can't see the actual boost. Above 31-32 psi it can be a problem and the ECU can freak out.

Ahhh, so this is why I have lambda issues when it goes over 29psi? I assumed it was due to lack of injector and overshooting e85 but I never feel anything. it just goes lean and the ecu deosn't seem to try to compensate.
 

PacDawg

Drag Race Newbie
Location
Gilroy, CA
I believe he said it had to do with elevation. Near sealevel it was causing issues. I think Sugar mouth is 4k+? I also don't have issues but am at 1k. Or if i do they are so subtle I don't notice.

He was tuned at EQT which is sea level but yeah I think he lives in Reno which the elevation is like 4.5k.
 
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