I was just wondering if anyone with the GM 3 bar sensors has had a problem with the zzp lower charge pipe? If you have them, you know that they rotate the sensor slightly to make the plug clear a pipe that runs down just beside the charge pipe and this apparently throws off the inlet temps by 12-15 degrees. I know that it has to be this rotation that skews the readings because I put the stock pipe back on and it returned the inlet temps to ambient when driving. I also double checked by reinstalling the ZZP lower pipe and it instantly went back to the 12-15 degree difference when driving. Nothing against ZZP, I love the upper pipe and the intercooler but I think that the lower may need a revision. Just a cautionary tale for anyone with a GM stage tune or someone just looking to replace the sensors. I spoke with Clear Image Automotive and they keep the sensors in the stock location and stock orientation. Not sure if it maters but I got the ZZP lower charge pipe that doesn't relocate the MAF sensor.

 

Good to know. I've been thinking about getting their pipes. Guess I'll skip their lower one. I like their upper one more than the other options out there.

 

Sounds like a boost /vac leak to me. I have the lower ZZP pipe and relocated my MAF next to the MAP sensor and my IAT's are within 1* of each other now that the sensors are a few inches apart. IAT1 is from the MAF.

Did you relocate the MAF or seal off the space? You may have a leak at the block off plate?

No issues with my ZZP lower CP for miles and miles. Great product IMO.

 

I have the lower pipe without MAF relocation so there is no block off plate just the hole for the MAP sensor. Your readings are accurate because you have the stock sensors, I have the sensors from my GM stage kit and they have a different plug that is a little longer so ZZP rotates the sensor mounting hole for clearance and it is this rotation that skews the readings. I do however love the upper pipe and intercooler.

 

Sorry, I have the GMPP 3 bar sensors, mods in profile. No issues here. It's a pressure sensor, angle in the pipe won't affect it. If it were a flow device then alignment would matter. Now if you didn't get a proper seal on it, that's a different story. I have the Bosch GMPP sensors, pigtails & Performance Autowerks o-rings, all from 'Werks.

 

Is there even any point in replacing the lower pipe? Has there been a single documented failure of that pipe? I like that it's a poor thermal conductor.

 

I replaced mine because after 2 midwest winters and high boost pressures the rubber hose ends were swollen and starting to crack. I did the MAF relocate at the same time to keep from having to retune every intake modification. My intake is MAFless.

I still have the stock IC so I figure that'll go sometime. 49k miles on it now.

 

I'm running the ZZP lower charge tube with MAF relocate. My IAT1 and IAT2 are also within a couple degrees of each other any time I check. The temp sensor is just a basic thermocouple. It does not require any special clocking.

 

This is a picture of mine before I put the stock lower pipe back on. It shows that mine rotates the sensor and has different placement of both the vacuum and the TMAP than the ZZP pipewith the MAF relocation. Was wondering if yours rotates it like this. I was going to try to mount it in the other hole that is for the stock sensor because that is the only thing that I can think to do.

 

This is a picture of mine before I put the stock lower pipe back on. It shows that mine rotates the sensor and has different placement of both the vacuum and the TMAP than the ZZP pipewith the MAF relocation. Was wondering if yours rotates it like this. I was going to try to mount it in the other hole that is for the stock sensor because that is the only thing that I can think to do.[/QUOTE]

Like the other poster said..it's not a FLOW sensor, so orientation shouldn't effect the readings. It may not be seated properly though.

Like the other poster said..it's not a FLOW sensor, so orientation shouldn't effect the readings. It may not be seated properly though.

 

OP - Perhaps the boss on the bottom of the sensor was never trimmed off per the instructions and it wouldn't sit flush? The GMPP install pdf specifies to trim it so it sits flush and seals properly. Mine was aready trimmed off for the stock CP so I don't know if it would matter on the ZZP pipe.

 

The ZZP tube does not require any modification to the sensor.

I was thinking about this a little more and the reasoning is actually pretty obvious. The ZZP tube mounts the sensor closer to the motor, which should by all means affect the reading when airflow is low. As airflow increases, the readings will be much closer to what they would be if you measured in the bottom section of the tube. Anyone who logs IAT2 on a supercharged LSJ setup will be familiar with this. When cruising, the IAT2s(measured in the intake manifold) are significantly affected by engine temps. When you go WOT, the IAT2s actually go down. It's just a difference in where you measure.

 

Thanks for all the input from everyone. I agree that it should raise the temp because how close it is to the motor but at 70+mph the temps don't go down they stay somewhere between 12-20 degrees higher than ambient, I also tried WOT with the same results. If the sensor had a leak would that account for a rise in temps? I thought that I might try to silicone the bottom of the sensor and then reinstall the ZZP pipe in the hope that it was just a leak.