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Hi all, I have a 2011 ZR1 with Kong2650, making 22-23 psi. I keep killing MAP sensors. I've been told the stock computer isn't set to see higher boost levels so it kills the sensors. Have any of you experienced this with a ZR1 and have you found a fix? The car is tuned by Shane at CT Performance and works very well aside from this issue. I've done what Greg @ Kong Performance suggested in HPTuners and still having issues. I know of another driver with same issue so I don't think it's my car related but we could have the same root problem...
22 PSI of boost is the top end of the 255 KPA allowed as a cap in HP Tuners and you probably keep resetting the computer
Two things may be an issue. You may need a higher 4 bar sensor, but you'd also need for HP Tuner to customize your tune to allow for more than the 22-23 pounds of boost your racecar is making. I would think HPT your under Characteristics you can obtain 500 KPA MAP Sensor Linear mark you may need to have HPT write your operating system to allow 500 KPA in your estimated table. That would allow your MAP to see up to about 45 pounds of boost.
A doable yet harder way to trick your computer how it views boost, Is to cut come of your tables in in half which would make the computer think its seeing 11 pounds of boost instead of 22 PSI, and this would give you more resolution in other tables. IF you didn't know what you were doing, it would confuse the heck out of the next car owner wondering why he pushing 22 pounds a boost, yet only getting .70 Grams per cylinder. Thats why it not recommended to do.
See if you can get a higher reading MAP sensor, and have HPT customize your tune to allow more than 255 KPA of boost.
Can you post a log showing KPA? I also have a 2650 and the 2.4 pulley. One day it was fine, flat lining at 255kpa and the next, the Kpa line is spiking downwards and would shoot back up. You can't feel it when driving and you can only see it in the data log. The driveshaft broke shortly after this started happening and it isn't running yet. I replaced the MAP sensor but it is still not back together so I don't know if the problem is fixed.
Do you mind telling me what Greg said to do in the tune?
Can you post a log showing KPA? I also have a 2650 and the 2.4 pulley. One day it was fine, flat lining at 255kpa and the next, the Kpa line is spiking downwards and would shoot back up. You can't feel it when driving and you can only see it in the data log. The driveshaft broke shortly after this started happening and it isn't running yet. I replaced the MAP sensor but it is still not back together so I don't know if the problem is fixed.
Do you mind telling me what Greg said to do in the tune?
I don't have a log of when it happened. I will try to get a log next time I go out to play.
Greg suggested to make sure the "High Voltage Check" is disabled and the P0107 code disabled in HPTuners.
Dave @DSX is helping me with this, we're trying to come up with a solution. He is going to make changes to the definitions in my tune file. Will keep you guys posted!
I don't have a log of when it happened. I will try to get a log next time I go out to play.
Greg suggested to make sure the "High Voltage Check" is disabled and the P0107 code disabled in HPTuners.
Dave @DSX is helping me with this, we're trying to come up with a solution. He is going to make changes to the definitions in my tune file. Will keep you guys posted!
Thanks. I will check my tune. Car is also going to DSX for a new tune since I am changing some things.
For you folks making 22-23 PSI of boost, are you doing this with the stock compression pistons ?
For that much boost, I would think you would want no more than maybe 9 to 1 compression ratio ... I would also think you would most certainly need forged pistons too.
For you folks making 22-23 PSI of boost, are you doing this with the stock compression pistons ?
For that much boost, I would think you would want no more than maybe 9 to 1 compression ratio ... I would also think you would most certainly need forged pistons too.
She loves every bit of it! Very solid set up aside from this MAP Sensor / Gauge issue. I might pulley down over the winter and get about 24 out of it, should be fun for sure!
For you folks making 22-23 PSI of boost, are you doing this with the stock compression pistons ?
For that much boost, I would think you would want no more than maybe 9 to 1 compression ratio ... I would also think you would most certainly need forged pistons too.
Diamond pistons. ~9.5:1 CR. If I had owned the car when the engine was built, I would have aimed for 10.5:1 as I run E85 full time.
She loves every bit of it! Very solid set up aside from this MAP Sensor / Gauge issue. I might pulley down over the winter and get about 24 out of it, should be fun for sure!
So going over 22psi on a 3bar MAP is just always a problem?
Here is a snip it of a data log. You can see the light blue MAP line not keeping up with the WOT green line. I am not seeing any signs of belt dust so I don't think it is slipping. The belt is new and I am running a Kong HD tensioner.
I checked the tune and P0107 is not disabled and the high voltage test is enabled.
Snippets dont help, but see what I was saying about hitting the hard top of 255 KPA. You can override the table to say 355KPA plus. I dont think the OP is killing MAP sensors as much as the tune is reaching the top end of its glass top it has pre-set.
Last edited by phils C5 vette; Sep 28, 2020 at 06:20 PM.
Snippets dont help, but see what I was saying about hitting the hard top of 255 KPA. You can override the table to say 355KPA plus. I dont think the OP is killing MAP sensors as much as the tune is reaching the top end of its glass top it has pre-set.
I posted the snippet to show what the failing(?) map line looked like vs before in case someone else has a datalog showing the same. I was not aware the kpa could be raised passed 255kpa via tweaking HPT. I'll let the tuner (hopefully) fix that once I get it back on the road.
Snippets dont help, but see what I was saying about hitting the hard top of 255 KPA. You can override the table to say 355KPA plus. I dont think the OP is killing MAP sensors as much as the tune is reaching the top end of its glass top it has pre-set.
ZR1 Map Sensor Issues
