Boost problems??
11-18-2021, 11:06 PM
#1
Boost problems??
I have a 2018 C4S. With the Oem tune, the power band and the way the turbo spools is very Linear/Na like. Low boost at low rpm ramping up to 16 psi at the upper rev range.
I recently got an Apr tune and it brings full boost on much earlier in the rev range and totally transformed the car. It’s been several months and I’ve recently gotten an oil change. 3 weeks later I just noticed my car now drives like Oem again?? I had an Indy shop do the oil change. Did they somehow reset my ecu?? Or is my car getting vacuum leak or what?? Maybe a winter thing?
It drives fine. Zero cel or codes. Just boost at low rpm on full throttle on any gear is limited to like 6psi then at 5500+ then it will start to ramp up to full spool again… it feels neutered..
vacuum leak, waste gate not opening, hose issues somewhere??
Anyone run into this issue? I’m gonna have the tune redone tomorrow to see if it’s a tune issue… if after and it’s still acting this way then I know it’s something mechanical.
I recently got an Apr tune and it brings full boost on much earlier in the rev range and totally transformed the car. It’s been several months and I’ve recently gotten an oil change. 3 weeks later I just noticed my car now drives like Oem again?? I had an Indy shop do the oil change. Did they somehow reset my ecu?? Or is my car getting vacuum leak or what?? Maybe a winter thing?
It drives fine. Zero cel or codes. Just boost at low rpm on full throttle on any gear is limited to like 6psi then at 5500+ then it will start to ramp up to full spool again… it feels neutered..
vacuum leak, waste gate not opening, hose issues somewhere??
Anyone run into this issue? I’m gonna have the tune redone tomorrow to see if it’s a tune issue… if after and it’s still acting this way then I know it’s something mechanical.
Last edited by 18 991 C4S whoo; 11-18-2021 at 11:18 PM. Reason: Added info
11-19-2021, 12:06 AM
#2
RL Community Team
Rennlist Member
Rennlist Member
call them and ask. if I had to guess, they knocked something loose. it's extremely unlikely they have a piwis and did an ecu update.
11-19-2021, 10:15 AM
#3
Rennlist Member
I have a 2018 C4S. With the Oem tune, the power band and the way the turbo spools is very Linear/Na like. Low boost at low rpm ramping up to 16 psi at the upper rev range.
I recently got an Apr tune and it brings full boost on much earlier in the rev range and totally transformed the car. It’s been several months and I’ve recently gotten an oil change. 3 weeks later I just noticed my car now drives like Oem again?? I had an Indy shop do the oil change. Did they somehow reset my ecu?? Or is my car getting vacuum leak or what?? Maybe a winter thing?
It drives fine. Zero cel or codes. Just boost at low rpm on full throttle on any gear is limited to like 6psi then at 5500+ then it will start to ramp up to full spool again… it feels neutered..
vacuum leak, waste gate not opening, hose issues somewhere??
Anyone run into this issue? I’m gonna have the tune redone tomorrow to see if it’s a tune issue… if after and it’s still acting this way then I know it’s something mechanical.
I recently got an Apr tune and it brings full boost on much earlier in the rev range and totally transformed the car. It’s been several months and I’ve recently gotten an oil change. 3 weeks later I just noticed my car now drives like Oem again?? I had an Indy shop do the oil change. Did they somehow reset my ecu?? Or is my car getting vacuum leak or what?? Maybe a winter thing?
It drives fine. Zero cel or codes. Just boost at low rpm on full throttle on any gear is limited to like 6psi then at 5500+ then it will start to ramp up to full spool again… it feels neutered..
vacuum leak, waste gate not opening, hose issues somewhere??
Anyone run into this issue? I’m gonna have the tune redone tomorrow to see if it’s a tune issue… if after and it’s still acting this way then I know it’s something mechanical.
Last edited by blackcheetah; 11-19-2021 at 10:17 AM.
11-19-2021, 11:04 AM
#4
Former Vendor
ECU will compensate for air density/temp, but that sounds outside of that realm; you're way more than a few psi off.
You say the boost characteristics changed 3 weeks after the oil change? I would take it in, or inspect the area around the oil filter for line that has come loose.
You say the boost characteristics changed 3 weeks after the oil change? I would take it in, or inspect the area around the oil filter for line that has come loose.
11-19-2021, 02:50 PM
#5
11-19-2021, 09:41 PM
#6
Case closed
Thanks for all the replies.
I had the Apr tune re uploaded today and it fixed the issues I was having and by issues, I mean no tune at all. What I was experiencing was simply the car on Base map. I believe the car was reverted back to the Oem tune by the shop that did my oil change. They must have the Piwis to do so…they did reset my service reminders and must have resetted the whole dam thing. Either that or the Apr tune somehow can revert back to the base tune which I doubt.
It just shows me how much different the car feels when tuned. Full boost and torque at 3-4k rpm is much more desirable for city driving. Base maps will not go over 6psi max before 5500 no matter what gear or how far down the throttle is and ramps up to 16psi by 8000rpm. I was studying 991.2 S base map dyno charts and the torque curve at 2-5k rpm is flat as those flat earth believers. Artificially flat…. I know Porsche intended the power band to be that way to preserve high strung Motorsport feel of their Na motors they replaced. Anyways issue is resolved!
I had the Apr tune re uploaded today and it fixed the issues I was having and by issues, I mean no tune at all. What I was experiencing was simply the car on Base map. I believe the car was reverted back to the Oem tune by the shop that did my oil change. They must have the Piwis to do so…they did reset my service reminders and must have resetted the whole dam thing. Either that or the Apr tune somehow can revert back to the base tune which I doubt.
It just shows me how much different the car feels when tuned. Full boost and torque at 3-4k rpm is much more desirable for city driving. Base maps will not go over 6psi max before 5500 no matter what gear or how far down the throttle is and ramps up to 16psi by 8000rpm. I was studying 991.2 S base map dyno charts and the torque curve at 2-5k rpm is flat as those flat earth believers. Artificially flat…. I know Porsche intended the power band to be that way to preserve high strung Motorsport feel of their Na motors they replaced. Anyways issue is resolved!
11-19-2021, 09:45 PM
#7
Rennlist Member
Thanks for all the replies.
I had the Apr tune re uploaded today and it fixed the issues I was having and by issues, I mean no tune at all. What I was experiencing was simply the car on Base map. I believe the car was reverted back to the Oem tune by the shop that did my oil change. They must have the Piwis to do so…they did reset my service reminders and must have resetted the whole dam thing. Either that or the Apr tune somehow can revert back to the base tune which I doubt.
It just shows me how much different the car feels when tuned. Full boost and torque at 3-4k rpm is much more desirable for city driving. Base maps will not go over 6psi max before 5500 no matter what gear or how far down the throttle is and ramps up to 16psi by 8000rpm. I was studying 991.2 S base map dyno charts and the torque curve at 2-5k rpm is flat as those flat earth believers. Artificially flat…. I know Porsche intended the power band to be that way to preserve high strung Motorsport feel of their Na motors they replaced. Anyways issue is resolved!
I had the Apr tune re uploaded today and it fixed the issues I was having and by issues, I mean no tune at all. What I was experiencing was simply the car on Base map. I believe the car was reverted back to the Oem tune by the shop that did my oil change. They must have the Piwis to do so…they did reset my service reminders and must have resetted the whole dam thing. Either that or the Apr tune somehow can revert back to the base tune which I doubt.
It just shows me how much different the car feels when tuned. Full boost and torque at 3-4k rpm is much more desirable for city driving. Base maps will not go over 6psi max before 5500 no matter what gear or how far down the throttle is and ramps up to 16psi by 8000rpm. I was studying 991.2 S base map dyno charts and the torque curve at 2-5k rpm is flat as those flat earth believers. Artificially flat…. I know Porsche intended the power band to be that way to preserve high strung Motorsport feel of their Na motors they replaced. Anyways issue is resolved!
Last edited by blackcheetah; 11-19-2021 at 09:47 PM.