Overshooting commanded boost targets

[nattypiso]

I've been experiencing this problem, and I can't seem to figure out why. The car tuned to about 24 PSI target boost. When I was recording a datalog, doing a WOT pull starting at 3rd gear 2k rpm’s, all the way up to 4th gear redline, I noticed I am slightly overshooting the target when looking at the datalog. It happens slightly at around 3k rpm’s (3rd gear), and 5.2k rpms (4th gear) and the car hits peak 26 PSI then tapering down to 23 PSI at redline.

My car is full bolt on and I haven't gotten a CEL for over boosting yet, but have been staying away from aggressive pulls ever since. I have conducted a smoke/pressure test for any leaks past my MAF sensor and everything is fine, no visual smoke coming out anywhere. All vacuum lines are connected properly, charge pipe worm clamps are tight and no leaks in Intercooler gaskets. Is there something that I am overlooking? I've been scratching my head for the past three weeks over this 2-3 psi over target.

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[Jester04]

Have you discussed with your tuner? Boost targets aren’t necessarily tuned towards- it’s a torque target, and the tune utilizes as much boost necessary to hit that torque target.

This^ boost targets and timing will vary depending on conditions. But chat with your tuner.

 

[nattypiso]

Have you discussed with your tuner? Boost targets aren’t necessarily tuned towards- it’s a torque target, and the tune utilizes as much boost necessary to hit that torque target.

This^ boost targets and timing will vary depending on conditions. But chat with your tuner.

Yes, I have talked with him and also sent datalogs for review. He said that "The issue is not related to our tune. You will see the same result on any other tune".

He also stated that the condition I am experiencing is a possible air leak, or a faulty Wastegate actuator but I have already diagnosed it with a smoke machine and no leaks found. I also checked my wastegate/wastegate command and is showing nothing out of tolerance.. at least from what I can see from the datalogs. Which leaves me to where I'm at now lol.

 

[Jester04]

Yes, I have talked with him and also sent datalogs for review. He said that "The issue is not related to our tune. You will see the same result on any other tune".

He also stated that the condition I am experiencing is a possible air leak, or a faulty Wastegate actuator but I have already diagnosed it with a smoke machine and no leaks found. I also checked my wastegate/wastegate command and is showing nothing out of tolerance.. at least from what I can see from the datalogs. Which leaves me to where I'm at now lol.

Honestly that answer really surprises me, these cars are torque based and never shoot for a static boost command. Some days it will boost a bit more than others. A wastegate failure is not very common and there would be severe overboosting if it fails to operate within it’s confines.

 

[nattypiso]

Honestly that answer really surprises me, these cars are torque based and never shoot for a static boost command. Some days it will boost a bit more than others. A wastegate failure is not very common and there would be overboosting if it’s failure to operate within it’s confines.

I'm not doubting the guy and the info he told me, because he's been in the game for a long time and is very well regarded in the tuning community. But I wanted to post on here and get second opinions/knowledge from others. Because I've diagnosed everything that he mentioned and I'm still experiencing a slight over boost. It's not dangerously high, but slightly enough to have me worried and annoyed as this is my daily driver.

And yes, my wastegate is still functioning. I verified that via sensors window in FP manager. WG is matching WGCMD and I don't see anything out of the ordinary, but I could be wrong.

 

[Jester04]

I'm not doubting the guy and the info he told me, because he's been in the game for a long time and is very well regarded in the tuning community. But I wanted to post on here and get second opinions/knowledge from others. Because I've diagnosed everything that he mentioned and I'm still experiencing a slight over boost. It's not dangerously high, but slightly enough to have me worried and annoyed as this is my daily driver.

And yes, my wastegate is still functioning. I verified that via sensors window in FP manager. WG is matching WGCMD and I don't see anything out of the ordinary, but I could be wrong.

Well it will be really hard to help you without any logs or data. Honestly I think there is nothing wrong with the car. These cars normally hit 26psi when tuned. And depending on the tuning approach the boost can be dynamic.

 

[nattypiso]

Well it will be really hard to help you without any logs or data. Honestly I think there is nothing wrong with the car. These cars normally hit 26psi when tuned. And depending on the tuning approach the boost can be dynamic.

Much appreciated for the reassurance and info! I'm uneducated of the limits of the OEM turbo. Despite being tuned, I honestly felt that hitting up to 26 PSI was bad because I remember reading somewhere that the factory tune originally limits boost at around 23 PSI, and that contributed to me being paranoid about slightly over boosting.

I do have datalogs of my WOT pull, cruising around town and highway cruising. If you'd like to glance over it. Maybe you'll find something that my tuner couldn't? it's always good to have a different set of eyes.

 

[Jester04]

Much appreciated for the reassurance and info! I'm uneducated of the limits of the OEM turbo. Despite being tuned, I honestly felt that hitting up to 26 PSI was bad because I remember reading somewhere that the factory tune originally limits boost at around 23 PSI, and that contributed to me being paranoid about slightly over boosting.

I do have datalogs of my WOT pull, cruising around town and highway cruising. If you'd like to glance over it. Maybe you'll find something that my tuner couldn't? it's always good to have a different set of eyes.

Just went over them, everything looks on point. Even on the boost spike the fuel pump quickly recovers and I saw 0 issues so you have nothing to worry about.

 

[nattypiso]

Just went over them, everything looks on point. Even on the boost spike the fuel pump quickly recovers and I saw 0 issues so you have nothing to worry about.

Much appreciated for going over my datalogs! as well as the extra knowledge in regard to boost/torque targets. Gave me extra peace of mind today.

 

[Jester04]

Much appreciated for going over my datalogs! as well as the extra knowledge in regard to boost/torque targets. Gave me extra peace of mind today.

Glad to help! Any other questions feel free to reach out. But tune looks good! Happy WOT.

 

[nattypiso]

Glad to help! Any other questions feel free to reach out. But tune looks good! Happy WOT.

Thank you! I actually do have another question in regard to supporting mods.

I have a drop in turbo (R660) just collecting dust in my garage.. haven’t installed it yet because I will be sending it back to RV6 so I can upgrade to their Anti-surge housing / inlet pipe elbow that's in development (currently at revision 3), supposedly details will be released in a month or two if their testing goes well.

But while I am waiting for their Anti-Surge Housing, I’m looking to get supporting mods for the turbo in the meantime, what would you recommend or what is needed? Is there a specific order on what to get first? (given that money is not a problem). I will be sticking to 93 Octane, but I also have access E85 available as well. I know you’re able to run FBO, Aftermarket Turbo and stock fuel system, but I also know that the turbo won’t run at it’s full potential going that route. I want to avoid that and make everything efficient as possible so nothing is working too hard.

 

[Jester04]

Thank you! I actually do have another question in regard to supporting mods.

I have a drop in turbo (R660) just collecting dust in my garage.. haven’t installed it yet because I will be sending it back to RV6 so I can upgrade to their Anti-surge housing / inlet pipe elbow that's in development (currently at revision 3), supposedly details will be released in a month or two if their testing goes well.

But while I am waiting for their Anti-Surge Housing, I’m looking to get supporting mods for the turbo in the meantime, what would you recommend or what is needed? Is there a specific order on what to get first? (given that money is not a problem). I will be sticking to 93 Octane, but I also have access E85 available as well. I know you’re able to run FBO, Aftermarket Turbo and stock fuel system, but I also know that the turbo won’t run at it’s full potential going that route. I want to avoid that and make everything efficient as possible so nothing is working too hard.

If you want to maximize the potential of that setup an upgraded High pressure fuel pump will be needed along with a modded fuel line and bigger injectors.

I have tuned people and even my setup on stock fuel system. But I really was able to push my setup with a upgraded fuel pump. You can use Hondata or the XDI system whichever you prefer.

 

[Jester04]

Thank you! I actually do have another question in regard to supporting mods.

I have a drop in turbo (R660) just collecting dust in my garage.. haven’t installed it yet because I will be sending it back to RV6 so I can upgrade to their Anti-surge housing / inlet pipe elbow that's in development (currently at revision 3), supposedly details will be released in a month or two if their testing goes well.

But while I am waiting for their Anti-Surge Housing, I’m looking to get supporting mods for the turbo in the meantime, what would you recommend or what is needed? Is there a specific order on what to get first? (given that money is not a problem). I will be sticking to 93 Octane, but I also have access E85 available as well. I know you’re able to run FBO, Aftermarket Turbo and stock fuel system, but I also know that the turbo won’t run at it’s full potential going that route. I want to avoid that and make everything efficient as possible so nothing is working too hard.

I am currently tuning another member here with a bigger turbo with a stock fuel system and the results are very promising.

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