Looking for Help with an SBD 500 Kit that Keeps Overboosting

[Irace86.2.0]

Originally Posted by HellHat

https://www.goosetuned.com/
He's the guy the shop I went to before I moved has been using for their stuff. R35s, STIs, G35/37s. After I moved I scouted the area out and every reputable tuner has a two month waiting list get looked at or they just don't get back to me. So I just stuck with him. The words from him were "The car thinks you are making 21psi out of nowhere"

Well, I have no idea where 21psi is coming from. That is absolute manifold pressure. Atmospheric pressure says 1bar on your upload, so absolute of 1.54bar is 0.54 boost or 7.5psi not 22.3psi. Really basic stuff. Maybe he is reading it wrong or maybe he didn’t scale the limits of the sensor correct. The 3bar map sensor can read 3bar absolute, so up to 2bar of boost or 29.4psi of boost, so even then, why the code? Seems like he needs to fix something on the limits or something that is causing the error/DTC.

Based on your peak mass airflow of 210 g/s, you are also not at 22 psi.

[HellHat]

Originally Posted by Irace86.2.0

Well, I have no idea where 21psi is coming from. That is absolute manifold pressure. Atmospheric pressure says 1bar on your upload, so absolute of 1.54bar is 0.54 boost or 7.5psi not 22.3psi. Really basic stuff. Maybe he is reading it wrong or maybe he didn’t scale the limits of the sensor correct. The 3bar map sensor can read 3bar absolute, so up to 2bar of boost or 29.4psi of boost, so even then, why the code? Seems like he needs to fix something on the limits or something that is causing the error/DTC.

Based on your peak mass airflow of 210 g/s, you are also not at 22 psi.

"I've tuned 100+ of these map sensors, its definitely not the scaling. I actually took a map from a car I just did that has the same setup as you. Your car still did the same thing.... so something is going on"

Is what he said. He seemed pretty sure it was not, in fact, the scaling. I get what you're saying though and it seems like that might be it. Maybe I just need to bite the bullet and get CSG or somebody to take a look at it

[Irace86.2.0]

Originally Posted by HellHat

"I've tuned 100+ of these map sensors, its definitely not the scaling. I actually took a map from a car I just did that has the same setup as you. Your car still did the same thing.... so something is going on"

Is what he said. He seemed pretty sure it was not, in fact, the scaling. I get what you're saying though and it seems like that might be it. Maybe I just need to bite the bullet and get CSG or somebody to take a look at it

Look at this post and Steve's response. Maybe scaling, maybe DTC needs to be removed or limits changed on when it goes off.

https://www.ft86club.com/forums/show....php?p=3171961
https://www.ft86club.com/forums/show...13&postcount=3

Did your tuner have an answer for why he said the car was pushing 21psi? Where is he getting that from? Did he scale in metric/bar and previously it was scaled in psi or something? I'm trying to figure out where he is getting 21psi from. The log you posted never got higher than 7.5psi.

I also really don't understand what you say when you say the car breaks up above 5.5k rpms. Does this happen intermittently, or does it happen all the time with the code and the breaking up? I ask because you went partial throttle in your log up to 7282 and then WOT twice to 6500-6900 rpms with a steady climb in rpms and vehicles speed and with a flat boost curve, so where is the problem?

[HellHat]

Originally Posted by Irace86.2.0

Look at this post and Steve's response. Maybe scaling, maybe DTC needs to be removed or limits changed on when it goes off.

https://www.ft86club.com/forums/show....php?p=3171961
https://www.ft86club.com/forums/show...13&postcount=3

Did your tuner have an answer for why he said the car was pushing 21psi? Where is he getting that from? Did he scale in metric/bar and previously it was scaled in psi or something? I'm trying to figure out where he is getting 21psi from. The log you posted never got higher than 7.5psi.

He hasn't explained where he's getting his numbers from and insists that the scaling isn't the issue. I'm about as confused as you are.

Originally Posted by Irace86.2.0

I also really don't understand what you say when you say the car breaks up above 5.5k rpms. Does this happen intermittently, or does it happen all the time with the code and the breaking up? I ask because you went partial throttle in your log up to 7282 and then WOT twice to 6500-6900 rpms with a steady climb in rpms and vehicles speed and with a flat boost curve, so where is the problem?

That was an issue on the previous tune they were running before we swapped the MAP. It wouldn't be represented on the logs that I posted. The only issue I have now is the P0068 popping up once I hit about 7k. That and while the code is throwing the throttle will cut randomly. I think it only happens when it's under a certain load, but I'm honestly not sure.



Until he gets back to me, I'm kinda dead in the water. He said something about rebuilding the file for a different year, but who knows when that will happen

[Irace86.2.0]

Originally Posted by HellHat

He hasn't explained where he's getting his numbers from and insists that the scaling isn't the issue. I'm about as confused as you are.



That was an issue on the previous tune they were running before we swapped the MAP. It wouldn't be represented on the logs that I posted. The only issue I have now is the P0068 popping up once I hit about 7k. That and while the code is throwing the throttle will cut randomly. I think it only happens when it's under a certain load, but I'm honestly not sure.



Until he gets back to me, I'm kinda dead in the water. He said something about rebuilding the file for a different year, but who knows when that will happen

Well, two things then: have him explain the 21psi thing because that makes no sense from your logs, and it could explain the problem, and maybe try having him disable that DTC or changing the sensitivity or threshold that makes it activate. That could be risky, but it might be necessary to see the problem and to rule out a sensor issue.