Boost Goes Down, Airflow goes up?

[DSM_munky_man]

Alright so I was browsing some logs and found this interesting. How can boost go down thru a 3rd gear pull but airflow still rise? Is it a boost leak? Or is my turbo running out of steam due to not porting? I think I would have the opposite? I never noticed this before, but yesterday I took my evap solinoid off and fuel regulator solenoid too. and my boost came off that. but no I have it hooked to the mani were fpr went and then have a T for one to go to boost gauge and the other to go to the AFPR I have. When I took thel ines off I didnt plug that metal hard line behind/under the intake. Is that my problem? is that even hooked to intake at all? Cause I idle great, no leaks high idle or surge or nothing. here is a pic of it, I cant seem to find the log, idt i saved it, but I took this pic while browsing thru it cause I found it interesting.

Boost is the grey line, airflow is the green dashed and rpm is red dashed.

 

[snowborder714]

No bumping.

Post the actual log. A screenshot doesn't help me at all.

 

[DSM_munky_man]

Sorry about that! ^ for some reason I didnt know that it was a rule for regular threads! for some reason I was thinking that was a rule for for sale threads but i was mistaking!! When I post that I was looking for the log at the time too and was going to post once I found it but I have it now.

Here is a clip of the 2 spots where It happened and you can see good long numbers on it.

 

[snowborder714]

I would do a boost leak test, check how your wastegate and MBC are plumbed, and check your wastegate actuator to see if it's fully opening and staying open.

What boost are you trying to run?

 

[livedsm4g63]

Well of corse your airflow will go up because you will be flowing more as you get into your pull. As your boost going down you may have a leak. Exp. (bov or boost controller)

 

[DSM_munky_man]

Hmmm, guess I will have to put together a BLT, damn.

 

[DSM_munky_man]

Havent done a BLT yet, but did another pull last night and Psi isnt reading the same as on the gauge as link as far as psi wise. But as I did my pull last night I especially watched the gauge, and to my knowledge, psi stayed consistant throughout the 3rd gear pull. So idk what it is doing in link, is this still grounds for a boost leak? I am goign to check it regardless, but putting up some extra info.

 

[delta448]

I get a "Incompatible file version while reading ByteRecord" pop-up when I try to open your log, can someone clue me in on that?

As for boost decreasing and airflow increasing, my best guess right now without seeing the log is that you're running a higher pressure ratio than the turbo can maintain as engine speed increases.

 

[DSM_munky_man]

As for boost decreasing and airflow increasing, my best guess right now without seeing the log is that you're running a higher pressure ratio than the turbo can maintain as engine speed increases.

If you can explain more on this I would appreciate it. I know though that at the psi I am at now, isnt even in the effeciency range of an evo3, That is why i dont get why psi is going down. I will check tos ee if I get that same error when I pull it up and maybe I can figure that out.

Edit: pulls up fine for me. Sounds dumb to ask ,but is it pulling up in the right program?

 

[keviebaby]

When I took thel ines off I didnt plug that metal hard line behind/under the intake. Is that my problem? is that even hooked to intake at all?

Are you talking about the large nipple that connects to the brake booster or the lines connected to the bracket supporting the manifold? I would make sure that all your vacuum lines are connected, do a boost leak test and find out where the leaks are coming from. If there is air coming out of it, fix it.

 

[DSM_munky_man]

Are you talking about the large nipple that connects to the brake booster or the lines connected to the bracket supporting the manifold? I would make sure that all your vacuum lines are connected, do a boost leak test and find out where the leaks are coming from. If there is air coming out of it, fix it.

It must be the lines connected to the bracket supporting the intake mani, Cause they are directly under the mani on the back side of the block/head area. All my vacuums that I disconnected and stuff are accounted for and connected or blocked, besides that metal line mentioned above.

 

[delta448]

If you can explain more on this I would appreciate it. I know though that at the psi I am at now, isnt even in the effeciency range of an evo3, That is why i dont get why psi is going down.

What amount of boost are you tuning at?

Edit: pulls up fine for me. Sounds dumb to ask, but is it pulling up in the right program?

I think I figured it out, I was using ECMLink 3.20.52 before. New version being installed now.

EDIT:
After looking at the log;

Are you assuming boost is dropping by looking at BoostEst?
I'd trust the gauge much more than that calculation...

Definitely BLT it, but I think your problem is in your tuning and not mechanical.

 

[DSM_munky_man]

What amount of boost are you tuning at?

17 according to my gauge.

think I figured it out, I was using ECMLink 3.20.52 before. New version being installed now.

Alright sounds good.

Are you assuming boost is dropping by looking at BoostEst?
I'd trust the gauge much more than that calculation...

Definitely BLT it, but I think your problem is in your tuning and not mechanical.

yes I was patially due to not paying attention to my gauge on that pull, but after I looked at it on yesterdays pull it stayed pretty consistant al lthe way up. I am getting the BLT dropped off here in a bit then will check it. And how come you think it is a tuning problem for boost dropping off?

 

[brian9397gsx]

I have a guess and I could be wrong but it seems as engine speed increases wouldnt the motor become more volumetrically efficient causing boost pressure to go down (because more air is entering the cylinder) and in the same token causing more air to flow? If Im off page I apologise

Which would only make sense if you had no boost leaks. But at 17psi I think this is not your case as my 2g held 19psi to redline on an evo3

 

[DSM_munky_man]

You may have a good theory there, sounds lke it would work to explain it. But the thing I dont get is that my gauge doesnt drop like that. So, anyway, got the tester and bout to head to a buddys to see what it says.

 

[livedsm4g63]

First of all I didn't realize you were looking at boostest. This changes a lot of things. Have you tuned your airflow yet? Boostest should be used to tune your airflow to mimic your true boost (shown on the gauge) Logging with a map sensor is the easiest way to do this. Go to the website. www.jeffgst.com and look under the tabs on the left. You have some catching up to do.

 

[DSM_munky_man]

Alright, got that caught up as to what he has on the calibration of it. Now just need to check it today, Also, when he says adjust it so many % that is over what it is already at correct? Exampl, if mine is at 11.7 and I need to add 17% then I move the slider to 28% adjust for that specific Hz correct? Or does it just need to go to 17% from 11% so a jump of 6%?

 

[livedsm4g63]

You'd move it up to 28 correct.

 

[DSM_munky_man]

alright, did the calibration for it, now it seems like it is more inline with initial boost levels just bout .5-1 psi off, but still tapers off, my boost gauge shows no tapering off. Still an issue I am assuming, just unsure of what it is, tomorrow I am doing the BLT and seeing what it will tell me.