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100% for sure I am not on the Tephra ROM/maps. I will finally have some time tonight to do some more data logs with my new laptop. After I see how that goes, that will help see what my next plan of action is.
Well I think I figured out my issue. My old laptop was indeed very very very slow at logging. So slow that it did not log half as much as my new laptop. Now that logging is under control and working how it should, I found the issue.
Boost cut issue - Not a boost leak. Not the solenoid freaking out. Boost cut is indeed cutting boost because of the load. My old laptop said I was hitting 255 load max. New laptop says I am hitting 280.3 load. Boost cut is set to 270 load. Problem? Yes indeed. Glad to see it works though.
I still have it set to 0 correction for the boost curve and it looks perfect. Peaks at 23 and tapers to 18 at redline. I got some knock counts up top but now that the logging is working how it should, it will be easy to take care of.
Awesome to hear you got it sorted! Once you mentioned the laptop being old/slow, a red flag went up right away. Funny: I recently had the same problem (automatic Windows updates slows my laptop to a crawl). Then you brought your lap top and I was thinking, *ding**ding* winna winna
Well I thought I got it all figured out. But back to the drawing board. Made all my changes in the tune, loaded in the new cal, took it for a spin and still boost cut.
The log shows that right at 220 load, 5500 rpm and 19.3 psi, it cuts boost down to 7.7 psi by 6500 rpm.
Where to go from here? I though that there should be no way for it to make less then the spring pressure on the wastegate which if I am correct is 14 psi? If this is true, there are 2 possibilities that come to my mind. Most obvious, a boost leak. Another possibility, could the BOV be opening up? Looks like I will be sticking my head under the hood tonight to see if I can find anything obvious.
"Boost cut" is a misnomer. It's not actually cutting boost. I believe it's fuel that gets cut (?). RPM drops, then boost follows. Sounds normal to me unless I'm misunderstanding.
If the DV was giving you grief, it would have opened during your boost leak test
So boost cut is fuel, not actual boost getting cut.... great thats not what is happening then. My boost is literally getting cut from 19 down to 7ish and will stay at 7 unless I shift. The more I do logs, the more it seems its rpm related then anything. Right at the magical 5500 number. That could be why I cant get it to do it in 4th, 5th or 6th. I havent been to 5500 rpm in 4th or higher.
Alright then, I am going to start eliminating things one at a time.
Step 1 - Bypass the WG solenoid. Rig up the MBC in place. This will eliminate the ECU/tune from the equation.
Step 2 - If it still does it, I am going to pressurize all the boost lines, check for leaks and verify that the WG and DV are working as intended.
Step 3 - If no problem is found yet, another boost leak test up to 25 psi. Fun....
After getting the boost set with the MBC, I went out testing. Same issue. It seems better but still does it. It does it worse the more I raise the boost. Conclusion - not a tune/solenoid issue. More testing to come.
Last edited by Lumpy Sticks; Oct 17, 2018 at 08:27 PM.
If the turbo was toast, I should be seeing smoke out the exhaust. No way the wheels would hit the housing without leaking. When I had one of the charge pipes off a couple days ago, it was dry inside as well.
It honestly sounds like the wastegate is opening on its own. Maybe I will see if I can mount the Gopro down there to see if it really is opening.
My MAP turbo didn't smoke when it died. I only found out it was broken when I rechecked shaft play. That sucker was brand new, too. WGA opening too soon is a definite possibility. For some reason I thought you had checked that already. If not, definitely do so! Hopefully that's it. That would definitely explain things.
I talked to Tuning Technologies in hopes to get some answers. They said there should be no way that A - I am hitting the boost numbers I am at with the stock solenoid/stock pill and B - There should be no way boost drops to 7 psi. Not good news.
I have not checked the WG yet so I will do that tonight. I already talked to Turbosmart and they are out of stock on the WG if I need a new one but will be in stock next week. Ohh the joys of car modding.
If I end up doing another boost leak check, I will take a look at the turbo while I am down there.
Oct 17, 2018, 11:20 AM
