What is the next upgrade?
- Thread starter NoGuru
- Start date
If the wastegates dont have the right amount of pre load once exhaust pressure reaches a certain point it can push them open.
Not sure what else mechanically could cause them to fall at a certain rpm
Not sure what else mechanically could cause them to fall at a certain rpm
I just grabbed another log to hit the gas in 2nd and the leak happen at 4972 RPM again around 17psi.
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This is completely incorrect for the stock vacuum controlled wastegate system. Tony did testing on this about 6-7 years ago, at only 15 in/hg it took more force to pull the gate open than a 30 psi boost control spring. At 25 in/hg which they see it maxed the strain gauge before moving it. The Vaccum systems do not work like a boost controlled system, and gate blow open is a non-factor.
Alright then, fair enough. So what could cause this if the only difference between properly functioning boost control is a turbo swap and no leaks are present?
Thoughts?
I would like to know as well as I am having the same issue with brand new upgraded turbos. Here is a log: https://datazap.me/u/rnmevo9/ng?log=0&data=3-22
Slow335is
Specialist
For all those who have heard about or are running Dynamicautowerx turbos. Here is their fb page where you can get more info about them and can place orders and ask questions and more. Please feel free to leave a review if you have bought a product as well.
Thanks. Looks like a real company making real products to me.For all those who have heard about or are running Dynamicautowerx turbos. Here is their fb page where you can get more info about them and can place orders and ask questions and more. Please feel free to leave a review if you have bought a product as well.
Dont stock frame turbos see 2 and 3 to one pressure ratios ? I thought I remembered reading how the gc turbos reduce exhaust pressure from very high levels so at 20 psi on stock people can have 60psi pushing on wastegate?
Stock turbos can produce 2.5-3:1 EBP but our strain gauge is 75+PSI. It maxed out before it budged the gate. Meaning unless you are approaching 80-90psi EBP you are not pushing that vacuum canister open. That is on stock turbos. GC have much less back pressure in the 1.5-2:1 range. So even at 30 psi, you are at 45-60psi well below pushing the gates open. Again testing we did going on 6 years ago. We are still the ONLY company to this day to run EBT or shaft speed sensors on stock frame N54 turbos to really see what was going on.
I just knew that it was alot better with the gcs when tested and that it's not common for people to be aware of. Now if old boost solenoids or leaky connections would that be issue or no ?
Also If compressor over speeds could it literally start losing grip on the air and slip so essentially cavitates like a prop running to fast ? I just cant understand why the boost falls off so fast usually when it is running out of turbo it's not so drastic.
I just thought of a way to test this if target 15 psi and see if it holds that to redline that could pinpoint a turbo issue right.
@NoGuru , how does the synapse BOV mount? My tial had a boost leak when the o-ring was left out inadvertently. Everything appeared fine on stock turbos, but once I did my MMPs, I had a boost leak at 15psi. I would have figured that missing o-ring would contribute to maybe a 5 psi loss, but not limit to 15psi no matter what, which was crazy. I know they did a smoke test to 20psi but might be worth a double check. I couldn't even pressure test mine past 15 psi because the inlets wouldn't hold past that, but they aren't designed to see boost anyways.
I have been having this issue ever since I put in bigger turbos on my car December of last year. Originally, I bought a set of used rb next gens to replace my perfectly working stock turbos. I took logs and noticed that I never held boost at higher rpms. I did smoke tests, pressure tests (by several different indy bmw shops), changed out my bov spring, boost solenoids, new vacuum lines, and even took it back to the guy who I had bought the turbos from to double check the installation as he went from rb next gens 15t to single turbo on his N54. Everything came back as if there was no leaks despite what my logs said.
One day, we (guy who sold and installed the turbos) were logging on the highway and the rear turbo shaft had snapped and there was lots of smoke coming out of the tail pipe. So maybe it was bad turbos that needed to be rebuilt you would think? I sent them back to Rob (excellent communication) for analysis and had them upgraded to next gen plus 17t. This took several months and again, had the guy put in the turbos in for me as he felt partially responsible for what had happened.
Fast forward to this day and I am still having the same issue on brand new, rebuilt turbos. Sorry for the long rant, but I felt like I needed to explain what I have been going through the past 10 months as it has not been easy (financially and mentally dealing with this). I am still not ready to throw in the towel as I want to tackle this issue and stick with my N54 for the next few years.
Edit: I also want to mention that I had an indy shop perform a compression test on the motor when I got my turbos rebuilt and all cylinders came back in the 180s.
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I think it is a vband but I haven't uninstalled that in a some time. Good call though, I will pull it and check all the connections.
I can tell you I was holding about 20psi before the new Turbos went in.
