EFR 6258 over boost problems
#1
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Hello All
Bit of an introduction. I am new here, and fairly new to Miata's and turbos. Purchased a stock 2003 NB around 2 years ago. Fun car to drive, way down on power for me. I am a child of the 60's , and have built and owned many 60's - 70's muscle cars over the years. Long story short, I decided to add a turbo. Wanted to start with the stock bottom end, and stick to about a 10psi boost limit. Went with the 6258 with .64 AR on a Kraken exhaust manifold and 3" full exhaust. Vibrant intercooler with 2.5 " charge tubes. Deutsch works injectors with an ME221 ECU. Car has a 6 speed with upgraded clutch.
Tried a dyno tune with the way the turbo was delivered, with the medium pressure waste gate boost canister. Turbo made over 20 psi. Waste gate moved freely. and you could watch it move and open up on the dyno pull. Next pull put a manual pressure gauge in line, verified the ECU pressure reading was accurate. Had to order the low pressure canister. Dyno pull part 2. Turbo now makes about 16psi. Put a pressure regulator on the canister, starts to open around 4 psi, all in before 10 psi. Waste gate moves the full 10mm + travel spec for the turbo, waste gate falls open freely when the canister is removed. Took the canister off, with the waste gate fully opened, still made 3-4 psi boost. I am going to open the exhaust before the muffler, and see what the boost is with just a straight pipe after the turbo.
Any help, words of wisdom, advise? I am lost here.
Paul
Bit of an introduction. I am new here, and fairly new to Miata's and turbos. Purchased a stock 2003 NB around 2 years ago. Fun car to drive, way down on power for me. I am a child of the 60's , and have built and owned many 60's - 70's muscle cars over the years. Long story short, I decided to add a turbo. Wanted to start with the stock bottom end, and stick to about a 10psi boost limit. Went with the 6258 with .64 AR on a Kraken exhaust manifold and 3" full exhaust. Vibrant intercooler with 2.5 " charge tubes. Deutsch works injectors with an ME221 ECU. Car has a 6 speed with upgraded clutch.
Tried a dyno tune with the way the turbo was delivered, with the medium pressure waste gate boost canister. Turbo made over 20 psi. Waste gate moved freely. and you could watch it move and open up on the dyno pull. Next pull put a manual pressure gauge in line, verified the ECU pressure reading was accurate. Had to order the low pressure canister. Dyno pull part 2. Turbo now makes about 16psi. Put a pressure regulator on the canister, starts to open around 4 psi, all in before 10 psi. Waste gate moves the full 10mm + travel spec for the turbo, waste gate falls open freely when the canister is removed. Took the canister off, with the waste gate fully opened, still made 3-4 psi boost. I am going to open the exhaust before the muffler, and see what the boost is with just a straight pipe after the turbo.
Any help, words of wisdom, advise? I am lost here.
Paul
#2
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For reference, my 6258 makes 9 psi on waste gate with the medium canister. Do you have the charts from your dyno runs? What kind of power were you seeing?
My head is ported and has oversized valves, so it may not be the best comparison, but you should be seeing less than 20 psi with the medium canister and no EBC. Waste gate preload is a sensitive area for the EFR turbos from my understanding, what was your procedure for that?
My head is ported and has oversized valves, so it may not be the best comparison, but you should be seeing less than 20 psi with the medium canister and no EBC. Waste gate preload is a sensitive area for the EFR turbos from my understanding, what was your procedure for that?
#7
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I live in Lancaster, Ohio. I am a little bit south - east of Columbus. As far as the ME221 goes, it was recommended by the person I bought the turbo "kit" from. The plug and play aspect of it kind of interested me, and he said he could provide support and do the dyno tune. Too early to tell if I made a mistake on that part of the build. The current problem is purely mechanical? I am not running any electronic boost control yet.
#8
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I finally got the chance to pull the muffler off today. It is a Magnaflow, straight through perforated pipe. No way this is causing any exhaust restriction. I can't think of, or find any flaws in the installation. Is there some way this is a bad turbo? I bought it new, it came sealed in the manufactures box. I guess if nobody has any great ideas, it is time to pull the turbo off. What could possibly be wrong with it?
Paul
Paul
#10
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What's your wastegate preload set at? Sounds like it's operating correctly, you should run a little boost with it open. But be careful, if it's disconnected the gate will touch and destroy the turbine wheel.
#11
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I put 2mm (2 turns) of preload on the current boost canister. The guy I bought the parts from is also the dyno tuner that I went to. I was there when they ran it with the waste gate "open", but I do not know what they did to the linkage to accomplish it. I did not hear any awful noises during the dyno pull, so hopefully they did not destroy the turbine.
Paul
Paul
#13
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Few things that come to mind:
- The wastegate actuator position was really picky with the EFR, when installing the wastegate arm needs to move of the wastegate actuator rod without any binding. There was a youtube video about how to adjust this by Trackspeed.
- Did you disconnect the boost solenoid to verify that the ECU is not controlling it?
- Remove the solenoid entirely, just a hose between compressor outlet and wastegate actuator.
- The wastegate actuator position was really picky with the EFR, when installing the wastegate arm needs to move of the wastegate actuator rod without any binding. There was a youtube video about how to adjust this by Trackspeed.
- Did you disconnect the boost solenoid to verify that the ECU is not controlling it?
- Remove the solenoid entirely, just a hose between compressor outlet and wastegate actuator.
#14
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My 6258 on kraken hardware with medium boost canister does 9psi and creeps to 11-12 psi by redline.
20 psi is a lot of boost, careful you will blow your stock motor. 20psi is like 350hp.
Try 1mm preload and make sure the arm is centered and not binding.
20 psi is a lot of boost, careful you will blow your stock motor. 20psi is like 350hp.
Try 1mm preload and make sure the arm is centered and not binding.
#15
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Even though sometimes you think the arm is not binding it really is. It takes a lot of fiddling with the waste gate actuator to actually get it lined up right. For me I could not make over 7psi due to the stock actuator that I had on my EFR 6258. I went ahead and just installed the boost control solenoid and that made a world of difference in control of my spooling for the car. It took some tuning, but was well worth it. Unless you feel like spending the cash on an aftermarket turbosmart actuator that TSE sells or an EBC you will have to fiddle with what you have more.
#16
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A bunch of things have been tried. The electronic boost solenoid has never been in line, only manual boost control. I will list the things that have been tried.
1. First run with the turbo as supplied, medium boost canister with pressure line from turbo housing to the boost canister
2. Verified boost pressure with manual gauge .
3 Switched to pressure line from intake manifold to the boost canister.
4.Moved (bent the bracket) to better align the canister. Dyno guys suggestion. We were out of room to clock the turbo more, charge tubes were hitting.
5. Videoed the movement of the canister rod during a dyno pull to make sure it was opening correctly.
6. Ran the car with the waste gate all the way open, pulled around 3-4 psi boost.
7. Switched to the low boost canister.
Covid intermission
8. I brought the car home.
9. Switched to the super short bracket and boost canister. Re-clocked the turbo to align perfectly. Put pressure regulator on the canister. Canister rod starts to move at 4 psi, all in (10mm travel) at about 7 psi. on the pressure regulator.
I will find the TSE video, to see if I can pick out anything to do differently. Is there anyplace I can send the turbo to have it checked out?
Paul
1. First run with the turbo as supplied, medium boost canister with pressure line from turbo housing to the boost canister
2. Verified boost pressure with manual gauge .
3 Switched to pressure line from intake manifold to the boost canister.
4.Moved (bent the bracket) to better align the canister. Dyno guys suggestion. We were out of room to clock the turbo more, charge tubes were hitting.
5. Videoed the movement of the canister rod during a dyno pull to make sure it was opening correctly.
6. Ran the car with the waste gate all the way open, pulled around 3-4 psi boost.
7. Switched to the low boost canister.
Covid intermission
8. I brought the car home.
9. Switched to the super short bracket and boost canister. Re-clocked the turbo to align perfectly. Put pressure regulator on the canister. Canister rod starts to move at 4 psi, all in (10mm travel) at about 7 psi. on the pressure regulator.
I will find the TSE video, to see if I can pick out anything to do differently. Is there anyplace I can send the turbo to have it checked out?
Paul
#18
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Correct me if i'm wrong.
#19
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Thanks for the TSE video. That is how I set it up, so that variable is out. We were having the over boost problem before the dyno guy switched the boost line to the intake manifold. I was thinking about switching it back just to rule out any leaks in the system. I will put the pressure regulator back on the boost canister to make sure it still works as it should.
Any good place to send the turbo while I have it off to verify there are no issues with it?
Paul
Any good place to send the turbo while I have it off to verify there are no issues with it?
Paul
Last edited by ogasman; 09-01-2020 at 06:03 PM.
#20
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Thanks for the TSE video. That is how I set it up, so that variable is out. We were having the over boost problem before the dyno guy switched the boost line to the intake manifold. I was thinking about switching it back just to rule out any leaks in the. I will put the pressure regulator back on the boost canister to make sure it still works as it should.
Any good place to send the turbo while I have it off to verify there are no issues with it?
Paul
Any good place to send the turbo while I have it off to verify there are no issues with it?
Paul
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