You had the Mbc set up correctly the first time for over boost issue( two t’s and some vacuum line in line with the line the comes off the charge pipe to the n75 then from the waste gate line to the n75) also boost leaks will cause boost fluctuations. Do yourself a favor and ditch the splitter valve they tend to leak and go with a forge or oem diverter valve
Hey man this might be too late for ya but that is very common for the ko4 to taper down in psi in higher rpm. They will spike then drop slightly and then hold pressure. Also it will probably build more consistent and higher psi boost in the winter because the air is denser I belive?
Hey what’s up. I do have a second video with a better boost controller that did a much better job. But yes it did taper a bit. What my brother was the huge fluctuations I was getting at the time.
I have a mk4 1.8t and u can def go down a rabbit hole of bad info seaching forums for pretty much anything on these cars weather its whats the correct spark plug gap or brand of spark plugs to what kind of oil to put in the transmission and of course anything related to turbo upgrades
Got that right. Unfortunately the people who know the answers are just tired of constantly answering the same questions every day so we have to rely on the search function. And the information that’s valuable so saturated with information that’s not valuable that we just don’t know what direction to go in.
@@trojangpete8 Yea I had two of the videos and wanted to show how these manual controllers can help. I did plan a wastegate video I just ran out of time and never had the chance to finish the editing.
My mk4 GTI is making the same damn problems and I can’t figure it out once you figure it out if really like to see those videos!! I’ve been searching forums and tried everything they all say something different
Hi thank you for commenting. Yeah the only problem with this engine is it was producing higher boost numbers previously. I have a couple other videos coming out showing the path I take to get the boost back I appreciate you checking this video out. I wanted to try and help people who have the same issue as I found online it seems common. Have you ever tried running a N 75J valve?
@@davesworld2132 i’m still on stock n75 and it’s fine but obviously tapers as i get higher in the rpm range. i’ve heard they really don’t matter because the tune tells the n75 what to request for boost based off throttle percentage and it’s all on the waste gate. i’ve seen people crank the waste gate with spring mods and such to get them to hold boost longer but all i’ve read says that these turbos aren’t all that efficient making high pressures in higher rpms i’m looking to go bigger in the near future and take apart this block
@@josephfinder5472 def helpful. Another I’m leaning toward a wastegate issue. And possibly changing over to an N75J Btw what are you running for a boost gauge?
@@davesworld2132 New south performance boost gauge. mounted on my steering column looks oem and i love it. even lights blue and red with the light switch at night. got it used for $50 and it’s mint
Also that boost issue u are havin could be caused by the diverter valve located close to the n75 pancake lookin thing they have a rubber diaphragm that fails when u run higher boost somtimes even stock boost will make it fail just because of high heat in the engine bay and crappy german plastics u can take it off and make a adapter to hook up to the boost side of the valve and put 20 psi of compressed air and see if it holds my guess to what is causing ur boost issue and if that checks out then i would try adjusting the spring pressure at the waste gate actuator on the turbo i bought a cheap ko4 off of Amazon and it barley had any spring pressure out of the box compared to the stock ko3
You know that’s not a bad idea. I changed a lot of the plastic parts because they were dry rotted and leaking oil but I couldn’t find a new pancake and that’s the original one. Thanks for the tip that’s actually very helpful.
@@kenphillips479 Thank you that’s very good to hear I’ve spent a lot of time editing and filming. I have a lot more coming out on this car that I thought would be helpful and fun to see. Thank you.
Yes Later in the video I run it in line. And show the results I have another video coming out showing a different type of wastegate controller and I do the same testing with that one as well.
Oh I thought you ran in in line from boost source to the n75 I was wondering if you ran it from the n75 to the wastegate basically applying less boost to the waste gate keeping it closed longer and open less
@@hobosandwhich Oh I see what you mean. My thought process was before the N75 because it operates based on pressure. I was trying to control when it opened and closed. I assume if we ran it after we may run into an issue where it will open and close but the control over the wastegate might be finicky. I would assume you can run into an issue where the wastegate has the open and maybe it can’t.
@@hobosandwhich lol like your style! Currently the 3 port which I highly recommend is on the car. After doing hours of research it seems like that’s the best way to go. I also realized after the fact there’s a way to modify this boost controller to work like a three port. But there around the same price and it was pointless to do so lol just buy the correct one
Turbo cars have both typically. A wastegate and a diverter. This car normally would have one in the intake but it was swapped out to a atmospheric style blow off valve.
Hi what’s up. I have another one coming out wed. And about 8-12 more planned for Nov-March. I made sure to have a lot of footage filmed so I can keep videos coming for you guys.
Here is a link to the entire K04 big turbo swap playlist on this Jetta from day one. ua-cam.com/play/PLqg4B1XxTlKJIvfi2m35scal1zC5APzGl.html
your videos help me out a bunch man thank you
That’s awesome to hear!!!! Thank you for letting me know.
Smart Same issue I rock with you champ!!!
Great response!
I wanted to do this on my TDI but learnt it'll only control turbo spikes. I might throw one on when I get a pd150 turbo.
You had the Mbc set up correctly the first time for over boost issue( two t’s and some vacuum line in line with the line the comes off the charge pipe to the n75 then from the waste gate line to the n75) also boost leaks will cause boost fluctuations. Do yourself a favor and ditch the splitter valve they tend to leak and go with a forge or oem diverter valve
Good morning how are you? I actually ended up filming a follow up video using that forge valve with much better results.
Hey man this might be too late for ya but that is very common for the ko4 to taper down in psi in higher rpm. They will spike then drop slightly and then hold pressure. Also it will probably build more consistent and higher psi boost in the winter because the air is denser I belive?
Hey what’s up. I do have a second video with a better boost controller that did a much better job. But yes it did taper a bit. What my brother was the huge fluctuations I was getting at the time.
Great content. Glad I found your channel.
Thank you very much I appreciate you watching. I have more Jetta Contin coming out in the next month or so
I have a mk4 1.8t and u can def go down a rabbit hole of bad info seaching forums for pretty much anything on these cars weather its whats the correct spark plug gap or brand of spark plugs to what kind of oil to put in the transmission and of course anything related to turbo upgrades
Got that right. Unfortunately the people who know the answers are just tired of constantly answering the same questions every day so we have to rely on the search function. And the information that’s valuable so saturated with information that’s not valuable that we just don’t know what direction to go in.
Where do you have your waste gate nut setting? Is it closer down the thread or further out?
Needs to be adjusted a bit more. I want to make a tighter
Right. That last run looked normal to me from what I read and see from boost pressure.
@@trojangpete8 Yea I had two of the videos and wanted to show how these manual controllers can help. I did plan a wastegate video I just ran out of time and never had the chance to finish the editing.
My mk4 GTI is making the same damn problems and I can’t figure it out once you figure it out if really like to see those videos!! I’ve been searching forums and tried everything they all say something different
Are you still running the stock turbo have you made any modifications?
Hell yeah!
I wish I could tag a friend of mine in this. That’s his favorite line.
completely normal with a ko3/ko4 turbo they aren’t big enough to produce that much pressure efficiently at higher rpm thus tapering off
Hi thank you for commenting. Yeah the only problem with this engine is it was producing higher boost numbers previously. I have a couple other videos coming out showing the path I take to get the boost back I appreciate you checking this video out. I wanted to try and help people who have the same issue as I found online it seems common. Have you ever tried running a N 75J valve?
@@davesworld2132 i’m still on stock n75 and it’s fine but obviously tapers as i get higher in the rpm range. i’ve heard they really don’t matter because the tune tells the n75 what to request for boost based off throttle percentage and it’s all on the waste gate. i’ve seen people crank the waste gate with spring mods and such to get them to hold boost longer but all i’ve read says that these turbos aren’t all that efficient making high pressures in higher rpms i’m looking to go bigger in the near future and take apart this block
@@davesworld2132 you very well could have a leak too just trying to share some info to possibly help. good luck!
@@josephfinder5472 def helpful. Another I’m leaning toward a wastegate issue. And possibly changing over to an N75J
Btw what are you running for a boost gauge?
@@davesworld2132 New south performance boost gauge. mounted on my steering column looks oem and i love it. even lights blue and red with the light switch at night. got it used for $50 and it’s mint
Also that boost issue u are havin could be caused by the diverter valve located close to the n75 pancake lookin thing they have a rubber diaphragm that fails when u run higher boost somtimes even stock boost will make it fail just because of high heat in the engine bay and crappy german plastics u can take it off and make a adapter to hook up to the boost side of the valve and put 20 psi of compressed air and see if it holds my guess to what is causing ur boost issue and if that checks out then i would try adjusting the spring pressure at the waste gate actuator on the turbo i bought a cheap ko4 off of Amazon and it barley had any spring pressure out of the box compared to the stock ko3
Just relized u already replaced the diverter valve mabe the spring pressure isnt set right on it?
You know that’s not a bad idea. I changed a lot of the plastic parts because they were dry rotted and leaking oil but I couldn’t find a new pancake and that’s the original one. Thanks for the tip that’s actually very helpful.
@@davesworld2132 no prob i really enjoy your ko4 swap videos
@@kenphillips479 Thank you that’s very good to hear I’ve spent a lot of time editing and filming. I have a lot more coming out on this car that I thought would be helpful and fun to see. Thank you.
Will installing boost controller turn check engine light off?
@@proscentgifts depends on what your light is for. What’s the code ?
@@davesworld2132 p2263
Can't I just blank off the N75 and connect the vacuum hose to my boost gauge?
You can but the engine might run a little twitchy and you might not achieve the maximum boost you’re capable of achieving
I totally disconnected my waste gate to see if the problem would be fixed and it didn’t solve it. Instead would only boost to 15psi then drop to 5
Hi. That def won’t help the turbo. The exhaust side of the turbo wastegate will open and close freely. Boost will be very erratic
Did you ever try to run it inline from the n75 to the wastegate?
Yes Later in the video I run it in line. And show the results I have another video coming out showing a different type of wastegate controller and I do the same testing with that one as well.
Oh I thought you ran in in line from boost source to the n75 I was wondering if you ran it from the n75 to the wastegate basically applying less boost to the waste gate keeping it closed longer and open less
Yeah if nothing else fails go with a 3 port boost controller or go fullsend with a 6 port boost controller
@@hobosandwhich Oh I see what you mean. My thought process was before the N75 because it operates based on pressure. I was trying to control when it opened and closed. I assume if we ran it after we may run into an issue where it will open and close but the control over the wastegate might be finicky. I would assume you can run into an issue where the wastegate has the open and maybe it can’t.
@@hobosandwhich lol like your style! Currently the 3 port which I highly recommend is on the car. After doing hours of research it seems like that’s the best way to go. I also realized after the fact there’s a way to modify this boost controller to work like a three port. But there around the same price and it was pointless to do so lol just buy the correct one
Is in it recommended to use diverter valves on these types of cars?
Turbo cars have both typically. A wastegate and a diverter. This car normally would have one in the intake but it was swapped out to a atmospheric style blow off valve.
JETTA UPDATE PLEASE!!
Hi what’s up. I have another one coming out wed. And about 8-12 more planned for Nov-March. I made sure to have a lot of footage filmed so I can keep videos coming for you guys.
Boost by gear