okay I have a gn1 performance 3in dp with 38mm wastegate and turbonetics 0-50psi boost controller and I cant control boost it keeps going all the way up to 25 plus sometimes over 30 and I let out instantly.im trying to get it to around 18. I have gone through and made sure I had the lines for the boost controller set up right and I still cant control the boost. it is a 57mm precision turbo. I have read maybe porting out certain holes in the dp will help but not exactly sure which ones and if there is something else I should try first before tearing everything apart and doing the porting. thanks for any help in advance.
cant control boost
- Thread starter jerritt
- Start date
- Joined
- May 28, 2001
That's the size of the puck?
Pull the dp and look at the carbon track around the hsg hole.
- Joined
- Aug 1, 2003
first off i would take a hose and run it direct from the turbo comprosser port to the bottom of the wastegate. make sure the port on top of gate is open ..if that wont drop the boost to where you need its either the spring in the gate is too large(strong) , or the wastegate passages needs to be opened
take off dp and look at the hole in flange that runs to the gate ...port that as big as the pipe inside
now make a template of the downpipe and transfer that to the turbo , open the wastegate hole in turbo exhaust housing
try again if still too low the gate may be defective or the gate outlet is not opened up where the thin pipe ties back into the 3" downpipe (has been discussed here before on those pipes where they didnt make the hole in the DP large as the pipe itself )
take off dp and look at the hole in flange that runs to the gate ...port that as big as the pipe inside
now make a template of the downpipe and transfer that to the turbo , open the wastegate hole in turbo exhaust housing
try again if still too low the gate may be defective or the gate outlet is not opened up where the thin pipe ties back into the 3" downpipe (has been discussed here before on those pipes where they didnt make the hole in the DP large as the pipe itself )
hey thanks for the responses I have been out trying a few things that I have read and yes it is an external gate. I ran a line from the turbo to the port on the front of the wastegate and It spiked so I took it off and hooked it from the turbo to the top port on the wastegate and the boost held at 12psi. so my question is the boost controller maybe bad? or do I still need to port out the turbo and downpipe? cant I just get a different spring for a boost level around 18 and just keep running it with just the hose connected where it was for the test or is that not a good idea? thanks again everyone
- Joined
- Aug 1, 2003
sounds like you screwed up and are confuse don the plumbing
the bottom is the side closest to where it bolts up and port will be on the side , the top has the port in the center of the aluminum cap that you remove to change the spring
if it held 12psi tuner style your gate will work if plumbed properly and if the variable valve is adjusted properly
the bottom is the side closest to where it bolts up and port will be on the side , the top has the port in the center of the aluminum cap that you remove to change the spring
if it held 12psi tuner style your gate will work if plumbed properly and if the variable valve is adjusted properly
this is the diagram I used when connecting everything so after I got the boost to 12-15 with the tuner test I put the boost controller back on and made sure I had new hoses in the correct order with zipties on each connection and it held at 15 my first hit and then the second hit it went up over 20 and I had to let out. im at a lose I don't mind doing the porting of the turbo but with what im understanding it doesn't seem like my issues are related to that but im not 100%. thanks again for the help everyone
Attachments
- Joined
- Aug 1, 2003
if it held tuner style the problem isnt the porting
its either the way you plumbed the valve or the way you have the valve adjusted ,
if you have the the lines reversed on the adjuster valve it wont work properly
start with the valve so almost no air blows through and adjust up from there
if you close it fully the air on top of gate will be trapped and wont allow the gate to open
if you want to run it with adjuster valve fully closed youll need a small pinhole drilled into one of the fittings on the top of gate to allow the gate to rise
if you dont connect the top and close the valve (basically tuner with a bleeder teed in ,you can open it as a bleeder and adjust up the boost that way
you arent using the gray stock tee are you
its either the way you plumbed the valve or the way you have the valve adjusted ,
if you have the the lines reversed on the adjuster valve it wont work properly
start with the valve so almost no air blows through and adjust up from there
if you close it fully the air on top of gate will be trapped and wont allow the gate to open
if you want to run it with adjuster valve fully closed youll need a small pinhole drilled into one of the fittings on the top of gate to allow the gate to rise
if you dont connect the top and close the valve (basically tuner with a bleeder teed in ,you can open it as a bleeder and adjust up the boost that way
you arent using the gray stock tee are you
- Joined
- Feb 18, 2006
External gates that use the stock waste gate port usually need porting to both the pipe and the turbo housing to control boost.
Start with the lightest spring you have for the gate. Run the boost hose direct to side port and leave top port open like already mentioned.
If boost continues to shoot up, you need some port work.
FYI Every down pipe I have ever worked on with a external gate has need port work to control boost.
Rick
Start with the lightest spring you have for the gate. Run the boost hose direct to side port and leave top port open like already mentioned.
If boost continues to shoot up, you need some port work.
FYI Every down pipe I have ever worked on with a external gate has need port work to control boost.
Rick
Okay so I have been working some crazy hours the past few days and couldn't do anything with the car but I'm planning on taking everything apart to go ahead and do the porting...I'm planning on using the gasket I have as a guide on the porting for the turbo but you guys are saying to port the dp as well? Where exactly should I port the dp? Just where the flange meets the turbo or where the dp meets the wastegate if that makes any sense lol thanks again for the help everyone.
Also should I completely take apart the turbo or do you think as long as I have it on a bench off the car I can do the port work without out taking the exhaust side of the turbo off?
Also should I completely take apart the turbo or do you think as long as I have it on a bench off the car I can do the port work without out taking the exhaust side of the turbo off?
I had the same problem with my 6765 precision turbo. The solution is to take the turbo off and match/machine the turbo waste gate hole to match the external waste gate mechanism. After i did this, no more spikes and the boost now can be effectively adjusted up and down.
- Joined
- Feb 18, 2006
Not porting the pipe so much where it meets the turbo. Port the inside edge of the flange so to smooth the path.
- Joined
- Feb 18, 2006
Sorry but just making the wastegate hole in the housing bigger doesn't always do the trick. Both the turbine and the pipe flange need to have the sharp edges inside smoothed out.
Okay so I will definitely be doing the wastegate hole on the turbo and it can't hurt to smooth out the flanges on the dp where the wastegate meets the pipe and where the turbo meets the pipe that all makes sense to me now....I have seen it brought up a few times about this exact pipe having problems with the pipe being to small from where the wastegate runs back into the dp is there a fix for this by just porting out that flange also? Or is cutting it off and putting a bigger pipe in its place the only way to do it? No knock to gn1 performance but this pipe has been nothing but trouble for me the entire time I have had it. Thanks again for the help everyone.
TR Custom Parts
Mark Hueffman - Owner
- Joined
- May 25, 2001
Did you get my email I sent you a couple of weeks ago?
Yeah I did get your email thanks for the info... so I ported the dp flange by the turbo and the turbo wg hole to a out and 1 1/4 ....should I also port out the hole in the dp where the waste gate meets the pipe coming from the turbo or is that not normally a problem? Thanks again guys
hey guys....yeah mark I did read your email just been busy doing all the porting. I opened up the wg hole in the flange of the dp to a little 0ver an 1 1/4 in and then made a template of it and opened up the wg hole on the turbo to the same size and rounded off the angle from where the turbo sits on the header to the wg hole in the turbo just to make the pass a little easier. I then put it all together and went out and it still goes up to over 30 and I let out as quick as I could. no offense to mark because I really like the stuff he sells and have spent hundreds of dollars through him but gn1 for sure dropped the ball with this pipe nothing has been right with it since the day I bought it from fit to function. the fact that gn1 suggest to cut the pipe open to enlarge the pipe going from the wg back into the dp just blows my mind that they would even sell it. so I guess that's what I am left to do just for anyone reading this is going through the same issues. unless anyone thinks maybe enlarging the holes where the wg sits on the pipe? I don't think anyone said to do this but I would think it would be worth a shot? thanks again everyone
