Need a little help.

[cml61386]

I'm feeling pretty dumb asking this but I actually want to lower my boost right now my car spikes a little over 15 psi and I don't wanna run that high without a fuel pump and a bigger turbo. I have a mbc that I made, tried to turn the boost down didn't seem to have any luck. Figured I'd ask. The car has 3" turbo back exhaust, 550's, afpr, maft pro and in the processes of tuning. As to why I want to turn it down some. Been busy playing with my new toy that has a straight six also, so I want to get my car up and running with nicer weather. Thanks in advance.

 

[dumbo]

If you made it, I think your the only one who can answer that question. With the mods you listed I'm sure 15PSI is within reason. But A fuel pump prolly couldn't hurt.

 

[jdub]

Is the wastegate bracket shimmed?

 

[cml61386]

The wastegate to my knowledge has never been touched. Well at least by me anyways. I was under the impression the stock CT isn't very efficient at that range. But what do I know haven't played with these cars as much as most. Guess I'll have to keep tweaking my boost controller and see if I can make it work.

 

[GrimJack]

Try taking the boost controller out. It it still doesn't drop, then it isn't part of the problem.

 

[grimreaper]

a boost controller cant lower the boost any lower then the wastegate. Example: waste gate spring is 6 psi, MBC can INCREASE boost above 6 psi, but not lower it. Only way to do that is to change the spring or put some slop in the waste gate actuator arm (poor response, not advised).

 

[jdub]

Take a look at the wastegate bracket...see if there are any washers between the actuator bracket and turbo housing. If there are, remove them.

As suggested, your wastegate actuato might be getting a bit "tired".

 

[dumbo]

How did you make your boost controller? 15PSI may be pushing it for a stock CT, I'm not sure.

 

[cml61386]

Found out how to make it on a dsm forum. Alright I'll take a look at the wastegate see what I can find. Thanks for the help.

 

[Poodles]

link to how to make it?

 

[jtran8]

beside all above advices , wastegate actuator malfuntion or the hose between compressor housing to wastegate leaks also can cause boost spike or creep .

 

[cml61386]

link to how to make it?

http://www.dsmtuners.com/forums/art...0-how-make-manual-boost-controller-works.html

 

[dumbo]

I would first try bypassing that and then see if it still hits 15psi. Atleast then you can narrow it down to being the WG, actuator, or signal hose,...or the MBC.

 

[cml61386]

I'll give it a try and see what happens.

 

[dumbo]

Problem found?

 

[cml61386]

Not yet had to pull the trans. out of my truck that destroyed the flex plate. Hopefully I'll get a chance this weekend and update with what I find.

 

[cml61386]

Finally took the car out for a spin. Ran once with the mbc adjusted car was around 18psi. So i took it off the car was right around 12 psi until the car shiftd into 3rd and it jumped to 15 psi. Looks to me that there are washers on the actuator bracket but they look like there factory. So am I lookin at replacing the wastegate actuator or is there another way to fix the problem? Sorry took me forever to reply back.