Boostin

[ClutchTSI/AWD]

I just hooked up my boost guage , and did some runs . I was getting 15psi to red line. Now when im in 4th gear at about 30 mph and hamer down she will go to 20psi and then settle back down to 15psi . I then did the restrictor mod , and I am pushing 16-17psi and also hitting 20psi while in 4th gear . I don't have a mbc and im pretty much stock eccept for my intake filter and bov. What seems to be my problem ?

 

[97GSTURBO]

Little bit of boost spike there huh? doing the BCS mod just makes it worse... Get a MBC. I can sell you one for $24 shipped.

 

[ClutchTSI/AWD]

Any one else have any thoughts .

 

[ryan2987]

definatly get the MBC soon. 16-17 psi seems alittle high for almost stock.

 

[ClutchTSI/AWD]

How would my boost get so high without having a mbc ?

 

[Black95GSX]

The Stock BCS bleeds off vacume like a boost controller to increase boost pressure -- keep in mind though, that it is doing this thinking your car is stock -- it doesn't monitor pressure and raise accordingly, it just assumes certain values.

As a temporary solution to prevent any issues do the following:
-disconnect the vac line that goes to the wastegate
-disconnect the vac line that goes to the turbo (tapped in the compressor housing)
-disconnect the vac line that goes from the BCS to the intake tube
-use a vac cap (from autozone/pepboys, etc) to plug the new hole in your intake pipe
-use a vac cap with a small clamp or ziptie to secure it on the tubo's compressor housing (you do not want to use that on a T25, it's too turbulant of a boost source)
-get a T fitting... T it into the vac line that goes to your BOV -- the "new" fitting from the T gets routed directly to your wastegate.

This should put you at low boost, so it will not be fun for racing/wot -- but it will save your ass and prevent you from running into further issues once you get a real boost controller.

Keep in mind if you do what I just described, when you do get a real boost controller, installation is as simple as going from the BOV T Line to the mbc to the wastegate.... PM me if you want more details.

 

[ClutchTSI/AWD]

Thanks for the info . The car isn't a daily driver so im not in need for a temporary fix . Do you think that the mbc. will solve my prob. or just help part of the prob.

 

[ryan2987]

the MBC should keep your boost under control.

 

[Bohrn]

how can a mbc lower the boost below the level that the wastegate is set to open at?? I know you can raise it above, but to lower it??

I also have too much boost. I have the screw backed all the way out of my mbc, and still I have 17 and up psi if I floor it. I have to soft foot it everywhere and keep my eyes on the boost guage if I get on it.

 

[ClutchTSI/AWD]

Originally posted by Bohrn
how can a mbc lower the boost below the level that the wastegate is set to open at?? I know you can raise it above, but to lower it??

I 2nd that .

 

[bottledbird68]

I'm having almost the exact same problem, only difference is I'm pulling 21 to 22 psi over 4,000 rpm in every gear! I already melted one head so I just installed a boost gauge tonight and this is what I found Any ideas?

 

[bottledbird68]

O.K., I slept on this one and here's what I came up with today. I decided to check and see if the wastegate actuator was working properly. Well, when I went to remove the arm from the wastegate I discovered it was rusted solid to it. So I freed it up and lubed everything up real nice then went for a test drive. Now I have between 10 and 12 psi in every gear. I also eliminated a high end stumble that I had, I'm guessing I was blowing the spark out. Now it revs free and smooth to redline, it also pulls much nicer . Now the only problem is every time I beat on it a little I blow oil out the oil cap and make a huge mess out of the engine bay. Guess 20 psi took its toll on my 118k mile rings . My advice, check to see that your wastegate travels smoothly. Good luck.

 

[Bohrn]

Mine moves fine, I have lubed and freed it up.

If I run a hose right from the turbo outlet to the wastegate actuator, I get 10psi. No prob.

But who wants to run 10psi?? And it has crappy throttle response too as the wastegate sorta opens at 8 or so. Never really holds any boost.

If I wanted that kinda throttle response I woulda bought a Daytona

No offence to any Daytona owners, I used to really like them, I drove a real nice Shelby Z the same day I drove my Talon, and after the Talon, the Daytona felt like a school bus.

 

[ClutchTSI/AWD]

Originally posted by Bohrn
how can a mbc lower the boost below the level that the wastegate is set to open at?? I know you can raise it above, but to lower it??