stock mbc turned down 20psi

[talongod]

MY car is totally stock with a boost guage and mbc which is turned down all the way and it reads 20psi and holds sometimes usualy drops down to about 18 why could this be?

 

[99gst_racer]

MY car is totally stock with a boost guage and mbc which is turned down all the way and it reads 20psi and holds sometimes usualy drops down to about 18 why could this be?

That drop in boost is due to your stock turbo. The T25 is very inefficient in the high-boost, high-RPM range. So having it drop a few psi is completely normal.
When I had a T25, I had it set at 14 and it always dropped to 12.

 

[cool_g_83]

If your car is "totally stock" then you have a t-25 turbo that is working harder than it should. That boost drop off is normal towards redline because it is out of its efficiency curve, but you running 20 psi on a basically "stock car" is not.....shouldn't be that high, might want to lower it before you put on some supporting mods.

 

[Jackripper_83]

I think what he is getting at is the MBC is turned all the way down, but it's reading 20 psi. Is that the problem, talongod? Or is the problem that it goes down to 18psi sometimes?

 

[talongod]

yes jack mbc is all the way down gosh dont u guys read and i have a 14b turbo (91 tsi awd)

 

[Jackripper_83]

Sounds like it's installed wrong. Are you sure you can't force it to turn down more?

 

[a_scobel]

...Completely stock, yet you have:
14b turbo Apexi N1 2.5""Downpipe Apexi N1 3"Cat Back UICP/s-pipe greddy type-s bov intake TurboXs MBC Exedy clutch Autometer Boost Guage Autometer Air/Fuel Guage s-afc II

Anyways..you sure you got everything hooked up correctly? MBC-wise?

 

[99gst_racer]

yes jack mbc is all the way down gosh dont u guys read and i have a 14b turbo (91 tsi awd)

Yeah, we can read. Update your profile. It says you have a 97 Talon TSI.....

You might be creeping, but I doubt it because you have the stock exhaust.
The MBC could be hooked up wrong. Or it could be broken/malfunctioning. Take the MBC off and run your boost directly off of the WG actuator. If the boost level is lower, then your MBC is to blame.

 

[KJS1820]

I think you have the vac lines to the boost controller backwards, it does make a difference and make sure your actuator is not sticking
Hope this helps!