Stock Boost

[YlwMSP]

Should the stock turbo taper down to like 3 or 4 psi of boost when in higher RPM? I hit 7 psi just fine, but then it tapers down to 3 or 4 psi. I also know that its normal for it to taper down some, but thats 50% of my boost right there. I just replaced the turbo with a brand new t25 back in December, along with fixing my boost leak last week. Just wondering if thats normal or not, and will my boost controller, once installed, help with that?

 

[turbomsp2003]

with my old stock wastegate my boost never tapered off not even a bit stayed at 6psi and when i replaced with an atp it still stays at 8psi without tapering off

 

[Brian_K]

have you checked for any boost leaks?

 

[YlwMSP]

I had a boost leak, then I fixed it.

 

[YlwMSP]

I adjusted my blow off valve to a harder setting, hopefully that makes a difference.

 

[AutoXSS]

My completely stock msp tapers off about a pound in second gear only during the last few 1000 rpm? All other gears show 6.5 all the way up to redline?

 

[AutoXSS]

My vacuum is at 19/20 at idle

 

[CHIQLES]

you maybe opening to early on the wastegate. causing you to loose boost. also your vaccum should be around -21 through -24. check your wastegate for leaks. also if you have a pump with a guage you can pressurize it and see how much it takes to open.

 

[AutoXSS]

Did some very quick looking at my vacuum hoses and found a small leak where my vacuum/boost gauge was spliced in by the previous owner. It was actually hissing. I must have made it worst while i was replacing my rear motor mount. Redid the connection and got the boost reading to stay constant through the rpm range, but only picked up to 20 in vacuum. I must still have a leak somewhere.

 

[AutoXSS]

Im just going to order the new vacuum hoses that go to the wastegate, the whole t-shaped series of hoses. Its $50 through the mazdaspeed motorsports program. Im sure they've never been changed and figure replacing the whole series is better. More than likely, id replace one part and have a leak at another.

 

[AutoXSS]

I did a search, but can't find it anymore......



I blew into the vacuum line that goes down to the wastegate. I did get some air noise, hissing, after getting some crazy bucking and fuel cut like symptoms. After tugging on it and blowing into it, and re plugging it, i got smooth boost again? Either way, Im getting all new hoses. My question is, when i get the new ones, can i just use regular hose clamps instead of those factory crimp style clamps? Does the wastegate nipple where the vacuum actuator line goes in have a crimp clamp too?

 

[AutoXSS]

Replacing the stock t series of hoses that go to the WG got me to 21 vacuum at idle with no AC. Still getting that 1psi drop at the top of second gear only. All other gears hold fine?