Boost only hitting 13psi?
 

Recently bought a 2006 ms6 with a 144k miles on it. The car was untouched when it came to mods except for a Cobb ap that was used for the Econ tune. After I got the car I flushed out the coolant and changed it did an oil change with the car super hot to make sure I got every drop of old oil out and put in 6 and so quarts of Ratella t6 and a Napa gold standard filter and finally did plugs gapped to .28 which fixed the one problem I was having with misfires and bucking. About a week ago I put on a CR cold air intake with a water repellent air filter that sits inside the fender and when I did that I also cleaned the maf sensor with maf cleaner. Now I have the stage 1+ tune 93 oct tune on my car. Other then the intake everything is stock still has both cats and the mufflers stock intercooler stock fuel pump internals. I’ve monitored my fuel pump and afr and the car doesn’t run rich or lean and the fuel pump at wot stays around 1625-1750. However the most boost I can get is 13.04 psi no matter what gear I’m in. I went and looked for cracks in the intercooler and didn’t see anything and did a once over to make sure all the clamps were good and tight. I guess I could do a leak test with some sort of homemade boost leak tester but other then a boost leak where and what should I be looking for? The Cobb tune says target boost is 16.5 +/- 1.5 and should taper down by redline which mine tapers down to 10-11 psi so I figured I’m underboost by at least 2 psi. Maybe I’m wrong and 13 psi is a normal peak number but I would assume not. If you guys could give me any input it would be very appreciated I’m new to Mazda’s and really new to turbo cars so dumbing things down would help. Also new to this forum so hope to be around helping out with whatever problems other guys might run into. Other then the low boost the only other issue I have is that annoying timing chain rattle at cold starts looking to take the valve cover off and investigating that soon and replacing the actuator tension era and timing chain once I have the funds for it.

:thinking: Maybe you need to calibrate your MAF for the new intake?

Datalog?
Picture of the installed intake ?

These cars are maf dependant so as soon as you change the maf pipe size it need to be adjusted.

it can be that or so many other things...

btw for the rattle, look at thread like ''how too vvt'', it isn't just a matter of lash adjuster...

I just took a data log so when I get on my computer I’ll upload that the intake is DC cai I’ll put the link for it so you can see it since my camera is busted on my phone. How would I go about calibrating my maf if that’s indeed the problem?

https://www.redline360.com/dc-sports...xoCNEMQAvD_BwE

Heres my data log looks good to me but like i said im new to all of this let me know what you see not sure what maf should be at...thanks

to calibrate maf you need ATR software or a tune but according to your log, you have something else in fault for your 12-13psi...Despite it may still affect the performance a bit. (You can compare inside dimensions to make sure)

I suspect something electric/mecanic with the wastegate since the log show a 40-50% wastegate duty and the boost isn't rising.
The first step is a boost leak even if it may not be the major problem, you need the system sealed tight prior to do anything else.(Replace inlet filter by the boost tester and listen for leaks...)
Then, check the wastegate electric solenoid, remove it and test it. Make sure when you powered it with a constant 12v, it flow freely FROM the wastegate to the TIH and stop when you remove the power. Check hose at the same time to make sure it isn't plugged by dirt or sludge etc.
You can also check if the wg arm is tight and secured at rest.

Did you try putting your stock intake back on to see if boost returns to normal?

Unless the new filter is very restrictive, i would expect more than 12-13psi with 40-50% WG duty from a healthy ko4. It seem to react on is own like if the ebcs isn't doing any leak s

With the stock intake I still only had 13psi just didn’t think anything of it since I wasn’t still new to the car.. gonna check the wastegate and the lines going to it

For reference, my K04 on spring pressure was about 10-11psi.

I think you have a vacuum/boost leak. Check the hose from the TIP to the EBCS, check the nipple on the EBCS, check the BPV recirc hose, check your hose from the IM to the BPV.

Also, logging fuel trims is helpful for diagnosing leaks.

Stock TMAP sensor?

YEs stock sensor and I’ll look over those vacuum lines as well and I can take anoth log with the fuel trims as well

a leak at the wastegate vacuum line would increase boost. look for something not flowing thru when looking there. A BPV could easily leak enough to drop boost too without making a leaking noise while driving...

interesting, mine made a bit more but it was early this summer and i had a DP on stock catback. I bypassed the ebcs vac hose to check something and was like 11-12 with peak at 14...