Well previously with the mods in my sig I was peaking at 22psi and settling to 19psi by redline.

Now, with my new mods, BR Deluxe FMIC, BR UICP, 272/264 cams, DC Sport Exhaust Mani, and Ebay/BR O2 housing I am getting weird boost readings.

I havent taken it to the track to get really good readings through 4th but from what I have seen it is now boosting the following.

1st gear-21psi settling to ~18psi
2nd gear-24psi settling to ~19psi
3 gear-25psi settling to ~19psi

What could be causing the different boost readings in each gear? Before I held the same boost in each gear, except 5th which would hit 24 or so. Is there a way I can check to see if maybe my boost gauge is reading inaccurate? I dont have a datalogger to see if my car is pulling timing or knocking but it seems to pull hard to redline and runs good. Anyone else experience this problem?

 

What wastegate are you running? Stock?

Also, i see your running a mbc, it might not be working properly.
i always use electricals, little more precise at controlling the boost.

Check for vacuum leaks, and by the mods you just did, the boost will definitely go up.

I just think your getting boost spike

 

Yes I am running the stock wastegate.

What can I do to check true boost levels?

Is there any way to check and see if my MBC is working properly?

 

It's normal to see higher boost in each successive gear, because there is more load. It shouldn't go from 21 to 24 from 1st to 2nd, but I'm not sure how well you can accurately SEE your boost gauge when violently boosting in 1st.

Also, remember that the more efficient you make the engine, the more your boost will taper. To check your actual boost, you'd need a MAP sensor. I also wouldn't recommend running such high boost on pump gas if that's what you're doing.

 

Yeah I dont want to run to high of boost but I also dont think its normal to have to run 17-18psi in 1st just to get my 3rd and 4th gear at 21-22psi. I am also wondering how accurate my gauge is as Ive heard some bad things about autometer gauges.

I remember reading the thread when BR tested the Ebay O2 housing that they ended up running 2psi more than stock without getting knock or timing pulled. Could this be a factor? Thanks for the help.

 

well, the exhaust setup is more free flowing, so boost will go up.

Like when you take off your cat, boost always goes up because of less back pressure and you hit your boost level more faster.

Maybe your mbc can't respond quick enough.

Start by adjusting your boost controller down a little bit, then go from there

 

Try to find a local friends with another MBC and swap it to test.