I installed a Hallman MBC and a DC Sports Downpipe/Cat-Delete and now there is a problem. I have not yet turned up the MBC, so it is still set to stock boost, but now I am boosting in excess of 20psi. When I did my first run when I installed in Downpipe and MBC (still set to stock boost), I was boosting consistantly at 17.5 psi. Then the next day (today), I was boosting 20+. I say 20+ because my Boost gauge only reads to 20, and the needle goes about 2-3psi after 20, then it is stopped by the pin (I would guess I was boosting at 22-23psi). I have a 2005 GSR Evo 8 (if that helps). I also threw a check engine light today as well. I checked all of the lines, and everything was installed perfectly, and when I brought it up to 7000rpms, there was no signs of detonation, fuel cuts, etc. It seems to be running fine. Now I want to know if there might be a problem here, or do you just boost more when installing a downpipe/cat-delete naturally.

Please let me know.

Thanks!

 

First off, if you installed a downpipe and testpipe chances are you are going to need an 02 bung. This is probably why you threw a CEL.

Next, you are going to need a boost gauge which ATLEAST reads to 25psi. You should be spiking at about 22-23psiMAX on 91 octane, hold at about 20-21 and it will taper off a little by redline.

 

okay, so it was an installer error, but now that I fixed it, I am boosting at 15psi, then it'll spike to 20-21psi, then it will drop back down to 14-15psi at 7000rpms. I keep adding more boost with my mbc, and it remains the same. I cannot boost more than 15psi. How many clicks, or rotations do I have to do on my MBC to add more boost? Or is there a problem with my MBC or install?