good explanation thank you. I know if you install an Cobb downpipe, Cobb says to remove the restrictor pill. Can you explain why Cobb would say to remove it? Im assuming the aftermaket downpipe would change the turbos boost characteristics?
When I ran an Invidia downpipe and I assume Cobb is similar, it has a bell opening over the entire outlet of the hot side where as the stock DP has only an opening for the turbo exit and basically a flat plate over the waste gate so the gasses mix in a tiny little cavity which is more restrictive. I'm guessing because the aftermarket DP is so much less restrictive there might be a risk of overboosting without an aftermarket boost controller but this is pure conjecture. I'll also add that I never did anything with the restrictor pill when I had mine swapped but I did run a Cobb stage 2 tune, I think without the tune you are throwing your money away with the DP because the ECU adjusts itself. This was on an 2012 WRX if that makes a difference.
Hey quick question. I have a Mazdaspeed 3 and am loosing boost pressure big time. I’m was working great before I got a muffler delete. Now it’s low boost pressure. I’m not sure if this has anything to do with it? Or it just needs a tune? Just trying to get some help, thanks!
Listen I know I’m about to sound stupid asf and this video is old but I recently bought a 2017 sti and it has a grimmspeed 3 port controller on it and I have no clue how to use it if you could help me out it would be appreciated
good explanation thank you. I know if you install an Cobb downpipe, Cobb says to remove the restrictor pill. Can you explain why Cobb would say to remove it? Im assuming the aftermaket downpipe would change the turbos boost characteristics?
When I ran an Invidia downpipe and I assume Cobb is similar, it has a bell opening over the entire outlet of the hot side where as the stock DP has only an opening for the turbo exit and basically a flat plate over the waste gate so the gasses mix in a tiny little cavity which is more restrictive. I'm guessing because the aftermarket DP is so much less restrictive there might be a risk of overboosting without an aftermarket boost controller but this is pure conjecture.
I'll also add that I never did anything with the restrictor pill when I had mine swapped but I did run a Cobb stage 2 tune, I think without the tune you are throwing your money away with the DP because the ECU adjusts itself. This was on an 2012 WRX if that makes a difference.
Hey quick question. I have a Mazdaspeed 3 and am loosing boost pressure big time. I’m was working great before I got a muffler delete. Now it’s low boost pressure. I’m not sure if this has anything to do with it? Or it just needs a tune? Just trying to get some help, thanks!
Check for boost leaks first.
i just ran into this problem
Listen I know I’m about to sound stupid asf and this video is old but I recently bought a 2017 sti and it has a grimmspeed 3 port controller on it and I have no clue how to use it if you could help me out it would be appreciated
Hi I recommend going to the GS website for the install and then getting a tune for it.