18G VF54 Max Boost w/ Catless Downpipe

Has anybody had any experience with the bnr 18g overboosting? I dropped the car off tonight and it will get on the dyno on Thursday. I expressed that the car may overboost with the catless downpipe, and they asked me what boost I want to run. The car has ARP head studs and the 18G is ported. I also have the Sti cams to help with exhaust flow, but I’m not sure where it should be capped. They also mentioned that 5th and 6th gears are where I would see an overboosting issue, and they only do pulls in 3rd and 4th. I need to get them an answer by tomorrow night. Eeek!

FYI your ECU has gear dependent boost control from the factory. This means that they can lower the WGDC for 5th and 6th to reduce the likelihood of over boost and/or to increase mpgs on the freeway. It might even make sense to have them set 6th to 0% WGDC since you probably won't ever need that anyways. You should really downshift for any significant acceleration instead of boosting in high gears.

If your running 93 then let them do their thing you'll run out of turbine flow before maxing out the compressor.

 

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That’s what I was hoping they would do, and after speaking with the owner that’s the route they’re going to take. Unfortunately the wastegate wouldn’t open until 22lbs, and wasn’t fully open until 25lbs. I swapped an oem actuator this weekend and will retune the Thursday after thanksgiving.