BEGi Separated Gases Downpipe

BEGi Separated Gases Downpipe for Mazdaspeed Miata

[10/26/2007] Reviewed by: Mark Brandt - mardan.brandt@verizon.net

Applicable to: '99-'05 1.8 liter

Highflow downpipe for Mazdaspeed Miatas (04 & 05) Downpipe has separate tubes for exhaust and wastegate gasses to improve performance

My MSM engine has aftermarket intake and exhaust and a larger turbo compressor wheel. The BEGi downpipe upsets the balance between exhaust and wastegate flow, rendering the wastegate ineffective. Boost creeps upward at mid rpm, and surges uncontrollably at revs above 5000. Continued use of the downpipe on MSMs with similar enhancements to my engine would almost assuredly result in connecting rod failure. Similar problems have been reported by other owners. This problem apparently does not exist if the MSM is bone stock other than the downpipe (but few people add a downpipe to a stock MSM).

I would suggest that you use a different downpipe if you plan any additional modifications to your MSM engine. BEGi offers a non separated gases pipe, as do other Miata vendors. If you are considering a BEGi separated gases downpipe for a modified MSM engine, make sure BEGi will take it back if it creates boost control problems. To date, they have not agreed to take my pipe back even though they were informed of the modifications to my engine and turbo system at the time of the order and the pipe is clearly unusable.

Over 30 minutes to remove completely