General Rotary Tech Support Use this forum for tech questions not specific to a certain model year

Boost spike after downpipe install

Old 12-26-18, 01:48 PM
Can Post Only in New Member Section
Thread Starter
Join Date: Dec 2018
Location: Virginia
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Boost spike after downpipe install

hey guys, I知 new to the rotary world and recently picked up a 92 FD. I tried searching the forums but coming up short on troubleshooting the issue. I installed an hks downpipe recently and now I知 getting boost spike of around 1bar (~14-15 lbs). The car is stock with only Apex段 intakes and catback exhaust. Prior to the install, I was hitting a consistent 10-8-10. 15lbs is definitely not safe from what I致e read. I致e checked the connections from the downpipe to ensure no leaks. Does anyone have any ideas as to why the boost spikes so high? Or what I can check to correct this? Thanks in advance.
FDIIIS is offline  
Old 12-26-18, 02:12 PM
is tempted
iTrader: (10)
Templeton's Avatar
Join Date: May 2006
Location: New Hampshire
Posts: 862
Received 8 Likes on 7 Posts
It is pretty typical to see this with an FD that has an upgraded intake and exhaust. You can put a restriction plate in the exhaust if you need a quick fix, but to do it right you will need to remove the turbos and port the wastegate.
Templeton is offline  
Old 12-28-18, 01:57 PM
RX7Club Vendor
iTrader: (41)
IRPerformance's Avatar
Join Date: Apr 2003
Location: NJ
Posts: 11,014
Received 57 Likes on 49 Posts
You have 3 mods that affect the flow through the motor and the stock computer cannot compensate. The general rule is 2 mods max before you need to look into upgrading the ecu and tuning the car. Either put a 2.25 or 2.5" restrictor plate in the exhaust to see if it helps, but better yet get a power fc and professional tune to guarantee the car is safe. Boosting that high is sure to cause engine damage in a short period of time.
Engine builds, single turbo kits, parts sales, performance upgrades, maintenance, tuning
732-662-1794 [email protected]
Brand new Mazda oem 13brew motors available. $4699 NO CORE FEE. VERY LIMITED. Check out our new turbo kits
IRPerformance is offline  
Related Topics
Thread Starter
Last Post
3rd Generation Specific (1993-2002)
04-11-13 10:31 AM
3rd Generation Specific (1993-2002)
11-18-07 12:58 PM
3rd Generation Specific (1993-2002)
08-17-06 03:47 PM
3rd Generation Specific (1993-2002)
01-13-03 12:07 PM
3rd Generation Specific (1993-2002)
09-29-01 11:03 AM

Thread Tools
Search this Thread
Quick Reply: Boost spike after downpipe install

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: