Boost spike after downpipe install

Reply Subscribe

Thread Tools

Search this Thread

Dec 26, 2018 | 01:48 PM

FDIIIS

Thread Starter

Can Post Only in New Member Section

Joined: Dec 2018

Posts: 3

Likes: 0

From: Virginia

Boost spike after downpipe install

hey guys, I’m 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’m getting boost spike of around 1bar (~14-15 lbs). The car is stock with only Apex’i intakes and catback exhaust. Prior to the install, I was hitting a consistent 10-8-10. 15lbs is definitely not safe from what I’ve read. I’ve 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.

Dec 26, 2018 | 02:12 PM

Templeton

is tempted

iTrader: (10)

Joined: May 2006

Posts: 885

Likes: 9

From: New Hampshire

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.

Dec 28, 2018 | 01:57 PM

IRPerformance

Sponsor

iTrader: (41)

Joined: Apr 2003

Posts: 11,347

Likes: 321

From: NJ

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.