E9X Boost issue after new intercooler?


New Member
Jan 5, 2024
Hi all,

For reference: MHD st2+ E30

Replaced my radiator this evening and decided to swap in the 5” VRSF intercooler I’ve had sitting on the shelf for a while

Before I installed the new intercooler I would hit 22.8psi sometimes 23

With the new intercooler in I’m only hitting about 15psi even with a reflash and I’m losing lots of top end boost.

Before I tear apart the car again I’m wondering if it could be a boost leak or something else based off my logs

Thanks :)


  • 2024-01-05 22_51_44 98G0B v1.84 stg 2 plus e30.csv
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  • 2024-01-05 22_50_10 98G0B v1.84 stg 2 plus e30.csv
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May 30, 2020
A set of graphs would have been easier to digest may I suggest..

On the grounds that all was well before then yes it’s a boost leak most probably..

I had one on my N54..couldn’t find it visually…but found it immediately with a cheap Amazon leak kit…

Logically it must be either the FMIC or one or more of the connections you disturbed.
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