boost oscillations

That spinning thing that makes all of the cool noises. OE and Aftermarket.

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BSOD2600
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boost oscillations

Post by BSOD2600 »

How much oscillation while on full boost would be considered normal? Using a hallman MBC with the stiff spring on my TD05. I was doing data logging and noticed it fluctuates ~2 PSI. Can't say I really notice it on my autometer boost gauge (but possibly because I'm paying attention to the road instead). I assume this fluctuation is from the MBC spring bouncing on the wastegate?

Image

Thoughts? Would using the stock boost solenoid help to lessen it?

'11 WRX Limited
'94 SS | 3" TBE, 07 TMIC, TD05H-16G, Revtronix Stage 2, Walbro -- Sold
'94 TW | R.I.P.
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Skruyd
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Post by Skruyd »

On a MBC will always fluctuate. The electronic ones don't do it as much because they can always adjust themselves.
91 Subaru Legacy SS (Driving) 3"TBE, Vrg FCD, 440cc, HKS Safc, Vf10, ebay FMIC, Jecs
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Adam West
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Post by Adam West »

I have the upgraded MBC from TurboXS with the bleed valve - supposed to take care of this issue??? but haven't put it on yet...

http://www.turboxs.com/uploaded_images/522.pdf
93SS 5MT White, TD05-16G, TMIC, 3"Turboback, Magnaflow, Alu Rad, H&R Sports, AGX struts, F/R STBs, Whiteline Sways, ALK+Endlinks, Odyssey 925, AC delete, Evo8 Recaros, Sparco 4p, 3.9 LSD, Hellas+air horns, IPD short throw, 99RSrims, s03's
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Legacy777
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Post by Legacy777 »

Where are you measuring boost? Stock vacuum/boost port?
Josh

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BSOD2600
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Post by BSOD2600 »

Those numbers come from the MAP sensor via ECU. My boost gauge is teed off the umm front left intake line.

'11 WRX Limited
'94 SS | 3" TBE, 07 TMIC, TD05H-16G, Revtronix Stage 2, Walbro -- Sold
'94 TW | R.I.P.
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