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Title: Flow problem.. Again! Post by: kacperoooni on July 12, 2019, 03:20:08 PM Hi,
I've just "finished" my beetle's tune. It's 1.8t AWU with 032BJ (AUQ, because of damos ;D), 430cc bosch green, DP 3", TIP 2.75", Hybrid k03/k04-064 turbo with 140x550x65 chinese FMIC. Car haven't been dyno'ed yet. The problem is low flow on relatively high boost. On about 1.3-1.35 bar at 6k I have only 190g/s flow. No leaks (tested about 30 times - REALLY. because of boost problem described in my other post), MAF is new OEM Bosch, DV new bosch, n75 new pierburg. Whole intake is 2,75" from turbo to throttle except oem flat pipe before intercooler and 2" throttle inlet(this black pipe). Is that a problem? Is FMIC too small? I don't want to go over MAP limit :/ I've seen cars that made 200-210g/s on 1.2-1.3 bar. Logs attached. Thanks in advance! Title: Re: Flow problem.. Again! Post by: nyet on July 12, 2019, 03:44:43 PM pressure drop is built into that log, you are reading pressure before throttle plate, so pressure vs MAF doesn't tell you anything except iat :)
log ps_w though to make sure your MAF calibration is right, maybe you're underscaled. Even so, the only real metric is dyno anyway. add IAT to your log while you're at it. Title: Re: Flow problem.. Again! Post by: kacperoooni on July 12, 2019, 04:15:02 PM pressure drop is built into that log, you are reading pressure before throttle plate, so pressure vs MAF doesn't tell you anything except iat :) log ps_w though to make sure your MAF calibration is right, maybe you're underscaled. Even so, the only real metric is dyno anyway. add IAT to your log while you're at it. Thanks for reply, iat was about 30 degree celcius, I checked it many times, maf calibration is stock, oem maf diameter and sensor. Ps_w isnt modeled pressure? Well I know understand nothing :/ Doesn't bhp depend on flow instead of pressure? I'm now scrolling vcds log on malone tuning log viewer and I see even 230-240g/s on 1.45 bar in some logs. And whaf does it mean thar pressure is built in that log? Title: Re: Flow problem.. Again! Post by: kacperoooni on July 14, 2019, 10:41:14 AM Waiting for pipes to arrive, gonna replace that oem flat pipe and throttle inlet pipe. I will report if anything changes.
Title: Re: Flow problem.. Again! Post by: nyet on July 14, 2019, 11:10:58 AM And whaf does it mean thar pressure is built in that log? You said Quote The problem is low flow on relatively high boost. If your problem is pressure drop, "high" boost at the turbo isn't being measured, the boost you are measuring is at the throttle body, so if you think the boost is too "high" for the maf readings you are seeing, it isn't because of pressure drop. Title: Re: Flow problem.. Again! Post by: kacperoooni on July 15, 2019, 01:16:33 AM You said Okay, I know that measured boost comes from MAP sensor between throttle body and IC. But my MAP's sensor pipe diameter is 2.5" and right after it (before throttle body) it is reduced to 2" by oem pipe(i dont know why i did this, probably because the space was limited). What else can cause problem? Head? Valves? Wrong timing? If your problem is pressure drop, "high" boost at the turbo isn't being measured, the boost you are measuring is at the throttle body, so if you think the boost is too "high" for the maf readings you are seeing, it isn't because of pressure drop. |