NefMoto

hi
running volvo TD04HL-19T on 1.8t with 8.8CR

compressor surging on WOT @3000-4500 when boost levels higher than 1.2 bar

any ideas how to avoid that?

Avoid 1.2 bar?

surging is not related to n75 activity?  with a fixed dc, does it still surge?

avoid mid-size turbo
back to k03
etc  :-\



i didnt try fixed wgdc hovewer this turbo pretty linear and i havent problem with controlling it

its about mass air flow because i see maf readings fluctuations when i hear that sound
boost level stays pretty linear with it
after 4500rpm it holds 1.6 bar with no problem but i dont like GT30 style when city driving  :(

i think its all because turbo cant pump that airmass thru the engine in mid-range rpms and going to left surge area of compressor map
the question is - can we elaborate this with a software or hardware without overbore the engine block and changing the turbocharger unit

Does the engine have VVT?

yes
but its turned off

turn it on and see if overlap helps, if not the turbos are crap

What's kfldhbn set to?

Same Volvo turbo on a Volvo S60 2.5T. Dual CVVT.
No matter how I adjusted cams, it still surged.
As soon as I went above 1.1bar at 3000-3500 or so, it started chirping like a bird. So I kept the boost gradually rising from 3k to redline.

Your turbo is poorly matched to the engine for low/midrange boost. It's outflowing the motor at 1.2 bar. There's nothing you can do about it other than lowering boost or changing turbo/cams etc.

take down the boost untill it stops surging, then taper up when rpm increases. Will make the car feel more linear too  :)

Try find an antisurge compressor housing

Sorry to potentially derail the thread but what are your methods for fixing wgdc? in KFLDRL or do you use KFLDRAPP?

KFLDRAPP w/ CWMDAPP = 8

I really don't get the tiny motor huge turbo thing,

Try a k24-7400 from a later volvo r? It should be pretty close to bolt in place. Compressor map surge line looks more promising.

19T is by no means a huge turbo lol

yep its definetely sounds like that (nice explanation btw :D )

well its pretty hard to find those turbos here

there is kinugawa offers $150 anti surge comp housing
but im using volvos comp housing with internal DV and different WG mounting

idk is there a reason to continue with that turbo or change to another T3-flange unit

19T pulls from 4500 and hits max 300g/s at ~6000rpm

well i was changed comp wheel to billet 7+7
just for curious
pid should be tweaked aswell and its 5120 file

dotted line - new comp wheel

Cool, you picked up 20g/s? Is surging eliminated now with the slower spool?

unfortunally i have no time to fix pid and test it with higher mid-level boost
but ive seen today 1.4 bar @3500 at 5 gear with no surging

as for maf readings - there is a slightly improvement. ~296 -> ~305