VF30 boost issue

[92legacyawdturbo]

Alright so I am curious and mind boggled and would like some of yours guys opinion on what I can try next to see if can fix the issue. Basically 1st gear only does like 10lbs which is normal I assume since its quick. 2nd and 3rd gear hit 14-15 lbs then after a second or two drop to about 6lbs. 4th gear holds 18lbs then will drop to 6lbs as well. So far I have tried going through the intercooler piping and put new t clamps on to make sure there were no issues there and made sure no holes were in the piping itself. Next I thought well maybe bad wastegate so replaced it with another wastegate and same issue. Ok well my next thought was maybe boost controller so I currently run a halman boost controller. Swapped it with another halman and even grimspeed, the issue is still there. There is no shaft play in the turbo at all either. So if I could get some other ideas where to go next on the issue would surely appreciate it as would like to hold a steady boost. Thanks

[cj91legss]

Differences in boost under load always vary. That one thing that sick about a mbc. But not from 18 to 6 psi.

Maybe you should fork over the dough and get an electronic controller. It's a worthy investment.

[wtdash]

Hi,

When I had a TD04 w/a hose that ran from the turbo to a 'coffee cup mod', I had a similar issue...the hose was collapsing.

If you're running a VF30 you must have fabbed up an intake that involves some silicone hoses? If you have any unsupported length of hose it likely will COLLAPSE under boost, which would drop your PSI's.


GL,
TD

[92legacyawdturbo]

Well running a front mount and running basically a 90 off each side silicone hose wise. Will check some more on it tomorrow during daylight.

[kimokalihi]

Same thing happened to my friend Robert. He kept saying it was fuel cut. Turned out to be the turbo inlet hose he used was radiator hose and it was collapsing under load and suffocating the engine. Silicone hose fixed that.

[92legacyawdturbo]

I will check in the morning time. Running a fuel cut defender when had the TD04 was no issue with fuel cut once I installed that. I am thinking the VF30 pulls more than the TD04 and as why it may be possibly collapsing.

[kimokalihi]

My friend had a td04 he just installed when he had this issue so that's certainly capable depending on what hose you're using.

[92legacyawdturbo]

Alright after some more testing this is what I think appears to be happening, sorry havent had much time. basically it seems to me that after 4500rpm that is when boost drops. Your thoughts ?