D4BF - turbo vacuum lines

[f1del]

hi , i have a D4DF and im not sure about my vacuum lines, my turbo doesnt seem to be boosting and the wastegate isnt opening, but one doubt remains, which vacuum line goes to the top of the fuel pump ? is that the boost compensator?

- i swapped from a D4BH to a D4BF which i got around 6 months ago, i have a boost gauge waiting to be installed, and im going to buy a manual boost controller and the plug for the boost relief valve, but im still unsure if my vacuum lines are connected correctly , and it definitely isnt opening up the wastegate as i had it straight piped for a while with both engines and the d4bh made alot more lovely spooling and wastegate "dumping" noises
i was running it without the vacuum pipe to the fuel pump for a bit but someone pointed it out and i connected it up , there was a small increase in power or throttle response but theres definitely lacking spooly noises - could the old washer on the wastegate bolts do the trick ? or is it even necessary to do that if i get the manual boost controller installed?

Cheers everyone !

 

[sck_nogas]

Stealing from @Growlerbearnz ....


You should have two boost nozzles on your turbo.

1. The outer part of the "conch" shell runs to your IP (Injection Pump) (which you can insert a tee connection for your boost gauge)
2. The inner part of the "conch" shell runs to your wastegate. (which you insert your boost controller to control the wastegate)

Make sense?

 

[f1del]

yes thanks alot for that diagram ! i think i might have to switch out the wastegate that i had left over from my old d4bh that i know worked because there was a notable "dumping"noise when the wastegate opened which, i havent heard at all since i swapped in the d4bf ,the issue is the old wastegate mounting points are at different rotation so to speak , is it possible to rotate the wastegate actuator arm/rod without breaking it? otherwise ill have to cut the bracket that goes on the intake manifold and somehow realign it

 

[sck_nogas]

If your wastegate spring is set too high, then the wastegate won't open. BUT... Isn't that what you want?

• Turbo CREATES boost by taking exhaust pressure and spinning thus sucking more air in and shoving it into the intake
• Wastegate REMOVES boost by taking exhaust pressure and leaking it out through the exhaust.

So, (making numbers up) if your wastegate is set to open at 17 PSI of pressure and your turbo creates 16 PSI, then you are never reaching the maximum allowed pressure and thus the wastegate never opens.

But, if your old wastegate is (set to/has weak springs that) open at 8 PSI of pressure and your turbo creates 16 PSI, then you are constantly hearing the whooosh of the lovely beautiful boost you've worked so hard to create go rushing out and getting wasted.

So, I'd first test my (old/new) wastegate with air pressure and a regulator to give it a "known" PSI and see what it actuates at.

 

[Growlerbearnz]

The wastegate doesn't usually make a noise on a 4D56 or D4BF: it opens gradually and merely allows some exhaust gas to leak past the turbine.

On a tuned gas engine turbo car the "whoosh" noise you hear is the blow off/dump valve, which releases intake pressure when the throttle plate is closed. Our engines don't have a dump valve (or even a throttle plate) so they shouldn't make a loud whoosh.

They *do* have an overboost relief valve on the inlet manifold, at the back beyond the wastegate actuator. It's a spring-loaded valve that pops open if intake pressure goes beyond ~13psi, and should be removed/disabled if you intend to make more boost than that. Check your relief valve and if it has any oily residue, then it's been opening and needs to be blanked off.

 

[f1del]

thanks so much for your replies , with the d4bh I only ever noticed the wastegate dumping/whooshing sound when id clutch in or change gear above 2500-ish rpm , it held the boost otherwise so now that i have the d4bf and it doesnt do it im a tad suspicious, i recently purchased a boost gauge & manual boost controller , all im missing is the plug to blank off the boost relief valve on the intake manifold, ( or do i try without blanking it first just to be safe?)
definitely going to see about getting the wastegate pressure measured to see whats going on , during the engine swap , i did have to change the intake manifold from the old engine to keep the intercooler functional which was a straight bolt on but maybe something like the distance from the rod changed a small bit but enough to stop it actuating properly .. also the turbo makes no spooling-up noises in contrast to the old turbo it only makes ever makes noise when spooling down and a mechanic also noticiced and revved the engine while pressing the interooler pipe with his hand and said it wasnt boosting enough , (not sure how much of a diagnosis that is lol) i have a straight pipe from the catalytic converter so i get to hear whats going on in detail , anyway thanks for the input , photo below is of my hyundai galloper based on a mk 1 pajero , but licenced to hyundai by mitsubishi , its 21 years old and im pretty sure its been on its side before i aquired it lol it was definitely neglected but its come a long way since then ive been adding bits and pieces over the last year and a half

 

[sck_nogas]

I'd definitely get the boost gauge installed first. See what you are generating without any tweaks. Then, I'd...

1. Shorten the pull rod of the waste gate to remain closed as much as possible
2. Then if I need to have my boost higher, install the manual boost controller between the turbo and the wastegate
3. Then if I want to make sure ALL my boost is kept inside, remove the boost relief valve and cap it.

That would be my order of operations