Hi All,

longtime reader, first time poster. Most of my build is a recipe from here and other parts of the community, so thanks. Finally thought Id join and contribute because Im spinning wheels in my head more than the truck on this issue. Also see if I can help contribute to other headaches too.

 

Issue relates to not achieving max boost out of the turbo, unless the wastegate is pinched. I dont see any boost leaks, and have plenty of fuel, more later.

 

in case sig doesn't appear or post. (Only listing relevant items)

 

2001 24v, S&B cai, banks monster ram, afe bladerunner, headstuds, hamilton valves and rods, DFI 7x.010, BD exhaust brake, Quadzilla,  3.54 on 275/70R18 (yes, its a little low on the gearing). Turbo is a Hx35 64/64 its set from factory at 40 psi. Valves adjusted recently.

 

Ive reached out to the vendor and theyve been helpful. Sent an additional WG actuator but have the same results. Im hoping Im missing something obvious.

 

Backing up a bit on build. Had RV275, hy35 j hook, original edge j w a. 0-60 8.5s not hard launch, at 34 psi boost (side note, this setup was almost completely clean except for boosted launches on 5x5 or other silly things also 19-21mpg). Bolted on this turbo, 0-60 7.5s at 29 psi.

 

Cool on right track, need more fuel I figure. Added DFI 150s and a quad. Still 29 psi..

 

Adjusted wastegate rod in, 34 psi max, about a dozen different times and adjustments. Used shop air gauge on boost reference hose to set 40-60 psi opening, with same results. Removed downpipe and plate, to visually inspect wastegate, appears all good.

 

Set quadzilla all the way frickin up, also different timing variations. 34 psi, and high egt cutout.(1400).

 

Built adapter plate for turbo intake to pressure test and look for leaks, all good. New MAP sensor from NAPA

 

The only way Ive found to go over that is pinching reference hose. Thats why Im leaning so heavy on the WG. Itll shoot up to 44 no problem quick, either my foot or defueler kicks in and backs out, and egts cooler (11-12?) these numbers are mostly from the quad, but had same from the edge too.

Please help, this is supposed to be the end of my build and having trouble. Id like to focus on more tuning soon and getting best mpgs out of this or possibly slight smaller injector setup.

 

Tomorrows saturday, so open to testing suggestions. Probably at least post a shot of hose pinched and unpinched. Although not handy with the excel to graph it.

 

Thanks for reading, and getting me this far along.

 

 

 

 

 

3 hours ago, SVALIN said:

So next test is reset actuator to 40 lbs and boost adjustable elbow. 

 

I am interested to hear the results.

 

- John

So I made my own adjustable elbow. Im noticing from online photos that there seems to be a vent drilled into it? Or atmosphere pressure? The one I made just put an allen to block off/restrict pathway. So if im missing something may have to try again.

 

it made no difference, several attempts at different amounts. I readjusted waste gate to open at 45 lbs, which has netted me 33 or so boost.

 

I installed a boost reference gauge, very similar to my back pressure setup. It showed the same pressure as my MAP sensor. No higher than 34. 1160 egt. 

So I guess that sorta settles it. Drive pressure has to be assisting the wastegate opening. When I adjust the arm all the way in, im getting more boost from preload, but also limiting how far the door can open, increasing Egt and drive pressure, and cant seem to get enough before running into choke point.

 

Another note about this/these turbos. Ive seen a lot of similar/close 64s on the market, spoologic, cheetah, stealth. So sorta bizzarre I seem to be only one running into this, but not seeing many other conclusions.

 

If Im missing something, let me know. Otherwise I hope I collected some useful data for spinning my wheels for a week.

1 hour ago, SVALIN said:

So I made my own adjustable elbow. Im noticing from online photos that there seems to be a vent drilled into it? Or atmosphere pressure? The one I made just put an allen to block off/restrict pathway. So if im missing something may have to try again.

 

The drilled hole is a vent and it is needed to make the boost elbow work.  If there is no vent, the boost flow can be restricted, but air will eventually fill the wastegate actuator chamber resulting in no change of wastegate operation, other than the wastegate will take a bit longer to open.

 

The drilled orifice is downstream of the adjustable restrictor.  The orifice will also act as a restriction, but as pressure builds the flow leaving orifice to atmosphere will match the flow passing through the adjustable restrictor at some point.  When this happens, the new pressure value acting on the the wastegate actuator will now be lower than the actual boost pressure value of the air entering the boost elbow.  The wastegate will not open.

 

1 hour ago, SVALIN said:

Drive pressure has to be assisting the wastegate opening.

 

Yes, this is true.  Exhaust flow that enters the turbine housing is exposed to some of the area of the closed wastegate valve.  That area can be calculated by measuring the diameter of the exposed area.  Example:

 

Formula to calculate force.  Diameter squared times .7854.  (D2 x .7854)  Let's say the exposed diameter of the closed wastegate valve is one-half inch.

 

.5 x .5 x .7854 = .19635 square inches.  I will round that to .20 square inches.  Multiplying .20 square inches by 50 psi (turbine drive pressure) will equal 10 lbs of force pushing against a mechanical spring.

 

The same method can be used to calculate the force of the wastegate actuator rod under a specific boost pressure.

 

- John

 

 

 

 

Mine is way different its two body halves with a spring and check ball inside the unit. As you screw it together it increases the boost pressure, loosen then there is less boost pressure. I gave up on those boost elbows since its just a controlled boost leak and now a regulator for the wastegate. The check ball keeps the line closed till the boost pressure is enough to open and push the wastegate. This also has a small bleed hole too to release the waste gate after the pressure falls again but works way better than those boost elbows. 

 

I got mine off of eBay from a place in China it took awhile but it was a mere $15 bucks or so. 

@Tractorman All very good information, paper calculations with BP are matching up closely with the WG numbers. This should be fairly true across the board, Even with units that have a lot less BP. I guess not many complaints though if say gate is set to 40 and getting 38.

 

@Mopar1973Man Pray tell more about this fingertrap invention. Having a constant boost leak isn’t ideal. I found a PPE 116030000 Boost valve that looks like what your describing. Its preset though much lower, 25 psi, and designed for a LB7. Ebay search resulted in nil.

 

 

20 hours ago, SVALIN said:

@Mopar1973Man Pray tell more about this fingertrap invention. Having a constant boost leak isn’t ideal. I found a PPE 116030000 Boost valve that looks like what your describing. Its preset though much lower, 25 psi, and designed for a LB7. Ebay search resulted in nil.

 

 

Here you go...

 

Inside is a check ball and spring but still has a small bleed hole to allow for the pressure to be released after the boost pressure falls. The check ball will close again keeping the boost going strong. 

 

Tested and proven at least on my truck. I pulled the wastegate hose loose and left it open not plugged. Then pulled 1 manifold bolt out as a open hole leak. As for max boost pressure was only down 5 PSI and had ZERO impact on EGT's on my truck made little to no different even while WOT operation. So as for the tiny pin hole boost leak has ZERO impat on performance nor will it change the EGT's when I've had a leak that was MASSIVE comparing it didn't run hot or smoke any differently. 

Thanks! @Mopar1973Man

 

I couldn’t find that specific unit. I did find a Swagelok 4-CPA2-3. Prefix SS for stainless, B for brass. Couldnt find brass in stock. About 40$. Adjustable poppet check valve from 3-50 psi. I set it to 40, starts to crack at 38. I attached 1/4” hose barbs on either side, and drilled a .040 hole on actuator side. Planning to mount as close to actuator for hose bleed off reasons.

 

I haven’t installed it yet, because I swapped back to RV275s for moment, and putting everything on it, can only get to 34 psi. So Ill have to wait before posting results on that. 

This is where my manual boost adjuster is mounted, the top of the alternator bracket.