Hi guys ,

I’m having huge issues with getting the turbo I build to boost more than 9 psi, I checked numerous things and I’m out of any ideas and I’m hoping someone has .I decided to build a turbo for my Volvo that would fit with minimum modifications to manifold , oil feed and return lines . The turbo setup is :

TD05HR - 16G 10.5 off an EVO 6
Replaced 12 blade reverse turbine with 9 blade forward one to fit the exhaust housing
Replaced the Reverse compressor wheel with Billet Forward one
Stock Compressor housing
Patrol TD42 T3 Exhaust Housing - compared the sizes and clearances with the EVO housing
Ported the stock Volvo manifold to match the T3 inlet , ported head to manifold inlets.
Forge internal Twin port Wastegate
No radial or axial play

What I have checked and done
Replaced the spring that was originally in the Forge wastegate with red - 20 psi one
Boost leak tested several time , no leaks
Ran the turbo with no boost control on the gate aping - no difference 6-7 psi
Preloaded the gate to a point that it barely opens to rule out exhaust back pressure opening the flap - got around 9 psi this way
Removed turbo to check for any problems with the flapper not sealing properly, flapper is perfect.
Weird thing is , when I get on the throttle from low rpm immediately I get 3 psi then it’s kind of laggy and around 4500 rpm I get to 6-7 psi

I’m completely baffled what might be the issue as I checked everything that could cause this, at least want comes to my mind, I even have two boost meters to compare and be sure one of them is a not trash . I would appreciate if any one can give me idea or clue to what might be wrong with all that

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Leak checks on the exhaust as well? I use a shop vac with the hose connected to blow shoved up the tail pipe. Then I go around everywhere with a spray bottle filled with soapy water. I was surprised how much a very small exhaust leak can hurt spool.

If you aren't running an EMS that has overboost protection be very careful with your testing.

 

I also used the soapy water on the leaks check , no exhaust leaks at all , double checked that when taking off the turbo and inspecting gasket and surfaces . No any problems over boosting as it’s not really boosting ‍♂️.

 

What engine is this on?

 

Volvo Red Block , 8v Turbo .

 

Most important piece of information is engine capacity. Most people here don't care what colour your block is and don't know what "Red" is code for. 1.8?

Check for restrictions. Intake. Connect a vac gauge at the compressor inlet - less than say 3"HG is OK. Alternately run the car with no pipework and air filter.
Exhaust. Pressure gauge at turbine exit. Less than 2 psi at fuul power. Alternately run the car with no pipework and muffer.

Who knows what that exhaust housing is. You originally had a 10.5 TD05 housing - did you seperate the header pipes - 1,4 to one entry and 2,3 to the other? The 16v 2.0 EVO won't boost much either unless it is connected that way. EVOs also came with 9.8 and 9.0 housings. One of those would have been a better option after the 10.5 didn't boost.

You could try advancing your cam 10*.

 

Soapy water with something forcing air or just the engine at idle? The leaks I've found weren't obvious without the shop vac forcing air.

I mentioned being careful about overboost because you swapped to a very heavy spring. If you find your issue and test you'll make 20 psi.

 

Rad block refers to 2.0 or 2.3 , one of the most common Volvo engine from that Era, called in the fields red block , that’s why I used that , not to stare the color of my block , mine is the 2.0 version .

Regarding the restrictions, before swapping to this turbo I ran 19 psi on TD04H 16T with no problems at all on either intake or exhaust side , sizes are more than enough to suit the td05h.I was planing on running without the filter to tick this out of the list, no matter it is with brand new decent sized filter.

I did just put the full information for the original turbo that’s why I put 10.5 , it is impossible to run twin scroll housing of an EVO on the Volvo manifold , conversion is Volvo to T3 flange , the housing I’m using is 6cm as I need faster spool , EVO 1-3 comes with 7cm , all of them
Have the same size turbine wheel .

 

Forcing air with to the desired pressure to run not at idle .
I am monitoring pressure constantly when testing , plus it doesn’t go past 8 psi

 

Have you checked the clearances between the wheels and the housings? Too much room and you'll get what you're describing here. Another thing I have seen is an IC tank cracked that opens up under pressure.

 

The new wheels I have put in we’re measured beforehand and compared to the original ones , using the original compressor housing and also measured the original EVO exhaust housing and the one fitted now , initially I was thinking that’s the issues but sizes are identical. Also pressure tested the system up to 30 psi on cold and hot engine to ensure something doesn’t open up due to temperature , no leaks. The only thing I can recall right now is if using the original banjo bolt for the feed line and this to be not enough to supply sufficient oil and cause oil starvation, realty doubt it but I’m out of ideas for now .

 

Your compressor cover doesn't match the rotation of the turbine/compressor wheel. First pic says it all.

 

Compressor wheel was replaced to match the compressor housing direction

 

Look at the housings, the turbine spins clockwise from the front, and the compressor wheel would be pushing air towards the closed end of the compressor cover. You actually mention it in your first post

You can't change the rotation of the wheel without changing the rotation of the cover.

 

I’m So stupid it was in front of my eyes all the time , you can change direction of flow with different wheels but not the direction of the housing , by changing the reverse wheel I just made it suck air instead of blowing it out of the hosing , but not the direction of where air is going I guess .

 

It happens. It still compresses the air, but the air backs up, and needs to flow out of the cover in the opposite direction. It'll be so much more efficient with the proper cover.

 

Well spotted Mnlx.