YD25 Compound Turbo

[dilmah]

Soo I think I killed the primary stock turbo on the weekend. its only making 17psi when it was easily pushing 25 before. Forefront time Id say!

 

[Rumpig]

That didn't take long!

 

[dilmah]

its been running at 23+psi for 2 years now, way off its map. bound to kill it sooner rather than later

If I bought a GTurbo grunter I recon the system would be good for 50+psi

 

[gazza414]

its been running at 23+psi for 2 years now, way off its map. bound to kill it sooner rather than later

If I bought a GTurbo grunter I recon the system would be good for 50+psi

which map ?..why did it kill it ?

 

[dilmah]

the stock navara turbo would be way off its map at 23+psi. Ive never seen mine go above 27psi and that with the manual boost controller turned all the way up under very heavy acceleration.

I really need to pull it out and have a look at it. I drove it today and it struggled to make 16psi

 

[gazza414]

are you saying the hot side "off" map killed the turbo ?

 

[dilmah]

Unsure yet, need to pull it out and have a look but there is a fair amount of oil in the piping before the intercooler

 

[xtturbo]

the stock navara turbo would be way off its map at 23+psi. Ive never seen mine go above 27psi and that with the manual boost controller turned all the way up under very heavy acceleration.

I really need to pull it out and have a look at it. I drove it today and it struggled to make 16psi

Maybe you should read the spec sheet of your turbo before trying this stuff...

The stock YD25 D22 Turbo is rated BY THE MANUFACTURER as having a maximum working pressure of 28 psi.

Also, if you have a look at the pressure map, you'll find that 23 psi, although out of the high efficiency range, is certainly still usable.

This is coming from someone who has:
a) Done the research regarding the turbo, and,
b) Run 20+ psi for the last few years.

More than likely you've lost boost due to a leak somewhere. At higher pressures its easy to get a leak around the intercooler piping hoses, especially given the volume of oil that builds up in the intercooler due to the crankcase ventilation valve.

 

[dilmah]

The funny thing is running high boost doesn't really make the Nav more drivable. Having 5psi at 1200rpm with the compound turbo setup makes it a joy to drive. I think I would know if I have a boost leak. When I got home all the hose clamps were done up tightly. I still havnt removed the primary turbo yet so I won't know for a few more weeks, got bigger things to do ATM.

I have however removed the turbo - intercooler piping and there is a fair amount of oil in there leading me to believe some sort of mechanical failure.

My crankcase vent is a hose that runs underneath the car

 

[happy john]

My stock Hitachi turbo produced a mighty 4 hp more when the boost was increased from 16psi to 21psi. Now it is set to 19psi and produces the same power.

 

[dilmah]

The only reason I was running mine so high was to stop waste gate creep and get it spooling faster. I wouldn't be surprised if I was making the same power at 20 psi than what I was at 24psi but it was a hell of a lot nicer to drive!

 

[dilmah]

So I had an idea last night: mount another W2A core between the primary and secondary turbos and run it off a second radiator. As Im turning my truck into a class 8 I will be running the W2A radiator at the rear of the truck so I can maximise airflow to the radiator. So there will be an intermediate cooler and an after cooler for this setup, on average intake air temps have gone up 20 - 40 degrees with the compound setup so I need to get these down somehow.....

 

[tweak'e]

what boost pressures are the two turbo's set to?
IC between them is good if the big one is running high enough boost for it to be worthwhile. the last thing you want is pressure drop.

 

[dilmah]

Pressure drop though the current core is less than 1 psi. I took one of the temp sensors out of the intake manifold and put the 2nd boost gauge in there before I installed it on the secondary turbo and they read almost identical.

Secondary turbo is currently set to 10psi, primary is at 25 psi until I get it tuned. I am planning to run around 30psi. I will run the the secondary at 12 and make the rest up with the primary.

That will be the biggest part of tuning, finding out what boost combo works best to make 30psi

 

[dilmah]

Finally got the MAF sensor welded in

I also have a manual boost controller on the secondary turbo now so I have been playing with the boost levels on each turbo trying to get the best spool rate

 

[Jased22]

If you were to start this build again. Would you go with the compound turbo or a d40 turbo and manifold?

 

[camo.b]

I saw a d22 for sale the other day with a gt2056v (d40 turbo) fitted with a gtx 11 blade comp wheel...
http://www.gumtree.com.au/s-ad/pomo...er&utm_medium=email&utm_campaign=saved_search

 

[Jased22]

A guy on the d22 facebook page is making good power with d40 manifold and turbo

 

[camo.b]

Whats he doing with the fueling?

 

[Jased22]

Not sure man. Just had a look and couldnt find his dyno sheet with all the info on what his done. Think it made 215hp. It goes hard seen a few videos of it