SASHO91
Zoom Zoom
Strap her down!!!!
Turbo dyno dilemma
- Thread starter Power Surge
- Start date
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Off Road SHO
Moderator
kzoosho
Holset HX52
I pulled the gate out the other day and completely dissasembled it. Replaced the housing oring, cleaned everything, and installed the new spring. Checked the opening pressure with regulated shop air and a boost gauge. Opens precisely at 13 psi. A little higher than the spring rating, but I'm not complaining. Gate seals perfect to the ring.
Driving the car, it's hard to tell what it's doing. Maybe I'll throw it back on the dyno today.
Were you planning on it opening at 13 psi? and if so if its not going over 13 then its opening. If its not hitting 13 psi then theres a leak some were.
Power Surge
SHO Member
Well, here's the latest...
Wastegate installed back in, with new spring that opens at 13 psi.
Car dynoed exactly the same. Same power, same boost no difference whatsoever.
Here's what I tried today...
- pulled the brake booster vacuum feed off the back of the intake to rule out boost being blown out that way
- disconnected the secondary feed so they are full time open to see if it had any affect on boost
- removed the bypass and blocked off to rule out bypass venting off boost
Not one of these things made ANY difference in boost. The secondaries being open full time killed a bunch of midrange power, but that didn't affect boost.
The last test I was going to try, was to pull the air cleaner off and run the turbo open. Once I got the tube off the turbo, I tried turning the impeller to see how it felt. It has some pretty good resistance. It also has some side play. And if you push it to the side, it gets harder to spin.
My guess at this point, is that I think the turbo is bad. That might actually make sense, because the car did feel like it was much stronger when I first ran it. The turbo shaft could have galled up the more I drove it.
This IS a brand name turbo, but I also did buy it off ebay. It was claimed to be recently rebuilt (and clearly was), but that doesn't mean it was done right.
Sorry folks. I don't have the money to fix this right now. So unless someone wants to donate me a turbo, it might be a while till I get her making some good power.
Wastegate installed back in, with new spring that opens at 13 psi.
Car dynoed exactly the same. Same power, same boost no difference whatsoever.
Here's what I tried today...
- pulled the brake booster vacuum feed off the back of the intake to rule out boost being blown out that way
- disconnected the secondary feed so they are full time open to see if it had any affect on boost
- removed the bypass and blocked off to rule out bypass venting off boost
Not one of these things made ANY difference in boost. The secondaries being open full time killed a bunch of midrange power, but that didn't affect boost.
The last test I was going to try, was to pull the air cleaner off and run the turbo open. Once I got the tube off the turbo, I tried turning the impeller to see how it felt. It has some pretty good resistance. It also has some side play. And if you push it to the side, it gets harder to spin.
My guess at this point, is that I think the turbo is bad. That might actually make sense, because the car did feel like it was much stronger when I first ran it. The turbo shaft could have galled up the more I drove it.
This IS a brand name turbo, but I also did buy it off ebay. It was claimed to be recently rebuilt (and clearly was), but that doesn't mean it was done right.
Sorry folks. I don't have the money to fix this right now. So unless someone wants to donate me a turbo, it might be a while till I get her making some good power.
kzoosho
Holset HX52
Well i can get you a garrett t3/t4 turbo for a pretty decent price man. But yea if you are only making 8spi of boost then thats a bad compressor. Let me know and i can see what size turbos we can get here.
Power Surge
SHO Member
I wouldn't complain if it were 8 psi
. It actually only hits about 5-6 at the most by 4500, then drops down as the rpms go up, to about 2 psi by 6500. It also spools real slow. So I'm guessing it's the shaft.
somedude_001
SHO Member
I wouldn't complain if it were 8 psi
It also spools real slow. So I'm guessing it's the shaft.
If I knew you better I would let you borrow my turbo so you could enjoy the full rediclousness of it, but I can't hand out $1300 to someone i've never met... no offence... I would love to see the goofy ass smile you would have the first time you hear its ear piercing shreek though.
kzoosho
Holset HX52
I wouldn't complain if it were 8 psi
It also spools real slow. So I'm guessing it's the shaft.
Thing is a unregulted turbo should be infinate amount of boost thats all. once you found that there are no leaks then you just arent boosting. Now if you are sure that you dont have an exhaust leak any where cuz that would slow your spool also.
Power Surge
SHO Member
Yes, there are no exhaust leaks, not even the slightest hint of a leak.
It's deinfitely an airflow issue. Looking at the MAF voltage log, it only goes up from 4.12 to 4.23 from 4800 to 6000 rpms. So increasing airflow stops pretty quick at 4800, which is also where power drops off. The LOAD log also follows suit, and matches the dyno torque curve (as it should). So at 4800, the motor is no longer taking in increasing amounts of air.
kzoosho
Holset HX52
Deff a turbo. I wouldnt run it anymore . It would suck for you to shred something in the turbo and **** the motor. I would pull the turbo and go through it. They have rebuild kits on ebay all day. But that is deff a turbo problem man.
Time to upgrade to a turbocharger that can handle the airflow and such of this high revving engine.
Power Surge
SHO Member
I'm pretty confident that the turbo I am running can power this motor fine. They are used all over the DIY turbo world, on everything from large 4 bangers to small block V8s, and make great power.
That stinks Sal. If I had an extra turbo laying around, I would send one out. I just sold a new T3/4 to a local guy. If I still had it, I would mail it out you. FWIW, I picked it up from another local guy for $200 (china made, but looked well built, and would probably be fine for 8 psi).
NCTaurusSHO
Guest
I have that same turbo you can get does it have the small exhaust ******? They are very easy to rebuild they sell major and minor rebuild kits at the most 50 dollors
Paul
Paul
NCTaurusSHO
Guest
I did not like the HC-1 it pulled ******* the bottom and that was it .I like the big diesel GT42
BlackonBlack89
SHO Member
So did you ever find out the problem???? Is the turbo to small or does it need a rebuild?
Are you gonna get a bigger turbo
?
Are you gonna get a bigger turbo
?
Brett
SHOs before HOs
It must suck to have this much money in wrench time into and have such a stupid problem holding you back. Im sure its discouraging but dont let it beat you! Minor set back compared to the actual task of putting the turbo on the car. Im stoked to see what kind of numbers your car will really make. Get it fixed ASAP! 
good luck
good luckHotRodKid
mmmmm ... turbo
Power Surge
SHO Member
I just got the rotating parts back from being computer balanced. I am going to try to get it back together in the next few days. The turbo is borderline on the rebuild specs for the bearing clearance, so it may or may not work 100%. We'll see.
Either way, the car is going up for sale. It will either be sold running as it should, or in need of a turbo. If it needs a turbo, I will offer to install a new turbo and then retune the car properly if someone who wants to buy the car wants to send me a new turbo for it. I'd rather see it leave here running the way it should.
Either way, the car is going up for sale. It will either be sold running as it should, or in need of a turbo. If it needs a turbo, I will offer to install a new turbo and then retune the car properly if someone who wants to buy the car wants to send me a new turbo for it. I'd rather see it leave here running the way it should.
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