mat88
Yorkshire and The Humber
Posts: 1,542
|
|
Aug 25, 2020 16:28:57 GMT
|
|
Well all rods are still in all holes.. and all the boost is still missing..
If anything it's maybe improved it by a psi. But it's by no means fixed. Flat out wide open pulls show maybe 4 psi at most..
I'm begining to think I've either got a huge boost leak. Or the turbo is simply too big (it's been done before so it shouldn't be)
Back to the drawing board
|
| |
|
|
|
|
Adey
Posted a lot
Posts: 1,442
Club RR Member Number: 171
|
|
Aug 25, 2020 17:06:05 GMT
|
|
huge boost leak, has to be surely unless you have a huge backend on the turbo but even then at top revs you should be seeing decent boost.
|
| |
|
|
mat88
Yorkshire and The Humber
Posts: 1,542
|
|
Aug 25, 2020 17:43:13 GMT
|
huge boost leak, has to be surely unless you have a huge backend on the turbo but even then at top revs you should be seeing decent boost. I'm beginning to think it must be.. going to have to try and cobble together some kind of smoke tester and see what on earth is happening. Cus it's not working at minute.. |
| |
|
|
lebowski
Part of things
Hillman Avenger, Clan Clover
Posts: 488
|
|
Aug 25, 2020 18:19:08 GMT
|
|
I can't help but think your turbo is too big. Boost leaks might lose you a few psi here and there, but if your wastegate is sealed off and you're still getting nothing, it doesn't look good. If your turbo is rated for 800bhp but you're only making 280(?), I think you're gonna struggle.
I know you say that others have used HX50's on these engines, but HX50 is a vague frame size, and there will be many variations available with different wheel and housing options. Similar to how a T3 could be fitted to everything from a 95bhp Metro to a 300bhp Cosworth. They have the same frame size but most definatly aren't the same turbo.
If I were you, I would start by trying to get a compressor map for your specific turbo if possible. I appreciate this may be difficult. With a bit of maths you can plot your engine values onto the map and it will immediately give you an idea whether the compressor side is anywhere near.
The turbine side will be difficult but there should be a cast size just inside the volute next to the flange. You may be able to compare it to those builds you've seen which have used this size turbo.
If you've already done this then of course you can disregard my advice!
|
| |
|
|
The Doctor
Club Retro Rides Member
Posts: 3,449
Club RR Member Number: 48
|
|
Aug 25, 2020 18:39:44 GMT
|
|
If I remember correctly from a few pages back, you had stavtech help you with the turbo? I can't imagine him giving you wrong advise... The stuff he posts on Facebook goes way above my head, but he seems like a guy who really knows his stuff.
|
| |
Last Edit: Aug 25, 2020 18:40:52 GMT by The Doctor
|
|
|
|
|
Aug 25, 2020 21:42:35 GMT
|
If the turbo is an HX 50 holset then you might not see sufficient boost occur before about 6000 rpm. As these turbos with design for about 12 L truck. The turbo I’ve got fitted to my Lexus V8 was for a 8 L truck. Where you see boost start about 1 1/2 thousand rpm. Bearing in mind that the car engine is half the size of the truck, so the gas flow will under be half the amount. You expect to see the boost start at over twice the RPM of the truck. A 4L engine revving twice as high it should give more or less the same gas flow as the 8L engine at half the revs. mine does start to spool  at about 3 1/2 of rpm and boost is on by 4000 rpm. Looking at the holset Data, they recommend that the HX 50 turbo is suitably up to 15 L engine, so with that in mind, an average of 12 L then your engine would have to be revving three times is high. So this would be around 6000 rpm to start the boost. A lot of people do use a holset turbos but I’m sure it’s normally the HX 35 as it is a smaller and produce boost low down the rev range. Remember this is not an exact science, as the gas flow on a diesel engine is far higher than a petrol engine due to their design. www.myholsetturbo.com/holsethx50.htmlA diesel engine is not directly comparable to a gasoline engine that way.. Hx50 is a commonly used turbo on V8 engines.on BMW V8 engines i've seen them been used to very good effect. Most important here is the size of the turbine and housing. But i guess it would be hard to find one with a housing and wheel big enough to not be able to make any boost on this V8. There must be a different explanation. I would block off the airfilter side and then pressurize the intake to look for any leaks. Sorry i'm to lazy to scroll back through the posts but did you also try without the air filter? They can be a big obstruction and if the engine cann't suck air in it also cann't compress it. |
| |
|
|
|
|
|
Aug 25, 2020 22:05:32 GMT
|
|
The air filter is a good call. Some friends of mine race a diesel radical in endurance races and spent the majority of one race wondering why they were making no power. 20 hours in they removed the new cone air filter they had fitted and hey presto!
|
| |
|
|
shyam
Part of things
Posts: 162 
|
|
|
|
What happens when you put your foot to the metal without being in gear? Does it sound like it's making 'better' turbo noises then when you're driving? Wouldn't advise removing the air filter if being used on road as lots of little stones, sediments, leafs etc can get sucked in quiet easily... I used a strong fine mesh wrap (doubled up) over the intake of my turbo when I had mine and it worked well....  Have you checked your intake gaskets? Any cracking in your manifolds? IF it is because you need to get into an extremely high RPM range, then you could look at having your turbo built with a billet bearing and grooved fins.. I did that with mine and it was amazing, boost started coming on much earlier (just after 1k rpm) .... but would make sure it's that before going ahead with it. |
| |
|
|
|
|
|
|
|
|
I wasn't advising running without an air filter, just trying without. If it makes a difference then a different or perhaps larger filter is required.
|
| |
|
|
shyam
Part of things
Posts: 162
|
|
Aug 26, 2020 11:07:18 GMT
|
I wasn't advising running without an air filter, just trying without. If it makes a difference then a different or perhaps larger filter is required. That's fine, not attacking the suggestion...I also found my turbo to be much more responsive without any filter, so I used doubled up sheet of mesh and wrap it around the turbo intake with a big jubilee clip and it worked as though there was no filter on.. I just wanted to put that idea out there, that's all... |
| |
Last Edit: Aug 26, 2020 11:07:54 GMT by shyam
|
|
mat88
Yorkshire and The Humber
Posts: 1,542
|
|
Aug 26, 2020 11:28:49 GMT
|
I can't help but think your turbo is too big. Boost leaks might lose you a few psi here and there, but if your wastegate is sealed off and you're still getting nothing, it doesn't look good. If your turbo is rated for 800bhp but you're only making 280(?), I think you're gonna struggle. I know you say that others have used HX50's on these engines, but HX50 is a vague frame size, and there will be many variations available with different wheel and housing options. Similar to how a T3 could be fitted to everything from a 95bhp Metro to a 300bhp Cosworth. They have the same frame size but most definatly aren't the same turbo. If I were you, I would start by trying to get a compressor map for your specific turbo if possible. I appreciate this may be difficult. With a bit of maths you can plot your engine values onto the map and it will immediately give you an idea whether the compressor side is anywhere near. The turbine side will be difficult but there should be a cast size just inside the volute next to the flange. You may be able to compare it to those builds you've seen which have used this size turbo. If you've already done this then of course you can disregard my advice! I'm not ruling out it being too big. But likewise as I've said it's been done before with this size (25cm exhaust housing).. If it is the case il be disappointed, but that's life. But before I right it off all together I'm going to be dammed sure I've ruled out everything else first haha. And as a comparison stav built a Merc with a 4.3 (I think) V8 and rear mounted a hx55.. so bigger again. Yet that worked perfect. I know there's model variations but bigger is bigger haha |
| |
|
|
mat88
Yorkshire and The Humber
Posts: 1,542
|
|
Aug 26, 2020 11:31:24 GMT
|
If I remember correctly from a few pages back, you had stavtech help you with the turbo? I can't imagine him giving you wrong advise... The stuff he posts on Facebook goes way above my head, but he seems like a guy who really knows his stuff. He did indeed spec the turbo haha. Messaged him personally and he advised. I was actually looking at buying a Borg Warner from him (similar size to this). But he said the hx50 compressor racing had available was a better bet for my goals.. so that's what I went with. He's also been helping me along with this boost problem and has suggested a boost leak as an option. So that's my next port of call. |
| |
|
|
mat88
Yorkshire and The Humber
Posts: 1,542
|
|
Aug 26, 2020 11:32:09 GMT
|
If the turbo is an HX 50 holset then you might not see sufficient boost occur before about 6000 rpm. As these turbos with design for about 12 L truck. The turbo I’ve got fitted to my Lexus V8 was for a 8 L truck. Where you see boost start about 1 1/2 thousand rpm. Bearing in mind that the car engine is half the size of the truck, so the gas flow will under be half the amount. You expect to see the boost start at over twice the RPM of the truck. A 4L engine revving twice as high it should give more or less the same gas flow as the 8L engine at half the revs. mine does start to spool  at about 3 1/2 of rpm and boost is on by 4000 rpm. Looking at the holset Data, they recommend that the HX 50 turbo is suitably up to 15 L engine, so with that in mind, an average of 12 L then your engine would have to be revving three times is high. So this would be around 6000 rpm to start the boost. A lot of people do use a holset turbos but I’m sure it’s normally the HX 35 as it is a smaller and produce boost low down the rev range. Remember this is not an exact science, as the gas flow on a diesel engine is far higher than a petrol engine due to their design. www.myholsetturbo.com/holsethx50.htmlA diesel engine is not directly comparable to a gasoline engine that way.. Hx50 is a commonly used turbo on V8 engines.on BMW V8 engines i've seen them been used to very good effect. Most important here is the size of the turbine and housing. But i guess it would be hard to find one with a housing and wheel big enough to not be able to make any boost on this V8. There must be a different explanation. I would block off the airfilter side and then pressurize the intake to look for any leaks. Sorry i'm to lazy to scroll back through the posts but did you also try without the air filter? They can be a big obstruction and if the engine cann't suck air in it also cann't compress it. That's the next plan. Pressurise the inlet side and see what is happening |
| |
|
|
mat88
Yorkshire and The Humber
Posts: 1,542
|
|
Aug 26, 2020 11:34:02 GMT
|
The air filter is a good call. Some friends of mine race a diesel radical in endurance races and spent the majority of one race wondering why they were making no power. 20 hours in they removed the new cone air filter they had fitted and hey presto! I actually tried it a few weekend back with the air filter removed. (Found a clean bit of road and prayed).. it actually made about half a psi of difference. Which shows the airfilter isn't going to be big enough to flow enough for my power goals. However it's not the root cause of the problem |
| |
|
|
mat88
Yorkshire and The Humber
Posts: 1,542
|
|
Aug 26, 2020 11:35:39 GMT
|
What happens when you put your foot to the metal without being in gear? Does it sound like it's making 'better' turbo noises then when you're driving? Wouldn't advise removing the air filter if being used on road as lots of little stones, sediments, leafs etc can get sucked in quiet easily... I used a strong fine mesh wrap (doubled up) over the intake of my turbo when I had mine and it worked well.... Have you checked your intake gaskets? Any cracking in your manifolds? IF it is because you need to get into an extremely high RPM range, then you could look at having your turbo built with a billet bearing and grooved fins.. I did that with mine and it was amazing, boost started coming on much earlier (just after 1k rpm) .... but would make sure it's that before going ahead with it. It doesn't really make many boost noises if I plant the loud pedal out of gear. Well it does, you can tell there there. But not like you'd expect. I did try it with the airfilter off but it made minimal difference. Cheers |
| |
|
|
mat88
Yorkshire and The Humber
Posts: 1,542
|
|
Aug 26, 2020 11:46:17 GMT
|
Firstly thanks everyone for all the suggestions. I'm sure I/we/you will get to the bottom of it haha I've knocked up a couple of bits this morning to pressure test it. Basically a lump of 2.5 inch ally pipe with a couple of tyre valves in. Capped off on the ends. Sealed with half a tube of tiger seal  My plan is to take the pipe of the turbo. Replace it with my special adaptor pipe. And take the pipe off the throttle body and cap it with the other one. Then put some smoke down one valve and some pressure down the other and see what happens. If that doesn't highlight anything il pipe the throttle body back in and do same again and see if I've leaks on the inlet. Hopefully il have a gaping big hole somewere I've missed and I can rectify it. So that's the plan for tonight. Fingers arms eyes and toes crossed haha. Anyways. Back to work. |
| |
|
|
Darkspeed
Club Retro Rides Member
Posts: 4,883
Club RR Member Number: 39
|
|
Aug 26, 2020 12:39:02 GMT
|
|
Have you measured the boost pressure on the outlet of the turbo? - Just thinking maybe the IC is not flowing.
|
| |
|
|
|
|
|
Aug 26, 2020 20:30:22 GMT
|
Matt, I presume you're making up something like this. If so it will work a treat. I was chasing boost leaks, shoved in just 5 psi and found them all thanks to a nice hissing sound. BTW, my intercooler was the main culprit, there's a good chance yours could be too.  IMG_20200405_142505212 by Johnny Slow, on Flickr |
| |
Last Edit: Aug 26, 2020 20:32:53 GMT by Woofwoof
Still learning...still spending...still breaking things!
|
|
mat88
Yorkshire and The Humber
Posts: 1,542
|
|
Aug 26, 2020 21:17:26 GMT
|
So we have good news  and bad news  but it wouldn't be a story by me if it didn't have more ups and downs than a lady of the night on a busy shift The affor mentioned pressure tester. Nothing clever or complicated but figured it should work..  Managed to grab the party smoke machine on my way home and rigged it up like so.. sadly it's not meant to blow down a pipe and it didn't really work   Reverted to the old fashioned method of putting air in and spraying everything with soapy water (in the spray bottle).. Fired compressor up connected the airline and with the throttle shut it would make 8/10/12/14 psi and hold it but could see it dropping back down on the gauge and could hear it leaking somewhere. Looked for the bubbles and sure enough the second "self sealing" valve was leaking slightly... (The one I fitted after mapping for the iacv).. Nipped the valve down and thought I'd figured it out. Before I realised that I had fitted that after mapping so that couldn't be the problem.. Cable tied the throttle open sprayed soapy water everywhere. Fired compressor back up and straight away the gauge wasn't climbing as quickly and I could hear bubbling (this is not good) Obviously some valves will be open some closed etc etc. So it's always going to take more filling than just the inlet piping... But even with the compressor on full blast it struggled to do 8psi.. (like barely) And the reason why.... Yup. All the gaskets between the inlet and the heads are leaking. Along with the gasket on the iacv... I'm not going to count all said chickens just yet. But I'm guessing that will do it   And why am I so curse word off about it (despite being happy I've found summat and my lashed up tester works).... I reused the gaskets with a wipe of instant gasket as I thought they all looked ok (they weren't obviously) It's an absolute pig of a job to take the manifold back off (fuel rail, fuel lines, injectors, water pipes, wiring, you name it, it's coming off) I should have done this as first job, I didn't I dived in with the blaming the wastegate which is now potentially ruined I've also welded manifold shut.. Did I mention I doubted myself when I reused the gaskets but thought "nah they look fine" So yeah. That's where I'm at. I'm fairly sure this is my issue. If the compressor can't make any pressure I doubt that turbo will especially with all the boost escaping. Now I need to find a supplier of the inlet manifold gaskets (il replace them all and do it right once) Stay tuned for the next episode when I'm taking everything apart again! (And hopefully finding my boost that's doing a better job of hiding than where's Wally) Thanks everyone for the suggestions Cheers |
| |
|
|
Adey
Posted a lot
Posts: 1,442
Club RR Member Number: 171
|
|
|
|
|
Glad you found something. Is it just me, i can never view your youtube vids, through the here or the youtube site
|
| |
|
|
and bad news 
but it wouldn't be a story by me if it didn't have more ups and downs than a lady of the night on a busy shift 
