Twin turbo,s dump valves ?
Discussion
Not really a problem but my 1uzfe twin turbo has two blow off valves each vac line going to the same point in the plenum and compressors connected straight to the wastegates . Gates are adjustable . They are definitely dumping one before the other and I'm running 6 psi
Not run twin turbos before so I'm thinking I need to put a guage line on each compressor to wastegate line and adjust the preload on the lazy one to balance them or am I missing something ??? Tia
Not run twin turbos before so I'm thinking I need to put a guage line on each compressor to wastegate line and adjust the preload on the lazy one to balance them or am I missing something ??? Tia
Apply pressure to both the gates, from same test air source etc and adjust them until both open at the same rate
After that how you plumb them...there are various ways, who knows which is best ?
After a post from Max ages ago, I opted to supply each gate from it's own compressor cover as opposed to tee'ing anything.
After that how you plumb them...there are various ways, who knows which is best ?
After a post from Max ages ago, I opted to supply each gate from it's own compressor cover as opposed to tee'ing anything.
Rigged them up and one has a leak so they were 3psi apart . These are some weird hybrid kkk for Amg and il struggle to find one but the leak was through a vent in the body so bodged a little something in to shut it up and wound them off to crack at 7 psi and they are opening nicely together now
I was expecting to hear the leak through the valve but it's quiet just need to track down a replacement
I was expecting to hear the leak through the valve but it's quiet just need to track down a replacement
It was leaking through the little vent hole in the body which I've plugged for now with a bit of ally welding rod . It's got to be the diaphragm split inside but I'd expect the leak to come through the valve guide now which it actually is with some leak detector spray on the valve stem but very very slight and they are cracking open nicely .
Pretty sure the turbine side is early 90,s Merc 250d but haven't seen anything and the numbers on the comp are drawing a blank. I've sent photos to kkk in the hope they can shed any light or il have to to some creative mods to get it to bolt on with a diaphragm from something else
Pretty sure the turbine side is early 90,s Merc 250d but haven't seen anything and the numbers on the comp are drawing a blank. I've sent photos to kkk in the hope they can shed any light or il have to to some creative mods to get it to bolt on with a diaphragm from something else
And is that what can be seen in the photo ? one appears to have something stuffed in the hole....but the other appears to have a hole ?
The lower port you're blowing into should be a sealed chamber in order for the thing to work. A leaky diaphragm would have unwanted air going into the top chamber
That said, in some rare cases, people use very soft springs, and only blow into the top chamber instead to keep the gate shut, rather than blowing the gate open.
But the soft spring is easily overcome by EGBP for a low boost setting with no pressure on the top of the gate.
The lower port you're blowing into should be a sealed chamber in order for the thing to work. A leaky diaphragm would have unwanted air going into the top chamber
That said, in some rare cases, people use very soft springs, and only blow into the top chamber instead to keep the gate shut, rather than blowing the gate open.
But the soft spring is easily overcome by EGBP for a low boost setting with no pressure on the top of the gate.
Pulled it to bits and it its all good inside which is a bit of s bummer but with my glasses on I can see a hole where I'd stuck a Tig rod to plug the "leak "
Close inspection of the other one and a quick twiddle with a 2mm drill bit and it's the same so bit of a boo boo pulling the other one to bits but it will crimp back together with a bit of a tool to crush it in the vice .
Upshot is they have a bleed orifice and even with the preload backed right off they crack at 11 psi which is too much so the holes need plugging properly to bring it down to 7 psi
Close inspection of the other one and a quick twiddle with a 2mm drill bit and it's the same so bit of a boo boo pulling the other one to bits but it will crimp back together with a bit of a tool to crush it in the vice .
Upshot is they have a bleed orifice and even with the preload backed right off they crack at 11 psi which is too much so the holes need plugging properly to bring it down to 7 psi
The bleed holes are 0.3mm and They came from a company doing r+d on turbos so most likely these were prototypes for something that never materialised as none of the numbers make any sense to kkk . Comp side is Porsche 944 turbo so late eighties but turbine housings are still a mystery .
Microsquirt with edis 8 ignition and Saab 345cc injectors.
Set myself a budget of £150 max spend per month 3 1/2,years ago and 5k later turned this
Into this
No intercooler but has water meth and its stock 10-1 comp so 8 lb to start with and maybe more with the meth as the air flow around the motor seems to be doing some intercooling
Set myself a budget of £150 max spend per month 3 1/2,years ago and 5k later turned this
Into this
No intercooler but has water meth and its stock 10-1 comp so 8 lb to start with and maybe more with the meth as the air flow around the motor seems to be doing some intercooling
Tony427 said:
Can I just ask what Turbos you are using?
Once through IVA I intended to turbo my Lexus engined Cobra but am now undecided between twin or single Turbo.
What would you advise?
Use would be only for mild hooning, too frightened of running out of talent to track the thing.
Cheers,
Tony
How much power ? and are you after new, used, cheap as possible ?Once through IVA I intended to turbo my Lexus engined Cobra but am now undecided between twin or single Turbo.
What would you advise?
Use would be only for mild hooning, too frightened of running out of talent to track the thing.
Cheers,
Tony
With a 4.0....and so many modern turbo petrol cars out there, there will be plenty of capable second hand turbos out there, although a lot of OEM stuff have odd flanges and fitments
On the cheap, Subaru TD04's are great fast spooling little units, or almost anything starting GT28 would be a decent bet. Or some of the KKK's fitted to either 1.8t or the 2.0 VAG group engines.
Il know more at the end of the month when it's on the Dyno . Stock compression is going to be the issue more than turbo size and I've booked a day to do it so we can get some road testing in as I have some intercooling from the airflow over the engine and turbos so the Dyno might produce lower results ,
I think I'm a bit lighter than a cobra at 860kg with fuel and driver so I just want a very safe tune with 7-10 psi . i don't seem to need to use boost very much but I'm sure that will change once it's safe to wring it's neck .
I think I'm a bit lighter than a cobra at 860kg with fuel and driver so I just want a very safe tune with 7-10 psi . i don't seem to need to use boost very much but I'm sure that will change once it's safe to wring it's neck .
mighty kitten said:
Il know more at the end of the month when it's on the Dyno . Stock compression is going to be the issue more than turbo size and I've booked a day to do it so we can get some road testing in as I have some intercooling from the airflow over the engine and turbos so the Dyno might produce lower results ,
I think I'm a bit lighter than a cobra at 860kg with fuel and driver so I just want a very safe tune with 7-10 psi . i don't seem to need to use boost very much but I'm sure that will change once it's safe to wring it's neck .
Running 9-10psi on the LS's is pretty common even with standard compression, so I think the 1UZ should be fine too at 7-8psiI think I'm a bit lighter than a cobra at 860kg with fuel and driver so I just want a very safe tune with 7-10 psi . i don't seem to need to use boost very much but I'm sure that will change once it's safe to wring it's neck .
Weather turned out to be good so grabbed try Laptop and a mate and went out for a few hours . Very conservative ign map and in the 11,s in boost its a different car at 7psi with both blowers behaving properly . Worked up to 6k in boost and sounds happy with air temp peaking at 50c at 6000 rpm . Im looking at adding a second air temp to the inlet manifold to see what effect the meth has and put an led in the dash so I can see when it's triggered
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