old grumpy men in hats - whats a wet turbo gonna do? am i gonna die?

saylor

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O wise and venerable forum !
(in b4 "get turbochargers by hugh MacInnes", its on order)

what if a guy took a motor home turbo plenum and stuck a draw thru turbo on his 440?

or even what if he bought the book "Turbochargers", by hugh macinnes, and figured out how to make a plenum?

then what? punch it?

i have read a bunch about it over the last few days, and i think i have everything figured out except the 'not blow off' - when you close the throttle blades there is a huge vacuum; there is a way to displace that but i havent understood it yet. you cant release that to atmosphere as this turbo design is wet - the gas is in the air mix already - we would all die in a fire.

the only other thing i dont have a handle on is boost pressure signal to the carb springs so you dont lean out. theres gotta be a way to make an eddie do it, because carters did it bitd.

lets blow stuff up.

- saylor
 
$_1.jpg
sorta, this, but bigger.

waaaaaay bigger.
 
So why that route? Why not just keep it simple with a "blow-through" setup?
 
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b/c a blow thru setup takes more money. and this is oldest school.

blow thru takes EFI or a blow thru carb w/e, and variable pressue boosted fuel regulator + return lines, blow off valve, sensors, bungs, carb hats, and stuff i dont know about.

this doesnt do any of that. its carbed with a regular old carb. it self limits its boost to a large degree. etc.

a wet turbo, or draw through turbo.

i will cut a hood for this. just fair warning.
 
wait blue man :) lookit the picture - THATS simple :)

carb stuck into side of turbo. attach to top of intake. punch it.

srsly - fitech by itself is thousan dorra. or a quikfuel or hollis blowthru.

turbos are chinar 100 dolla up to 1500 for real ones. this style of turbo must have a carbon seal to hold in the bearing oil in the turbo. or it will be ungood.
 
i need some good shots of the plenum construction. ive seen side feeds that go into the side of the intake, and ive seen ones that are stacked straight vertical. internally, on some, there is a deck, with reed valves that are open normally, and close when the PSI hits them.

some look like they just jam into the turbo intake flange.

i havent seen a twin in this configuration. yet.
 
View attachment 348411
gratuitously stolen pic from a bodies - anyone a member over there?

a guy named bohica2xo designed this.
I am, but don't follow too much turbo stuff. I'm lost with the approach you're trying, because like you, I haven't read about it. If you are using cheap Chinese turbos, go over to Hot Rods website, they did that on a ford, Chevy, and a Dodge block. Silly power cheap. They had the advantage of having it out if the car, so they could route the tubing wherever they wanted, something you can't do in car. It might be worth a look. It was cheap. If I was to do a turbo setup, is spend some money and have it right (or close) when I'm done, but I've also accept d the fact that everything is going to cost more than I'd hoped for. Good luck with it, and share what you did to make it work.
 
Draw through requires a turbo that has seals designed to run under vacuum in a wet environment. The cheap Chinese turbos don't have that and the application specific ones are not common and probably not cheap. A regular turbo on draw through will suck oil and detonate on boost.

There are some issues with draw through like throttle lag and potential disaster from a backfire into a plenum full of pressurized air and fuel but they can definitely make some steam. There is a guy on Moparts with one on a stock 318 that he has been playing with on his dyno and he is in the 500 hp range with similar torque.

Kevin
 
Are you planning to run an intercooler? I would not put a Chicom turbo on anything, cheap but you get what you pay for. This will also generate some considerable additional engine blow by which also has to be dealt with to keep oil foaming and contamination down. You will also need an oil cooler to keep oil temps down. Probably also into forged piston territory depending on how much boost you intend to run. Block girdle also a good idea. I don't think there is a cheap simple way to build a 440 turbo and have it live for any length of time.

Dave
 
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I am, but don't follow too much turbo stuff. I'm lost with the approach you're trying, because like you, I haven't read about it. If you are using cheap Chinese turbos, go over to Hot Rods website, they did that on a ford, Chevy, and a Dodge block. Silly power cheap. They had the advantage of having it out if the car, so they could route the tubing wherever they wanted, something you can't do in car. It might be worth a look. It was cheap. If I was to do a turbo setup, is spend some money and have it right (or close) when I'm done, but I've also accept d the fact that everything is going to cost more than I'd hoped for. Good luck with it, and share what you did to make it work.
slow down there hoss, i read every page on the internet about it.
Draw through requires a turbo that has seals designed to run under vacuum in a wet environment. The cheap Chinese turbos don't have that and the application specific ones are not common and probably not cheap. A regular turbo on draw through will suck oil and detonate on boost.

There are some issues with draw through like throttle lag and potential disaster from a backfire into a plenum full of pressurized air and fuel but they can definitely make some steam. There is a guy on Moparts with one on a stock 318 that he has been playing with on his dyno and he is in the 500 hp range with similar torque.

Kevin
yup you can buy carbon seal kits you are 100% correct.
Are you planning to run an intercooler? I would not put a Chicom turbo on anything, cheap but you get what you pay for. This will also generate some considerable additional engine blow by which also has to be dealt with to keep oil foaming and contamination down. You will also need an oil cooler to keep oil temps down. Probably also into forged piston territory depending on how much boost you intend to run. Block girdle also a good idea. I don't thing there is a cheap simple way to build a 440 turbo and have it live for any length of time.

Dave
this style of turbo does not take an intercooler. that would be extremely bad.
 
slow down there hoss, i read every page on the internet about it.
In three days? By bad, I thought you said you just started reading it three days ago, I see you've been reading for a few days. Name is Scott, I'm too far north to be called Hoss. :lol:
 
guys the T/A, the buicks, the GN, all those had this type of turbo, pre fuel injection.

Those early turbo engines suffered from major problems with pre-ignition, ie knocking because the input combustion gases could not be kept at a constant temperature. The turbo speeds up as engine rpms increase providing more boost. The down side is that the higher the boost, the hotter the air fuel mixture becomes and the less dense air leans out the engine and detonation or burned valves/pistons is the eventual result. Manufactures compensated by running richer mixtures which helped but negated most the efficiency gains from the turbo. Early boost control valves suffered from erratic operation which made consistent engine operation difficult. Modern turbo engines have intercoolers to cool the compressed gases so they stay at a more consistent density in addition to knock sensors and elaborate mixture controls.

Dave
 
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If it were me I would consider instead a centrifugal belt driven supercharger. Much more predictable in it's boost curve. Also they can't runaway like a turbo in bad situations and blow your engine as easy. I didn't see any blow off valves either on the compressor line. With a supercharger there would be more room opportunity for an intercooler and blow off valve and you wouldn't have to jerk around with exhaust plumbing. I have two buddies both with 99 BMW M3's supercharged like this . Both at different levels of boost and tune. Only rode in the milder one that he road races at tracks in the NE area. 8 psi and it hauls *** and relatively stock engine wise. The suspension is highly modified. It is very fast and reliable. The other guy is on the hairy edge [more boost, bigger injectors] as such there is more concern of breakage even though the engine and trans etc is modified.

IMG_8787_0.jpg
 
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Blow through carb is easiest way unless you have a thing for electron flow.
Unless you have the umteenmillion parameters sorted and turbo sized just right for narrow rpm band you need a waste gate. Blow off valve is the evil twin to this, needed for dumping pressure when throttle blades are closed (no throttle blades is why diesels were made for turbos).
Suck through turbos have the problem right in the name, "suck"
You will need forged pistons and piston thermal coatings would not hurt because your combustion temps are going to be sky high with all the on the ragged edge of detonation with wet/sucky turbo.
Any carb can be blow through with little modifications. Think about it, your carb is fighting off 5-7 psi of atmospheric pressure all the while it's idling, 10-14 psi when letting off at high RPM in gear. So you still think that 10-12 psi trying to get out is a problem? That's only at full song when RPM and load are right, the rest of the time it's much less. Spring and jetting adjustments being the worst of sorting out, and big leaks (choke linkage, gotta go)
Power piston springs will need to be lighter and jetting will need to be fatter,( more air needs right amount of more fuel, gasoline's fatal flaw). Everything needs referenced back to same pressure as float bowl vents(air horn area) is going to see. Nothing can be left to vent to atmosphere, you are making atmosphere so you have to stay with it.
A gasoline engine without a charge air cooler (" intercooler" though technically not correct) is a lesson in.... Well you would be better off beating your head on a rock prior to doing that instead of after.
Cam is also very important the valve timing events need to be for turbo application to work efficiently.
Hope this helps. Others will have 2-3 cents to offer but it is anal worry wart stuff. Sort the big problems the details will line up to be knocked out one by one.

One other point to mention is that first picture with the Quadrajet, those carbs don't have enough fuel in them for a NA small block there is no way that thing is keeping up with a turbo Big Block
 
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Those early turbo engines suffered from major problems with pre-ignition, ie knocking because the input combustion gases could not be kept at a constant temperature. The turbo speeds up as engine rpms increase providing more boost. The down side is that the higher the boost, the hotter the air fuel mixture becomes and the less dense air leans out the engine and detonation or burned valves/pistons is the eventual result. Manufactures compensated by running richer mixtures which helped but negated most the efficiency gains from the turbo. Early boost control valves suffered from erratic operation which made consistent engine operation difficult. Modern turbo engines have intercoolers to cool the compressed gases so they stay at a more consistent density in addition to knock sensors and elaborate mixture controls.

Dave

Hey Dave, correct me if I’m wrong but aren’t these the kind where you floor it and it kicks in two blocks later? This is the system that made “turbo lag” a household word right??? Just wondering because I remember anything turbo short of an ‘87 regal type T was dog&#%& slow. Those turbo trans ams were a joke. If you had to guess what % HP gain could you really expect - on the street - not a race car with a system like this?
 
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