Turbo 200 Becomes lean after about 5 seconds of WOT NEED HELP URGENT

thatblue_67stang

Well-known member
I need help. I have built a turbo 200 and it performs great. i have a electric fuel pump supplying a fuel pressure regulator with 60 gallons per hour of fuel. this fuel regulator is boost referenced so every psi of boost increase one psi of fuel. all of this is feeding a holley 2300 350 cfm carb. i have it on a custom intake manifold. my problem is that after a few seconds at wot throttle my fuel leans out to about 14afr which is not good. my afr at WOT for the first 5 seconds is about 12. some people have said its fuel puddling in my intake. some say its my fuel delivery systeem up to the carb and some say its my carb. i dont think its my fuel delivery because i met a guy who brought his turbo 200 up to 250 hp and still used the stock lines. I really enjoy the car but cant run full throttle for very long.
 
drag-200stang":3ap6u3qt said:
At that time , what is your boost psi and what is your fuel psi showing on your gauges ?


throttle is WOT so its always max boost. so 5psi lol. but as to fuel idk my gauge is inside the engine bay. i might invest in another gauge so i can see it in the car. but its a holley pressure regulator so im guessing its working haha
 
You cannot guess ;)
Do not put the fuel psi gauge inside unless it is electric...Get some foam and tape it to your cowl if it is not...Test tape first so you do not pull your paint off.
Not sure , can you see your boost gauge?
 
drag-200stang":34zpsvjy said:
You cannot guess ;)
Do not put the fuel psi gauge inside unless it is electric...Get some foam and tape it to your cowl if it is not...Test tape first so you do not pull your paint off.
Not sure , can you see your boost gauge?


yes i have 2 boost gauges one directly to the turbo and one on the manifold. reason i have 2 is to see if i have a boost leak in between. i think fuel pressure is about the only gauge i dont have.
 
drag-200stang":2txu3d30 said:
You cannot guess ;)
Do not put the fuel psi gauge inside unless it is electric...Get some foam and tape it to your cowl if it is not...Test tape first so you do not pull your paint off.
Not sure , can you see your boost gauge?


if you want to talk i have a facebook or instagram that i would love to talk to you. ive been trying to figure this out becuase this is the only problem with the car.everything else is great. and when it goes WOT its fast and fun.
 
drag-200stang":2cyk329r said:
You cannot guess ;)
Do not put the fuel psi gauge inside unless it is electric...Get some foam and tape it to your cowl if it is not...Test tape first so you do not pull your paint off.
Not sure , can you see your boost gauge?


any ideas?
 
thatblue_67stang":1crxv4ys said:
drag-200stang":1crxv4ys said:
You cannot guess ;)
Do not put the fuel psi gauge inside unless it is electric...Get some foam and tape it to your cowl if it is not...Test tape first so you do not pull your paint off.
Not sure , can you see your boost gauge?


if you want to talk i have a facebook or instagram that i would love to talk to you. ive been trying to figure this out becuase this is the only problem with the car.everything else is great. and when it goes WOT its fast and fun.
Sorry I do not do those two.
At this point you need to see if you have about 4.5 psi more fuel pressure at the carb than boost pressure at the hat when it goes lean...I did draw thru ,not experienced with blow thru , I am now moving on to mpefi , much better control...For some good blow thru info google, ''hangar 18 mods''
Let us know what you find...Good luck.
 
The Well tubes need one less hole to stop emulsification of the fuel air mix when the hydrostatic fuel grade line is drawn down. IF its making 300 horespower, then its consuming at least a quart of fuel a minute, and the drow down curve on the float is way down to below the sight glass, so thats where you need to start blocking holes from the lowest one first and on up if that doesn't stop the lean out.

Normally, a Holley or Autolite or Motorcraft has five holes of 25 thou down its well tube on both sides.


TMC make a special finer 6 hole e-tube, but thats for special Weber Power Plate applications. You need less holes, maybee four, with the base or bottom ones plugged up to richen up the air fuel. Holley 2300_4150 series havehalf round 342 thou Well Tube



Holley 2300 & 4150 series has round 342 thou Well tubes

TMC's extra emulsion tube well tube.
Holley+well+emulsion+sm.jpg




Soldering up or JB Welding one hole each at the bottom of the well tube will help richnen the air fuel mixture at certain points high in the rev range.


You want flat fuel, and the emulsion/well tube is exactly how to do it.

https://www.youtube.com/watch?v=1pkFSA_rRFI



Lotus had this problem in 1979 to 1980 when the Essex Esprit Turbo was being given a 40% power boost with a T03 60 turbo on a tiwn Dell Orto DHLA 45 2-bbl carb system.

They reprofiled the well tubes, and added an open section to the top of the carbs air horn to force the fuel level down by ramming air into the bowl vent.
 
xctasy":3d3tmld9 said:
The Well tubes need one less hole to stop emulsification of the fuel air mix when the hydrostatic fuel grade line is drawn down. IF its making 300 horespower, then its consuming at least a quart of fuel a minute, and the drow down curve on the float is way down to below the sight glass, so thats where you need to start blocking holes from the lowest one first and on up if that doesn't stop the lean out.

Normally, a Holley or Autolite or Motorcraft has five holes of 25 thou down its well tube on both sides.


TMC make a special finer 6 hole e-tube, but thats for special Weber Power Plate applications. You need less holes, maybee four, with the base or bottom ones plugged up to richen up the air fuel. Holley 2300_4150 series havehalf round 342 thou Well Tube



Holley 2300 & 4150 series has round 342 thou Well tubes

TMC's extra emulsion tube well tube.
Holley+well+emulsion+sm.jpg




Soldering up or JB Welding one hole each at the bottom of the well tube will help richnen the air fuel mixture at certain points high in the rev range.


You want flat fuel, and the emulsion/well tube is exactly how to do it.

https://www.youtube.com/watch?v=1pkFSA_rRFI



Lotus had this problem in 1979 to 1980 when the Essex Esprit Turbo was being given a 40% power boost with a T03 60 turbo on a tiwn Dell Orto DHLA 45 2-bbl carb system.

They reprofiled the well tubes, and added an open section to the top of the carbs air horn to force the fuel level down by ramming air into the bowl vent.

I'm not familiar with these holes you are talking about. I have a holley 2300 350cfm and dont know where those would be. If I even have any.
 
I'd say one of two things.
Fuel pressure problem as talked about by Drag, or you need more jetting after your accelerator pump circuit has completed spraying.
If you have not increased the size of the passage on the power valve circuit, read up on that, that is what I did on my setup and it ran 20lbs boost with a blow through turbo setup. I'm sure I posted that info is on here somewhere.
 
I don't do electric fuel pumps for this reason. Its all very messy, and its possible to deliver aerated fuel to the carb if the fuel piuckup at the tank is being influenced by another source. Down here, we drag race and have steep graients for luanch boats with uni body cars...so all Fords down here ran stillage pots and all imported US Fords except the early twin fuel pump Mustangs with CFi or the Turbo 2.3 EFi....they had dreadfull issues with electric fuel pump supply when you added boost.

I refuse to use anything like the standard electric fuel pumps.

Aerated fuel is the bane of some electric fuel delivery problems.




ccrp_0807_10_z-carburetors_basics_guide-emulsion_tube.jpg


https://www.hotrod.com/articles/ccrp-0807-holley-carburetors-basics-guide/":1ngv81an said:
Emulsion Immersion
You’ll see references here to emulsion circuits, an important-sounding term that describes mixing fuel with air. Think of it as blowing bubbles in the fuel. All carburetors mix air with fuel in the venturi just before it enters the engine. But carburetors also mix air with fuel farther upstream inside the carburetor in the main well to make the liquid fuel easier to manage. Holley carburetors use a parallel air well that transfers air into the main well through two, three, and sometimes five holes that can be seen in the metering block photo (page 36). While this passage is called an air chamber, fuel still resides in this chamber at the same level as the fuel in the float bowl. As fuel demand increases at higher engine speeds, the float level drops, uncovering the lower holes in the emulsion circuit, which adds more air and leans out the air/fuel ratio. Combining the main jet flow area with the area of these emulsion holes and the high-speed air-bleed (along with a raft of other minor inputs) creates the basic fuel curve.

Unless you already know all about Holley metering idiosyncrasies, these emulsion circuits should be left to professional tuners. Just so you know, the basic function follows that increasing the size of these emulsion holes will reduce fuel flow and lean out the overall fuel curve. Increasing the size of the high-speed air-bleed will also delay the onset of fuel flow in the main metering circuit. Reducing the diameter of the high-speed air-bleed produces the opposite effect.

Think of the emulsion tube in the main well as a straw immersed in your favorite soda. A light amount of suction (pressure differential) on a straw with no holes pulls a large amount of liquid very quickly. What’s really happening is atmospheric pressure pushes the liquid from the glass into your mouth. If you place a small hole in the straw above the liquid level, this introduces air into the straw, requiring a greater pressure differential (or more time) to move an equal amount of liquid up the straw. The liquid that is pulled up the straw will have tiny air bubbles mixed in with the liquid. What you’ve created is a simple emulsion tube. The difficulty comes in figuring out the size, number, and placement of emulsion holes in the metering block. The good news is that Holley has worked all this out for you, but at least now you know what those holes do and how important they are to an engine’s fuel curve.



A set of replacable air bleeds, jets and emulsion tubes by the old Weber/Edelbrock and now TMP kit.

TMPCarbsWeberPowerPlatefor2300and4150_4160Holleycarbs.jpg
 
fast64ranchero":39nkyu6i said:
I'd say one of two things.
Fuel pressure problem as talked about by Drag, or you need more jetting after your accelerator pump circuit has completed spraying.
If you have not increased the size of the passage on the power valve circuit, read up on that, that is what I did on my setup and it ran 20lbs boost with a blow through turbo setup. I'm sure I posted that info is on here somewhere.


i have drilled it slightly bigger. but 5 seconds seems like a long time for the accelerator pump to still be active
 
xctasy":2u0tsrd8 said:
I don't do electric fuel pumps for this reason. Its all very messy, and its possible to deliver aerated fuel to the carb if the fuel piuckup at the tank is being influenced by another source. Down here, we drag race and have steep graients for luanch boats with uni body cars...so all Fords down here ran stillage pots and all imported US Fords except the early twin fuel pump Mustangs with CFi or the Turbo 2.3 EFi....they had dreadfull issues with electric fuel pump supply when you added boost.

I refuse to use anything like the standard electric fuel pumps.

Aerated fuel is the bane of some electric fuel delivery problems.




ccrp_0807_10_z-carburetors_basics_guide-emulsion_tube.jpg


https://www.hotrod.com/articles/ccrp-0807-holley-carburetors-basics-guide/":2u0tsrd8 said:
Emulsion Immersion
You’ll see references here to emulsion circuits, an important-sounding term that describes mixing fuel with air. Think of it as blowing bubbles in the fuel. All carburetors mix air with fuel in the venturi just before it enters the engine. But carburetors also mix air with fuel farther upstream inside the carburetor in the main well to make the liquid fuel easier to manage. Holley carburetors use a parallel air well that transfers air into the main well through two, three, and sometimes five holes that can be seen in the metering block photo (page 36). While this passage is called an air chamber, fuel still resides in this chamber at the same level as the fuel in the float bowl. As fuel demand increases at higher engine speeds, the float level drops, uncovering the lower holes in the emulsion circuit, which adds more air and leans out the air/fuel ratio. Combining the main jet flow area with the area of these emulsion holes and the high-speed air-bleed (along with a raft of other minor inputs) creates the basic fuel curve.

Unless you already know all about Holley metering idiosyncrasies, these emulsion circuits should be left to professional tuners. Just so you know, the basic function follows that increasing the size of these emulsion holes will reduce fuel flow and lean out the overall fuel curve. Increasing the size of the high-speed air-bleed will also delay the onset of fuel flow in the main metering circuit. Reducing the diameter of the high-speed air-bleed produces the opposite effect.

Think of the emulsion tube in the main well as a straw immersed in your favorite soda. A light amount of suction (pressure differential) on a straw with no holes pulls a large amount of liquid very quickly. What’s really happening is atmospheric pressure pushes the liquid from the glass into your mouth. If you place a small hole in the straw above the liquid level, this introduces air into the straw, requiring a greater pressure differential (or more time) to move an equal amount of liquid up the straw. The liquid that is pulled up the straw will have tiny air bubbles mixed in with the liquid. What you’ve created is a simple emulsion tube. The difficulty comes in figuring out the size, number, and placement of emulsion holes in the metering block. The good news is that Holley has worked all this out for you, but at least now you know what those holes do and how important they are to an engine’s fuel curve.



A set of replacable air bleeds, jets and emulsion tubes by the old Weber/Edelbrock and now TMP kit.

TMPCarbsWeberPowerPlatefor2300and4150_4160Holleycarbs.jpg


is there any way i can contact you besides this forum to talk to you and have a conversation about all of this. im 20 years old and this is my first boosted carb car and i want to learn everything there is to know about this
 
I see you switched from the 500 cfm to the 350 cfm 2300.

Where is the boost reference line for the fuel regulator connected to?
 
pmuller9":1hqjhyo3 said:
I see you switched from the 500 cfm to the 350 cfm 2300.

Where is the boost reference line for the fuel regulator connected to?


i have a vacuum block on the firewall connected to where the brake booster is ussually connected on the carb. im thinking of routing the fuel regulator to take boost directly from the turbo
 
thatblue_67stang":1ou0qm42 said:
i have a vacuum block on the firewall connected to where the brake booster is ussually connected on the carb. im thinking of routing the fuel regulator to take boost directly from the turbo

The fuel regulator boost reference line needs to see the pressure that the carburetor is seeing.
The line needs to connect to the carburetor hat or the tube running to the hat.

Have you been able to temporarily mount the fuel pressure gauge on the hood or someplace you can see it to check fuel pressure under boost?
 
The Hogan style intake is what Does10's ran.

Your system is similar to fast64rancheros and JTurbo's

As long as you copy the image link when it shows on your screen in below 800 by 500, it'll show up if you use "" around it without the 66 and 99's

""
then add
"https://i.imgur.com/lQnilNi.jpg"

lQnilNi.jpg



Follow the basics first. All advice given is good, although I'd never, ever reduce the size of a carb on a turbo car, Does10's did it, and loved it.


A carb is a fuel supply device, not a restrictor plate. Restrictor plate engines are found in NASCAR, F1, LeMans and the World Rally Championship, and they area rated between 129 and 85 cubic inches of engine per sqaure inch of restrtor plate.


They exist to stop people going faster. On a turbo engine, when the area of the venturis is below 1.375" each (500 cfm), it's 2.969 sq inches of area serving a 200 cube engine, or 67 cubic inches of engine serving 1 sq inch of plate restriction.
200/2.969= 67 or near too.


Add a 350 cfm carb with 1.1875, thats 2.215 sq inches of restriction, or 200/2.215 or 90 cubic inches per square inch of restriction.

Production turbo carb engines are never restricted that much. If the specs are greater than a 85 cubic inches per 1 inch of carb venturi, then its a restrictor plate engine. It might help you get on boost, but it'll drive the air correction holes in your carb crazy, and you'll then be constantly goijg over other stuff to fix it.


Keep the 500 cfm carb, and check that the fuel delivery is not aerated on boost. Your intake manifold could be causing other issues, but thats okay....the carb has to deliver fuel, not restrict air. The 4412 makes 352 hp normaly aspirated in a good 289. Its got all the good stuff to ensure gasoline flows at wide open throttle.

I'm all for being conservative, but never go back from the optimum on Breathing, Exhaust, Ignition, Gearing, Head flow or cam Timing.

Fuel delivery is simple. The Italians got it all figured out before WWII. The worst thing you can do is go backwards on Breathing.

It might be safer to avoid torch downs from too much fuel at the delivery point, turbos that are not Fuel Injected are a risk when you go over 14 psi, but most fuel trim is making sure you do the basics right, and then adjust the well tube holes if all other avenues didn't help you.
 
It is a 200 six with a stock cam and rev limited to 5000 rpm.
The 350 cfm carb sitting on a large custom plenum is not a restriction plate at that engine flow rate.
 
pmuller9":3kz0wc7z said:
It is a 200 six with a stock cam and rev limited to 5000 rpm.
The 350 cfm carb sitting on a large custom plenum is not a restriction plate at that engine flow rate.


500 cfm is way to much as you said for a stock six. I had the 500 on it and it would flood the engine at start and throughout the whole rpm range. I am going to try giving the regulator boost right from the turbo.



Also extacy, a 350 is technically to big for this engine doing the right conversion. I went from like a 150cfm to a 500 then to a 350.
 
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