Algod

anyone running a draw through set up on there FB? just wondering

jim_chung

iTrader: (2)

Yup,

Original Cartech draw through system with IHI turbo with approx 8 lbs boost and Holley 390 cfm carb.

wecycle

I am considering building a drawthrough for one of my '79's
A Garret TII from a Shelby Dodge with a 3310 Holley vac. secondaries.
If I do all the fabrication it should be quite low cost.
What are you running? Or are you in the planning stage like me?

blwfly

iTrader: (4)

whats draw through?\




srry im learning as i read everything

OneRotor

iTrader: (3)

it's a turbo setup where the a/f mix is drawn by the turbo through the carb (hence the name draw-through), compressed, and sent into the engine. i don't think you can run an IC on a draw through setup, but i'm not positive.

Re-Speed.com

iTrader: (3)

When I picked up my Sa the PO had used a turbo from a 86 or so thunderbird. He made the intake manifold and used an old Rochester carb in draw though setup.

The intake manifold was basically a plenum box. The carb had a huge velocity stack on it and poked up out of the hood. He made some mad max hood scoop looking thing as well.

I pulled it all of as soon as I got home with the car. Even though you can find that same turbo on ebay for 25 bucks, I decided to go back NA with it.

Long story short, he had problems with the fuel puddling (sp?) in the intake manifold. from what I understand the problems with draw through are puddling of the fuel and not being able to run a intercooler.

I am not saying not to do it though.


-billy

Nicholas P.

iTrader: (1)

tunafish

This is my setup. This years projects: I am replacing the black silicone sleeves with blue 4 layer silicone and switching to stainless steel t-bolt clamps. I am replacing the air cleaner with a turbonetics carb bonnet very low profile 2 ¾ inch and installing a cold air intake to it. Last I am in the planning stages of building a water methanol injection system I invision two jets one on the cold air intake before the carburetor the other in the carb box after the fuel has been pressurized through the turbo.

wecycle

Advantages and disadvantages of blowing or drawing through the carburetor.

Many things are simpler with drawthrough and a carburetor.
Water injection can be used to cool the charge air. instead of an intercooler.
Blowthrough will handle higher boost better.
Blowthrough works well with EFI.

1 . Location of carburetor and linkage
Blow Through - No change
Draw Through - Must be moved

2. Fuel pump
Blow Through - Requires either extra pump or one compensated for compressor discharge pressure
Draw Through - No change

3. Positive crankcase ventilation
Blow Through - Must be moved to compressor inlet
Draw Through - No change

4. Fuel evaporation system
Blow Through - Must be equipped with check valve to prevent supercharging fuel tank
Draw Through - No change

5. Carburetor leakage
Blow Through - All holes and shafts must be sealed or complete carburetor boxed
Draw Through - No change

6. Distance from carburetor to cylinder
Blow Through - No change
Draw Through - Much longer

7. Carburetor float
Blow Through - Might collapse unless made of closed-cell plastic
Draw Through - No change

8. Turbocharger oil seal
Blow Through - Nothing special required
Draw Through - Must have positive seal on compressor end

9. Compressor surge
Blow Through - Can be a problem on deceleration
Draw Through - Not ordinarily a problem

10. Compressor size
Blow Through - Inlet pressure always atmospheric so maximum capacity always available
Draw Through - Inlet pressure below atmospheric so slightly larger physical size is required in some cases

11. Carburetor size
Blow through - No Change
Drawthrough - Size to match airflow at the boost level desired

12 . Carburetor inlet temperature
Blow Through - Low temperature at low load, high temperature at high load
Draw Through - Constant temperature, regardless of load

13. Vacuum source for brakes, air-conditioning, etc.
Blow Through - Sporadic, requires check valve
Draw Through - Must be picked up between carburetor and compressor inlet

tunafish

WECYCLE I have to disagree with you on several points in your post The stock fuel pump is not adequate for the blow trough setup a minimum of a least 5psi is required. I am using a Holley Red. The incline vapor valve also needs to be removed it is too restrictive. One of the secondary jets needs to be drilled out with a .076-.078 drill. Remove the secondary vacuum actuator that controls the secondary butterflies of the carburetor and stretch the spring ½ to ¾ inch longer and lower the float level .25mm lower than stock the carb. The carb spacer needs to to be reworked also.

Algod

yeah i recently bought an 85 with a draw through setup. i wanted to make it blow through. but it looks like it has a lottttt of potential just as a draw through. so i'm going to keep it that way. i was wondering what kind of boost controllers can be put on them. also what kind of exhaust should i get to safely run higher boost