Got started with my turbo project today. My car has had a ProCharger and EFI on it for the past four years but I've decided to go big single turbo. I'm using a Garrett GT47R with 102mm compressor wheel. Today I started by cutting a hole in the passenger inner fender where I intend to locate the turbo. Here's a few pics...

 

AWW-sum! Did you ever get any runs in with the blower?

Hey, smell the glove!

 

I did go to the track a couple times with the blower but had various problems with my slicks and traction so the car didn't run the times it was really capable of. Those other problems have been sorted out now, so hopefully my next outing with the turbo will yield better results... because as you already know "It's one louder"

 

Please tell me you're getting a better hat before you get that thing running!

 

no kiding

 

Looking good!!!

 

He is running EFI so hat design is not as critical.

 

a wize guy ehh

 

We spoke abotu that a little earlier. He's going to get one of those hats that will hold a beer on each side and has a long straw so he can drink at will.
It's gonna be cool.

 

It takes a strong willed man to cut that first hole in to his virgin challenger!

 

looks like he already had a hole in that same inner fender. i would love to take a rare mopar car and turn it into a race car. If i never plan on selling it than it doesn't matter what it is worth. Same thing i told my dad with his 340 4speed 1972 duster, about backhalfing.

Steve

 

Not sure how EFI would change air distribution within a hat. If anything I would think the air distribution would be worse. You still need a good hat whether you go EFI or carb, period. With unequal air distribution you can get the situation where you have a real rich condition on certain cylinders and a lean condition on other cylinders. Your sensor may still be reading rich, yet you maybe sitting on grenade about to happen, all while running EFI!

He has a good hat on there. It's a SDCE hat and a lot testing went into that hat.

 

You're right EFI wont change the air distribution in the hat. My point was that with a carb, poor air distribution through the hat will lead to a high variations in booster signal through the carb which will lead to poor fuel distribution in addition to poor air distribution. With fuel injection, fuel distribution will not be affected by a bad hat. Air distribution, may be. Under boost conditions you may find that the air distribution is not so bad after passing through the throttle body of an EFI engine. I have never run experiments to varify this, but this is my opinion. Others are certainly welcome to comment.

 

What I mean by poor air distribution is for example having twice the air at the back of the carb or throttle body than in the front. Ultimately this leads to one cylinder having twice the air than the other. I would assume this scenario comes from the bends in the system. This bend are irrespective of whether you have EFI or a carb. Unless you have some system(usually a good hat) to equalize the air distribution, you can potentially run into problems.

 

I'm having trouble understanding/believing the theory that there will be a problem with distribution because of that airhat. Granted, I'm certainly no rocket scientist, but if the fuel is injected directly into each intake port right in front of the valve and the entire manifold is pressurized with boost... won't each port/ intake valve opening sequence see the same boost pressure, air volume and fuel delivery?

If your theory is correct - then I'm prolly in a world of hurt? or am I?







CBE Air/Water Intercooler/Airhat

 

I am no expert. If I am wrong then I am wrong. What I can tell you is the little experience I have. When dyno tuning my centrifugally blown engine, we measured the amount fuel being sent to the front of the carb and the back of the carb. With the hat I had on their, the back of the carb would in a consistent manner send 1.5-2X the amount of fuel than the front of the carb. Change to a good hat and it would even out to a 1:1 ratio. I can only assume the air distribution/pressure is not the same from one side to the other with a bad hat.

 

OK, I understand where you're coming from.

I think that we're talking about two different animals here between port efi and carbureted. A carb will in fact be effected a whole lot more by high and low pressure areas as the air moves thru the venturis and draws fuel from the carb. I don't think it works quite the same way in this application.

 

Yes the carb is affected in a consistent manner at 2x-1.5x the fuel. And this is a result of differences in pressure areas. Does that really change anything or just confirm that one side of the hat is moving a lot more air than the other, in effect causing the pressure difference. Remember its 2x-1.5X consistently thru 3k-6k rpm. I dont look at this number as a minor deviation.

 

Any bump, deviation or even the shape of the carb itself will have an effect on airflow over/thru the carb venturies - especially if it's hitting the carb at an angle as apposed to straight down. Since the air must draw the fuel, wherever it's moving fastest is where it will get the most. I'm sure it shows up in plug readings if you're running a dual-plane intake. A single plane wouldn't be AS picky I wouldn't think.

EFI doesn't have that problem. It's fuel is deposited consistently in each intake port. I would think that as long as the intake manifold and plenum is pressurized with boost, that the same amount of pressurized air will flow thru each intake valve regardless of what happened when it went thru the throttle body.

 

Ah, but the deviation in airflow was affected by the hat not the carb as shown by changing of the hat. This would make sense sense since the air is "generally" not changing path as it goes thru the carb. EFI is fuel distribution, it does not take into account air distribution. Or better yet, EFI has one point of reference for air distribution while a carb has 2. The fact that 1 side is pulling more air than the other is a sign of concern for a carb as well as EFI. At least that is the way I look at, again I am not expert just the experience of shock when dyno testing.

This is an interesting quote because you could also say the exact same thing about each side of the carb but measuring has shown that their is a difference. Maybe their are many dynamic variables at work. Sometimes I feel the more I learn the less I know!