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3.0 Supercharged Drag Car Build with PICS

30K views 464 replies 21 participants last post by  mopar969 
#1 ·
Okay so it has begun. I am building my 1993 dodge daytona with the 3.0L and 604 trans to be a drag racing machine. It will be a supercharged 3.0L and the 604 will have the 4.28 gear ratio found in the chrylser pacificas. I will post pics tomorrow but below is what I have bought already and what I have done. As well as Issues I and questions I have.

1. I installed hijackers in the rear and installed a kit so I can control each shock separately.

2. The 4.28 gears are bought and are in the process of being put in the only thing I am waiting for is the snap ring pliers I ordered to get the pinion snap ring out.

3. The supercharger was just bought at the junkyard it is the eaton m90, this one came off of a 1990 ford thunderbird super coupe.

Okay so at the moment I want to finish the supercharger aspect of my project first the big problem I have is that I dont weld. So, how can I make a mount to position the supercharge and how should it be positioned so it does not affect how it gets oiled. Maybe somone can sell me one? Should I post in want section doubt to many people did this

Lastly, I want to intercool this setup but the supercharger from the junkyard did not come with a throttle body and i spent money to buy the bigger 58mm throttle body and have the intake ported. How can I set this up so I utilize the port work on the intake manifold??

Also, the louder this thing sounds the better!!!
 

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#141 ·
A super charger works in the full spectrum of the power band. But the boost is totally related to RPM. So at idle the RPM's are so low that any boost that might be produced would be so small you'd never no it. In fact the RPM might be so low that the impellers might not be able to create boost. So you'll end up with vacuum at idle. The big question is just how the SC will respond to the motor. Lets face it this SC wasn't designed for this motor or set up. So until the motor is up and running it will be a crap shoot just how it will behave.
 
#143 ·
Well like I said till this motor is up and running we really wont know for sure, one thing you can do if you do get boost you can get a vac pump to run the vacuum systems that need it.
 
#144 ·
The by pass is in the system to prevent boost at idle.

GM units can have the by pass internally as there is no intercooler.

Intercooling adds another level of complexity.

Thanks
Randy
 
#145 ·
You need the bypass with a blow through setup because without it there will be nowhere for the air to go when the throttle is closed. You would blow charge pipes or worse. With a draw through setup the supercharger pulls vacuum at idle because it's trying to "draw through" the closed throttle. You don't need a bypass with a draw thru setup unless you want to enable/disable the supercharger. You could use a BOV as a bypass. It would be better to buy one that has a hose barb/flange on the outlet so you can pipe it back to the intake. If you setup the BOV to dump to atmosphere you will lose efficiency and the supercharger will be super loud when not in boost. It will still be somewhat loud with a recirculting BOV because the only thing muffling the sound of the supercharger will be the air filter. Basically all the bypass needs to do is connect the superchargers outlet to it's inlet. When the supercharger is bypassed it takes almost no energy to turn it. This helps with efficiency during cruising/idling.

You won't "get boost at idle" with a supercharger no matter how it's set up, as long as you still have a working throttle...

I tried to find the FMU I have on ebay but I couldn't. I remember seeing it in universal turbo kits and then one day there was someone selling 5 separately. I went to bid on the auction later that day and somebody already bought them. The next day they were back on ebay for $30 instead of the original $20. This was about 3 years ago. I'll take a picture of it for you maybe it will help find one. The cool part about this particular Chinese knockoff FMU is that the real Vortech rebuild parts fit.
 
#148 ·
In regards to fuelling, as long as your fmu is referanced off the manifold then it wont matter if the bov is recerculating or not because these cars use a map sensor. The reason some cars need a recirculating bov is because they have a mass air flow meter, the air has been messured already so if it is dumped into the atmosphere the car will still add the fuel but it wont get the air, there-for making it go rich, this is the same no matter what method of FI you use. Now it may make a differance to the supercharger if it is recerculating, this i dont know, but not fueling.

And like Knightmoves said, there is no way of knowing exactly what you need till you put it all together and try it, this is how home built forced induction goes. You may get lucky and get it right the first time, or you may go through a few engines till you get it right.
 
#149 ·
Dumping the air will not cause a rich condition. If the FMU is set up right it will drive pretty much like it does stock until you open the throttle enough to get past 0psi. On my setup it felt kind of like the whole range of the throttle N/A moved to the first quarter of throttle once supercharged. Once you got to 1/4 throttle the engine would be seeing atmospheric pressure. The more throttle you give it the more boost you have. If you mash the gas from a stop you have full boost till redline. The boost isn't as tied to RPM as people tend to believe. Boost stays pretty steady throughout the RPM range at any given throttle position. This is because relative to the engine the supercharger spins at a fixed speed. When the engine RPM increases the supercharger spins faster but so does the engine this equates to the same boost at any engine RPM. But there is more to the story. The engines Volumetric efficiency will affect boost. That's why on one engine you could get 10psi and another get 14psi with the same supercharger and the same pulley ratio. Boost will start to increase once you reach the RPM where your VE starts to drop.

With a blow through setup, you will absolutely need something to get rid of the huge amount of pressure that will build in the charge pipe when the throttle closes. Your supercharger will be fighting the closed throttle without it. I ran like this for a couple weeks when I first put my setup together. The charge pipes would blow off or rip every time I let off the throttle. The belt would let out a loud squeal at the same time.
 
#152 ·
I feel that the only way to bypass the fuel regulator on my 93 fuel rail is to buy the older style 3.0 rail from 88 to 91 and cut th regulator off and flare the line. Or is there another way? Given my type of fuel rail that has regulator bolted onto the aide not the end of the rail?
 
#153 ·
I feel that the only way to bypass the fuel regulator on my 93 fuel rail is to buy the older style 3.0 rail from 88 to 91 and cut th regulator off and flare the line...
That's how mine is set up. The main reason being that my original 3.0l was an 87' so I had the rail already. The thing that sucks about this setup is that you pretty much have to remove the intake plenum to change the return hose. It's difficult to tighten/loosen a hose clamp in that location. The good thing is that the individual rails are connected together with larger pipes at both ends so in theory you can use a more powerful fuel pump and still maintain good fuel pressure at idle. I don't think anyone has actually overrun the newer rail but it's always good to have a bigger fuel system than you think you need.

I think the best way to go about it is to add an AN fitting to the rail. That way you have a good connection and it will be easier to remove with the intake on if needed.
 
#157 ·
Think of fuel pressure regulators as bypass valves, the fuel goes from the pump to the injectors, then dead heads at the fuel pressure regulator, when the pressure reaches the set amount the regulator opens and bleeds off the extra pressure through the return line. If you want to increase pressure you have to block the return line with a fuel pressure regulator (your fmu in this case) that is set at a higher limit.

The opposite goes for lowering fuel pressure, if you want to lower fuel pressure the new regulator would have to be placed before the stock regulator BUT its return line must bypass any other regulator in the system (making them useless) other wise the stock pressure regulator would just block the fuel till it reaches the stock fuel pressure regulators opening pressure. NOTE: This method is not advisable for lowering fuel pressure, while it will work it creates mutiple points of failure, it wont work with most FMU setups, and it doesen't circulate fuel through the fuel rails as it should, leaving no way for water or any other contaminates to leave the fuel rail other than through the injectors. The only way you should lower fuel pressure is to replace the stock regulator.


As for the o2 sensor location, the instrustions for your wideband should tell you how far from the motor it should be placed, but it needs to be before the split in your exhaust.
 
#158 ·
Awesome explanation thanks. Last question for a while now is des the older 3.0L fuel rail make a difference for my build. I thought I read that they allow more fuel but with the fmu I guess it doesn't matter what fuel fail you have correct?

Also for my wideband 02 sensor I would need that installed on the downpipe before my exhaust splits because if it is on one of the side pipes my readings will be incorrect?
 
#159 ·
Hey i would rather you ask tons of questions and not blow your engine then be shy! A bigger fuel rail can flow more fuel to the injectors and can flow more fuel through to the fuel pressure regulator.

Flowing more fuel to the injectors is pretty self explanitory, the fuel rail has to be able to flow the amount of fuel that the injectors need, so if you have massive injectors and are running them at full potential you may need a bigger fuel rail to supply them with enough fuel. I dont have any real numbers but i imagine you would have to be pushing insane horsepower numbers to need to worrie about that. As lightbulb said, i dont think anyone has maxed a fuel rail out, ondanti would be the only person that i know of that has pushed big enough numbers to be concerned about maxing one out.

Flowing more fuel through the rail to the fuel pressure regulator is not as simple as it seems. Lets say you upgrade your fuel pump to a 400lph pump, if your fuel rail can only flow 300lph then it will act like a restrictor, raising the fuel pressure uncontrollably and putting lots of stress on the fuel pump. Additionally when the motor starts using a large amount of fuel the fuel pressure will start to drop back down as some of the extra fuel is now going into the engine, this unstable fuel pressure will make it almost impossible to tune. These are hypothetical numbers ofcorse.
 
#161 ·
How many psi do you think you will be at? I wouldnt run your setup with the stock injectors. With an fmu you will most likely need a quality 225lph fuel pump to push out the fuel pressure you would need even on a low boost setup. The problem with your set up is that you are stuck with what you got, you cant start at a very low boost and work your way up, so you cant really wait and see on the fuel , you have to do it from the time the supercharger goes on.
 
#163 ·
Thats alot of boost!

The stock fuel pump can supply the fuel volume for 300hp, but thats at the stock fuel pressure, when you increase fuel pressure the volume of fuel it can pump will go down, the other problem with the stock pump is that it cant build up as much fuel pressure as a high performance one can. There is also the fact that it may be wore out, or even a replacment pump (from autozone or the like) that works fine at stock pressure but cant supply the high fuel pressure. I tested the pump in my car and it ran out of steam around 85psi at an idle.
 
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