LincolnMarkVII
Active member
The original thread can be found here: http://fordsix.com/forum/viewtopic.php?t=47511
The short of it: I'm working on picking up a 250 for my '83 Fairmont, and I'd like to build it for making all its power from idle to 4000 RPM, with no concern for ever going past 4000. I'll be looking to use the CI aluminum head, fuel injection, (probably Megasquirt) and probably a truck/RV type cam. 200-250 at the rear wheels would be ideal, (2900 lb. car) but I'm more concerned with making it a torque monster than raw horsepower numbers. 3.55 or 3.73 gears will likely be used along with an overdrive transmission. One thing that's changed between that thread and this one is that I'm giving more thought to going to a T5 or T56 instead of an AOD.
The Fairmont will likely never see a track of any sort, but I'm building it more or less like a road racer. Slightly lowered, Cobra IRS out back, subframe connectors, torque box reinforcement, strut tower brace, etc. I may even try my hand at learning how to make my own fiberglass or carbon fiber body panels to lighten up the front end. I don't drive like a maniac or with a lead foot, but those times I do open the taps I want it to feel just right.
I started this new thread with the intent of focusing on forced induction. Originally I had wanted a supercharger, but I was told that that would be less than ideal for my goals. (I want power, but I do want to try to keep decent fuel economy at part throttle) I started thinking about a turbo, then I read the Tempo EFI thread in this section and got to thinking: What about two small turbos (like an IHI from a Turbo Coupe or a turbo Probe) set up with custom intake and exhaust to behave almost like two connected inline-3s? What I mean is making a small intake and exhaust for just the back 3 cylinders, and another pair for the front 3, and not physically connecting them in any way.
Why am I pursuing this line of thinking? I'm thinking about trying to maximize throttle response, minimize turbo lag, and even any lag that may occur from a longer distance between the turbo and the intake valves. I also would like to keep front end weight down if possible.
I don't have a specific question other than whether or not I'm pursuing a valid line of thinking. I know this won't be cheap to do right. I'm mostly not concerned with that. (I'm not looking to spend hundreds of thousands, but I expect it to be in the low tens of thousands when all is said and done) This car is a once-in-a-lifetime type project for me. I would like to toss out a few things and see what kind of feedback I can get on it. Some points to note:
- I don't want to mess around with intercoolers if I can avoid it. Lots of plumbing involved there.
- Yes, I realize that that probably limits me to 5-7 PSI at best with no other changes.
- I would, however, be willing to use some sort of methanol injection setup to get beyond that boost level.
- I would be willing to set up a 2-stage boost controller triggered manually or triggered by a low fluid sensor in the methanol tank.
- The 80,000-ish mile/1976-vintage 250 will be getting a rebuild before being used.
- I don't expect to do a rebuild as cheaply as possible. I'll do what needs to be done to handle all this.
- I'll probably use one of the fancier MSD boxes that includes crude traction control for those times that the woman would need to drive it.
- For fuel injection, I was thinking about two larger injectors.. one in each small intake.. as opposed to trying to set up multi-port. Perhaps the injectors from a CFI 5.0?
- I was thinking a second pair of similar injectors for the methanol injection.
- For lack of a better description, the image in my head of the small intake manifolds is that of something shaped crudely like the circular Mopar "M" logo.. with the throttle body at the top of the M where the three legs meet, and the injector just behind that.
- I have also considered that other intake setup with the six small throttle bodies.. I would have no problem with that.
- Yes, I'm quite possibly insane.
With all this in mind, could a setup be built that's superior to using one large turbo connected to all six cylinders by the conventional means?
Well I've written myself into a corner here, so I'll post it for now and see how many people tell me I'm on crack, I mean see what questions pop up before I regurgitate any further thoughts/details/silliness.
The short of it: I'm working on picking up a 250 for my '83 Fairmont, and I'd like to build it for making all its power from idle to 4000 RPM, with no concern for ever going past 4000. I'll be looking to use the CI aluminum head, fuel injection, (probably Megasquirt) and probably a truck/RV type cam. 200-250 at the rear wheels would be ideal, (2900 lb. car) but I'm more concerned with making it a torque monster than raw horsepower numbers. 3.55 or 3.73 gears will likely be used along with an overdrive transmission. One thing that's changed between that thread and this one is that I'm giving more thought to going to a T5 or T56 instead of an AOD.
The Fairmont will likely never see a track of any sort, but I'm building it more or less like a road racer. Slightly lowered, Cobra IRS out back, subframe connectors, torque box reinforcement, strut tower brace, etc. I may even try my hand at learning how to make my own fiberglass or carbon fiber body panels to lighten up the front end. I don't drive like a maniac or with a lead foot, but those times I do open the taps I want it to feel just right.
I started this new thread with the intent of focusing on forced induction. Originally I had wanted a supercharger, but I was told that that would be less than ideal for my goals. (I want power, but I do want to try to keep decent fuel economy at part throttle) I started thinking about a turbo, then I read the Tempo EFI thread in this section and got to thinking: What about two small turbos (like an IHI from a Turbo Coupe or a turbo Probe) set up with custom intake and exhaust to behave almost like two connected inline-3s? What I mean is making a small intake and exhaust for just the back 3 cylinders, and another pair for the front 3, and not physically connecting them in any way.
Why am I pursuing this line of thinking? I'm thinking about trying to maximize throttle response, minimize turbo lag, and even any lag that may occur from a longer distance between the turbo and the intake valves. I also would like to keep front end weight down if possible.
I don't have a specific question other than whether or not I'm pursuing a valid line of thinking. I know this won't be cheap to do right. I'm mostly not concerned with that. (I'm not looking to spend hundreds of thousands, but I expect it to be in the low tens of thousands when all is said and done) This car is a once-in-a-lifetime type project for me. I would like to toss out a few things and see what kind of feedback I can get on it. Some points to note:
- I don't want to mess around with intercoolers if I can avoid it. Lots of plumbing involved there.
- Yes, I realize that that probably limits me to 5-7 PSI at best with no other changes.
- I would, however, be willing to use some sort of methanol injection setup to get beyond that boost level.
- I would be willing to set up a 2-stage boost controller triggered manually or triggered by a low fluid sensor in the methanol tank.
- The 80,000-ish mile/1976-vintage 250 will be getting a rebuild before being used.
- I don't expect to do a rebuild as cheaply as possible. I'll do what needs to be done to handle all this.
- I'll probably use one of the fancier MSD boxes that includes crude traction control for those times that the woman would need to drive it.
- For fuel injection, I was thinking about two larger injectors.. one in each small intake.. as opposed to trying to set up multi-port. Perhaps the injectors from a CFI 5.0?
- I was thinking a second pair of similar injectors for the methanol injection.
- For lack of a better description, the image in my head of the small intake manifolds is that of something shaped crudely like the circular Mopar "M" logo.. with the throttle body at the top of the M where the three legs meet, and the injector just behind that.
- I have also considered that other intake setup with the six small throttle bodies.. I would have no problem with that.
- Yes, I'm quite possibly insane.
With all this in mind, could a setup be built that's superior to using one large turbo connected to all six cylinders by the conventional means?
Well I've written myself into a corner here, so I'll post it for now and see how many people tell me I'm on crack, I mean see what questions pop up before I regurgitate any further thoughts/details/silliness.
