Want to change my truck's asperation and I have all my buds (that are addicted to subies) tellin me to turbo it. However, my grandfather thinks I should either just go for more cubes or run with a supercharger. I'm under the assumption that superchargers are more for pure high end power and turbos are greasy quick lots of low end power. any thoughts?

I'm running a 73 390 with motorcraft 2100 two bbl in a 76 f-150 explorer.

 

If you are going with a blow thu setup, there is a lot of tuning involved, both ways. Even if you go EFI, there is a lot of tuning, both ways.

If it is your daily driver and you REALLY want to boost it, I would go with a roots s/c. Turbos are MUCH more picky when it comes to the tune.

Just remember, there is A LOT more involved than just bolting it on an running it.

 

There are two different types of superchargers- centrifugal and roots style. Roots style are the ones most OEM use- the ones that bolt to your intake manifold. They use lobes that mesh together and create boost as the lobes rotate and mesh together, they force the air out and built pressure. They work best at building low RPM torque, when your cylinder pressures are at their lowest. For this reason, they are considered the most forgiving method of adding boost. Most won't add much power to the top of the rpm band, but they will product a lot more power under the curve- good for truck use.

Centrifugal superchargers look like little belt or gear driven turbos. Indeed, their internals are basically the compressor section of a turbo with a gear or belt driven side to spin it. They generally build little to no boost at low RPMs and are good for providing maximum high rpm power.

Turbos come in all shapes and sizes, from ones small enough to turbocharge a 300cc engine to gigantic bulldozer turbos that your motor might never spin fast enough to get any boost out of. Setting up a turbocharger will require exhaust manifolds, piping, fuel management (theoretically a carb will match the greater air flowing through it with greater fuel, but you will need to rejet and probably go with a larger fuel pump, at minimum), a carb hat... for street use you will want an intercooler of some sort. Most of these same things are true for superchargers, too, though. The nice thing about turbochargers is that you can dial in the boost you want to run. Run a light wastegate spring and you can save mpg, or dial up more boost with a boost controller for when you need extra power.

With either type of power adder, though, anything in a kit type form will likely cost thousands, and anything you cobble together will need to include oil pressure and return lines, piping, bracketry, belts and pullies for supercharing or exhaust manifolds for turbocharging, an intercooler, fuel management, upgraded ignition capable of retarding timing on boost, etc.

I'm kind of a fan of the nasty whistle of a turbo myself, but either option will be a lot of work compared to rebuilding what you have with decent heads, higher compression, or a hotter cam, or dumping it and swapping in a better motor.

 

the question comes to my mind of why you decided you want to change the aspiration? most want to bore/stroke it, bigger cam, bigger carb, etc etc..... Are you going for looks, sound, or just thought aspiration change was needed for some reason?

 

Yeah, esp with that 2 bbl. I think you have a lot more "easier, cheaper" hp you could be wringing out of the 390 before you go ape**** with forced induction.

 

Well, good question, I just thought that you dont many supers/tubos on trucks and my I thought it'd be cool to be a little bit different, however, I'm also very... umm... stereotypical and will most likely do my big ford the "RIGHT" way, a huge ****ing 460 bored and stroked to hell, either uncorked or with short glasspacks and huge rear tires. I like that idea better.

 

Turbocharging is fun, and you get a real neat sense of power from them. I Turbocharged my 300 -6 cylinder this last year and it's so much fun. I run about 8 psi boost as of now. It's like hitting the turbo button on the game controller when the boost kicks in. Lots of work and lots of learning. Well worth my time for sure.

I think a supercharger for a V8 should be fairly easy to accomplish. Turbo V8's can get messy, but when done right are an art-form in themselves.

 

How much of an increase in HP can you expect using a Roots style supercharger on a 390?


OJ

 

hasteranger summed it up very well, just be mindfull of your compression ratio and how much boost you throw at it. Do plenty of internet research and read plenty of "How to" books before you start tossin dollars at it.

 

Too many variables to answer. Static C/R, fuel type, boost levels, etc.

 

Turbo's take few to spool and are generally less effective lower in the rpm range, but make the most efficient h/p adder. Superchargers make gobs of low end torque. Either take lots of tuning to get streetable.

I'm running an A460 block punched to 545 cu's and an 8-71 Hampton making 1150 honest h/p in my jet boat. It has literly taken years to learn how to read/listen/tune the engine correctly. It's definately an art !!! But I wouldn't change it for the world, nothing like the whine of a 3" belt at 6,600 rpm's

Adding cubes is quite affordable nowadays. You can make a quick 521 or 557 out of a stock 460 block. You can safely run 10.50 c/r w/ aluminum heads, and even add a little spray. It's easy to get 500 h/p n 500 lb.ft. of torque outta a 460 based engine. And as an added bonus the only underhood thing that'll need attention is the size of the radiator. Adding a hair dryer or blower requires lots of underhood changes that'll add considerable cost and time to your project.

 

And you don't have pictures of this??????????!!!!!!!!!!!!!!!!????????????? come on man and put some pictures up!

 

I think your basically stock (and probably a little tired) 390 will not hold up very well to boost. The engine should be built for forced induction. I would freshen up the 390 and add some aftermarket parts like a lumpier cam, 4 barrel intake manifold and carb, headers and etc.

 

I'm with DKF on this one...if your 390 is tired at all, adding forced induction to the equation is asking for trouble. Unless an engine is relatively new, slapping a turbo or s/c on it will usually shorten the lifespan of a "seasoned" engine.

If you're set on putting forced induction on your FE, I'd say you'd need to rebuild the 390 first, and make it purpose built for that application. The compression ratio has to be set to allow for the amount of boost you're going to throw at the plant. If your plant has a relatively high CR, you're going to be limited by the amount of boost you can throw at it safely. If your CR is too low, your induction system then has to make up for power you just threw away by not having the CR at the optimum level for the amount of boost to be used. That is basically throwing money away just to be "different". So, again, if you're dead set on forced induction, you need to make sure the FE can handle whatever boost you're thinking of thowing at it. If we're only talking like 5 to 8 lbs of boost, you'll have some leeway, but honestly, that's a huge investment for marginal gains when that 390 could be improved in other ways without as much expense.

Now, with regard to turbo versus supercharger, I'd say the s/c is the way to go for this particular application. Unless you find some sort of turbo setup that can spool up REALLY fast, your 390 isn't going to utilize its potential. I know with the improvements in turbos that have been made, there is sure to be a turbo that can become effective much lower in the power band than they used to be, but I still think the turbo is too rpm dependent to be of much use in an FE based engine.

The supercharger solution is the same depending on configuration....if you went with a centrifugal supercharger, you're in the same boat as the turbo. It's rpm based, and has to ramp up boost as rpm's increase. So, I'd steer clear of the centrifugal setups like Paxton, Vortech, ATI, and the like. They're great for other applications, but in this instance, I don't think you'd be happy with the product.

A roots or "twin screw" type of supercharger is most likely the best solution for your needs if you absolutely want forced induction. They can make boost at relatively low rpms. For example, the s/c from Kenne Bell claims that it makes full boost at 1800 rpm. I don't know that they have an application for your engine, but I'm just using them for an example. I'm sure you could find an application from either Weiand, Eaton, Dyers, Magna Charger, or Whipple.

The downer here is that height of some of these types of blowers can pose a problem unless you want to cut a hole in your hood. Installing a centrifugal s/c is easier as it's about the same as putting in an alternator with regard to position (plumbing is another matter entirely).

Speaking of plumbing, a turbo system by definition is going to pose a much larger plumbing project as opposed to a blower. It's just the way it is due to how a turbo works, after the exhaust. Both blowers and turbos can be intercooled, and that poses plumbing issues in and of itself.

There's an article out there where someone put a set of twin blowers on a 390 FE. They were Paxton units, and I imagine the twin blower setup helped with low end power as it would double boost up through the power band. I'd think that'd be a bit of a project, and terribly expensive for dual blowers, but it's doable.

I suppose you can do anything you want, but it depends on how deep your pockets are.