stroked, supercharged and snorkle combination?

[lost1]

OK guys, keep in mind I'm still pretty early in the stages of building my rig and I'm learning as I go...that said, I have this crazy idea of stroking my 4.0 to 4.7 and then bolting on a supercharger. My question is about the snorkle I've got on there though; is it providing enough airflow for that kind of power or am I going to need to figure something else out?

Right now the snorkle's attached to the stock airbox with a drop-in filter. I want to find a way to set it up using a conical filter and open up that restrictive stock opening. I'd really rather not get rid of the snorkle, its saved my engine twice. (and it makes the Jeep easier to pick out in a parking lot. )

Also, I think the drivetrain's strong enough for all that, and my rear axle's the 8.25 29-spline so that shouldn't be an issue. But I have concerns about that Dana 35 up front for those occasions I want to get her dirty.

The floor is now open for criticism!

 

[5-90]

How large is the snorkel, and does it have any "pinch points" or sharp turns in it? Both will impede airflow...

Beyond that, I don't think it will present a problem to your blower - and you can always make a bigger one, if you need to. 4" dryer vent line comes to mind. The throttle body and cylinder head intake ports are going to be bigger problems - a port/polish job (using a flowbench!) and a bored throttle body are both indicated.

Remember to plan for the additional displacement of the stroker when laying out your supercharger (but you probably already knew that...)

Oh - I think you'll find that the front axle is a Dana 30, not a Dana 35 (I've gotten them mixed up as well, and been called on it, so don't feel bad...) I'd probably want to go with 44's fore and aft, or a Ford 8.8/9 combo (but I just happen to prefer the Danas.) I don't see a need to go with a 44/60 setup - that would probably be overkill, unless you like to "slip and stick" while you're off-road (in which case, the larger shafts are more tolerant of such treatment.)

5-90

 

[lost1]

about that D30, now that you mention it...duh.
The snorkle's ARB and there are a few twists and turns to the hose running to the box. I plan to get rid of that as soon as I can figure out a solution for using a conical filter, but till then I don't really need the xtra airflow that'll provide anyways.

 

[5-90]

I feel the same way when I get them crossed...

5-90

 

[BigWes]

If you do supercharge it, i assume you will have it tuned at a shop (or at least hope so) when they are doing it, they can adjust it to the amount of air your jeep can bring in, you just may not be able to make as much boost with the ARB. Def. upgrade the axles, at least chromo shafts at the bare min. also, that kind of power on AW4(?) i presume..will eat that tranny...look into at least a shift kit to keep the slippage down...any idea on what the compression would be after the stroker? if you have a choice, keep the compression low so the charger wont eat that motor once its on too....hope that helps some, feel free to correct me on anything..

 

[CartsXJ]

If you do supercharge it, i assume you will have it tuned at a shop (or at least hope so) when they are doing it, they can adjust it to the amount of air your jeep can bring in, you just may not be able to make as much boost with the ARB. Def. upgrade the axles, at least chromo shafts at the bare min. also, that kind of power on AW4(?) i presume..will eat that tranny...look into at least a shift kit to keep the slippage down...any idea on what the compression would be after the stroker? if you have a choice, keep the compression low so the charger wont eat that motor once its on too....hope that helps some, feel free to correct me on anything..

You don't know the AW4 very well do you? That tranny, when properly cooled (i.e. heavy duty cooler) and maintained, well last up too at least 400 HP. Its the same tranny used in supera's, yota pickups and suv's.

 

[lost1]

x2


I just rebuilt it, so it oughta be fine so long as I use my head to think and not my boot.

 

[Beej]

If I recall correctly, Gojeep found that the Arb snorkel allowed for the same cross-section of a 3" tube at all places including bends, meaning it will not restrict airflow. It'll be on his site somewhere...

 

[5-90]

Reduced cross-section isn't the only thing that will reduce fluid flow - a change in direction will also do so (albeit to a lesser extent.)

That's why the intake ports for the AMC242 head were raised somewhat with the #7120 casting - and why the #7120 head breathes better. Less change of direction going into the chamber.

5-90

 

[lost1]

^
You guys know WAY too much about this stuff.

 

[87manche]

think of this:
when venting anything out of the house the general rule is that a 90* elbow is like adding 3 feet of pipe. I know that the circumstances are different, but I'm just using that to illustrate the point of airflow redirection having an impact.

 

[Beej]

True about the restriction around bends, I wasn't thinking about that.

How much larger does the opening have to be in order to reduce that restriction? Or is it better to consider it a function of the radius of the turn like in a head?

 

[5-90]

True about the restriction around bends, I wasn't thinking about that.

How much larger does the opening have to be in order to reduce that restriction? Or is it better to consider it a function of the radius of the turn like in a head?

The latter case.

I haven't had any "formal" training in fluid dynamics, but I do know that larger radii are better than smaller ones for maintaining airflow, and that, for instance, a 45* bend will be better than a 90* (that doesn't necessarily mean that two 45* bends will be better than one 90*, but I think you see where I'm going.)

Anything other than a straight duct will cause a restriction in overall fluid flow (gaseous or liquid, in fact) due to internal turbulence and internal friction. I'm sure there's a way to balance it by increasing the tube size - but it will have to stay increased, or you lose the benefit when you go through a bell/reducer on the other side...

5-90

 

[SCW]

The latter case.

I haven't had any "formal" training in fluid dynamics, but I do know that larger radii are better than smaller ones for maintaining airflow, and that, for instance, a 45* bend will be better than a 90* (that doesn't necessarily mean that two 45* bends will be better than one 90*, but I think you see where I'm going.)

Anything other than a straight duct will cause a restriction in overall fluid flow (gaseous or liquid, in fact) due to internal turbulence and internal friction. I'm sure there's a way to balance it by increasing the tube size - but it will have to stay increased, or you lose the benefit when you go through a bell/reducer on the other side...

5-90

The differences are very slight for the various bends. More important is velocity, keep it down (with large pipe) and losses are reduced