It’s just a way to package a tunnel ram under a stock hood. The magnum was designed as a truck engine and nothing else. Long runner low end tq that dropped off at 4400rpm
When I opened it up I always wondered what the engineering was behind all that volume? Maybe pre-charge for start up with air on the inside of the closed throttle body?
Basically it's a tunnel ram and the long intake runner's are great for building low RPM torque. Chrysler call's it Ram-O-Sonic intake principle. The shape of the intake and runners creates a intake pulse. Gases once in motion keep going as the intake valve is closing. GM called it RAM AIR. They are type's of induction that have some of the characteristics of Forced induction. Also see Chryslers Cross Ram induction with dual quads from 1962. It's well proven and been around over 60 years.
A problem with the leaking plenum is the bolts are too long and don't hold it tight enough. Shorter bolts will fix a leaking plenum plate along with a new gasket. Please let us know how your engine responds to the modifications.
I did mine but I don’t believe you actually need to block off the the area. Only because you looking for more airflow into the heads. So more air will be improvement for power. Just think about it for now. But I would get the intake manifold from a 5.2 less work.
I feel like it’s wasted space and compromises air flow efficiency. I could be totally wrong but I want to try and see if reducing it makes a difference.
@@lokiryder5235it's not going to do anything because the Throttle body flange is the restriction. The intake runner's flow 199cfm each x8= 1792cfm. The throttle body is the problem. The best solution is a Supercharger or Turbo to force the Air through the throttle body venturies.
Your mods will not show any improvement. The pan is only 1 1/2" away from the mouth od the port runner. You need to trim the runners all the way back until they are even with the adjoining runner.
@@lokiryder5235I’ve seen it, can’t recall if it was hypotek, or Beyer..: but I do recall seeing that manifold. Only issue is why ? Stock throttle body flows around 635cfm more than enough for stock, and aftermarket throttle body’s flow as much as 1,200cfm so what’s really gained with multiple TB’s 🤷🏻♂️
The thing is that you lose the low RPM torque because you have to cut out the long intake runner's. Buy 3 intake manifolds and Cut out the intake runner's. Then cut off the throttle body flanges from 2 of them. Then mock up and weld them together and grind and blend it all for maximum flow. That's a major pain in the ass. Just buy a ModMan intake manifold and the triple duce top plate. They run around $500.
I gotta wonder if the keg shape was intended to circulate the air flow in some way? Why else would they even include all that extra volume?
It’s just a way to package a tunnel ram under a stock hood. The magnum was designed as a truck engine and nothing else. Long runner low end tq that dropped off at 4400rpm
When I opened it up I always wondered what the engineering was behind all that volume? Maybe pre-charge for start up with air on the inside of the closed throttle body?
Basically it's a tunnel ram and the long intake runner's are great for building low RPM torque. Chrysler call's it Ram-O-Sonic intake principle. The shape of the intake and runners creates a intake pulse. Gases once in motion keep going as the intake valve is closing. GM called it RAM AIR. They are type's of induction that have some of the characteristics of Forced induction. Also see Chryslers Cross Ram induction with dual quads from 1962. It's well proven and been around over 60 years.
A problem with the leaking plenum is the bolts are too long and don't hold it tight enough. Shorter bolts will fix a leaking plenum plate along with a new gasket.
Please let us know how your engine responds to the modifications.
You are right, I address this issue on a recent job = 1997 Grand Cherokee replace head gaskets
I did mine but I don’t believe you actually need to block off the the area. Only because you looking for more airflow into the heads. So more air will be improvement for power. Just think about it for now. But I would get the intake manifold from a 5.2 less work.
Any update on this?
Keggers suck but you can get a buck a pound for scrap aluminum , get the old school intake manifold it's night and day .
Why do you want to reduce the plenum volume?
I feel like it’s wasted space and compromises air flow efficiency. I could be totally wrong but I want to try and see if reducing it makes a difference.
@@lokiryder5235it's not going to do anything because the Throttle body flange is the restriction. The intake runner's flow 199cfm each x8= 1792cfm. The throttle body is the problem. The best solution is a Supercharger or Turbo to force the Air through the throttle body venturies.
Your mods will not show any improvement. The pan is only 1 1/2" away from the mouth od the port runner. You need to trim the runners all the way back until they are even with the adjoining runner.
Thanks, it’s an idea I’ve had for a while and want to try it out. I do believe you are right, thank you for the advise.
I think if a guy was creative you can make a 3 two barrel set up with that manifold somebody out there let me know before I try it
I believe there is someone that did that with 3 throttle bodies, I really like the idea and I’d like to see if someone has done it myself
@@lokiryder5235I’ve seen it, can’t recall if it was hypotek, or Beyer..: but I do recall seeing that manifold. Only issue is why ? Stock throttle body flows around 635cfm more than enough for stock, and aftermarket throttle body’s flow as much as 1,200cfm so what’s really gained with multiple TB’s 🤷🏻♂️
The thing is that you lose the low RPM torque because you have to cut out the long intake runner's. Buy 3 intake manifolds and Cut out the intake runner's. Then cut off the throttle body flanges from 2 of them. Then mock up and weld them together and grind and blend it all for maximum flow. That's a major pain in the ass. Just buy a ModMan intake manifold and the triple duce top plate. They run around $500.