S port vs MPII

[XxSlowpokexX]

Just curious. What if any are the advantages of the MPII over the S port?

I always figured the MPII was reated based on the S port because there was a lack of late model cases to be had....So is there a difference or an advantage of one over the other?

I'd perfer seat of teh pants or boost related differences then solely dyno related as different day different dyno can always be an issue


Thanks All

Damon

[ricardoa1]

It will be tough to find someone that has tested both on the same car, since they both perform similar. The inlet is the same size and the port is identical on an MPI or MPII. Aside from the back plate expoxied I dont see much bennefit for one over the other.
Now if you are talking about the magnuson S port, then the MPs should be a little better since that S port was designed with the stock inlet in mind. I think they only massaged the outlet but I could be wrong.

[XxSlowpokexX]

Inlets massaged on S port. I;m just not familiar with the MP blower products at all

[XR7 Dave]

MPII has more porting on both inlet and outlet. The S-port is more effective at low OD, MPII will be better at higher OD's. If not overdriven enough the MPII will suffer slightly on the bottom end. High performance blowers are like high performance cams. Lowered seal timing means lower efficiency at lower rpms.

[XxSlowpokexX]

Hey Kenny I may need that 10% Jackshaft back..JK hehe

[Slysc]

Damon,

Do you know anyone with a messed up S-port case?

[Pablo94SC]

Originally Posted by XR7 Dave

MPII has more porting on both inlet and outlet. The S-port is more effective at low OD, MPII will be better at higher OD's. If not overdriven enough the MPII will suffer slightly on the bottom end. High performance blowers are like high performance cams. Lowered seal timing means lower efficiency at lower rpms.

Do you mean that the rotor timing was changed due to the revised inlet port design on the MPII so that it can handle higher RPM? Do you have a recommended OD range that the MPII seems to perform best at? What would you say the maximum blower RPM of the MPII is? Thanks.

[Pablo94SC]

Originally Posted by Slysc

Damon,

Do you know anyone with a messed up S-port case?

I have my late mode case with the window in it.

[Slysc]

Originally Posted by Pablo94SC

Do you mean that the rotor timing was changed due to the revised inlet port design on the MPII so that it can handle higher RPM? Do you have a recommended OD range that the MPII seems to perform best at? What would you say the maximum blower RPM of the MPII is? Thanks.

No, I think what he means is that the duration of the overlap where the rotor seals to the case is reduced so at lower rpms you get less efficiency but at higher RPMs the larger inlet and outlet flow better.

[Slysc]

Originally Posted by Pablo94SC

I have my late mode case with the window in it.

That's the one Are you going to make a planter out if it or can I do some experimenting with it?

[Pablo94SC]

Originally Posted by Slysc

That's the one Are you going to make a planter out if it or can I do some experimenting with it?

Experiment away... but if it's good, I might want it back. I'll ship it back to ya in the box the heads come in. Need the rotor pack and snout too? I might use my old rotors and snout in the early model case I have here.

[Pablo94SC]

Originally Posted by Slysc

No, I think what he means is that the duration of the overlap where the rotor seals to the case is reduced so at lower rpms you get less efficiency but at higher RPMs the larger inlet and outlet flow better.

Gotcha. Then it's not really about OD as much as blower RPM. That's good news for those willing to run the engine at higher RPM.

[XxSlowpokexX]

But at Higher RPM's I would assume you would need the blower to spin that much faster to compensate for airflow. So just revving the blower higher wont help. Needs to be OD'd

probably why my DIII performed so well

[tim]

I weent from a 13.9 at the shoot out in 2006 to a 12.52 in 2007. Big secret get big enuogh injectors to suport it. Drive it 20% and holy hole shot bat man! Ask the people that were at the shootout!!

[Pablo94SC]

My only problem Tim is I need to keep the torque around 420lbs or less in order to benefit from lock-up at WOT. Otherwise I'll burn up the TC's clutch. Maybe I'll go with the 15% OD setup from MP and see what happens.