early and late model rotors

If the rotors are identical then why can't the old style 89 to 93 case be ported modded cut re machined and flow as good as the new style 94 95 or even the mpx?
 
the reason i ask is i would like to find a late model rotor pack and have it rebuilt.When i rebuilt my girlfriends 95 s/c i did the snout and coupler and the needle bearings,i purchased the rotor pack bearings and seals but was not comfortable with timing the rotors,So i put it back together and noticed when its cold it seems to rattle a little bit untill it gets heated up.runs fine just annoying really.My car does not make the rattle at all its also a 95 but a 5 spd.Anyway i wanted to have another rotor pack ready incase i have any issues with hers.
 
If the rotors are identical then why can't the old style 89 to 93 case be ported modded cut re machined and flow as good as the new style 94 95 or even the mpx?

They are talking about the rotor packs. The three different cases are different. And won't flow the same.
 
Sorry for the thread highjacking!! I was also wondering if the rotors were the same also but for a different reason. I know the cases are different but with the rotors being the same that means the cases on the early blower can be modded to flow as good as the MPX. Ofcourse I say that because I have a 4020 CNC machine, a lathe, and a tig welder. I'm going to cut and replace the back of the cases on my early style blower because I think the $1500 price on the MPX cases are too much to pay given I have the equipment to mod my own cases. Also making a new inlet plentum that will be larger than any on the market.
 
the reason i ask is i would like to find a late model rotor pack and have it rebuilt.When i rebuilt my girlfriends 95 s/c i did the snout and coupler and the needle bearings,i purchased the rotor pack bearings and seals but was not comfortable with timing the rotors,So i put it back together and noticed when its cold it seems to rattle a little bit untill it gets heated up.runs fine just annoying really.My car does not make the rattle at all its also a 95 but a 5 spd.Anyway i wanted to have another rotor pack ready incase i have any issues with hers.

There are supercharger experts such as wade at emery machine, magnum powers and John Bond performance that will do this for you. Rotor timing is not something that can be done effectively by hand.
 
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Sorry for the thread highjacking!! I was also wondering if the rotors were the same also but for a different reason. I know the cases are different but with the rotors being the same that means the cases on the early blower can be modded to flow as good as the MPX. Ofcourse I say that because I have a 4020 CNC machine, a lathe, and a tig welder. I'm going to cut and replace the back of the cases on my early style blower because I think the $1500 price on the MPX cases are too much to pay given I have the equipment to mod my own cases. Also making a new inlet plentum that will be larger than any on the market.

I don't think you could even come close the only thing an mpx case has in common with a late model m90 is the rotor bore. The dimensions of the case overall thickness and everything about it is different. Look at my thread on my mpx called mpxs max
 
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Sorry for the thread highjacking!! I was also wondering if the rotors were the same also but for a different reason. I know the cases are different but with the rotors being the same that means the cases on the early blower can be modded to flow as good as the MPX. Ofcourse I say that because I have a 4020 CNC machine, a lathe, and a tig welder. I'm going to cut and replace the back of the cases on my early style blower because I think the $1500 price on the MPX cases are too much to pay given I have the equipment to mod my own cases. Also making a new inlet plentum that will be larger than any on the market.

That is exactly what the MPII and MPIII were, early style cases with the backs cut off and a new one epoxied on. You can get huge gains that way over the stock early style case, but you ultimately won't be able to match the MPX.
 
Sorry for the thread highjacking!! I was also wondering if the rotors were the same also but for a different reason. I know the cases are different but with the rotors being the same that means the cases on the early blower can be modded to flow as good as the MPX. Ofcourse I say that because I have a 4020 CNC machine, a lathe, and a tig welder. I'm going to cut and replace the back of the cases on my early style blower because I think the $1500 price on the MPX cases are too much to pay given I have the equipment to mod my own cases. Also making a new inlet plentum that will be larger than any on the market.
My inlet plenum is pretty big I dont think you can make it any bigger without losing your wiper motor. http://www.sccoa.com/forums/showthread.php?t=129273&page=3
 
Dave I got the idea of making my own plentum after seeing yours. It looks awesome. I may not be able to flow as good as the MPX however with all the equipment I have at my shop I think I can get some real gains without spending crazy money. I could make my own cases for alot less than I can buy an mpx for. Not blasting the mpx at all its a great investment for anyone that doesn't have the ability to make something of there own. I have a 50K dollar cnc so I think I'm better off to build my own stuff. My wipers have been out for quite awhile so losing the wiper motor isn't a big deal at all. Anyone have any results with the MPII MPIII setups?
 
Sorry for the thread highjacking!! I was also wondering if the rotors were the same also but for a different reason. I know the cases are different but with the rotors being the same that means the cases on the early blower can be modded to flow as good as the MPX. Ofcourse I say that because I have a 4020 CNC machine, a lathe, and a tig welder. I'm going to cut and replace the back of the cases on my early style blower because I think the $1500 price on the MPX cases are too much to pay given I have the equipment to mod my own cases. Also making a new inlet plentum that will be larger than any on the market.

The early case can be modded to flow similar to what is possible with the S port late model blower but it requires cutting the entire inlet end off the blower and replacing it with a new bearing end plate with the rectangular inlet that is located up higher on the ends of the rotors. This has been done for years by Magnum Powers and was called an MPII then later the smiley face inlet configuration was done the same way and it was called an MPIII. The new end plates were actually secured with bolts and epoxy. Welding would likely cause case distortion.

The MPX is made by the same person who made the MPII and MPIII and instead of reworking used housings, it uses a new casting and also has the silencer ports removed along with a few other things that make it more efficent.

In the end you can machine and weld on the stock early model stuff till the cows come home, and it still won't be as good as a MPX housing and matching inlet plenum.

David
 
Dave I got the idea of making my own plentum after seeing yours. It looks awesome. I may not be able to flow as good as the MPX however with all the equipment I have at my shop I think I can get some real gains without spending crazy money. I could make my own cases for alot less than I can buy an mpx for. Not blasting the mpx at all its a great investment for anyone that doesn't have the ability to make something of there own. I have a 50K dollar cnc so I think I'm better off to build my own stuff. My wipers have been out for quite awhile so losing the wiper motor isn't a big deal at all. Anyone have any results with the MPII MPIII setups?

If you have the skill and the know how, I would bypass the rectangular modification, which in essence is a copy of the MPII, and try to copy the MPX smiley inlet. You would of course need to to create a matching inlet but that would be quite easy with a billet of aluminum for the flange and then you could tig it to a modified inlet. With all the equipment you have, this would just require your time.

I would start with a later rectangular case, if you have, as the floor is raised up under the rotors where the oval port is open. Otherwise you will also need to fabricate the triangular filler block for the bottom as well.
 
I think in the end the MPX will out flow what I build. However if I was going to spend the money on the mpx I'd just buy a different blower ie kenne bell. Custom fab inlet will be really easy. What ever back plate I make for the blower will mirror another program for the inlet plate to begin fab of the whole inlet. I will be using the old style blower for this build as I dont have a new one on hand. I will post pics and start a new thread when I start this project. Probably tear into first of next week and be back on the road by the end of the week. Will need to get a throttle body to match up to the custom inlet. Any ideas of what TB I can grab off any other vehicle? Not really interested in buying something crazy expensive.
 
I think in the end the MPX will out flow what I build. However if I was going to spend the money on the mpx I'd just buy a different blower ie kenne bell. Custom fab inlet will be really easy. What ever back plate I make for the blower will mirror another program for the inlet plate to begin fab of the whole inlet. I will be using the old style blower for this build as I dont have a new one on hand. I will post pics and start a new thread when I start this project. Probably tear into first of next week and be back on the road by the end of the week. Will need to get a throttle body to match up to the custom inlet. Any ideas of what TB I can grab off any other vehicle? Not really interested in buying something crazy expensive.

Use your stock sc throttle body for the bolt pattern but make the inlet hole 85mm+ inside diameter.
 
The real differences between the MPX and the late model is the inlet and outlet shapes. The rotors are the same so the internal case is as well. If you can replicate the inlet and outlet, you will come close. It will be a gigantic improvement over your stocker.

The TB shape is unique and is only shared by the 94-95 Mustang throttle body. The Mustang has a different style linkage so you have to remove it and swap on the sc linkage from your stock tb if you plan to use one.

BBK 75mm tb's for the sc can be found from $125-200 depending on the condition. Sometimes the MP 85mm come up from $225-300. Not I giant investment if you are already saving money on a blower and inlet.
 
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