SC Safe RPM and In Series - As in Dual SC.
- Thread starter supercoop
- Start date
Dual SC's
Just an idea based on the guy who has the 1600 HP GTO where he runs Dual inline Blowers. One blower is bigger than the other. My idea is to spin one Eaton 90 faster than the other one. I will have to do a lot of bench testing first. It wil be a lot fun to see how this turns out.
I would like to create 100 HP more using max size TB, IC tubing and install headers and larger exhaust.
Will the heads be the limiting factor on flow or will I just need to ring the block and use happy gas ?
Thanks for your guys replies.
Just an idea based on the guy who has the 1600 HP GTO where he runs Dual inline Blowers. One blower is bigger than the other. My idea is to spin one Eaton 90 faster than the other one. I will have to do a lot of bench testing first. It wil be a lot fun to see how this turns out.
I would like to create 100 HP more using max size TB, IC tubing and install headers and larger exhaust.
Will the heads be the limiting factor on flow or will I just need to ring the block and use happy gas ?
Thanks for your guys replies.
kenewagner
Registered User
Fancy idea but not very practical. It take HP to turn a blower and the M90 is not a real efficient blower. It has been discussed many times on these forms about twin charging. Using a turbo to provide boost to the intake side of the blower. It would also provide the air flow on the top end. Two superchargers under the hood is more a novelity than a practical way to make HP. The heads would likely be a sticking point. Anything could be done though but not sure you would be happy with the results
Ken
Ken
RE: Twin Superchargers
Thanks Guys !! for each of your informative replies and I understand now that 2 blowers may not be where I want to go. As well as, if 2 blowers were effective then other people would also be doing it.
As far as cost vs novelty ? I will sit down and figure out the costs associated with Conventional upgrades that are very popular on Sccoa compared to my not-so-conventional concept of using 2 blowers with and without certain conventional options installed.
I will do this over the winter and really get detailed.
Ever since I bought my 91 SC, I am just not the same
Thanks again,
Rob
Thanks Guys !! for each of your informative replies and I understand now that 2 blowers may not be where I want to go. As well as, if 2 blowers were effective then other people would also be doing it.
As far as cost vs novelty ? I will sit down and figure out the costs associated with Conventional upgrades that are very popular on Sccoa compared to my not-so-conventional concept of using 2 blowers with and without certain conventional options installed.
I will do this over the winter and really get detailed.
Ever since I bought my 91 SC, I am just not the same
Thanks again,
Rob
RE: Twin Superchargers
90bkbrd,
Thanks for your question and it is good one that I just through to the wind.
Yes, under hood and through it. They are going to be stacked one on top of the other with a narrow-flat water cooled IC in between them.
Actually, inital consideration and evaluation with other mechanics and two engineers resulted in both superchargers will be spinning slower than OEM. We have also discussed using a restrictor baffle to prevent backwash/cavitation between the two blowers which I am told will have the first blower running at a higher pressure with a drop trough the IC and then repressurized in the 2nd blower to the intake. (A lot of this is above my head).
There is concern for HP loss due to driving the second Eaton. But, I will know a lot more next month when I spin both blowers in series and simulate Zero to WOT. At first we will be using just round PVC piping (easy instrutment hook up and cheap to do).
I have a couple engineer friends who work for Rockwell assisting me in the initial calculations to determine the pulley sizes for both blowers. One supercharger is going to spin faster than the other.
I will know a lot more after testing.
If this setup seems strange to most of you. I agree with that assertion but, it is going to be a lot of fun to try and make it work. Imagine a supercharger with 2 sets of twin-screw rotors. A set of gears that can be easily changed to allow custom speed chages between the two sets of rotors. Also imagine this 4 rotor blower will fit under the SC hood. Yea, thats what I am taking about.
It all started the day I drove my 1st SC home and saw a need for speed.
Rob
90bkbrd,
Thanks for your question and it is good one that I just through to the wind.
Yes, under hood and through it. They are going to be stacked one on top of the other with a narrow-flat water cooled IC in between them.
Actually, inital consideration and evaluation with other mechanics and two engineers resulted in both superchargers will be spinning slower than OEM. We have also discussed using a restrictor baffle to prevent backwash/cavitation between the two blowers which I am told will have the first blower running at a higher pressure with a drop trough the IC and then repressurized in the 2nd blower to the intake. (A lot of this is above my head).
There is concern for HP loss due to driving the second Eaton. But, I will know a lot more next month when I spin both blowers in series and simulate Zero to WOT. At first we will be using just round PVC piping (easy instrutment hook up and cheap to do).
I have a couple engineer friends who work for Rockwell assisting me in the initial calculations to determine the pulley sizes for both blowers. One supercharger is going to spin faster than the other.
I will know a lot more after testing.
If this setup seems strange to most of you. I agree with that assertion but, it is going to be a lot of fun to try and make it work. Imagine a supercharger with 2 sets of twin-screw rotors. A set of gears that can be easily changed to allow custom speed chages between the two sets of rotors. Also imagine this 4 rotor blower will fit under the SC hood. Yea, thats what I am taking about.
It all started the day I drove my 1st SC home and saw a need for speed.
Rob
I think the real issue though is the two ovens under the hood though, plus somewhere around 50-75HP of drag.
IMHO performance is nowhere in this equation. I understand you want to run a multistage compressor setup but the M90 is not designed for this and most multistage compressors I familiar with are piston not rotor.
IMHO performance is nowhere in this equation. I understand you want to run a multistage compressor setup but the M90 is not designed for this and most multistage compressors I familiar with are piston not rotor.
slowpoke
Registered User
i dont recall every hearing of such a thing being done or even tested. im only 32 but still been around the block a lil. i think it would be good to see what it would do. who nows, this guy might be on the next stage of boost for all of us, at the very least we get to find out what happens. the way im thinking of this is the 2nd blower is going to be compressing air that is already compressed possibly creating even greater psi. if it works out that way my big concern would be that our heads are already at there max with just 1 blower, are they really going to be able to handle even greater psi with out blowing off. sounds like this guy is going forward with the testing regardless what we say or suggest. so only time can tell.
90blkbrd
Registered User
Under a stock hood you have less than ~3 inches of clearance with a stock setup. You want to add another ~8"-10" with another M90 and a IC/baffle. I think you need to go outside with 4 Kleenex boxes (2 wide and 2 tall) and set them right above where the current M90 is and then get into the drivers seat and check out your view.
I believe this idea is possible and could work, but the money and time wasted would be better utilized by buying a MPx or Whipple and having your engineers build you a inlet.
I believe this idea is possible and could work, but the money and time wasted would be better utilized by buying a MPx or Whipple and having your engineers build you a inlet.
David Neibert
SCCoA Admin
I think you are headed towards a big smoking pile of failure by trying to run 2 m90s in series. It would work a lot better and be much easier to package if you used a centrifical blower to force feed the m90 in it's current location..force feeding it with a turbo would be even better.
If you insist on using two m90s, run them in parallel, not series.
David
If you insist on using two m90s, run them in parallel, not series.
David
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RE: Twin Screwing Up - Maybe ~..~
Okay Guys and mayble gals, Thanks for the comments as they're helpful to us but, there are 2 caveats that I need to mention concerning my madness behind this proposed "upgrade". I have to use a M90 as it is OEM.
1. My insurance on my 91 SC is only $88 every six months as this is my 2nd car and is "Non-Modified. As in, no aftermarket "Non-OEM" equipment. Placing a 2nd M90 under the hood is an OEM Part, Technically, Right ?
2. The proto-type with 2 M90s stacked in series is for show as well as some extra go and it would be OEM stock parts. And, I want it out the hood too. Has anyone every just moved their Supercharger up through the hood for show ? No HP gain that way. I hope to gain just some HP above and beyond the additional drag and still be consider an OEM part and have very, very, very cheap car insurance. This car will not be a daily driver, only for strip and short trips in town.
However, the latest comments give way to some more questions on my end.
1. If we did run the M90's in parallel won't both M90's still not produce more than 15 psi without bigger plumbing and porting all the way to the exhaust tips. And, both M90's would still have to be Over Driven which is not OEM ? More pressure is what is needed to get around the head port restriction. We won't blow the ports on the manifold or heads by raising the pressure and if I blow the HG's, I will copper ring a block in the future. Again, this is not about resulting in a lot more HP.
2. Will Parallel M90's also build more heat as they push against each other and subseqently require a very large "air cooled" IC ? Whereas, if the M90s are in series, the 1st M90 will act as a primer charge "running slower than OEM speed with "Less" heat buildup, then cooled with a water IC "more effiecent", the 2nd M90 is then allowed to boost the pressure higher than 15 psi (if wanted) at a lower RPM than OEM. (No Over Driven blower equates to a OEM modification using only OEM Superchargers). And, if I want more pressure, I change the pulleys and inch back to stock OEM speed but, no more on the 2nd blower. Did I mention that the by-pass is history.
2. I can buy a used M90 for just a little more than what it cost for a 90mm MAF that fits in the palm of my hand and it doesn't spin either Again, I want to keep it OEM.
3. 50-75 HP Drag. Well, we hope not as we are not going to spin either M90 as fast as original OEM. The 2nd M90 will be spinning at peak speed "max air pressure" (or less if possible) at 5,000 engine RPM. The 1st M90 will only spin as fast as necessary to supply air to the 2nd blower without pressure loss across the water cooled IC at any giving time.
4. Why is there a Super Charger Output "Bypass" valve on these blowers at all ? The reason I ask is as I am cruising at 60 mph @ 2500 RPM in my 91 SC and at 20 inches of vacuum the M90 is not doing a thing but, heating up my engine compartment. Is it all because of this Bypass valve that gives way to engine vacuum so I can control the heater door ?
Finally. Twin-screw compressors have been used for many years in "Multi-Stage" In-Series applications in gas fields and refineries and not let us forget race cars. I overhauled many of these twin-screw compressors when I was in my 20's. We understand that the M90 was not designed to be installed in series but, I hate the fact that there is this by-pass valve in my car that just turns the M90 off because some engineer at ford didn't want to add a vacuum pump to a ford Thunderbird SC to open and close the stupid heater door.
Again, a recap. We are only wanting a little more HP but, 100 would be nice but, not a chance. The drag on the engine will not be 50-75 HP as neither blower will be spinning faster than OEM. If we can get 20 PSI at 3,000-3,500 RPM and it all stays together "just 1 time" under WOT. It will be twin singers under my hood for a long time. And, I am not talking about sewing machines
With that all said. I would like to thank you all for your comments. Is there any more major concerns that I should be considering in my quest.
One last thing, that 21 inches of mercury drop (vacuum) will be on the inlet side of that 1st supercharger and never seen again. This setup will be full-time pressure and that is where the big payoff is going to be. I might just want to find the name of that engineer at Ford who decided to install that SC by-pass valve and mail it back to him. I really do believe that in 1989 electric vacuum pumps where NOS at AutoZone
Am I wrong about the By-Pass valve, If so, please let me know.
Thanks again and peace,
Rob
Okay Guys and mayble gals, Thanks for the comments as they're helpful to us but, there are 2 caveats that I need to mention concerning my madness behind this proposed "upgrade". I have to use a M90 as it is OEM.
1. My insurance on my 91 SC is only $88 every six months as this is my 2nd car and is "Non-Modified. As in, no aftermarket "Non-OEM" equipment. Placing a 2nd M90 under the hood is an OEM Part, Technically, Right ?
2. The proto-type with 2 M90s stacked in series is for show as well as some extra go and it would be OEM stock parts. And, I want it out the hood too. Has anyone every just moved their Supercharger up through the hood for show ? No HP gain that way. I hope to gain just some HP above and beyond the additional drag and still be consider an OEM part and have very, very, very cheap car insurance. This car will not be a daily driver, only for strip and short trips in town.
However, the latest comments give way to some more questions on my end.
1. If we did run the M90's in parallel won't both M90's still not produce more than 15 psi without bigger plumbing and porting all the way to the exhaust tips. And, both M90's would still have to be Over Driven which is not OEM ? More pressure is what is needed to get around the head port restriction. We won't blow the ports on the manifold or heads by raising the pressure and if I blow the HG's, I will copper ring a block in the future. Again, this is not about resulting in a lot more HP.
2. Will Parallel M90's also build more heat as they push against each other and subseqently require a very large "air cooled" IC ? Whereas, if the M90s are in series, the 1st M90 will act as a primer charge "running slower than OEM speed with "Less" heat buildup, then cooled with a water IC "more effiecent", the 2nd M90 is then allowed to boost the pressure higher than 15 psi (if wanted) at a lower RPM than OEM. (No Over Driven blower equates to a OEM modification using only OEM Superchargers). And, if I want more pressure, I change the pulleys and inch back to stock OEM speed but, no more on the 2nd blower. Did I mention that the by-pass is history.
2. I can buy a used M90 for just a little more than what it cost for a 90mm MAF that fits in the palm of my hand and it doesn't spin either
Again, I want to keep it OEM.3. 50-75 HP Drag. Well, we hope not as we are not going to spin either M90 as fast as original OEM. The 2nd M90 will be spinning at peak speed "max air pressure" (or less if possible) at 5,000 engine RPM. The 1st M90 will only spin as fast as necessary to supply air to the 2nd blower without pressure loss across the water cooled IC at any giving time.
4. Why is there a Super Charger Output "Bypass" valve on these blowers at all ? The reason I ask is as I am cruising at 60 mph @ 2500 RPM in my 91 SC and at 20 inches of vacuum the M90 is not doing a thing but, heating up my engine compartment. Is it all because of this Bypass valve that gives way to engine vacuum so I can control the heater door ?
Finally. Twin-screw compressors have been used for many years in "Multi-Stage" In-Series applications in gas fields and refineries and not let us forget race cars. I overhauled many of these twin-screw compressors when I was in my 20's. We understand that the M90 was not designed to be installed in series but, I hate the fact that there is this by-pass valve in my car that just turns the M90 off because some engineer at ford didn't want to add a vacuum pump to a ford Thunderbird SC to open and close the stupid heater door.
Again, a recap. We are only wanting a little more HP but, 100 would be nice but, not a chance. The drag on the engine will not be 50-75 HP as neither blower will be spinning faster than OEM. If we can get 20 PSI at 3,000-3,500 RPM and it all stays together "just 1 time" under WOT. It will be twin singers under my hood for a long time. And, I am not talking about sewing machines
With that all said. I would like to thank you all for your comments. Is there any more major concerns that I should be considering in my quest.
One last thing, that 21 inches of mercury drop (vacuum) will be on the inlet side of that 1st supercharger and never seen again. This setup will be full-time pressure and that is where the big payoff is going to be. I might just want to find the name of that engineer at Ford who decided to install that SC by-pass valve and mail it back to him. I really do believe that in 1989 electric vacuum pumps where NOS at AutoZone
Am I wrong about the By-Pass valve, If so, please let me know.
Thanks again and peace,
Rob
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90blkbrd
Registered User
I'm trying to not be mean or to insult you but....
I will guarantee that the drag on this setup will be 100 hp or more. It's a simple fact, eaton's use HP.
You really need to so a search and read up on the bypass valve because you really have no idea what you are talking about. I'll let the other members write a thesis why it is there and why it is important.
By altering your engine compartment with another supercharger is automatically not OEM. If you think this alteration will keep your OEM rating you are GREATLY mistaken. If your insurance company needs to do any special work to repair your car back to what it was before it was wrecked or if you try and say your value is more than OEM, then your car isn't OEM.
I will guarantee that the drag on this setup will be 100 hp or more. It's a simple fact, eaton's use HP.
You really need to so a search and read up on the bypass valve because you really have no idea what you are talking about. I'll let the other members write a thesis why it is there and why it is important.
By altering your engine compartment with another supercharger is automatically not OEM. If you think this alteration will keep your OEM rating you are GREATLY mistaken. If your insurance company needs to do any special work to repair your car back to what it was before it was wrecked or if you try and say your value is more than OEM, then your car isn't OEM.
kenewagner
Registered User
I have followed this for awhile and will add my 2 cents. If your insurance is dictating your ideas than I think you are incorrect with yor thinking that having 2 M90s makes it aceptable to your Insurance company. Heres my thoughts
1 The throttle body is poor on a stock SC. You are going to need a huge TB to provide air to two SCs and a custom plenum to attach them together.
2 You mentioned a water cooled IC? (Number 3)How is that OEM
3 You will be surprised how much HP 2 M90s can eat
4 You will need more fuel to provide a correct AFR. Bigger injectors. Not OEM
5 Sticking the blowers out of the hood might make a insurance guy raise his eye brows some
6 A SC is not worth much on the blue book anyway should you have an accident.
7 If you dont like the by pass than just wire it shut.
8 The by pass allows for outstanding gas milage, if you wire it shut you wont like the constant boost your blower is making
9 Are you going to tune this (Modifacation) ??Cause you are going way outside normal (OEM) parameters.
10 with stock heads and cam you are wasting your time trying to make HP. Higher boost doesnt mean more HP in this case. It just means you are trying to push more air into the engine than it can process.
11 Your going to need a huge MAF to flow the air. Not OEM
I cant see anything your doing that qualifys as stock or OEM
Im running a twin screw with more than 20 lbs of boost. I can tell you that is an efficent way to make boost. If you are worried about higher insurance you shoud just stick with a stock car
Ken
1 The throttle body is poor on a stock SC. You are going to need a huge TB to provide air to two SCs and a custom plenum to attach them together.
2 You mentioned a water cooled IC? (Number 3)How is that OEM
3 You will be surprised how much HP 2 M90s can eat
4 You will need more fuel to provide a correct AFR. Bigger injectors. Not OEM
5 Sticking the blowers out of the hood might make a insurance guy raise his eye brows some
6 A SC is not worth much on the blue book anyway should you have an accident.
7 If you dont like the by pass than just wire it shut.
8 The by pass allows for outstanding gas milage, if you wire it shut you wont like the constant boost your blower is making
9 Are you going to tune this (Modifacation) ??Cause you are going way outside normal (OEM) parameters.
10 with stock heads and cam you are wasting your time trying to make HP. Higher boost doesnt mean more HP in this case. It just means you are trying to push more air into the engine than it can process.
11 Your going to need a huge MAF to flow the air. Not OEM
I cant see anything your doing that qualifys as stock or OEM
Im running a twin screw with more than 20 lbs of boost. I can tell you that is an efficent way to make boost. If you are worried about higher insurance you shoud just stick with a stock car
Ken
RE: Twin Screws
I will insert foot in to my mouth, then shoot it I will rethink this for the next few weeks.
Yes, you both above are exactly right, I do not really know why the Bypass Valve is really there and my upgrades can not be OEM 100%. So I will do more research.
I am a newbie when it comes to Supercharger theory and functionality. And,
I do appreciate you comments and no offense taken.
Thanks,
Rob
I will insert foot in to my mouth, then shoot it
I will rethink this for the next few weeks.Yes, you both above are exactly right, I do not really know why the Bypass Valve is really there and my upgrades can not be OEM 100%. So I will do more research.
I am a newbie when it comes to Supercharger theory and functionality. And,
I do appreciate you comments and no offense taken.
Thanks,
Rob
Let confirm what I am hearing and academically it could work.
Blower 1 will compress to say 75% of max then go to a IC then to Blower 2 where this compressed air gets compressed more another 75% and then into an other IC.
I pulled the 50-75hp of drag cause I remember hearing that a M90 puts about 35hp of drag.
My concern would be the effectiveness of your ICs, cause if I'm thinking right your going to need a IC system that is at least 95% effective with most of the work being required by the first one (100+% efficient is the only way I'd do that one or its a waste of time). Then where a two ICs going to be mounted, when we already have a problem with the one?
Blower 1 will compress to say 75% of max then go to a IC then to Blower 2 where this compressed air gets compressed more another 75% and then into an other IC.
I pulled the 50-75hp of drag cause I remember hearing that a M90 puts about 35hp of drag.
My concern would be the effectiveness of your ICs, cause if I'm thinking right your going to need a IC system that is at least 95% effective with most of the work being required by the first one (100+% efficient is the only way I'd do that one or its a waste of time). Then where a two ICs going to be mounted, when we already have a problem with the one?
RE: ICs
I appreciate your comments as I am getting it in both ears. My engineer friends "Areo Space Dynamics" and "Purpultion" specialists say it will work, in theory. And those who have experience in M90 system MODS saying it will turn a blackeye and be a waste of time and money.
As proposed, the 1st IC will be Water Cooled and directly between the 2 superchargers (this has been very succesful for others who run dual inline SCs). Thickness will be determined after testing is done. The 2nd one will be a doubled Air Cooled IC in stock location and if that is not enough then a lower IC (3rd unit) below radiator will be considered.
Again, all of this is in the planning stage and flow, pressure, SC 1/2 seed/ratio will be determined after testing is done maybe sometime next month (depending on my work load). I am also going to rethink it all too. Not much money will have to be spent to get to the "Most Likely will or will not work" stage.
I don't really know enough about all of this but, I sure will know more after testing. We will be using an OEM MAF, Inlet Tube, TB and Plenium connected to SC 1. Other test specifics are still to be determined.
SC 1 & SC 2 Compression Ratio:
I do feel that the compression ratio for SC 1 and SC 2 are unknown at this time. The feedback from my engineer buddies is this. We will spin SC 1 and SC 2 at different speeds to accomplish the requied Compression ratio between both SCs to reach a 20 psig intake charge. The theory being that SC 1 will take it to 60 or 70% pressure and the SC 2 will take it to 20 PSIG.
Some say you can't get 20 psi without a huge MAF / TB and larger associated piping and overdriving the M90 as that has been their own experiences. Okay, fair enough and I believe them that 1 M90 can not move enough air without all these MODS but, all I am going to test is 2 M90's / 2 stage process / 2 IC's to reach 20 psig at the Intake Manifold. If it works on without major modifications on the inlet side of SC 1, WOW.... Talk about turning the world on its side. However, if it does not work without major MODS, I am still going to have a 2nd SC out of my hood but, just not as much HP for the Money. (Or maybe not at all after the initial tests are done.)
And, there is the Injector and Fuel Pump considerations that will also have to be determined once these initial tests are done (if successful) to provide correct A/F/R (and, possibly a bigger MAF / TB / Plenium, IC tubing)
Thanks again for thoughts,
Rob
I appreciate your comments as I am getting it in both ears. My engineer friends "Areo Space Dynamics" and "Purpultion" specialists say it will work, in theory. And those who have experience in M90 system MODS saying it will turn a blackeye and be a waste of time and money.
As proposed, the 1st IC will be Water Cooled and directly between the 2 superchargers (this has been very succesful for others who run dual inline SCs). Thickness will be determined after testing is done. The 2nd one will be a doubled Air Cooled IC in stock location and if that is not enough then a lower IC (3rd unit) below radiator will be considered.
Again, all of this is in the planning stage and flow, pressure, SC 1/2 seed/ratio will be determined after testing is done maybe sometime next month (depending on my work load). I am also going to rethink it all too. Not much money will have to be spent to get to the "Most Likely will or will not work" stage.
I don't really know enough about all of this but, I sure will know more after testing. We will be using an OEM MAF, Inlet Tube, TB and Plenium connected to SC 1. Other test specifics are still to be determined.
SC 1 & SC 2 Compression Ratio:
I do feel that the compression ratio for SC 1 and SC 2 are unknown at this time. The feedback from my engineer buddies is this. We will spin SC 1 and SC 2 at different speeds to accomplish the requied Compression ratio between both SCs to reach a 20 psig intake charge. The theory being that SC 1 will take it to 60 or 70% pressure and the SC 2 will take it to 20 PSIG.
Some say you can't get 20 psi without a huge MAF / TB and larger associated piping and overdriving the M90 as that has been their own experiences. Okay, fair enough and I believe them that 1 M90 can not move enough air without all these MODS but, all I am going to test is 2 M90's / 2 stage process / 2 IC's to reach 20 psig at the Intake Manifold. If it works on without major modifications on the inlet side of SC 1, WOW.... Talk about turning the world on its side. However, if it does not work without major MODS, I am still going to have a 2nd SC out of my hood but, just not as much HP for the Money. (Or maybe not at all after the initial tests are done.)
And, there is the Injector and Fuel Pump considerations that will also have to be determined once these initial tests are done (if successful) to provide correct A/F/R (and, possibly a bigger MAF / TB / Plenium, IC tubing)
Thanks again for thoughts,
Rob