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Greg Gordon
- Verde
- Posts: 1552
- Joined: Mon Nov 29, 2004 7:06 pm
Of course hotter cams can give more power, but all cams are a compromise to some degree and the stock cams are pretty good all around streetable design. What cams are best depends on so many factors. Barry can probably make good suggestions about aftermarket cams, I can't.
As far as I know pulleys can be pulled off of all Magnuson superchargers. I have never heard of needing a different nose drive to change pulleys. Perhaps some OEM units were made that way to prevent people from playing with boost.
A 7.5:1 3 liter with 15 pounds of boost, Megasquirt and headers should put down about 300 horsepower at the wheels. That seems like a good power per dollar motor to me.
GTV6GPTT's posts are always very amusing to me. He definatly has some strong opinions. If you are going to go with 8 pounds of boost on a 3 liter you are far better off with a M62, unless you are building a very high reving motor. Thats not to say you can't use a M90 with 8 pounds on a 6500 rpm 3.0. You can but it would be better to use a M62 in that situation. According to the Jim Steck chart a 8.5:1 motor could get away with about 10 pounds of boost, and a 7.5:1 motor about 15 pounds. Hmm I wonder which would make more power....
Superchargers are rubbish at high boost? I hope someone tells John Force before he gets started on his motor for next season. We could have a Turbo vs Supercharger debate, but that should probably be in another thread.
As far as I know pulleys can be pulled off of all Magnuson superchargers. I have never heard of needing a different nose drive to change pulleys. Perhaps some OEM units were made that way to prevent people from playing with boost.
A 7.5:1 3 liter with 15 pounds of boost, Megasquirt and headers should put down about 300 horsepower at the wheels. That seems like a good power per dollar motor to me.
GTV6GPTT's posts are always very amusing to me. He definatly has some strong opinions. If you are going to go with 8 pounds of boost on a 3 liter you are far better off with a M62, unless you are building a very high reving motor. Thats not to say you can't use a M90 with 8 pounds on a 6500 rpm 3.0. You can but it would be better to use a M62 in that situation. According to the Jim Steck chart a 8.5:1 motor could get away with about 10 pounds of boost, and a 7.5:1 motor about 15 pounds. Hmm I wonder which would make more power....
Superchargers are rubbish at high boost? I hope someone tells John Force before he gets started on his motor for next season. We could have a Turbo vs Supercharger debate, but that should probably be in another thread.
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Greg Gordon
- Verde
- Posts: 1552
- Joined: Mon Nov 29, 2004 7:06 pm
With good injection it should idle just fine, with l-jet it would be tricky with injectors that big.
My dad's motor is only .010 overbored. that's almost nothing just a few ccs, not 3200ccs. They say you can bore them .040 , but .010 seems like a safer number.
To make it a 3.2 you would need new liners and some expensive machine work, probably not worth it. I think JJ or Barry have a 3.5 kit, that might be good.
My dad's motor is only .010 overbored. that's almost nothing just a few ccs, not 3200ccs. They say you can bore them .040 , but .010 seems like a safer number.
To make it a 3.2 you would need new liners and some expensive machine work, probably not worth it. I think JJ or Barry have a 3.5 kit, that might be good.
No Greg,I dont have kits...speak to JJ.. 
Hmm, I am not about to buy any liners. I am over my head as it is with my current shopping list. (Pistons, rods, balancing, valve springs, rings, gaskets, water injection, intake plumbing...)
Plus, I fear that I am on the edge of breaking driveline items with my projected output. Although more power has been tried by the likes of JJ and Jes, I feel like I have worse luck than those guys. At the very least, I would end up changing donuts all the time.
If I avoid buying things like performance cams and liners, I will sooner be able to afford a sweet custom driveshaft setup. Maybe an aluminum or carbon one with M5 donuts...
Sooner, whatever that means.
Hmm, I am not about to buy any liners. I am over my head as it is with my current shopping list. (Pistons, rods, balancing, valve springs, rings, gaskets, water injection, intake plumbing...)
Plus, I fear that I am on the edge of breaking driveline items with my projected output. Although more power has been tried by the likes of JJ and Jes, I feel like I have worse luck than those guys. At the very least, I would end up changing donuts all the time.
If I avoid buying things like performance cams and liners, I will sooner be able to afford a sweet custom driveshaft setup. Maybe an aluminum or carbon one with M5 donuts...
Sooner, whatever that means.
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Greg Gordon
- Verde
- Posts: 1552
- Joined: Mon Nov 29, 2004 7:06 pm
Normally I am all for a displacement increase but it probably not really worth in on a supercharged motor. Don't worry too much. 3 liters is closer to ideal for the m90 anyway. Based on information in David Visard's book "How to Build Horsepower" I actually think that used liners bored .010 are better than brand new liners.
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la_strega_nera
- Platinum
- Posts: 494
- Joined: Tue Feb 21, 2006 10:05 pm
- Location: Sunny Euro-Brisney
No, I'm pretty sure you can still change the pulley, (the SVT M112s are pressed I think?) you need a proper pulley puller so you don't damage the pulley.zambon wrote:I just realized that my supercharger has a press on pulley. I think that means that I will need to buy a new nose cone in order to change the pulley size. Is this correct?
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SydneyJules
- Verde
- Posts: 619
- Joined: Sun Dec 19, 2004 1:57 pm
- Location: Sydney
If you are going off books, read books published after 2002.
http://www.automotive.eaton.com/product ... rs/M90.asp
Running the m90 at 1.5-7 ratio will be plenty to flow enough for the 3L.
7.5:1 ? are you serious? On programmable EFI ???
What dumb assholes these guys must be:
Mini the cooper S: Compression Ratio 8.3
Holden ecotec charged: Compression ratio: 8.5 : 1
1980s MR2 cr: 8:1 / Toyota 4AGZE III : cr 8.9:1
Land Rover Range Rover Sport Supercharged: cr 9:1
Why do they have to run low comp? Superchargers AKA Super Air Heaters!!!
If you have to use that m90 keep the comp drop the boost, and you will have a happier motor. You want to go fast? Scrap the whole supercharger idea.
“According to the Jim Steck chart a 8.5:1 motor could get away with about 10 pounds of boost, and a 7.5:1 motor about 15 pounds. Hmm I wonder which would make more power....”
My bet would be on the 10 psi on 8.5:1 at least you could tune it and run nice bit of timing, not having lower comp have extra hot air and need to run cooling.
“I hope someone tells John Force before he gets started on his motor for next season.”
I don’t know who this john is but your point is irrelevant, his car isn’t for street use and I would be curious to the types of racing fuels they are using to get any power out of a blower.
Turbo VS Supercharger… what a waste of time. A smart person knows the clear winner there.
http://www.automotive.eaton.com/product ... rs/M90.asp
Running the m90 at 1.5-7 ratio will be plenty to flow enough for the 3L.
7.5:1 ? are you serious? On programmable EFI ???
What dumb assholes these guys must be:
Mini the cooper S: Compression Ratio 8.3
Holden ecotec charged: Compression ratio: 8.5 : 1
1980s MR2 cr: 8:1 / Toyota 4AGZE III : cr 8.9:1
Land Rover Range Rover Sport Supercharged: cr 9:1
Why do they have to run low comp? Superchargers AKA Super Air Heaters!!!
If you have to use that m90 keep the comp drop the boost, and you will have a happier motor. You want to go fast? Scrap the whole supercharger idea.
“According to the Jim Steck chart a 8.5:1 motor could get away with about 10 pounds of boost, and a 7.5:1 motor about 15 pounds. Hmm I wonder which would make more power....”
My bet would be on the 10 psi on 8.5:1 at least you could tune it and run nice bit of timing, not having lower comp have extra hot air and need to run cooling.
“I hope someone tells John Force before he gets started on his motor for next season.”
I don’t know who this john is but your point is irrelevant, his car isn’t for street use and I would be curious to the types of racing fuels they are using to get any power out of a blower.
Turbo VS Supercharger… what a waste of time. A smart person knows the clear winner there.
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Greg Gordon
- Verde
- Posts: 1552
- Joined: Mon Nov 29, 2004 7:06 pm
Oh, Sorry, .010 is in INCHES. I should have made that clear. Most machine shops still like to use inches so ten thousands or .010" is what I tell them. It's a very slight overbore.
GTV6GPTT: The use of relatively higher compression ratios on factory supercharged cars like the Mini Cooper S, Cobalt SS etc. is for off boost fuel economy. I don't think that's what we are looking for here. If it is then go with, 8.8:1 and 7+ pounds of boost. This results in almost no loss of fuel economy and about 50% more power.
The heat can be knocked back down to very near ambient on either set up we are discussing and the effective compression ratios are the same in both cases. A factor some may be overlooking or just plain don't understand is that 15 pounds of boost on a 7.5:1 motor than just a 1/3 more air than 10 pounds on a 8.8:1 motor. The heat can be knocked back down to very near ambient on either motor and the effective compression ratios are the same in both cases. All things being equal the 15 psi motor will put out a lot more power then the 10 psi motor.
GTV6GPTT: The use of relatively higher compression ratios on factory supercharged cars like the Mini Cooper S, Cobalt SS etc. is for off boost fuel economy. I don't think that's what we are looking for here. If it is then go with, 8.8:1 and 7+ pounds of boost. This results in almost no loss of fuel economy and about 50% more power.
The heat can be knocked back down to very near ambient on either set up we are discussing and the effective compression ratios are the same in both cases. A factor some may be overlooking or just plain don't understand is that 15 pounds of boost on a 7.5:1 motor than just a 1/3 more air than 10 pounds on a 8.8:1 motor. The heat can be knocked back down to very near ambient on either motor and the effective compression ratios are the same in both cases. All things being equal the 15 psi motor will put out a lot more power then the 10 psi motor.