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Old 11-24-2008, 12:15 AM
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Carburetors, CFM and Dual Superchargers

Hey Everyone,

Well I'm about to start making my next project... Its going to be a twin M90 supercharger setup on a 383 Chevy. I just got the Superchargers rebuilt and I'm not sure how much Carburetor I'm going to need.

383 Chevy, all forged
9.3 Compression running E85
Comp cams xe274H with 1.6 full roller rockers
Airgap RPM intake
1 3/4" hooker fenderwell headers
3" aerochamber mufflers

The question is 1 or 2 Predator Carbs? We are dealers so I get a good price on them and have been very happy with mine so I'm sticking with them. They Flow 930cfm so i'm thinking 1 should be enough? The superchargers are going to be spinning about 14K rpm at 6000rpm

Thanks
Jordon
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Old 11-25-2008, 08:38 PM
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anyone ?
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Old 11-25-2008, 09:16 PM
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**********************

Last edited by 68NovaSS; 03-01-2013 at 10:37 AM. Reason: Classified, not allowed in forums
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Old 11-25-2008, 09:32 PM
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i was just wondering how you are going to put these supercharges on a sbc?
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Old 11-25-2008, 10:03 PM
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383 @ 6K @ sea level
0# 665 cfm
2# 755 cfm
4# 845 cfm
6# 936 cfm
8# 1026 cfm
10# 1117 cfm
12# 1207 cfm
14# 1298 cfm
16# 1388 cfm
18# 1479 cfm
20# 1569 cfm

At 9.3 SCR, 10 lbs of boost will put the effective final static compression ratio at 15.5 which may be about the limit for E85. Don't take this as the final word on the subject, just as a starting point to dial from. You may find a way to run a much higher EFSCR.

Last edited by techinspector1; 11-25-2008 at 10:09 PM.
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Old 11-26-2008, 09:37 PM
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Thanks for the info Tech, I think I'm going for twin Predators. They are self adjusting so it shouldn't be a problem to go too big.

I'm actually surprised more people haven't done this. I got mine at the u-pull it for $70ea. Rebuilding them is easy, all the bearings and seals are off the shelf parts and cost about $20 if you shop around. The most expensive part so far has been the bottom pulley at $170.

I will take some pics along the way but right now our business has been really busy.

Jordon
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Old 11-26-2008, 11:39 PM
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Those huffers were designed to move dry air. Better make sure the seals and such are gonna be ok with gasoline or E85 or whatever you plan to run.
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Old 11-27-2008, 01:10 AM
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I hopefully got it covered. Form some of the message boards I have read quite a few people have used them with carburetors and no problems. Too be on the safe side I got new rear bearings with seals, the bearings are standard rear alternator bearings for GM cars, Been soaking them in E85 for the past week with no change in the seals. I have also been thinking about putting zerk fittings on the rear bearings but their only $3.50 ea so I'll probably call it good.

I have been planning this for months, making drawings, figuring the easiest way to make parts out of stock sized steel. I have even been dreaming about superchargers. I even have a note pad on my night stand
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Old 10-09-2009, 11:55 PM
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Quote:
Originally Posted by techinspector1
383 @ 6K @ sea level
0# 665 cfm
2# 755 cfm
4# 845 cfm
6# 936 cfm
8# 1026 cfm
10# 1117 cfm
12# 1207 cfm
14# 1298 cfm
16# 1388 cfm
18# 1479 cfm
20# 1569 cfm

At 9.3 SCR, 10 lbs of boost will put the effective final static compression ratio at 15.5 which may be about the limit for E85. Don't take this as the final word on the subject, just as a starting point to dial from. You may find a way to run a much higher EFSCR.
What about a 454 ho with a 8-71 supercharger compression at 8.75:1 staic compression? 5psi only for now
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Old 03-01-2013, 10:16 AM
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Did you ever complete your project? Pics? I bought a M90 a couple of years ago to put it to my 350. Got side tracked with motorcycle stuff. Trying to get back on track with this project. I have some ideas, but looking for others that have done this and how.

Last edited by zoomzu; 03-01-2013 at 10:23 AM.
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Old 03-01-2013, 10:30 AM
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what are m90's off of?
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Old 03-01-2013, 10:55 AM
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Quote:
Originally Posted by gearheadslife View Post
what are m90's off of?

It's an Eaton M90 mine came off a 3.8 Buick Bonneville.
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Old 03-01-2013, 12:03 PM
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They came off a T-Bird. Yes I did get it running and it ran very very strong. I just could not bring down idle enough to make it workable on the street with the Predator Carbs.

I still have it and may put it back together one day when I get some extra cash for some carburetors.
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Old 03-01-2013, 01:43 PM
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Quote:
Originally Posted by xxllmm4 View Post
They came off a T-Bird. Yes I did get it running and it ran very very strong. I just could not bring down idle enough to make it workable on the street with the Predator Carbs.

I still have it and may put it back together one day when I get some extra cash for some carburetors.
Looks nice, thanks for the pic.
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Old 03-01-2013, 02:34 PM
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any photos of the intake manifold? Consider possibly just using one Predator carb?

What is your target power output? It's probably within the reach of one predator carb.
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