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Guest Message by DevFuse
 

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Supercharger


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42 replies to this topic

#26 WJM

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Posted 02 June 2005 - 09:16 PM

Also, wouldn't this be easier on a turbo car? Since the fuel management and engine is built for boost?


in theory...yes. But I am ditching all the stock EMS for something else that is fully 100% tunable.

#27 reddevil

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Posted 02 June 2005 - 10:42 PM

pulley ratio to psi depends upon two major factors. First is what size is the engine, second is what SC you are using. The m45 is .75 liter per revolution, the m62 is 1 liter per revolution, the m90 is 1.5 liter per revolution, and the m112 is 2liter I think.

Also of psi importance is the intercooler. I ran 12 psi without an intercooler. As soon as I installed the IC, psi dropped to 6 psi!

As it stands, I am (was) getting about 8-9 psi on a 2.2 engine, running a 2-1 pulley ration, using an M62, with a Subaru AWIC.

#28 LPGsuperchargedBrumby

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Posted 03 June 2005 - 02:22 AM

The m45 is .75 liter per revolution, the m62 is 1 liter per revolution, the m90 is 1.5 liter per revolution, and the m112 is 2liter I think.

Also of psi importance is the intercooler. I ran 12 psi without an intercooler. As soon as I installed the IC, psi dropped to 6 psi!

As it stands, I am (was) getting about 8-9 psi on a 2.2 engine, running a 2-1 pulley ration, using an M62, with a Subaru AWIC.



if my rusty memory serves me right i seem to remember working out that with a matched engine and blower (as in 2 liter engine & a 2 liter per revolution SC) every time you increase the blower speed by a full ratio ( i.e 1:1 to 2:1) you should gain 14.7 psi of boost ( i know, i know, blowers arn't 100% efficiant....so you won't get that in the real world ) in theory.

reddevil, what the hell kind of intercooler did you have, thats the worst pressure drop iv'e ever heard of, a couple of psi is normal but a 50% loss????

#29 Myxalplyx

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Posted 03 June 2005 - 04:16 PM

I would love to have this done to one of my XT6s. I hope you guys are successful with it.

#30 reddevil

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Posted 03 June 2005 - 09:16 PM

It went from the 12 psi to the 6 psi because of a few reasons, one being the intercooler.

Without the intercooler, I had a beautiful 2.75" diameter pipe straight from the SC to the throttle body. Not a single sharp bend OR reduction in pipe diameter. Pretty much as close as you could get to a direct connection from the SC to the Throttle body so there was little, if any, restrictions for the air flow to come in contact with.

Now when I installed the IC, I had to cut the piping, bend it down AND constrict it from the 2.75 diameter to the 1.75-2" diameter of the IC. And then of course there is the IC itself. I don't care how well the IC flows, if you constrict a large pipe to a small pipe, you are going to lose some pressure.

I was able to get the pressure back up to about 8-9 consistantly in the end by fabricated a much nicer connnection from the SC to the IC using the stock Mercedes part and some nicer piping, as well as installing a gasket between the SC and the SC exhaust port.

The IC I am using is the stock 90-94 Legacy AWIC.

#31 Myxalplyx

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Posted 04 June 2005 - 08:08 AM

I don't care how well the IC flows, if you constrict a large pipe to a small pipe, you are going to lose some pressure.


I'm an idiot! Now that I got that out of the way, I'll ask this. I thought that pressure INCREASES when you go to a smaller pipe. I thought this applied to not only fluids (Like a fuel pressure regulator) but gases as well (like exhaust pipes).

So in your case, I would've thought that if it was only a factor of going from the supercharger to a smaller pipe within the intercooler that boost pressure would increase. This is not taking into account the 'restrictions' inside of the intercooler itself. The 'restrictions' inside of the intercooler I'd say would cause you to loose boost pressure.

#32 reddevil

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Posted 04 June 2005 - 11:42 AM

Yeah sure the pressure increases in the smaller diameter pipe. But thats not where you measure PSI. You measure that in the manifold. And if less air gets to the manifold because of a smaller diameter pipe, then you have lower psi.

#33 TheSubaruJunkie

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Posted 04 June 2005 - 01:45 PM

Not to mention the inlet on the AWIC is 1.75 and the outlet is 2" i believe. So he's going from large, to small, back to large.

-Brian

#34 grossgary

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Posted 04 June 2005 - 02:23 PM

what does AW in AWIC stand for?

i'd like some more info on supercharger installation. what issues are there to confront?

i assume you need a blow off valve to compensate for when the throttle closes. and something to cut boost once it reaches whatever max boost you want. for instance if you want to stop at 10 psi...you need some sort of cutoff right?

awesome setup, thanks for posting the pictures.

#35 NorthWet

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Posted 04 June 2005 - 02:45 PM

what does AW in AWIC stand for?...

Air-water. (ie - water as the coolant)

In regards to pressure, TECHNICALLY the pressure in the smaller pipe will decrease (and the velocity increase) in accordance with Bernoulli's Principle. Realistically, the restriction causes increased flow resistance and thus a pressure drop across the smaller pipe(s) (and resultant flow reduction).

Also in regards to pressure, the functioning of the IC will inherently cause a drop in pressure, in accordance with gas laws. It is removing heat from a fixed-volume environment, which will cause an increase in density and a decrease in pressure. You really aren't looking for an increase in pressure per se but an increase in total oxygen into the cylinder, which the increase in density gives you.

And, just to nitpick :grin: , gases are fluids (as are liquids), but gases are not liquids. (Nit, nit, nit!)

#36 Myxalplyx

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Posted 05 June 2005 - 10:19 AM

And, just to nitpick :grin: , gases are fluids (as are liquids), but gases are not liquids. (Nit, nit, nit!)


You are correct sir. I had to look up fluid at 'dictionary.com'. :) Edumicate me!


i assume you need a blow off valve to compensate for when the throttle closes. and something to cut boost once it reaches whatever max boost you want. for instance if you want to stop at 10 psi...you need some sort of cutoff right?


The pressure is determined by the size of the pulley on the supercharger. "




Q: How do you change the boost?

A: On any belt driven blower, such as the Powerdyne, you can change the amount of boost by changing the size of the pulley on the blower. The smaller the pulley the faster the blower runs and the more boost it makes.

Posted Image Currently Powerdyne offers two boost levels, a six pound unit and a 9 pound unit."





Check out these supercharger FAQs for some information.
http://www.powerdyne.com/tech.htm
http://www.theoldone.com/sc/faq.html

#37 Myxalplyx

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Posted 05 June 2005 - 10:36 AM

Anyone have any engine pics of the Subaru R2? What is it? Here are the specs.........
"The Subaru R2 has a new supercharged four-cylinder twin overhead-camshaft petrol engine with an Active Valve Control System which provides a wide power range which is fully exploited by the seven-speed sports gear shift."
http://www.ultimatec...php&carnum=1784

You can always try to steal some supercharging ideas from Porsche.
Posted Image
http://www.928motors....com/928sc.html


I haven't heard of anyone trying to steal the idea off of the old 1 car 'concept' supercharged 2.5ltrd subaru that was made a while back. Subaru decided not to go through with it. I believe it was a Baja that was supercharged. They scrapped the whole thing and would not give any info to anyone about it. The company that did the design also wouldn't share any info with anyone. I know because I was one of the peeps that called them. I forgot the name of the company though.

Ah (In my Yoda voice).........The Subaru ST-X it was called. Subaru Truck Xperimental.

Re-edit....went looking for an engine pic.
Posted Image

#38 WJM

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Posted 05 June 2005 - 09:55 PM

I haven't heard of anyone trying to steal the idea off of the old 1 car 'concept' supercharged 2.5ltrd subaru that was made a while back. Subaru decided not to go through with it. I believe it was a Baja that was supercharged. They scrapped the whole thing and would not give any info to anyone about it. The company that did the design also wouldn't share any info with anyone. I know because I was one of the peeps that called them. I forgot the name of the company though.

Ah (In my Yoda voice).........The Subaru ST-X it was called. Subaru Truck Xperimental.

Re-edit....went looking for an engine pic.
Posted Image


scrapped? No...i seen it in person about 8 months ago...its alive and strong in....*gasp*...a warehouse near me. ;) I have all that secret info. muhahahaha :banana:

#39 JWX

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Posted 05 June 2005 - 11:40 PM

hehehe I saw it to

#40 RenaissanceMan

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Posted 09 June 2005 - 01:00 AM

In the late 80's & early 90's toyota MR2's were available with an SC12 supercharger, which everyone might be interested in. It is VERY similar to an Eaton M62, only it runs 1.2 Liters per revolution. Like the M62 it has an electric clutch for it.


I managed to get a good one on ebay for $200. I have a rebuilt EA82T that awaits it. I wasnt planning on running any more than 9 psi of boost. I'll get it done one day and let you know how it turns out.

#41 Myxalplyx

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Posted 09 June 2005 - 09:20 PM

scrapped? No...i seen it in person about 8 months ago...its alive and strong in....*gasp*...a warehouse near me. ;) I have all that secret info. muhahahaha :banana:


You need to break into that warehouse and uninstall it. You need to do it NOW. Go Will! It is your destiny. :brow:

#42 WJM

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Posted 09 June 2005 - 11:13 PM

You need to break into that warehouse and uninstall it. You need to do it NOW. Go Will! It is your destiny. :brow:


no...changed my mind again. turbop it is.

#43 JWX

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Posted 10 June 2005 - 01:21 AM

I swear WJM is a girl :)




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