Axial Flow Supercharger
503wtq Boosted Bimmer
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From: Los Angeles, California
Originally Posted by Richard Paul
You may keep it but you will have to cut some of it away to fit the supercharger.
The better idea if you must keep it is to hang it on the wall in your office.
Smart move would be to sell it and just use the one in the kit.
Three choices, that's nice isn't it?
The better idea if you must keep it is to hang it on the wall in your office.
Smart move would be to sell it and just use the one in the kit.
Three choices, that's nice isn't it?
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Joined: Mar 2005
Posts: 1,587
Likes: 1
Originally Posted by Richard Paul
You may keep it but you will have to cut some of it away to fit the supercharger.
The better idea if you must keep it is to hang it on the wall in your office.
Smart move would be to sell it and just use the one in the kit.
Three choices, that's nice isn't it?
The better idea if you must keep it is to hang it on the wall in your office.
Smart move would be to sell it and just use the one in the kit.
Three choices, that's nice isn't it?
Fer crizzz sakes guys, they occupy the same piece of real estate. If I didn't have to supply a new brace I really wouldn't. About that brake brace, I might develop a stand alone one for sale. I have been thinking about it as a product since I found out that it really works, even on the street.
If it will be welded to the brace or not we haven't figured out yet.
If it will be welded to the brace or not we haven't figured out yet.
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Joined: Mar 2005
Posts: 1,587
Likes: 1
Originally Posted by Umbra
Can't tell from the photo's but I assume there is going to be an intercooler as well or maybe not?
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Joined: Jan 2005
Posts: 210
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From: Palmdale, CA
True, but if the SC is really that efficient it could, in theory, reduce the mechanical heat from the compressor. Obviously the air will still heat up from compression, but it may not be enough to warrant the need for an IC with the kit.
I can't make you go back to the begining of the thread, it's to long, so:
Heat added to air from compression=YxT1 abs over eff of compressor
Y=Pr^.283-1
So if you have 7.5psi pressure that is Pr1.5
1.5^.283-1=.12
.12x(70+460)=63.6 degrees temp rise with 100% eff
You can't get 100% no way no how, but if you could it would still heat the air this much.
Find the heat rise for given eff, divide by eff.
Therefore if you have 50% eff you put 63.6 over .50 = 127 deg temp rise.
Or 60%= 63.6 over .6=106
50 is good for a roots 60 for a centrifugal and 85 for my axial flow.
So 63.6 over .85=75 temp rise
So while there is temp rise it is under the limits for safe operation of the Rotary.
IC or more correctly AC are not free tools, they have negatives mostly for street engines. The add complications, weight and cost. It take pressure away to push air through the radiator. Use them when you have to and not just to say you have one. I think somewhere in this thread RotaryGod has given you a lecture on how the IC can add heat to your street engine. I'm sure he will give it again if you ask nice.
As long as we are doing math I'll give yo something else. HP to compress air.
lbs/sec x T delta X .3395 = HP to work the air. To that you must add the external loss. Like bearings, gears, belt drive and more.
So .5lbs X 75 X .3395 is 12.73
.5 X 127 X .3395 = 21.5
It doesn't matter if you take the HP from a belt or the exhause or an electric motor or a steam engine in the trunk that's what it takes.
BTW I just took .5 lbs/sec out of the air it doesn't mean anything. It could be close but not exact.
Edit: For a stock unblown Rx8 it is .5/sec. How about that, I just guessed. For a blown engine it is .5 X the density ratio. The density ratio is dependent upon the heat of the gas. Dr=Pr x T1 over T2
So if you have 75 + 530=605
560 over 605=.87
1.5 x .87=1.3
x .5=.65 lbs/sec
.65x75x.3395=16.5 HP to compress the air with 85% eff
I'll let you figure out the other blowers
Heat added to air from compression=YxT1 abs over eff of compressor
Y=Pr^.283-1
So if you have 7.5psi pressure that is Pr1.5
1.5^.283-1=.12
.12x(70+460)=63.6 degrees temp rise with 100% eff
You can't get 100% no way no how, but if you could it would still heat the air this much.
Find the heat rise for given eff, divide by eff.
Therefore if you have 50% eff you put 63.6 over .50 = 127 deg temp rise.
Or 60%= 63.6 over .6=106
50 is good for a roots 60 for a centrifugal and 85 for my axial flow.
So 63.6 over .85=75 temp rise
So while there is temp rise it is under the limits for safe operation of the Rotary.
IC or more correctly AC are not free tools, they have negatives mostly for street engines. The add complications, weight and cost. It take pressure away to push air through the radiator. Use them when you have to and not just to say you have one. I think somewhere in this thread RotaryGod has given you a lecture on how the IC can add heat to your street engine. I'm sure he will give it again if you ask nice.
As long as we are doing math I'll give yo something else. HP to compress air.
lbs/sec x T delta X .3395 = HP to work the air. To that you must add the external loss. Like bearings, gears, belt drive and more.
So .5lbs X 75 X .3395 is 12.73
.5 X 127 X .3395 = 21.5
It doesn't matter if you take the HP from a belt or the exhause or an electric motor or a steam engine in the trunk that's what it takes.
BTW I just took .5 lbs/sec out of the air it doesn't mean anything. It could be close but not exact.
Edit: For a stock unblown Rx8 it is .5/sec. How about that, I just guessed. For a blown engine it is .5 X the density ratio. The density ratio is dependent upon the heat of the gas. Dr=Pr x T1 over T2
So if you have 75 + 530=605
560 over 605=.87
1.5 x .87=1.3
x .5=.65 lbs/sec
.65x75x.3395=16.5 HP to compress the air with 85% eff
I'll let you figure out the other blowers
Last edited by Richard Paul; Jun 13, 2006 at 10:54 PM.
I edited 3295 with some more numbers.
But I just did another one. Using the Dr of 1.3 times the original HP of my car at 170 it comes out 221. We got 219. That shows that the additional air was of more value because all the drains were taken by the original air.
All this can be adjusted for this and that but it is a better predictor then using Pr or just psig. Use the Dr now that you know how to get it, to estimate HP when FI.
But wait we were only running 5psi for the dyno runs?????????? Guess I got something from the tuning.
But I just did another one. Using the Dr of 1.3 times the original HP of my car at 170 it comes out 221. We got 219. That shows that the additional air was of more value because all the drains were taken by the original air.
All this can be adjusted for this and that but it is a better predictor then using Pr or just psig. Use the Dr now that you know how to get it, to estimate HP when FI.
But wait we were only running 5psi for the dyno runs?????????? Guess I got something from the tuning.
Last edited by Richard Paul; May 25, 2006 at 07:48 PM.
Originally Posted by Rootski
So, wait... only 219 horsepower? 
50hp from 5psi. It'll get more boost when we find some tuning bugs we have. It has nothing to do with the sc, it always had some problems since it was new.
LOL - no, but I know my engine is strong from the factory - no isuues yet, except going up Mt. St. Helens on the 13th under heavy load the car acted up like I had a compression brake applied. Let off the gas, and everything retuned to normal. Hasn't done it since - weird.
