What kind of power?

Sean said:
More efficient in terms or heat production but the parasitic loss is still far higher then a centrifugal.
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I actually think this is backwards. At least it was back when I ran KB blowers in the mid 90s.

The KBs back then (Lyshom Compressor) made a lot more heat than the cent. blowers, but took a lot less power to turn. Hence 20psi easily with a 6 rib belt.

Maybe something has changed since then.
 
In terms of supercharger efficiency (heat production and air flow) worst to best.....

Roots blowers (Eaton, Magnuson etc)
Twin Screw blowers (Whipple, KB etc)
Centrifugal blowers (Vortech, Procharger etc)

In terms of parasitic loss on the motor since they are all belt driven it is going to depend on the size of the supercharger and it's rotor efficiency. I.e.....a 1.8L Eaton will soak up less power at 12,000 rpms than a 3.4L Whipple, even though the Whipple has the more efficient twin screw rotor profile.

Of course the new Eaton TVS rotors are changing things up a bit.

--Joe
 
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KB's are supposed to be more akin to turbo compressors. We did some testing with KB,Lobe style and Turbo and centrifugal stuff on a blower cobra once upon a time when I worked for a company and we tested all this stuff at the various boost levels.

in order of effiency.

Roots
High Helix Lobes "New Eatons"
Lysholm,Twin Screw "High helix"
Centrifugal
Turbo


We stabilized all the testing by keeping the intake temps the same or as close as possiable.

In order of heat

Rootrs
Eaton "High Twist"
Centrifugal, turbo

The turbo sometimes edged out the centrifigual and it went the other way across the rpm band. As the blower speeds got up the turbo would beat it. At low compressor speeds on the turbo it was worse then the centrifigual.

Measuring intercooler heat disapation the centrifigual and the turbo were light years better then the Roots. That was measuring disappated BTU's.



Fryguy302 said:
I actually think this is backwards. At least it was back when I ran KB blowers in the mid 90s.

The KBs back then (Lyshom Compressor) made a lot more heat than the cent. blowers, but took a lot less power to turn. Hence 20psi easily with a 6 rib belt.

Maybe something has changed since then.
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Well it currently makes 0rwhp and 0rwtq. They did a compression check on the motor before the install and I have low compression on 3 cylinders. 2 of the cylinders are next to each other so my guess is a head gasket the other one is on the other side of the motor. Thats the one thats worrying me. Hopefully I get some news on it soon.
 
Well at least you caught it before you melted a piston or something really bad like that.

Not that head gaskets are a lot of fun or anything....
 
It is most likely a ringland or exhuast valve damage. The factory head gaskets on these 4.6L motors are nearly indestructable.


KENNEBELL2.6 said:
Well it currently makes 0rwhp and 0rwtq. They did a compression check on the motor before the install and I have low compression on 3 cylinders. 2 of the cylinders are next to each other so my guess is a head gasket the other one is on the other side of the motor. Thats the one thats worrying me. Hopefully I get some news on it soon.
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Thats sad to hear about the compression.

If you don't mind, I'd like to piggy back on this thread and ask the same question

99 Cobra 4V DOHC
Vortech SQ S-trim, intercooled
10lbs
Anderson Power Pipe
Bassani midlength headers and catted x
FR500 catback

Lidio's dyno next Thursday, lol.

~Eric
 
I;d say that seems like a bit much on the boost. I would tell ya that if it makes good power your at the thermal load limit of the piston.I would pulley it down to 8psi if it starts making 10psi or more if the motor is stock. If anything so much as hiccups at that power level its going to break something.


rockthemullet said:
Thats sad to hear about the compression.

If you don't mind, I'd like to piggy back on this thread and ask the same question

99 Cobra 4V DOHC
Vortech SQ S-trim, intercooled
10lbs
Anderson Power Pipe
Bassani midlength headers and catted x
FR500 catback

Lidio's dyno next Thursday, lol.

~Eric
Click to expand...
 
Lidio said the same thing. I figured since it was intercooled it may not be as big of a deal.

I have the 3.33 pulley and a stock crank pulley. On an S-trim, thats 10psi, right? I just want to make sure. Should I really step it up to a 3.47 before next thursday? I've got other cars, I'd just rather not kill this thing on the first pull.

~Eric
 
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