View Full Version : What kind of power?
KENNEBELL2.6
04-14-2008, 03:36 PM
What kind of power do you think my car will make. 4.6 2 valve, pi heads, crower stage 2 cams(dont know the numbers), steel cobra crank, forged rods and pistons 10:1 compression with a 2.6 KB at 10 - 12 lbs? I really dont know what to expect Ive never had a boosted car before only a 100 shot of nitrous. Thanks
ReiKo
04-14-2008, 03:41 PM
550ish
KENNEBELL2.6
04-14-2008, 03:43 PM
I really have no idea but thats about a 100 more than I was guessing.
Why not run lower compression and have the option to throw lots of boost at it?
--Joe
KENNEBELL2.6
04-14-2008, 03:52 PM
I would love to do that but the motor was done a year ago when I had no intentions of doing this. So when it blows up I will definatly do that.
I would love to do that but the motor was done a year ago when I had no intentions of doing this. So when it blows up I will definatly do that.
Just keep it cool and run good plugs and gas.....it will be fine unless you get crazy with the psi.
--Joe
team_southside
04-14-2008, 04:04 PM
550ish
x2 but it will more than likely have to have a race gas tune in it.
1BADAIR
04-14-2008, 04:49 PM
430
LITTLEMAGS
04-14-2008, 05:32 PM
it will be close to 500....
DeFormula
04-14-2008, 09:18 PM
450 was the first number that came to mind.
Depends on the dyno. A roots blower is going to eat power. I would say this might be comparable to an upgraded pulley 4.6 dohc cobra motor. Depending on whose dyno it gets on could be anywhere from 420-500hp.
Depends on the dyno. A roots blower is going to eat power.
KB is a twin screw not a roots. So quite a bit more efficient.
--Joe
jtcstrat
04-14-2008, 09:45 PM
my car just made 430 on a mustang dyno with a built motor vortech v1 and 10-11 lbs
I would say close to 500
More efficient in terms or heat production but the parasitic loss is still far higher then a centrifugal.
KB is a twin screw not a roots. So quite a bit more efficient.
--Joe
sardeanie
04-14-2008, 11:31 PM
470-500 rwhp. When's dyno time and who's doing it?
KENNEBELL2.6
04-15-2008, 07:36 AM
470-500 rwhp. When's dyno time and who's doing it?
I dont know when it will be done but Lidio is doing it. Im taking it down today.
More efficient in terms or heat production but the parasitic loss is still far higher then a centrifugal.
Not debating that. I was just correcting your roots blower comment.
--Joe
jtcstrat
04-15-2008, 08:40 AM
I dont know when it will be done but Lidio is doing it. Im taking it down today.
Well good luck!
Is his dyno a dynojet?
KENNEBELL2.6
04-15-2008, 08:44 AM
Yeah
I had a feeling it was the helix vs the lobe. Yeah the helix is alot better by far then a roots. I didn;t take the comment personally. If its Lidios dynojet I will go with between 460-500
Not debating that. I was just correcting your roots blower comment.
--Joe
Fryguy302
04-15-2008, 10:19 AM
More efficient in terms or heat production but the parasitic loss is still far higher then a centrifugal.
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
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.
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.
LITTLEMAGS
04-28-2008, 01:38 PM
update on numbers??
KENNEBELL2.6
04-28-2008, 01:47 PM
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.
coldblue012
04-28-2008, 08:59 PM
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.
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.
rockthemullet
05-02-2008, 01:11 PM
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.
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
rockthemullet
05-02-2008, 03:54 PM
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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