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Comp XE268 power range

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Old Dec 19, 2008 | 12:49 PM
  #1  
wrsjr's Avatar
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From: Birmingham, AL
Car: 1991 Camaro RS
Engine: 355
Transmission: 700R4
Axle/Gears: 10 bolt Richmond 3.73 posi w/ discs
Comp XE268 power range

Has anyone with a Comp XE268 had their engine dyno'd? I dyno'd my car last night and noticed the power band dropped off after 5500 rpm. Comp advertises that the cam ranges up to 5800rpm. Just trying to see what other results people are having.
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Old Dec 19, 2008 | 02:22 PM
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From: Milwaukee
Car: 92 Firebird, 77 Trans Am SE, 86 Z28
Engine: 5.7 HSR, T/A 6.6, empty
Transmission: T-5, TH350, T-5
Axle/Gears: 3.08 posi, 3.23 posi, 3.23
Re: Comp XE268 power range

I don't have a 268 cam but I have a 256 which is close and I have the same issue. The 256 ranges up to 5200 but my engine peaks at 4600. I think it has a lot to do with the intake the engine has on it. Is your TBI TPI or carb?
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Old Dec 19, 2008 | 03:55 PM
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From: Calgary, AB, Canada
Car: 1982 Trans-Am
Engine: 355 w/ ported 416s
Transmission: T10, hurst shifter
Axle/Gears: 10 bolt, true-trac, 3.73
Re: Comp XE268 power range

heads and intake have a big effect as well.
You have 180cc ports, that will lower your RPM band.

I had heavily ported 416's with my cc268. It was running out of breath around 5500RPM as well. No dyno results. I just cammed it up instead
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Old Dec 19, 2008 | 04:36 PM
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From: Allenhurst, GA
Car: '81 Z-28
Engine: Soon to be a 383
Transmission: Muncie
Axle/Gears: 3.42
Re: Comp XE268 power range

That's the power range for that cam. To raise the power range, you will need a stiffer cam. Your heads will support the power as long as you have enough compression.
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Old Dec 19, 2008 | 04:55 PM
  #5  
wrsjr's Avatar
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Joined: Aug 2007
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From: Birmingham, AL
Car: 1991 Camaro RS
Engine: 355
Transmission: 700R4
Axle/Gears: 10 bolt Richmond 3.73 posi w/ discs
Re: Comp XE268 power range

I might consider a larger cam one day then. I know I have the set-up to support a larger cam, I just went with the 268 based on the fact it said the rpm ranged up to 5800rpm which is where I wanted to peak out. The XE274 advertises 6100 or 6200 so I might step up to that cam one day.
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