Hi

Is anyone using the comp cams HR262-12 cam, p/n 08-300-8, in their LB9 IROC? I've been thinking about the swap and figure it should be good for about 40bhp from what i've heard. Has anyone got a dyno graph of this cam fitted or a one of a simmilar spec?

Also, those of you that have the cam, how do you find it? It the idle still smooth and does it deliver good power and more power higher up the rev range? I'm looking for more power up over 5000 to 5500 RPM


Thanks for the help guys

Rob

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1987 IROC-Z Auto (LB9)
Black/grey with the stance of a streetfighter

Mods
Custom exhaust. 4 Inch pipe from the headders all the way back to a single muffler at the rear. No Cat.

Future mods:
K&Ns
RAM Air
New Underdrive pulleys-either March performance pulleys or Auto Specialties Performance
Air foil

 

RMK,

The lift numbers look good, and the LSA is right on factory specs for good compatibility with the ECM, but the duration looks a little short for higher RPM operation. The longer stroke/bore ratio 305 will tolerate a little extra duration since the heads are pretty restrictive. You might have to advance the cam timing a few degrees to compensate and get good high-RPM flows, but a little more duration would probably be safe. Another way to compensate would be to install 1.94 valves on the intake side and provide some extra lift for the exhaust valves.

If you aren't looking for built-350-like power levels, the cam you selected is certainly a vast improvement over the stock profile.

The 264HR might be a good choice in a straight-up timing installation as an option, but you really should gather all pertinent data on your car, like modifications, planned mods, rear gearing, etc., and call Comp's Tech number for an opinion on duration in a 305 TPI. It's free, and another opinion can't hurt.

In any case, if you want a little more on teh top end, you'll probably find that the fuel delivery becomes a problem with the extra intake air flow, so start thinking about an adjustable FPR conversion.

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Later,
Vader
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"I cannot take this any more... Saying everything that I've said before..."
Adobe Acrobat Reader 4.0

 

Vader

I was hoping to get nearly 300bhp from all of my planned mods listed in my sig along with the new cam and possible the edelbroc manifold and siamised runners. Would this be possible?

Also, where is the FPR located?

Thanks again

Rob

------------------
1987 IROC-Z Auto (LB9)
Black/grey with the stance of a streetfighter

Mods
Custom exhaust. 4 Inch pipe from the headders all the way back to a single muffler at the rear. No Cat.

Future mods:
K&Ns
RAM Air
New Underdrive pulleys-either March performance pulleys or Auto Specialties Performance
Air foil

 

The FPR is on the rear of the fuel rail. Big thing sticking up like a sore thumb.

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87 Z28 305 TPI, Auto, 2.73, Gutted air boxes, K & N fillters, SLP Airfoil, Dyno Max 3" cat back, Accel 8.8 mm spirals, Accel cap and rotor, Accel coil, rapid fires, and 160 Stat.
Best 15.414 @ 87.47.

 

It's under the hood? I was worried that it would be connected to the sending unit.

------------------
1987 IROC-Z Auto (LB9)
Black/grey with the stance of a streetfighter

Mods
Custom exhaust. 4 Inch pipe from the headders all the way back to a single muffler at the rear. No Cat.

Future mods:
K&Ns
RAM Air
New Underdrive pulleys-either March performance pulleys or Auto Specialties Performance
Air foil