When you say peak do you mean where the run was stopped or where you actually shift it? Or do you mean peak as in the horsepower number is no higher than it is at 6600? Are your heads ported? What intake manifold does it have? What size valves?

Even though you have a "228/232" cam what is the ICL and LSA? Comparing duration and LSA will get you into trouble when trying to compare two cams that have very similar numbers. You need to look at the valve events and where the intake valve closes to compare where a cam peaks.

When I say peak I mean the point in the graph where the horsepower figure has reached it's highest recorded number and then after during the run that number is never eclipsed again. For example:



That is my dyno graph for my car cam-only. My cam "peaks" at 6100-6200rpm, yet carries that peak number all the way to 6600-6700 before it begins to very slightly fall off. Again in reference to my graph, some people would say it peaks at 6600-6700 because that's where it starts to slowly lose power.

 

On the dyno we took it right to 7000. The car made peak HP (470) at 6550RPM, and carries all the way to 6900 or so. The heads are the PRC 5.3 heads - which do have the larger sized valves in them, and the intake it an LS6 with a ported TB. Car has a lightweight flywheel (18lb - monster S2)/UD pulley (shouldn't really effect where the motor peaks). The rest of the cam specs are 111 LSA, and the lobes are XER.

With that said, the intake is nothing special, so I am assuming it is the heads that help give it the extra RPMs?

EDIT: With the tight LSA it gets into the powerband VERY fast.

I don't mind the fact that it peaks so high - we will see what it does with a FAST 92/92 setup this year. I actually need the RPMs thru the traps anyway.

 

Martin is a world class guy he wouldn't steer you wrong I can't wait to get my custom cam put in the LQ4 I'm putting together Martin knows his ****!!

 

Is the cam installed straight up on a 111ICL? If so that is a big swing in intake valve close point compared to the cam in question which will highly influence the peak rpm horsepower and torque are made. Not only that, but the larger valves and larger intake port(I'm not quite sure how large PRC ports the 5.3 heads, but I'd bet they are larger than a stock 241, 853, 243 etc.) which will also influence the rpm peak horsepower is made.

Here is a good comparison for you....this car has a stock LS1 bottom end, 243 heads with stock valves that have had a valve job, milled to 11.5:1, Ebay 1x3/4" headers, Fast 78, 3.5" merge, 3.5" cat-back and a 224/236 110+3 camshaft.





His cam has the same IVC point as the cam I recommended to the OP and in my experience in past times doing this exact same profile it peaks at 6100-6200 every time with stock port work and stock valves.

Thanks for the kind words Ryan.

 

Better yet, and that's a nice cam selection!

 

That is a nice lineup of cams.

 

Why is the 227 234 cam on a 110 LSA? Great lineup Martin

 

Dang that is a TON of torque for 346 cubes. I'm jelly.

P.S. thanks for explaining all that to me. I figured that was the case, but that just backed it up.

 

The max torque value on that graph is not correct, there are two spikes in the torque trace that are skewing the max values. That said it made 414rwtq which is still impressive for a 346 with stock port work.

No problem man, I wasn't trying to act like you were wrong, just explaining the process that goes into shaping the power band of an engine.

 

Overlap. Overlap broadens the torque curve indefinitely and when you have an IVC event of 40.5 degrees with 10.5 degrees of overlap, the thing is going to make stupid torque at low-speed. It will also make a later opening exhaust valve event carry more torque past peak torque increasing the peak horsepower number. Combined with an early peaking 40.5 degree IVC event, you don't have to turn the engine 6400-6500rpm to make 440rwhp+ with a 346 that has good compression.

It's all a product of the combination and how the parts are chosen to work with each other.

 

even if the the number is slightly skewed that is massive torque for an mostly stock ls1.. ill definitely be going with tick ant the cam martin recommended

 

Let's get her done then!

 

K perfect lets do.. ill let you know once im ready to order.. probably just after christmas