Dyno Results - 355 - for my ole Stepside RC

[Ed_P]

Been busy... It's not in yet. old one came out today. lots of prep to do. I'm shopping for a new alternator bracket now since my dumb ass broke the old one ( pot metal). The part number is odd. I see the old pot metal style then I see another metal bracket, says it's compatible... I dunno. I need to research it

 

[shovelbill]

Race gas can give you some fudge room in milder applications to run a little more timing / make more power. Oxygenated fuels can be run a little richer and help a little, too.

i agree.....i ran oxygenated fuel, or a blend in my "street shovel" because it was purpose built. i've since de-tuned her to run on pump gas.

all the Harley engines i've done and were tuned on the dyno were done with the gas that is typically accessible to the owner, with compression ratios taken into account of course.....it cost a few ponies and some folks questioned my thought process........some bikes i had tuned with 89 octane as opposed to the 91 HD recommends......this was especially true for the bikes that saw lots of cross country use. after all, higher octane isn't available all over the place.

my own bike, with static set to 10.2:1 and 192 pounds cold cranking was tuned on 89.......sure it cost a "tad" of performance, but i built her as mile gobbling distance rider. the entire bike's recipe was built around my cam choice......

heat range for the plugs can be used to tune as well.....i always round and smooth the ground electrode....i run the coldest plug i can away with for detonation free operation in high CR applications.....with resistance matched to the ignition and wires.

when i do tune my HT383E, i will tune with 87 octane as that's all i run in her. the motor was designed to run on that with the factory tune.......that's the main reason i don't think i'll be using the Hypertech tuner, it requires 92 octane and is designed for a 350.......though it did work well in Tachyon's application.

 

[shovelbill]

This is completely subjective. It's difficult to hammer down exactly what the powerband of an engine will be based solely on a set of cam specs. Many other factors play into this, such as transmission (and stall rating if applicable), gear ratio(s), tire size, vehicle weight, engine combination and compression ratio, etc.

Maybe as a general rule, in an otherwise stock engine/vehicle, it would get you close.

much better answer than mine....i should have been a bit more specific.

painting with a broad brush, i'd have to say that cam manufacturers list an RPM range to give an idea where a particular cam would work best for a typical application........i'd also say that cams are designed for 3 applications, low, mid and high rpm ranges.......typically the intake close and duration are the most predominant factors that determine just WHERE a cam would perform best.....again, that's just my opinion based on my experience.
of course anything can be modified to meet a PARTICULAR application by a variety of ways.....ie; Compression ratio or how the rocker arm ratio plays on lift and duration.

if a cam card says 3,500-7,000 rpms, i sure wouldn't choose this for a tow rig or a rock crawler.

there's no real voodoo to cams, but there's a lot to understand as they are the BRAINS of the operation......lol.

the wrong cam choice for a particular build can DESTROY any chance of success......or the potential for peak performance.

my apologies to the OP for continuing to derail the thread.