The main difference between the 13 and older cams and the 14 and newer HO cams is the amount of overlap. The newer cam has more which equates to more low end torque.

 

Both of you are correct in that the newer cams have more overlap or duration than older versions, and that does make a difference.

However, it is the difference in lift that makes far more difference, and comparing a 255 cam with .556" lift to a stock cam is not logical.

Also, I was commenting on differences between current 103 models, not on differences between older and current 103 models.

 

Disagree. It's not the lift, it's the lobe timing that made the difference here. Early closing like an 255 to increase torque.

Just included the pic so you can read the words, "closer to a SE255 etc etc".

However, if you want to argue you win.

 

I threw a set of 255 cams in my bike at about 6000 miles and then a set of Andrews 57s around 13k
I think I spent around 200 bucks for each set of cams, I do my own work so hunting around for deals on parts is where I save money.

Changing the cams was the most notable difference in the bike. I had gotten big torque gains from the 255s and more top end/scary fast from the Andrews.
If you do you're own wrenching it maybe worth it. I could never see myself spending hundreds of dollars on labor or 1000k-1500k in performance upgrades for another 10-20hp

 

Actually, it's both. Always.

 

You're not getting it. Since the new OEM cams did not increase lift, and there clearly is an increase in torque and HP, it's obviously the change in lobe timing. That's all I'm saying.

 

I found this.



Edit, i see it's all ready been posted

 

Actually, I do. If you change one and not the other, it makes a difference. If you change both, it makes a difference. Lift and timing specifications both make a difference. They're both involved in mixture flow.

Perhaps my post was unintentionally confusing. The point I was trying to make is that none of the OEM cams are remotely close to the specs of an SE255. Going to a 255 cam in a stock motor, assuming a/c, exhaust, and tune are done, will make a huge difference in performance, far greater than the difference between '13 and '15, far greater than the difference between base 103, HO 103, and Twin-Cooled HO 103.

 

Since stock 88/96/103 heads stop flowing any more cfm/air/fuel at around .500 lift, cam lift above that makes little/no difference without headwork. It is ramp angle, timing and duration that makes the performance difference with stock heads.

 

That's a great graphic, and I'm definitely saving a copy of it! But, that's NOT what the OP was asking about, at all. He's not asking about the difference between a '13 and older cam compared to a '14 and newer cam.

He asked this:

"103 High output cams?
The 2015 RGS special has the SE255 cams I do believe?"

The answer to his question is: "No."

And then, this being the internet and all, the thread went completely off the rails.