Can someone explain to me how the dyno chart isread? I hardly ever get to 5500 rpm. At 70mph I am at 3000rpm.I am looking into a hd big bore kit. This is what I am thinking about. Any suggestions? I already have theSE 2 into 1,Hypercharger with stinger trap,( SE 44mm cv carb & big bore intake - not yet installed ). Would like the 1550 stage4 kit which include: big bore cylinders, TCHC forged pistons, TC performance heads & compression release. Now to the fun part! Should I go with the 203, 211,257 or 253cam.Alsowhich ignition sys. the pro adjustable or the pro race?For now I can only do the cam kit. Also on the 2 into 1 exhaust,should I remove the baffel and packing or leave it in, or just remove the packing?
Another question, the 1550 w/ cnc ported heads looks realy good to. stage 4, or cnc ported heads?

 

You have a lot of choices to make,and only you can decide.Go talk to the dyno people and try to get an idea of what you want for performance and where you want it.Then they might make suggestions.Most Harley riders want all the torque the V-Twin can muster,and maybe a hp number to brag about.

 

Maybe I'm asking the wrong questions!

 

You know that beyond a certain point, reliability, drivability, and cash all suffer as the hp goes up.

 

If I understand your question, you want to wind up with a dyno sheet that indicates max torque and a higher HP numbersin the lower RPM cruising range, such as 2000-3000 RPM. It's like a very good professionalengine builder asked me when I wanted them to build me my first racecarengine, " I will not start building an engine until you answer this question, howmuch performancedo you want doing what?" The answer dictated every part he used, it's all in the combination. Based on your objectives, as an example,you need small port, long runnerinduction/exhaust for low RPM port velocity and tuned lengths, you need a conservative cam to matchtheports andyour RPM rangeto build higher cyl pressures down low, etc, etc. Let a good professional, experianced builder (grey hair helps)lead you once you answer the question. One mismatch in the combo and you have a dog. I have seen so many engines that produced more performance then the sum of the parts because everything worked in perfect harmony.

 

Whoa! What? I think you lost me even more. Let me start over.
Right now all I can afford is a cam job. I am told the biggest I can go is the 211. Later I want to install the jugs n heads. Only 95". Not intrested in anyting bigger. Would a 203 or 204 be better? What is the difference between the two.A friend tried to explain tq is better to get going, hp to keep going! OK, but then what? Once going the rpm is at 3k not 62k or above as shown on tq curve. Maybe that is what is throwing me off. When I look at the tq curve at 3k, hp is really low and tq is high. Then hp goes up. Tq goes up a little but then drops.Again, at hiwy speed I am at 3k. I don't hardly ever go over 45k on accel. Also with the SE 2-1, with or w/o baffle, with or w/o wrapping? I really am ignorant on this.

 

I would not spend too much time worrying about Dyno numbers.Make sure the bike is running as good as can be,keep it maintained,and enjoy.A Dyno run will tell you what you need if you need to know it,and the operator should be able to tweek the motor where it needs to be,O2 etc.

 

204

 

Sorry, sometimes I get a little carried away, I was trying to give you some engine basics so if someone is giving you bad info,it would help you identify it. As a general rule, when it comes tohigh perf bolt ons and especiallycams, you areusually giving up something to gain something. When moving up tomore and more aggresive cams, you are simply moving the performance capability of your engine from a lowerto a higher RPM range. If you were to nowbaselinedynoyour bike from 1000-6000 RPM, then add one of those cams and againdyno it,then overlay the TQ and HP graph lines from both runs, it would indicate aloss of both TQ and HPat givenlower RPMpoints and gains at the higher RPM points. Were not going to get into a TQ/HP discussion here, for another day, the only thing that you need to know about TQ/HPis this, at any givenRPM, if you increase or decrease one, it will increase or decrease the other because they are mathematically related. I've just retiredfrom being a professional autocustomEFI dyno tuner for the past 15 yrs and the constant error that many make is choosing too large of a cam for their application, the bigger is better syndrome. I always followed and preached, ifyou have it down to two cams, choose the smaller one, and having potentially got too carried away again, I've finallyanswered your question on whichcam.

 

the operator should be able to tweek the motor where it needs to be,O2 etc.

02?