Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[skyhook]

looking for the bottleneck on my build:
'08 fxdse2 110"
stock pistons, cylinders, stock 50mm throttle body and injectors
r&r cycles stage 4 cnc ported 96" heads with 1.94 intake valve and 1.63 exhaust valve
se257 cams
se aircleaner
200 ccp, 4% leakdown
power commander, custom map
supertrapp supermeg 2 into 1, 20 discs, "swiss cheese" endcap, see pic
see dyno, 5th gear

[skyhook]

dyno

[kng103]

probably not the right cam choice for your build.

[d-rock]

I would also guess the cams.  The specs should say where the power range is.

[Unbalanced]

The best place to get an answer would be from R&R they setup the heads and know where the air flows are in terms of amount and velocity.   I would suspect the cam as the culprit and would suggest asking Reggie what he recommends.

[skyhook]

thanks for the help...when I talked to r&r, reggie wanted to sell me gear cams...I told him I'd be using chains and no roller rockers...he said the heads were 87cc...I figured that made 10.4 with my setup without milling...I told him I wanted 257's, he said they'd work ok, 258's would be better...guess my compression figures were wrong because it tests at 200ccp and 4% leakdown, thinking of changing to a longer cam, gonna experiment with more discs in the muffler first

[vagabond6542]

looking for the bottleneck on my build:
'08 fxdse2 110"
stock pistons, cylinders, stock 50mm throttle body and injectors
r&r cycles stage 4 cnc ported 96" heads with 1.94 intake valve and 1.63 exhaust valve
se257 cams
se aircleaner
200 ccp, 4% leakdown
power commander, custom map
supertrapp supermeg 2 into 1, 20 discs, "swiss cheese" endcap, see pic
see dyno, 5th gear

The formula HP= (Torque X RPM)/5252 has your answer to the fall off.
You would need to increase the torque to a flatten curve to keep the horsepower from falling off.
The problem with that last statement is, the faster the rpm, the less time there is to intake a bigger fresh air/fuel charge to increase the torque.  There are only two cures for the problem, a longer duration on the intake valve or a higher lift in the duration you are presently using. Then there the mechanical limits the lifter system can take at the highest engine rpm. I wish you luck in your solution.
I hope this was of some help.

[SirMichael]

 I've used the 258 cams before in a 103 build, It was all mid-range & top-end!! Depending on your heads, The 258 will not fall off like the 257 is doing on you!!

                                                                          MIKE

[gremlush]

I have been doing this stuff for 30+ years ,so let me give you my 2 cents.  Your S=T pipe makes good tq. BUT,will drop like a rock on large motors. Too small of collector ,ran one on Merch 120" same thing. Put your STOCK header pipes back on {with cross-over} and cycle-shack slip-ons. Drill 8-12 extra holes {same size} in the baffles.  They come with 6 rows of 4 holes in each row. Start by drilling 2 extra rows. total 8 ,but you will end with with 12 extra. Trust me !  The 257 is a GREAT cam ,just like the Andrews 67. and will pull HARD to 6500. You will pick up 10+ hp. with the cycle=shacks with 12 extra holes. I have tested ever damn pipe on the market ,and cycle-shacks are what I run !!! Go to a dyno shoot out some time , what do they run ? You will have the same tq. or better too. Dewey

[old wrench]

SE cams seems like you either have it on the bottom or you got it on the top  I like to run S&S or Andrews, I like the S&S a little better and there geardrive seems to be smoother with less noise. The 585 cams come in strong at 2800 and give you a good high torque run up to 5800.

On the exhaust like yours I drill a center hole with a stepped tapper bit, starting at 1/2 do a run then up one more step and a run I continue this until power starts to drop and replace the cap, drilling it back to the size that gave me the best power, just my 2 cents hope it helps

[DCFIREMANN]

I have to agree with the above post. IT IS YOUR EXHAUST!!!!!! Supertrap on small motors only. Hell a Thunderheader would have given you better numbers and it does not like big motors either. I would look into a Borzilla or Fatcat for the 110.

Be Safe

THE DAWG

[gremlush]

I have LOST  7 -12 hp. with ALOT of 2 - 1 pipes , vs. cycle -shack , but they all had about the same tq. within 2-3. The ONLY 2-1 pipe that will 'carry' the tq. curve like a c-s ,is the fatcat. For those of you that want to know what hp. is . take your tq. # and times it by the rpm ,then ,divide it by 5252 . Lets say ,you have 85 tq. at 5000 = 425000 then divide by 5252 = 80.92 hp. thats why hp. and tq. lines ALWAYS cross at that # 5252.  A jap bike only makes 65tq.  {lets say} but it will hold it for 14000 rpm , 65 times 14000 rpm = 173 hp. anyway ,when you get a pipe that will HOLD your tq. ,your hp. goes up. Very simple. Like I said ,cycle-shacks vs. your super trap = 8-10 MORE hp. and 'around' the same tq.

[skyhook]

happen to have a fatcat on the wife's bike:  '07 dyna, 96", street port heads, 37 cams, 9.8 compression...maybe I'll swap the pipes from one bike to the other

[SPIDERMAN]

Try this for a cheap solution to your problem. Remove ALL of the discs,  replace the endcap and see what you think. Loud yes, but the drop-off at 4,500 will go away. 

B B

[old wrench]

happen to have a fatcat on the wife's bike:  '07 dyna, 96", street port heads, 37 cams, 9.8 compression...maybe I'll swap the pipes from one bike to the other

  Look out skyhook she may swap your pipes if you take her fatcat, we put one on a bike the other day and it helped. I was surprized at how good it sounded, that is one heavy pipe.