I have a 09 rkc with stage 1 done (kerker muffler, bub7 true duals headers and se ac)

I lost some low end torque (typical with true duals) and I would like to fix that lost.

kerker muflers are a free flowing muffler with a straight core desing, I am thinking on changing kerker for supertrapp se series wich has some retention and backpreasure in order to help pushing at low rpm.

I also would like to change cams to a 255 in order to get some low end torque with duals.

one of the reasons I would like to change kerkers for supertrapp se series is because bike will get louder with 255 cams and kerker are loud enought right now so supertrapp will quiet it down a bit and add backpreasure.

the questions are:

do you think I'm doing wrong changing kerkers for supertrapp se if im going to do 255 cams too?

will supertrapp se mufflers become a plug with true duals and 255 cams because the have more retention?

will supertrapp (being more restrictive than kerker) and 255 cams help to have some low end torque back?

will the bike fall flat after 4500 rpm because of this cams and the supertrapps?

I live in Madrid (Spain) wich is a crazy traffic city, sometimes yo need a bike that pushes hard and fast from 0 to 40 because of the traffic. most of the time I ride fast and hard in the city, some other time I cruise on the highway with 2 up. (just to add some more infor of my riding style if it helps you to answer my questions)

thank you for your help

BTW please dont say get a 2 into 1 exhaust, I know 2 into1 is better than duals but I hate the look of 2-1 in a road king classic so 2 into 1 it is not an option! lol

 

Lots of info on the 255's and different exhaust in the search section. I had to go to 1.75 baffles in my pipes to get the torque i wanted down low.

 

I have a 96 with new Anderson 37G cams. Low torque 234 gear are very nice. i was looking at the 255 but this cam was the better choice since i was not going to do any head work.

 

Supertrapp, ( which owns Kerker BTW,) is excellent because you can tune the pipe to the proper back pressure by adding/ removing discs, regardless of your cam choice. I have a White Bros. E Pipe on my FLTRSEI with their version of discs and love the torque with Andrews 26G cams.

 

I would just up grade the cams to TMAN 555 Cam or A FUELING 525 Cam leave the exhaust alone.

Or just up grade the exhaust will be cheaper than cams and exhaust.....

Did you tune the bike?

And I do offer a ghost pipe for my Dragos S/C/S 2 into 1's
For those who like the true dual look but want the perfromance of a 2:1 exhaust. I had to say it...... sorry.. get 2 into 1

 

stiggy the supertrapps im talking about are the se series wich has no disk inside, it is just a regular core but more restrictive. I dont know if they'll do the trick.

Drago's I had to go with SE cams because where I live theres no dyno tunners so I have a friend in the USA who owns a dyno and can send me the map for the cams but right now we only have HD SE cams maps.

installing other cams will be a problem because theres no way I can find the right map for my SERT.

About the 2-1 with a gost pipe, IMO is even worst.. I mean, If you put a 2 into 1 in your bike, dont pretend it to look like a true duals system, thats a fake and I like real things.

So do you think supertrapps with true duals will have enought flow for a 255 cams stock 96 engine or they'll become a plug at mid-high rpm?

Thank you

 

Sounds like you got a good deal going on the 255 cams I would put them in and ride it. Made a night and day difference for me with my true duals. Then if you think you still need more grunt then look at the pipes just because the dyno shows that the 255's fall off on torque around the 4k you still have horsepower moving you along fairly well at that point. I dont really ride much over 4k I just shift but there are times I run over the 4k its not like it falls off like I say the transition from torque to horsepower is just fine remember shift man! You will find yourself having the capability of being in a higher gear than you are now with all of the available torque out of these cams

 

I do not know if you know but you can purchase just the se series baffles to go in you kerker slipons as they have the same body. I just put Supertrapp se series baffles in my Screamin eagle street thunder slipons. Baffles are about $60 piece so not cheap but cheaper then new muffles if you like the look of your present ones.

 

have you notice a lost in low end torque with the duals like I did? I put a dyno map on my bike, however thers no low end torque, my 09 used to be a fast hard pulling bike with stock system, now is a rocket at high rpm but it needs a life to go up there.

how is your idle and overall sound once you put the 255 cams?

thank you

 

thank you for the tip, how does the se baffle sound compared to the screaming eagle thunder?