back to stock??

[metalfusiontech]

I am presently running Khrome Werks 3" HP plus slipons with a Fulsac dual system. I am going to replace the mufflers with a set of Monster Ovals. My question is.. torquewise, would I be better off by going back to stock headpipe with the crossover or would the difference be minimal as opposed to staying with the Fulsac setup?. Thanks in advance

[RK101]

IMO I don't think it makes much difference. I've heard discussions from both sides on which is better performace wise. I like the T/D for the sound and the heat off my right leg.

[FLTRI]

No disrespect to RK101, but there is a bit of difference (5-10tq) in power between tru-duals and the stock 2into1 system, right in what I call the sweetspot of power (1500-2500) for baggers.
Folks who opt for tru-duals are doing so for looks and sound, not performance. While peak numbers are similar, it is the around town and cruising that the differences are felt.
Now if your engine is big enough ie: 120-124ci, you probably will feel the difference, however a cammed up (high overlap), 88-103 certainly will.
Just my $.02 based on many tunes with all kinds of engine builds and exhaust systems,
Bob

[wavlovr1]

Bob, have you seen any improvements in performance with the 2009 changes to bagger exhausts?

Thanks Jim

[RK101]

FLTRI Non taken. Like I said I've heard pro's and con's from both sides.
Maybe it's because I'm running the Andrews 26 cams that I don't feel the tQ loss your talking about. I'm running the V/H true duals and have plenty of TQ in the 1500 to 2500 range. In the upper range I feel the T/D have it over the "y" pipe. This is a seat of the pants dyno and knowing how my bike feels. Before and after.  The monster ovals and how restrictive or not restrictive they might be might have allot to do with the outcome of what he actually gets I would imagine.

[FLTRI]

Bob, have you seen any improvements in performance with the 2009 changes to bagger exhausts?

Thanks Jim

Actually yes, the new system (2into1into2) works very well partly because it no longer has the left pipe reversion as with the earlier design. I wish I could bolt one on my 03RG but the oil pan, and prolly other diffs make it not worthwhile, IMO.

[FLTRI]

"My 103 we went from 2 in 1 Propipe to V&H true duals & even tried a set of Rinehart duals, no significant change on the dyno between any of the three exhaust systems."

Sometimes engines are somewhat non-responsive to exhaust changes due to low compression and/or little-to-no overlap to the cams (ie: stock, SE255, etc)

[FLTRI]

Not sure why your engine didn't repond to exhaust changes like most builds do. Was each exhaust system retuned for best performance or were the systems swapped and dyno runs made without retuning?

[moose]

for the most part by bud had 3 or 4 different systems on his 07 bagger. and the results are in the ears of the beer holder. His theory is its louder its faster. Remember you can put lipstick on a pig (hog) and its is still a pig (hog).

on his bike with him and the bike a thousand pounds you can get only so much. I give him an a for effort he gets next to me and starts racing his motor and trying to speed up on me. Mines a Jims 120 all done over I tell him he is like an ant crawling up an elephants back side thinking of rape.

jmho
moose

[FLTRI]

"....and the results are in the ears of the beer holder"
"Remember you can put lipstick on a pig (hog) and its is still a pig (hog)."

....and you can install 20 different exhaust systems on your bike and unless each system is properly tuned for best WOT performance no valid power comparison can take place, just beer drinking and liar's dice at the bar.

[FLTRI]

"This is all fine & well Bob to hang your hat on the "perfect tune" reply to all postings but IMO the reality of it is most exhaust systems & builds & mods are bolted on & the motor is started & RUN."

First let me apologize for getting your dander up, but I think I know how it happened. You have a carbureted bike, right?

With a carb bike, when the air speed/velocity thru the intake changes, (because the exit or exhaust restriction and dynamics changed) the carb reacts accordingly by reducing or increasing the fuel flow.

An EFI system, on the other hand, must rely on specific mapped fuel delivery every TP/RPM to compensate for changes from the exhaust system's dynamics, restriction, etc. It has no ability to decide to change its "jetting" if it is not mapped.

For this and other reasons there are many other side programs necessary to an EFI base map to get the engine to behave properly, such as accel enrichment, warm-up enrichment, idle control, etc.
Stockish engine - almost anything will work because there is no overlap, but not the case with high strung engines.

It really isn't all about every engine must have the perfect tune but it sure as heck should have the basic VE fuel requirements spot on it will show up as flat spot(s), poor mileage, backfires, intake coughs, hesitations, etc.

"A well built attention spent on details like deck height & squish performance build (with proper EFI remapping) is going to perform well with most any performance exhaust seeing small changes to different performance exhaust changes, like mine proved with the dyno results to prove."

Once again, sorry for not realizing you have a carbed bike,
Bob

[FLTRI]

"My question is.. torquewise, would I be better off by going back to stock headpipe with the crossover or would the difference be minimal as opposed to staying with the Fulsac setup?"
Simple Answer: yes, the stock system will improve lower rpm torque over the Fulsac setup.

Whether you can feel the difference between the 2 will come from paying close attention to 1500-2500 rpm throttle response and power.
Virtually any 2into1 will perform better in these areas that any 2into2 system, just the nature of the beast.

I do note on these forums there are those who absolutely have to get every available HP/TQ that can be sqeezed out without a care in the world as to how loud and obnoctous the system is.
And there are those who are satisfied being within a few HP/TQ as long as the bike runs great and has the HD sound without drowning out the stereo.