Back Pressure

[NorthAlabamaSpyder]

Would be interested in hearing any differences in back pressure, sound of the RLS cat delete pipe vs Lamonster's cat delete pipe with the monster baffle installed. Thx in advance

[krakum1967]

I am getting the performance tip for the Two Brothers Exhaust today, its all I can afford this payday. But I have the baffled two brothers with no tip, its LOUD, and I need the tones dropped just a schoonch, its supposed to add power too, I will let you know if the added back pressure helps. The performance tip is basically a torque cone you put in the end of the pipe.

[woods]

I installed the RLS delete with ceramic coating last spring and put on about 4000mi with it.About the only time I notice it being any louder is in town at low speed and it's not a lot.I can't vouch for any power increase,if there is I'm sure it's minimal.BUT...I did get a 10% plus mpg increase!And heat on feet is noticeably less.A worthwhile mod and with enough miles ridden will pay for itself!

[BLUEKNIGHT911]

IMHO BRP has the computer parameters set for a certain amount of Back Pressure. I believe there is some degree of variance built in. ….Ideally any change in the Exhaust system will agree with those parameters. …. I also believe any combustion engine that is COMPUTER controlled will not benefit from what you could do with an engine to increase it's power output.... An engine that functions because of a computer ie. Brain, is not likely to accept changes.... There was a video of DYNO results ( from an Intake and Exhaust company ) that I had suspicions about …. " PMK " gave a nice explanation of how the " DYNO " may not have given a truly accurate picture..... good luck …. Mike

[NorthAlabamaSpyder]

While I truly appreciate all the answers I am really looking to compare the Lamonster pipe vs the RLS pipe. I am having the ECU flashed as we speak and want to open the exhaust up but keep some back pressure. I have the Lamonster pipe now. Ordering a Two Bros exhaust and was thinking of changing to the RLS pipe to go with it.

[troop]

I'd just keep what you have. You'd likely not feel any difference and the bike will run just fine..

[2dogs]

IMHO BRP has the computer parameters set for a certain amount of Back Pressure. I believe there is some degree of variance built in. ….Ideally any change in the Exhaust system will agree with those parameters. …. I also believe any combustion engine that is COMPUTER controlled will not benefit from what you could do with an engine to increase it's power output.... An engine that functions because of a computer ie. Brain, is not likely to accept changes.... There was a video of DYNO results ( from an Intake and Exhaust company ) that I had suspicions about …. " PMK " gave a nice explanation of how the " DYNO " may not have given a truly accurate picture..... good luck …. Mike

BK, you beat me to the answer. Without an ECU flash the only changes an owner can likely accomplish is looks, sound, weight, heat and handling. With all the modification add-on and take offs the best we can do probably is reduce performance a little rather than increase it. I know I'm going to catch he!! for saying this by some one who just spent $700 on a performance muffler.

[308gunner]

While I truly appreciate all the answers I am really looking to compare the Lamonster pipe vs the RLS pipe. I am having the ECU flashed as we speak and want to open the exhaust up but keep some back pressure. I have the Lamonster pipe now. Ordering a Two Bros exhaust and was thinking of changing to the RLS pipe to go with it.

Adding the RLS pipe...without baffles...combined with the flash..and two bros is a fantastic move...it will sound and perform great...let the la monster pipe go..get the RLS!!

[troop]

Selling a perfectly good LaMonster cat delete pipe/Monster baffle at a 50% loss to buy a new RLS cat delete pipe makes zero sense. A difference in sound? Certainly, but not in performance. I really need to see some actual dyno results between the two to make that determination. Again, save your money and use what you have..

[308gunner]

Selling a perfectly good LaMonster cat delete pipe/Monster baffle at a 50% loss to buy a new RLS cat delete pipe makes zero sense. A difference in sound? Certainly, but not in performance. I really need to see some actual dyno results between the two to make that determination. Again, save your money and use what you have..

I owned both the la monster and now RLS...the RLS with the resonator....with no additional baffles... surpass the lamonster...the deep tone and increased performance is incredible..and since he's doing the flash it will be even better...he will lose a few bucks by letting go of the la monster...about 100 bucks...no big loss.

[RICZ]

I installed an RLS cat delete mainly to reduce heat on hot summer days. Other benefits are: 12 fewer pounds, throatier sound and little to no increase in decibels.

[308gunner]

Did you get your ECU back yet?..if yes..what is your opinion of the flash upgrade?

[NorthAlabamaSpyder]

Did you get your ECU back yet?..if yes..what is your opinion of the flash upgrade?

It just got there Friday. Not sure how long it takes. Killing me cause it is going to be 65 degrees here today.

[308gunner]

It just got there Friday. Not sure how long it takes. Killing me cause it is going to be 65 degrees here today.

65 degrees....perfect...put on a coat...install it..the ECU is plug n play...no break in period...youre going to love it!!!

[troop]

65 degrees....perfect...put on a coat...install it..the ECU is plug n play...no break in period...youre going to love it!!!

It just got "there", not back to him.

[308gunner]

It just got "there", not back to him.

Whoops...my bad...I thought he already got it back...it should be done by Tuesday..back to his house by Thursday.

[PMK]

I owned both the la monster and now RLS...the RLS with the resonator....with no additional baffles... surpass the lamonster...the deep tone and increased performance is incredible..and since he's doing the flash it will be even better...he will lose a few bucks by letting go of the la monster...about 100 bucks...no big loss.

Read what you posted, gave it some thought. Decided I would love to hear your reasoning as to how two cat deletes, neither have baffles, one has a glass pack resonator and the other is a non crimped stainless tube, each nearly identical length and similar diameters...with no other changes, and focusing not on sound but increased performance only, please explain why the resonated straight thru tube outperforms a non resonated straight thru tube.

[PMK]

While I truly appreciate all the answers I am really looking to compare the Lamonster pipe vs the RLS pipe. I am having the ECU flashed as we speak and want to open the exhaust up but keep some back pressure. I have the Lamonster pipe now. Ordering a Two Bros exhaust and was thinking of changing to the RLS pipe to go with it.

In the past, those running Two Brothers mufflers found them needing the tip restrictor as they were too free flowing.

That said, I suspect that even with the remap flash, and removing the converter, unless you plan to ride at 50% and above throttle at all times, the engine might be better mannered for all around riding with a bit less than full open race pipe.

[2dogs]

In the past, those running Two Brothers mufflers found them needing the tip restrictor as they were too free flowing..

Exactly!

[308gunner]

Read what you posted, gave it some thought. Decided I would love to hear your reasoning as to how two cat deletes, neither have baffles, one has a glass pack resonator and the other is a non crimped stainless tube, each nearly identical length and similar diameters...with no other changes, and focusing not on sound but increased performance only, please explain why the resonated straight thru tube outperforms a non resonated straight thru tube.

The resonator adds some slight back pressure just enough for the bottom end....a good bottom end kick.. but not too much..to effect your top end, which would be a restriction, which is bad...this is why I DON'T run any baffles..it hurts your top end performance ..the la monster is too free flowing, no back pressure..which hurts the bottom end performance...the resonator reduce the loud harsh sound....it's richer and deeper....also... Both pipes were compared with the flashed ECU...at the 1/8th dragstrip..so I know the extremes of both pipes...the RLS is better.

[PMK]

The resonator adds some slight back pressure just enough for the bottom end....a good bottom end kick.. but not too much..to effect your top end, which would be a restriction, which is bad...this is why I DON'T run any baffles..it hurts your top end performance ..the la monster is too free flowing, no back pressure..which hurts the bottom end performance...the resonator reduce the loud harsh sound....it's richer and deeper....also... Both pipes were compared with the flashed ECU...at the 1/8th dragstrip..so I know the extremes of both pipes...the RLS is better.

If the resonated bypass pipe uses a simple hole style perforated tube, backpressure through the tube is the same. If the resonated bypass pipe uses dimpled whistle slot style holes, then technically it is a baffled design.

Your test data of the dragstrip is typical of seeing dyno runs where the operator would swap a component without resetting the baseline in the computer. If you attended the dragway, and disconnected the battery prior to any runs, allowing the computer to clear, the disconnected again during the parts swap, at least the baseline settings would be consistent. Not saying optimized, merely the same baseline.

Since you did make 1/8 mile passes, are you willing to share the timeslips, and how many gearshifts were made during each run?