1200GS Exhaust - Opinioins please

[sauce25]

I did a search and did not get much for threads on aftermarket exhausts for the GS.

My question is which one do you have and do you like it? I like the Akra and Remus which seem to be the most popular.

Also have any of you had to remap the Fuel Injection (add fuel) when adding the slip-on. Did you use a Power Commander? I have owned several FI and carb bikes and they all needed to be rejetted or remapped when even just a slip on was added. Without remapping it backfired on decel a lot and just ran lean. The BMW dealer told me that the bike will compensate for the slip-on. Because of past experiences I just don't believe him. None of the FI bikes I have owned have ever been able to compensate for that much more fuel to make the popping on deceleration go away which is a text book sign of a lean condition. Thanks in advanced for you help.

sauce

[Das Boot]

Originally Posted by sauce25

I did a search and did not get much for threads on aftermarket exhausts for the GS.

My question is which one do you have and do you like it? I like the Akra and Remus which seem to be the most popular.

'Both Akra and Remus are approved by BMW, Both have have an offiicial BMW Part number!'

Also have any of you had to remap the Fuel Injection (add fuel) when adding the slip-on. Did you use a Power Commander? I have owned several FI and carb bikes and they all needed to be rejetted or remapped when even just a slip on was added. Without remapping it backfired on decel a lot and just ran lean. The BMW dealer told me that the bike will compensate for the slip-on. Because of past experiences I just don't believe him. None of the FI bikes I have owned have ever been able to compensate for that much more fuel to make the popping on deceleration go away which is a text book sign of a lean condition. Thanks in advanced for you help.

'The any slip on itself is just a weight savings and subjectively a better sound. No increase in performance gains, without chaing out the entire system. The BMW Remus and Akra slip on's do not need any type of remapping.'

sauce

Best of luck

[BobMCP]

You must have misspelled exhaust if you didn't get much info here with your search.
I have a Staintune/Remus Y-Pipe setup and like the result, you will not see much HP gain on the GS, but the improved throttle response and sound made it a worth while mod for me, but I am sure others may disagree.
I do have some decel pop and I am considering a Power Commander and Dyno Tune at some point, it does run quite well as is but I have had other bikes PC/Dyno Tuned to remove the slight imperfections in the FI Mapping and think this also is worth doing.

[Throttlerocker!]

I went with the Keihan headers and Staintune endcan. Both work well together, they were $539 (can) from ca-cycleworks.com and $490 for the headers with a 10 year warranty with the crossover pipe and O2 ports (original diameter too) from keihan.co.uk delivered. I also bought the larger intake snorkel (wunderlich item-Nippy Normans or Santa Cruz) and a hi flow air filter from BMW of Atlanta. Oh yeah and a Dobeck fuelbox from customdynamics.com for $249 delivered. Everything together did the complete job. No surging and smooth rideability with a nice improvement down low (under 4200 rpm) and above 4200 well lets just say It woke the sleeping beast up nicely.
You could try just the header and the fuelbox to start, then as money allows......
The bike sounds nice (not to loud under 4200) and sweet in the upper rrrr's!!!!!

[tmex]

I have the Remus on my 12GS and it does save substantial weight, but does virtually nothing for the performance (which I expected) or the sound (which is dissappointing). The Akra on my F8 does nothing for performance either, but I do love the sound. Nothing beats the sound of the Akra IMO except perhaps the Termignoni's on a Ducati.

[SCQTT]

You can save a few pounds, but you are not going to get much more in the way of HP unless you toss huge money at it.

Even stock they have a lean pop on closed throttle deceleration. It is only going to get more pronunced with a more open pipe.

They sound like crop dusters to start with? You want that to be louder?

Stock is cock, just ride the dang thing.

[LTCOliverNorth]

I picked up a used Staintune from an inmate here for the sole purpose of losing some weight. The can's build quality is great! The can is 4" to 6" longer than stock which does not pose an issue with my TT panniers; if you have tight clearances it's something to consider. It does pop on decel, but it popped on decel just as much with my stock can - only it's louder now :)

[RogerJ]

What Scott said. Also, the back-popping gets worse still if you go to a larger airbox/snorkel mod to put more air through the beast without some concerted tuning efforts.

[Disco Dean]

I have the Laser system from Holland that I purchased at DualSport Plus here in Ontario.

First - no back popping issues for me - no more or less at all with this system.

I like it a lot - savings of about 11lbs which is good for about 1.5 hp in weight. With the homologated insert it is louder but nice and sounds like a very big 4 stroke motocrosser - I like it. Not too big an increase in power. But - With the competition insert in it is quite loud but still not as bad as a chopper or anywhere near. Power with that insert in is about 5+hp which can be felt - approx 6% or so...

The finish and materials are top notch - see pics included.

As stated here before by me and others - there is no way to change the mapping and no need to without a BMW computer - the bike does compensate for the change in the exhaust. that you will have to believe as we have dyno and race bike experience with that here - no matter how hard we tried we could not change the mixture as measured at the exhaust - the bike changed the mapping to suit the increased flow parameters - the only way to do that is with a comp - but it stayed the SAME as stock with changes to exhuast and also to the airbox etc.

For what it is worth the reason I chose the Laser is because it has the cross over tube and while it does not change the performance in my experience it does help balance out the exhaust and contribute it to being a bit smoother.

- I also like the springs - segmented assembly as it allows for a bit more precise fit and I just like the springs.

Price was good and on the lower side of the remus and much cheaper than the Akro.

I have noticed a few interesting things.

One of which (3000km on the exhaust and 40k on the bike) Fuel Mileage !!!! has gone down strangely enough - it is better by about 3.5% - I totally did not expect that one. And, I even think I am riding it harder to hear the stupid thing growl

Your call - thinking back I think I should have gone for a new GPS and custom seat first but I love the exhaust...

Dean

[Wallowa]

Originally Posted by Disco Dean

I have the Laser system from Holland that I purchased at DualSport Plus here in Ontario.

First - no back popping issues for me - no more or less at all with this system.

I like it a lot - savings of about 11lbs which is good for about 1.5 hp in weight. With the homologated insert it is louder but nice and sounds like a very big 4 stroke motocrosser - I like it. Not too big an increase in power. But - With the competition insert in it is quite loud but still not as bad as a chopper or anywhere near. Power with that insert in is about 5+hp which can be felt - approx 6% or so...

The finish and materials are top notch - see pics included.

As stated here before by me and others - there is no way to change the mapping and no need to without a BMW computer - the bike does compensate for the change in the exhaust. that you will have to believe as we have dyno and race bike experience with that here - no matter how hard we tried we could not change the mixture as measured at the exhaust - the bike changed the mapping to suit the increased flow parameters - the only way to do that is with a comp - but it stayed the SAME as stock with changes to exhuast and also to the airbox etc.

For what it is worth the reason I chose the Laser is because it has the cross over tube and while it does not change the performance in my experience it does help balance out the exhaust and contribute it to being a bit smoother.

- I also like the springs - segmented assembly as it allows for a bit more precise fit and I just like the springs.

Price was good and on the lower side of the remus and much cheaper than the Akro.

I have noticed a few interesting things.

One of which (3000km on the exhaust and 40k on the bike) Fuel Mileage !!!! has gone down strangely enough - it is better by about 3.5% - I totally did not expect that one. And, I even think I am riding it harder to hear the stupid thing growl

Your call - thinking back I think I should have gone for a new GPS and custom seat first but I love the exhaust...

Dean

Hey Dean,

What was the cost as we see it on your bike and do you have the Hp and Torque curves with and without the system? Thanks..

[sauce25]

Originally Posted by BobMCP

You must have misspelled exhaust if you didn't get much info here with your search.
I have a Staintune/Remus Y-Pipe setup and like the result, you will not see much HP gain on the GS, but the improved throttle response and sound made it a worth while mod for me, but I am sure others may disagree.
I do have some decel pop and I am considering a Power Commander and Dyno Tune at some point, it does run quite well as is but I have had other bikes PC/Dyno Tuned to remove the slight imperfections in the FI Mapping and think this also is worth doing.

I just tried it again and nothing specific to my question. Try it now…none that come up have exhaust in the title. This thread comes up though!

I think you will benefit from the Power Comander.

[sauce25]

Thanks for the reply's. I do want a louder pipe as well. You all agree that the AKRA is louder? And sounds pretty good? After reading you reply's it just confirms my thoughts. Like a few said above it is already backfiring Stock, how is it going to get better by adding more air and no fuel!!!

[(sp?)]

Here are the dyno run numbers for my R1200GS w/ StainTune slip-on. no mapping changes done, or required (see lambda value)

[Wallowa]

Originally Posted by (sp?)

Here are the dyno run numbers for my R1200GS w/ StainTune slip-on. no mapping changes done, or required (see lambda value)

Where are stock values to compare against? And can you explain the abbreviations [I see torque and Hp]? Again..just me ..but I have only seen these based on RPM not mph.. Thanks!

[(sp?)]

STP - standard temperature and pressure, e.g. a value corrected for temperature and altitude.

these runs were taken one evening after JohnJen, Javarilla and I had just done OVADs on our bikes. I don't have the stock data but do have an RPM correlated graph.