PSA - GPR Exhaust

[jmckeown]

Hey All,

I recently ordered and installed a GPR exhaust system on my r1100r and I love it!

I purchased it on ebay, $299 shipped from GPR in Milan. Fit & Finish are top notch.
Included was the muffler, two pipes (one that attaches to the header, another that attaches to the first pipe and the muffler), and all the clamps, etc needed for a install.
I am SUPER happy with this purchase and wouldn't hesitate to buy another.

It sounds great. Much deeper/throatier than stock. At idle it is only slightly louder than stock, and at cruising speeds, say 65 mph in 5th gear it is louder than stock, but barely. Before I heard more wind noise and almost no motor at that speed (no windshield, shoei qwest helmet). Now I hear the motor quite a bit better, but it is by no means droning or annoying - even without earplugs. (I commute 15 minutes to work each day and wanted to be able to do that without earplugs)

When you get into the throttle you DEFINITELY hear it, but it's not at all too loud. My dad/riding buddy says it sounds great, plenty loud, but never obnoxiously/painfully so.
Oh, and the weight savings are incredible - stock exhaust weighed in just shy of 30 lbs, the gpr is 6.

Out with the old - in with the new!

[jmckeown]

And some videos - Before


After:


hope this helps someone!

[captaincable]

sounds great does it improve the power
Mike

[jmckeown]

I believe I saw something on GPR's site about a 3-5 hp increase. I don't really know because I haven't had the bike dyno'd ever and we all know the 'ole butt dyno isn't too accurate.
It definitely doesn't feel like it's lost anything. I think it feels a little quicker.

The big thing I was going for was losing all that weight and making the bike a bit louder. I also really like that it gets rid of the cat... When I went to put the old exhaust in storage the motor had cooled to the touch but the cat was STILL quite warm - I'm glad to have that heat buildup away from the bike.

[miker1100r]

Does your bike run as well as it did with the original exhaust throughout the entire RPM range? I would also really like to get rid of that heavy, unsightly cat.

[miker1100r]

I was so interested in this product that I went ahead and did a lot of research into it, including reading reviews on other forums. I went ahead and pulled the trigger on it. Found it on ebay and on Amazon.
Thanks for posting about it!

[jmckeown]

Sorry I hadn't checked back more recently!
I have ZERO regrets with it - hope you have the same experience. I ordered direct from gpr via ebay. They shipped FROM ITALY and I had the muffler within 3 business days - crazy.

The look, sound, etc are all great and I think the bike runs fantastic - my mechanic agrees.

[miker1100r]

I got the new muffler and pipe kit and installed it yesterday. Haven't ridden the bike yet as it has been raining.

There was no parts list and the instructions were really bad! On the bright side the quality is very good and it was easy to install.

I notice you didn't use the little offset bracket to hang the can from the passenger foot rest. I did but I may try it your way as it appears to be a bit of a cleaner installation.

I left the unrestricted baffle in to try first. Sounded good in the garage! We'll see how it sounds on the road when it stops raining.

We will periodically have to repack the mufflers. Hope ordering the repack kits isn't too much of a pain.

Love the cleaner, sleeker look of the bike without that big, brown can underneath! Supposedly there is a "catalyzer" in the system.

Enjoy!

[jmckeown]

Interesting stuff.

You are right that there was no parts list and not much as far as directions.

Mine did not come with anything to hang it from the footrest (the mount they provided that goes around the silencer bolted right up to the stock location for me) or any kind of drop in silencer (which I was surprised by)
I am happy with the sound/flow etc though. I was aware of the need to repack from time to time - we'll just see how that goes I suppose.

[WineGuyD]

I've been looking into installing the GPR Deeptone exhaust on my '96 R1100R...has anyone mounted this specific exhaust on this model bike? Roughly how long a project is this? And does it make sense to mount two units...one for each cylinder?

[Robert_California]

I've read (somewhere) that after removing the cat and installing a more free-flowing muffler, the exhaust is HOTTER and may melt the luggage.
Is this baloney? Can you notice a difference?
Also, re-packing an exhaust is a pita.
Still for the price you got a killer deal! I'm intrigued, but worried about my luggage case.

[jmckeown]

@WineGuy -

I thought about that one - I think it would be the same basic system as the one I mounted - just with a different canister that slips on the pipe (it's just held on with springs and the strap to the rear subframe). I would think it'd just be the one canister.


@Robery_California:

I can't say that I've noticed a difference - I don't have luggage currently, but am hoping to get some and won't hesitate to put some on. Worst case scenario some heat tape on the bags would solve the issue. Some people may think the pipe gets hotter, but that's just due to the fact that the factory pipe has lots of heat shields and the GPR does not - (which is part of the reason it shaves 25ish pounds off the bike!)

[CRazyCam]

Well, I have taken your words in account and ordered one of these.

I must admit, I really don't want my bike to be noisier than it is, but the thought of it being 10 kilos lighter really does appeal to me. (That's what old age creeping up on you does.)

Has anyone using these after market exhausts found that you need to change anything in the fueling department?

I sure hope the new muffler won't melt my neat city panniers.

regards,CrazyCam

[CRazyCam]

OK folks, so how the devil does the big clamp holding the front of the exhaust system to the back of the two header pipes come undone?

I undid the nut that I thought was holding it tight, but not a skeric of movement.

I've disconnected all the other attachments to the exhaust system, but can't get the front bit loose.....

regards,CrazyCam

[CRazyCam]

OK, several hours and a can of penetrating oil later, I managed to get the old exhaust off the bike.
I suppose, after 16 years in position, that was fair enough.

New pipe now fitted, reset Motronic, and ready for testing.

There does appear to be plenty of clearance between the muffler and the panniers, but I'll keep an eye on temps and see how we go.

regards,CrazyCam

[CRazyCam]

Test ride went well.....

I can't say that I felt any great difference in the bike's performance, it just made a bit more noise.

It wasn't aggravatingly more noisy, I have left the "plug" in the back of the muffler, but it was a bit of a change from the magic carpet business of swishing through the bends in almost complete silence.

Yesterday wasn't terribly hot, about 23 or 24 C, but the bike, in slow traffic felt a bit cooler than normal.

There was no issue with the panniers getting hotter. There appears to be plenty of air space and flow so I don't think it will over heat the left side box, although I am in the habit of keeping beer and other essential supplies in the right hand box anyway.

Once I get home, I parked the bike in the garage, and, I just couldn't get over the vast amount of air space that had appeared under the bike..... it just seems weird, not having that blooming great heavy box hanging in there.

regards,CrazyCam

[WineGuyD]

I can't say that I felt any great difference in the bike's performance, it just made a bit more noise. It wasn't aggravatingly more noisy, I have left the "plug" in the back of the muffler, but it was a bit of a change from the magic carpet business of swishing through the bends in almost complete silence.

Hi CrazyCam, I'm considering either your GPR or the Deeptone with the goal of shedding weight and getting a sound more like a Triumph Thruxton or similar Brit twin...would you say that the sound of your exhaust fits that goal? Would be appreciated if you could post a video of the exhaust tone with and without the db killer. Thanks!

[CRazyCam]

Hi CrazyCam, I'm considering either your GPR or the Deeptone with the goal of shedding weight and getting a sound more like a Triumph Thruxton or similar Brit twin...would you say that the sound of your exhaust fits that goal? Would be appreciated if you could post a video of the exhaust tone with and without the db killer. Thanks!

Hi Eli.

Out of the box, a Triumph Thruxton is quieter, until it gets some kind of after market muffler.

Yeah, the GPR on my R850R does sound much like the old school Pommie twins... sort of "fruity" rather than just loud....
hard to explain really.

As for a video, sorry mate, but I am a 65 y.o. guy who still uses his mobile phone to talk to people, not to record videos....
I really wouldn't know how to even start posting one.

BTW, after today's testing run, I fuelled the beast and it seems like there was a fractional improvement in fuel consumption.... worked out at 4.75 litres per hundred kilometres, but, of course, one ride of 133 kilometres isn't conclusive.

regards,CrazyCam

[smutny]

There's nothing in the BMW info that I have where I see that these GPR mufflers wouldn't fit my 2000 R1100R. But all of the eBay listings indicate the years 94-98. Am I missing something that changed from 98 to 99?

[wyoplinker]

Smutny,

I had the same question a couple of months ago. I asked the guys at GPR and they said everything should fit fine. I ordered the GPR Deeptone exhaust, and it went on without a hitch. I think I remember reading somewhere though, to not touch the O2 sensor while you have it off. I had a friend help me when I did the swap and he was the one that actually pulled the O2 sensor out of the old pipe. I forgot to tell him not to touch the actual sensor part, and when I looked down he was brushing something off of it with his fingers. I don't know if this affected anything or not, but when I put the new exhaust on the bike ran like crap. Where it ran fine with the stock exhaust, it ran like it was excessively lean with the new one. I went ahead and bought one of the Dobeck Performance (Techlusion) Gen3 "Beemerbonebox" - 1333ST Fuel Injection Controller For All R1100R, RS, RT, GS Models (NOT R1100S) doohickeys and put that on. It's been running great ever since. I would be interested to find out if anyone else has their bikes run too lean after putting one of these pipes on.

The GPR deeptone is quite a bit louder than I thought it was going to be. It seemed especially loud when it wasn't running right. I think I'm probably going to get their (GPR's) db killer for it off of Amazon. It's only another $50, and I think most of that is shipping. If I was ordering another exhaust from them now, either on eBay or where ever, I would buy the db killer at the same time. The deeptone doesn't come supplied with one, but it slides easily into the back of the muffler and is held in place with a set screw.

Hope this helps,
Chris