Exhaust

[dcbinder]

What is the best replacement exhaust out thre for the RS. I only want to do this once, but I also want something that will boost the HP since I may not move up to the ST or new RT at all until there looks improve, or at bare minimum they add cruise control to the ST. I did test drive the new RT, it was really smooth, but still too heavy for my tastes. So I guess tha puts me replacing this exhaust. Any recommendations???

[barryg]

I have a 94 R1100RS. I added the Staintune exhaust, this was back in 97. Their wasn't alot of exhaust aftermarket options then, like there are now. That system never sounded or performed right no matter how I tuned it. I added the Techlusion control box and the bike now sounds and performs great. It has a nice pleasant performance sound and the bike is very responsive. Infact I get a lot of comments at rallies about how good the bike sounds. If I were going to upgrade this bike from scratch the first thing I would add would be a good set of aftermarket shocks, then the Tech. control box, then the updated exhaust. Good luck with your upgrades.

[BubbaZanetti]

you may have better luck with a new chip, like something from techlusion, these bikes are pretty hard to add much HP to. most people opt for an aftermarket exhaust to improve sound, not performace. check out makers like remus, staintune and laser


and welcome to the forum! :thumb

[lkchris]

If you really believe you can improve your bike's performance with an aftermarket exhaust, you should purchase the most expensive aftermarket exhaust you can find because obviously it will be the best.

[lorazepam]

If you really believe you can improve your bike's performance with an aftermarket exhaust, you should purchase the most expensive aftermarket exhaust you can find because obviously it will be the best.
you forgot the little stick guy. :stick

I changed my exhaust because I wanted to get rid of all the heat under the transmission, and because I could. BMW spends a lot pf money to get the exhaust right on these bikes. I dont think there really is an improvement on power by just changing the exhaust syatem. In fact, the Kbike guys have proven that is just the opposite.

[philc]

can you just replace the cat{foot warmer} with a Y pipe and keep the stock muffler ? that should gain some performance without adding much NOISE! and getting rid of that HEAT. 02 1150 gsa :burnout

[lorazepam]

can you just replace the cat{foot warmer} with a Y pipe and keep the stock muffler ? that should gain some performance without adding much NOISE! and getting rid of that HEAT. 02 1150 gsa :burnout

Depends on the model you have. I believe on the GS bikes, it is a two piece system. On the RT and RS, it is a one piece cat/exhaust.

[lkchris]

BMW spends a lot pf money to get the exhaust right on these bikes.

They probably do, but don't forget they're just plain talented.

Also don't forget that BMW buyers pay a lot of money, too, and they pay for the talent and the experience.

BMW's middle name ain't "motor" for nothing.

[jm1515]

can you just replace the cat{foot warmer} with a Y pipe and keep the stock muffler ? that should gain some performance without adding much NOISE! and getting rid of that HEAT. 02 1150 gsa :burnout

I recently did this w/ my 04 Roadster.
Used a StainTune collector and kept the stock can.
Bottom line...smoother throttle response. Engine spins much easier. I think I've picked up some loose torque somewhere...my rpm vs mph benchmarks have gone down, ie, 4000rpm in 5th used to = 60mph. Now it's just about 62mph. 3000rpm in 6th used to = 60mph. It's about 62mph now...
The sound is definitely better, and not much louder at all.
Vibes have been reduced noticeably at all rpm.
And I can't fell any heat on my ankles. Used to long for Nomex socks, now I can't feel a thing..even with flip-flops....

[Markst1]

"my rpm vs mph benchmarks have gone down, ie, 4000rpm in 5th used to = 60mph. Now it's just about 62mph. 3000rpm in 6th used to = 60mph. It's about 62mph now..."

It seems to me that this would require a change in the transmission or final drive. How can changing the exhaust system change the rpm to mph ratio?
Is it really a good idea to ride in flip-flops?

[jm1515]

"my rpm vs mph benchmarks have gone down, ie, 4000rpm in 5th used to = 60mph. Now it's just about 62mph. 3000rpm in 6th used to = 60mph. It's about 62mph now..."

It seems to me that this would require a change in the transmission or final drive. How can changing the exhaust system change the rpm to mph ratio?
Is it really a good idea to ride in flip-flops?

I'm no expert, Mark, but those are my observed results.
I think it has to do with the fact that HorsePower= Torque x RPM /5252.
Therefore T= Hp x 5252/RPM.

Hypothetically now, you can plug in any values you want for T, Hp & RPM, and just say those give you 60mph on your bike.
If you increase the T value by making your engine more effective, and this is the crux of the 'performance exhaust' arguments AFAIC, RPMs will be lowered for any given speed, all other things being equal.....
Of course, I've been known to be FOS before.... :deal

And, NO I don't ride in flip-flops..... :nyah

[widebmw]

Hypothetically now, you can plug in any values you want for T, Hp & RPM, and just say those give you 60mph on your bike.
If you increase the T value by making your engine more effective, and this is the crux of the 'performance exhaust' arguments AFAIC, RPMs will be lowered for any given speed, all other things being equal.....
Of course, I've been known to be FOS before.... :deal

And, NO I don't ride in flip-flops..... :nyah

The relationship is RPM to speed. You can change HP and torque and it won't change your speed at a given RPM.
You can shift gears or change the rear tire size, that will change your speed.

[boofer]

Well its like this, see!! Before the staintune, his driveshaft was Slipping :thumb


Tim

[jacco]

The stock BMW exhaust was so heavy that the rear tire was more compressed ---> smaller circumference ---> more RPM per MPH... :type

(couldn't help myself, sorry...) :dance

Have a good one,
Jacco