BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

Ok i have been reading up on doing some of the hp mods, removing the catalitic converter(sp) i know reduces the weight and gives you hp.. anyone know approx how much hp you gain, and with the weight loss being so low how does it effect the center of gravity and in turn how does that effect the handling? also are there ne other weight reduction mods that can be done?

another question.... i was looking at the vid on decaning... i assume that means removing the pipe.... arent there laws in California that state you cant do that.... ne one know?? and if i remove the pipe what are the draw backs/advantages. i am new to street bikes so sorry if i use the wrong terminology

JohnnyFive

Just removing the cat and the original muffler and replacing with a cat elim pipe and aftermarket muffler reduces the bike's weight by about 17 to 18 pounds. The center of gravity is hardly afected at all.

Basic HP gain is in the order of 3 hp, due to lesser exhaust restriction and better cylinder scavenging.

boxermania wrote:JohnnyFive

Just removing the cat and the original muffler and replacing with a cat elim pipe and aftermarket muffler reduces the bike's weight by about 17 to 18 pounds. The center of gravity is hardly afected at all.

Basic HP gain is in the order of 3 H, due to lesser exhaust restriction and better cylinder scavenging.

That's it? I hardly seems worth the money to remove the cat in that case. You can always just pull the muffler and leave the cat, and save a fair bit of weight, maybe a slight increase in power, and no cost.

I need to lose personal weight, that would really help the performance of the bike.

There is huge gains to be made in the wheels..and lighter wheels is like more power...they're not cheap though.

DJ

Ancient hot rodding Q&A

How fast can I go?
How big is your wallet?

Here's some nice wheels for our bike and what you save in weight.

DJ

Stock front 14lbs 3oz rear 15lbs 15oz

PVM front 8lbs 10oz rear 10lbs 7oz


total poundage saved - 11lbs 1oz

DJ Downunder wrote:Here's some nice wheels for our bike and what you save in weight.

DJ

Stock front 14lbs 3oz rear 15lbs 15oz

PVM front 8lbs 10oz rear 10lbs 7oz


total poundage saved - 11lbs 1oz

Plus the weight of the many, many, many, many loose coins out of your pocket that you have to spend, I guess

Actually the weight issue has ben covered before. on this board. The removal of approximately 20 pounds ct and muffler) equals to adding 4 hp to the bike.

One of my friends which is an avid poster to this site and shall remain nameless sugested, in my case, to loose some avoirdupois and save my money.....which actually is the best solution.

Unfortunately for my friend, due to unforseen circumstances, we no longer comunicate on a regular basis.

Hey guys,

I started by removing just my can and replacing with a small short pipe. I did gain some HP. Then I replaced the CAT and installed a Ztechnik full exhaust. The titanium Z4040. The total weight is only 6LB. The Hp gain is about 26% and torque about 15%. The power is amazing...Looking for more. I need a power commander now to eliminate surging in mid-range.

BigRockR.....04 Rockster Citris....

Strange, but true ...

BigRockR........

First, I like very much the design of the Ztechnik full exhaust, however, it is obvious to me that you haven't run before and after dyno runs on your bike. There isn't a exhaust available for a stock R259 engine, at least that I know of, that will produce the hp and torque gains that you claim.

A well tuned stock bike will record somewhere between 75 to 77 hp on the dyno, this has been well documented on this site and
with BMW dealers that perform mods, such as SJBMW.

Replacement of the Cat and the can will yield 3 to 4hp for about a 5% gain, significantly les that your claim.

boxermania wrote:There isn't a exhaust available for a stock R259 engine, at least that I know of, that will produce the hp and torque gains that you claim.

How about the chart from their website right above here? The (manufacturer) claimed gaps between the stock and aftermarket pipes look pretty big to me?

This is the Remus system....from the Moto One site.. http://www.moto-one.com.au/performance/index.html

DJ



This is the Staintune..no cat..and a chip.



This is Staintune..no cat..chip..cams..and throttle body tubes.

hirsty.......

The (manufacturer) claimed gaps between the stock and aftermarket pipes look pretty big to me?

I maintain that the stock curves are not representative of a stock bike and the chart has the wrong nomenclature Hosepower is not a DIN term, it's a SAE term. Hence the dificulty in understanding the graph......

DJ's graphs are much more representative of the changes in question, see the first one posted.....I also have some graphs in my home computer, unfortunately I'm away using my laptop.

This is not an attack on any ZTechnik users, it does seriously qustions a claim by a manufacturer that is an impossibility.....if the claim was real and factual, guess what would be the set-up that everyone and it's brother would be using.

Anyone that has explored the R259 and its hp potential via add ons knows that there are just a handful of hp to be had.....serious hp, requires, cams, compression and other more race oriented and expensive mods.

Sorry......but based on my experience I stand by my comment until proven otherwise.....hey, tell you what. I have a buddy with a stock 04 Rockster, I will check the bike out and pay to put it on the dyno to baseline it, we will then remove the exhaust and install the Ztechnik and run it again and see what the gain is, we will share and post he results.

Do you think we can swing a complete exhaust from ZTechnik.....Ahh, and the results, hp and torque will be reported in SAE uinits......

better still - lose weight - no more burgers, beer and french fries ... salads and so forth are the things to go for, also a bit of running ... apart from performance in the bike department these upgrades increase pulling (girls I mean) power and increase average life expectancy!

duke.....excellent point.....of course with the last statement in your post I see why you are in the dog house.......

Trying not to Hijack this thread, but I have a couple of questions regarding the dyno claims and especially the charts that DJ posted. Were those graphs RWHP or at the engine? Also, what affect does temperature have on HP for these bikes? Any way Boxer, when you dyno your friends R, if the temp isn't noted on the graphs, could you jot it down so we know what a good stock run at XXX temperature is.

Clicking on that Moto One link might explain more.

I'm sure they are at the rear wheel...no idea about the temp..you're right though..air temps can make a difference.

DJ

Lobo1625.......the dyno yest will depend on ZTechnik giving me an exhaust to try out......

In the meantime I'll share an earlier post

http://r1150r.org/board/viewtopic.php?t=3203&highlight=

4th one down.......BTW all these dyno readings are RWHP, these bikes have a 18% to 20 % looss due to the gear losses. So if you have 80 hp at the wheel, that will be ~ 95 hp max at the crank. Also temperature correction will have to be made, but this is small correction and not too significant if you always use the same dyno.

Enjoy...........