Header pipes R80GS basic
 

I have decided to replace the header pipes on my basic. The original pipes had a standard cross-over piece but I have seen some for sale for a paralever 80GS that just has the 2 pipes without the cross-over. Anyone know if this arrangement is ok interms of carb balancing etc? If this was such a good idea why wasnt the bike factory fitted with them in the first place? I have already got rid of the (rust) collector box in favour of a Y-piece, is a change of header-pipe configuration as well going to cause any problems?
cheers
mark

Best setup = crossover + collector

low-rev torque is affected tremendously.

I have dual balance-pipes and have tested singel balance pipe on one of my R100 bikes. The R100 lost so much low-rev torque that I "tossed" those down-pipes.
At higher revs 4500(?) and up - it seems not to matter so much.

If you ride at 3000rpm and below off-road... I strongly recommend that you use -dual- balance pipes.

MOTOSPEED.se - Your Performance Partner
Made a serious study into balance pipes on R1100 japanese engines back in the late 80:ties or early 90:ties. I have not found that study on their homepage now... however, they used their study in their ads back then. Just ask them and they should send their old ad/study to you -:)

Thanks for your replies, I will stick to the cross-over pipes

I have a 1984 R80ST that's been modified to be a monolever GS. I'm looking at replacing the stock exhaust system so I don't ruin it on a long trip to south america (I've saved all stock parts for the bike so that I can make it stock again someday if I want) I was thinking of using a system off a paralever GS, but thought I'd ask if it's worth adding the forward balance pipe. I probably wouldn't use the HUGE GS collector because there probably isn't any room for it in the space for the ST / G/S collector which is much smaller. I would probably go with a y-pipe instead. Any input? Any reasons I shouldn't?

Hi Wrangler, simplemind,
I have a 84' R80RT BMW and an 81' G/S.
The RT has the crossover and the G/S does not. I notice no difference in the performance of the engines.
The RT has 400,000kms on it and has been around the world.
The G/S has 40,000miles and has been around the block.

Wrangler,
You do not need to worry about wrecking your exhaust on a south America trip.
Watch out for the Topes (speed bumps, mostly unmarked) in Mexico and parts of Central America.
The Canyon del Pato road (a must) up to Huaraz in northern Peru has some pretty big sharp rocks, and Ruta 40 in Argentina is kind of hard on the undersides of bikes, but mostly it is good going.
The hardest part of a South America trip is Central American Border crossings. Check out Jeff Munn's Central America border crossing info on ADV Rider, it is helpful stuff.
The best part of a South America trip is the wonderful People you will meet and the Amazing places you will get to go to.
Suerte Amigo :Beach:

Y piece on my 80GS is fine
 

I have a complete stainless steel Keihan exhaust system on my 1992 paralever GS including the y piece replacement for the collector box, it all works fine and last for years

My '82 R80 G/S has no crossover on the (I believe) stock pipes, just the collector box at the rear. I have run this system as well as a supertrapp with the larger header pipes (from an R100), no cross over, and a 'Y' type collector replacement - again it seemed to be fine. Any changes to your exhaust can affect carburetor setting, so it is worth making sure that your bike is tuned properly to the exhaust fitted.

Balance Pipe = Low RPM torque
 

The R80G/S from 1980 to 1987 produced 56.7 Nm / 41 ft lb at 5,000 rpm. This model did not have the balance pipe and the collector box was a simple but flawed design.
The Later models fitted with balance pipe and large centre box was giving 61 Nm / 44 ft lb at 3,750 rpm.
The short shaft and centre stand of the pre 87 models does not accommodate the larger centre box so in this case fitting some of the aftermarket systems might not have much of a negative influence on low RPM torque.
If you do not mind the slightly reduced Horse Power and prefer torque at low RPM it will be best to stick with the original exhaust from BMW on all the models from 87 onward. Basically this is all the models fitted the with Parra-lever suspension.

Hi Mark, post us a picture of that bike of yours...I like the looks of that tank you have fitted.