4 to 1 what a difference

[saaz]

Some years ago I ahd the chnace of trying the standard pipes and a cheap 4-1. The 4-1 strangled the bike (it has the current mods, 78 GS100 1085 kit, ported head , cams etc). The standard pipes were actually better! Both did strangle the bike so much that it was not much better than standard.

The real 4-1 I now have liberates the power.

The moral is good design is best, just because it is a 4-1 does not make it better

 

[Anonymous]

I've always been curious about how these are supposed to make more power. With cars you do the exact opposite- the high performance route is to go with a DUAL exhaust. We motorcyclists get dual exhaust from the factory, but can't wait to rip it off and replace it with a single. Obviously they DO make more power (otherwise you wouldn't have to re-jet), but it seems bassackwards. I remember back in the 80's there were one or two companies making high performance 4-into-2 exhaust systems- has anyone had any experience with these? If so how did they compare performance-wise with the 4-into-ones?

 

[Anonymous]

4 into 2 or 4 into one is really not the reason for more power. It comes from free breathing and tuning to match. I believe a stock exhaust system could be better than a modified system if the owner of the machine takes the time to properly tune.

 

[oldschoolGS]

The problem is how do you get the stock system to flow? You can cut out the guts, but they usually sound like cr@p and look even worse. There is no substitute for a good 4-1 as far as performance and weight reduction goes. With these old air cooled GS motors, if you are gonna make big power you have to free up the exhaust. Now modern bikes like the GSXR1000 or my TL1000S are different, with pressurized airboxes and fuel injection, tuning is different and can be difficult as some bikes are specifically designed with a certain exhaust flow. But these modern machines already make maximum power from the factory. When you think GS though, think 68 Chevy small block and Hooker headers. Ride On, Ed.

 

[Diamondj]

I just wanted to mention that it may be possible to get the Supertrapp/Kerker folks to make you a new 4 to 1 system for your GS. I recently called them about a replacement Supertrapp core for my GS1000 and while they don't stock it, they were willing to make me one! A new replacement core for a Supertrapp system is $33.73. If I wanted a Kerker core it would have been $92 and change as I guess there is more to the Kerker core? It can't hurt to give them a call (216-265-8400) and see if they will still make a system to order....

 

[Anonymous]

OK, here goes: Dennis Kirk shows that V&H makes several models which fit old Gs models. Some stock looking 4 into 2, some 4 into 1. Now, my 1100 is plenty quick; I also get great gas mileage on the highway...highest on highway was 53.8mpg (running ~ 70/75 mph)...bike is bone stock except for K&N stock style filter inside the air box. On one occassion, I got 210 miles on just just 3.67 gals. of fuel. I about dropped dead when I figured the mileage for that tank...just a hair over 60 mpg!! I had to have made an error somewhere..??? This was cruising along in some lower altitudes around Knoxville TN, and some higher around Robbinsville NC (Cherohala Skyway--@5000 above sea level at highest point, I think.) I was taking it easy, and a good bit of the time, I was running in top gear about 50mph, so not a lot of rpm's. Maybe that was the reason for the otherwise very high gas mileage. How much would a PROPERLY tuned 4 into 1 header and jet kit hurt my fuel economy?

 

[1100ED]

OK, here goes: Dennis Kirk shows that V&H makes several models which fit old Gs models. Some stock looking 4 into 2, some 4 into 1. Now, my 1100 is plenty quick; I also get great gas mileage on the highway...highest on highway was 53.8mpg (running ~ 70/75 mph)...bike is bone stock except for K&N stock style filter inside the air box. On one occassion, I got 210 miles on just just 3.67 gals. of fuel. I about dropped dead when I figured the mileage for that tank...just a hair over 60 mpg!! I had to have made an error somewhere..??? This was cruising along in some lower altitudes around Knoxville TN, and some higher around Robbinsville NC (Cherohala Skyway--@5000 above sea level at highest point, I think.) I was taking it easy, and a good bit of the time, I was running in top gear about 50mph, so not a lot of rpm's. Maybe that was the reason for the otherwise very high gas mileage. How much would a PROPERLY tuned 4 into 1 header and jet kit hurt my fuel economy?

It may increase the gas mileage.

 

[Anonymous]

i have a yoshimura4-1 on my 83 750e love the sound.quiet in town. crack it open and it screams.also i can change the oil with it on and retain my centerstand.M 8)

were did you get the yoshi exhaust system?? do you think it would fit on my 78 GS750E?