Exhaust

[FJscott]

I'm looking at exhausts and have a question. other than the obvious weight savings, is there a benefit of a 4 into 1 system
versus the 2 into 1. Better scavenging? has anyone seen a Dyno sheet comparing different systems?

Scott

[ELIMINATOR]

I thought it was related to the position of the maximum torque? 4 into 2 give more torque, obviously far more complicated than that though. Thyen of course, would most of us really notice?

[Pat Conlon]

4 into 2 vs. 4 into 1.....the 4 into 1 scavages better, flows better, esp. at higher RPM's.

Over the last 30 years I have only seen 1 properly designed 4 into 2 system on a FJ.
The FJ's firing order is 1-2-4-3 so a properly designed 4 into 2 system would mean that the head pipe off of cylinder #1 should be connected to the head pipe of cylinder #4.
Then #2 and #3 should be connected together.
This is awkward, but I have seen it on one system. The #1 head pipe crossing over 2/3 connecting to #4 looks goofy and you can't get the pipes to be equal length.

It's really no big deal.
I think access to the oil drain is more important, than the intricacies of exhaust gas flow.
Something a 4 into 2 system has to it's benefit.

I am more than ready to ditch the Kerker 4 into 1 system on my '92 in favor of a 4 into 2 into 1 system coming soon from RPM, just so I can get access to my oil drain.
For years I have been pulling the oil cooler left side oil pan fitting to drain my oil *but* I can't do that anymore with the 6 AN oil line fittings on the RPM oil cooler. I have to remove the Kerker....and I'm tired of it....hint: Randy?

[racerrad8]

...I have to remove the Kerker....and I'm tired of it....hint: Randy?

I am just waiting on hopefully the last header tubes that I had modified to get the proper fit. We had a problem with just one more pipe and I hope to see it next week.

If that new pipe corrects the last fitment issue I was having then it will be going into production the next day.

I hope it is very soon as I do not want to have to make anymore changes.

Randy - RPM

[Pat Conlon]

Cool beans, thanks amigo!

[FJ1100mjk]

Too bad they don't make these for the FJ too...

http://www.z1enterprises.com/ItemDetails.aspx?itemDescription=Exhaust+System+ZeCross+Z1+%2f+KZ900+4-2+&item=PM86-020

Sweet! No problem with oil drain plug access on these.

[keand3]

...I have to remove the Kerker....and I'm tired of it....hint: Randy?

I am just waiting on hopefully the last header tubes that I had modified to get the proper fit. We had a problem with just one more pipe and I hope to see it next week.

If that new pipe corrects the last fitment issue I was having then it will be going into production the next day.

I hope it is very soon as I do not want to have to make anymore changes.

Randy - RPM

+1 

[JMR]

4 into 2 vs. 4 into 1.....the 4 into 1 scavages better, flows better, esp. at higher RPM's.

Over the last 30 years I have only seen 1 properly designed 4 into 2 system on a FJ.
The FJ's firing order is 1-2-4-3 so a properly designed 4 into 2 system would mean that the head pipe off of cylinder #1 should be connected to the head pipe of cylinder #4.
Then #2 and #3 should be connected together.
This is awkward, but I have seen it on one system. The #1 head pipe crossing over 2/3 connecting to #4 looks goofy and you can't get the pipes to be equal length.

It's really no big deal.
I think access to the oil drain is more important, than the intricacies of exhaust gas flow.
Something a 4 into 2 system has to it's benefit.

I am more than ready to ditch the Kerker 4 into 1 system on my '92 in favor of a 4 into 2 into 1 system coming soon from RPM, just so I can get access to my oil drain.
For years I have been pulling the oil cooler left side oil pan fitting to drain my oil *but* I can't do that anymore with the 6 AN oil line fittings on the RPM oil cooler. I have to remove the Kerker....and I'm tired of it....hint: Randy?

What system was that Pat?

[Pat Conlon]

It was 15+ years ago....sorry I can't remember. I also saw a used one for sale and one of our FJ members from the Yahoo list bought it.
 

[PaulG]

I'm looking at exhausts and have a question. other than the obvious weight savings, is there a benefit of a 4 into 1 system
versus the 2 into 1. Better scavenging? has anyone seen a Dyno sheet comparing different systems?

Scott

If you want to just add a set of slip-ons to to the existing collector I came accross these Marving's from Italy.  They make them for FJ1200's from 86-89 and '92.

http://en.marving.com/fj-1200-1992/accessories/couple-of-cylindrical-%C3%98-114-end-mufflers-black-chromium-plated-omologated-1039.html

They are imported by Monster Parts in Boise, ID., for less than $400 a set. (plus ~$100 shpping) I was communicating with them in the fall.  Here is some of what they told me:

"We don't keep that on the shelf, but can order it from Marving.  They are built to order and build time is usually around 4 weeks.  Price is $379.  Estimating the size/weight at 30 pounds, shipping would be Priority Mail International  Max. length 79", max. length plus girth 108"  6 - 10 business days $100.40"

"I havent ordered this model pipe from them before but based on experience with similar models jetting is not usually required, but there are performance benefits from jetting with a stage-1 type kit with the new pipe.  There is not a removable baffle, also we get these made for us without the logo badge riveted on, so you can leave it off if you want.  Shipping has to come here as we combine orders to spread out the shipping expense."

Also Delkvic in Colorado makes a whole buncha' stuff:

http://www.delkevic.us/?section=shop&bike_manufacturer=yamaha&bike_model=yamaha_fj1200d_%28_1992%29

I was seriously considering either of these, but found a steal of a deal at the Toronto M/C show last week.  I bought a pair of Hindle aluminum cans for $100 ea. that they were discontinuing.  I just need to find or fab up a pair of connector pipes to match them to the collector box.

The Hindle sight http://hindle.com/ has some Dyno info for their 4 into 1 systems, but they don't make anything specific for FJ's, like most companies now.  Though it may give you an idea of what you may expect from other systems.

Hope this helps.