GXSR Exhaust for a GS1100

[kichigai]

For those who have done the GSXR suspension upgrade, one common problem we encounter with the smaller front wheel is ground clearance with the exhaust. It sounding like adapting a 4-2-1 exhaust is the way to go. I am trying to find a solution by adapt a GSXR exhaust as suggested by 80GS1000. I will definatly post this up if I can make this work but first I have a few questions.

http://www.thegsresources.com/_forum/showpost.php?p=567870&postcount=180

He mocked up a '89 GSXR 1100 4 into 2 into 1 exhaust on the bike to see the difference in ground clearance between it and the old Vance and Hines 4 into 1. He said that the difference was huge!

Now, I gathered that the exhaust port spacing is just fine.

I have been told by a friend that a GSXR exhaust would work on my GS1100 with some changing of the spigots and flanges on a Air/Oil
GSXR 1100's from '86 to '92.

Before I go on a hunt for a doner exhaust, I need some additional information which I hope can find the answer.

1)
Is the exhaust tubes, flange and colar size on a 86-92 GSXR 1100 same as a GS 1100?
2)
Is a 86-92 GXSR 750 the same as a GSXR 1100 only shorter due to the smaller displacment?
3)
What about using a 93 and later GSXR exhaust? Is the tubing, flange and colar size the same or smaller diameter?

4)
Has anyone ever actually done this before?

If anyone can answer any of the listed questions, it would be appreiciated.

Thanks Kich


"Pictures posted by by 80GS1000"
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[RJ]

I have a 1987 750 header (which is for sale if interested, no dents no rust through, cheap) and can tell you that the spacing is the same. You may need to do some minor massaging to conform to the chassis of a GS1100E. The head tubes are smaller than a Vance and Hines megaphone header but they are equal length which gives it better flow characteristics, whereas the V&H is just a straight shot from the head to the collector.

The collars are totally different and will have to be cut off of a GS1100/750 pipe and welded onto the GSXR header. Can't really comment on the GSXR 1100 pipes although the collars are the same.

'93 and later pipes are out as the spacing is different due to water cooling of the engines.

[kichigai]

Thanks RJ!
I just sent you a Email! By the way, when you say the collar on a GSXR 1100 is the same, do you mean the same as a GSXR 750 or the same as a GS 1100?

Keiichi

[Junkie]

I have a 1987 750 header (which is for sale if interested, no dents no rust through, cheap) and can tell you that the spacing is the same. You may need to do some minor massaging to conform to the chassis of a GS1100E. The head tubes are smaller than a Vance and Hines megaphone header but they are equal length which gives it better flow characteristics, whereas the V&H is just a straight shot from the head to the collector.

The collars are totally different and will have to be cut off of a GS1100/750 pipe and welded onto the GSXR header. Can't really comment on the GSXR 1100 pipes although the collars are the same.

'93 and later pipes are out as the spacing is different due to water cooling of the engines.

Is that a 4-1 or a 4-2-1? If the latter I'm very interested. It ought to bolt right up to my bike, as the gsxr header port sizes are correct for the 2g 16v 750s at least.

edit: kichigai has dibs of course

[kichigai]

RJ, is your header a 4 into 2 into 1?

[kichigai]

Hayabusa Exhaust for GS1100ESD

OK., I did some research and found that the 1999-2007 Hayabusa headers are made of steel and do come in the 4 into 2 into 1 but is a dual exhaust. I ordered one on ebay to see if it can be modified to fit my GS1100. Has anyone ever tried this??

I took my GS for a canyon run and noticed that my Vance and Hines exhaust still rubs when making sharp right turns. I think this can be resolved if I can find a way to suck up the exhaust closer to the engine.

[tone]

Hello guys i think ive covered this a few times before

gs etc & gsxr port spacing is the same, collars will fit, 750 gsxr exhausts are too short in the downpipe for a gs11, exhaust will need tweaking around the sump & footrest area in most cases, 4-1 or 4-2-1 gsxr exhausts with a decent race baffle work very well on older stuff, stock downpipes, secondry & a can is the cheapest way to go but you will get better results from an aftermarket system

some may require you to rejet to suit

Watercooled bikes have a different exhaust spacing & even if tou tweak then to fit they will stick out a long way from the head to the first bend & wont follow the frame

Think that about covers it any more questions ?
btw yea i have done it a number of times, cheers tone

[kichigai]

Thanks Tone for the info! The info is helpful but the big question that I have is:

What year GS or GSXR exhaust is made of steel and come in a 4-2-1? Most I have seen are made of titanium or stainless steel! Would be great to find one that only required minor fab work. Unfortunatly I cant weld titanium.

The collector on the 4 into 1 is too big and hang too low to the ground so I have to come up with another option.

So do you think I have ground clearance concerns??

[LilTinc]

Dumb question:

How much would custom built tube run. I know for cars they run $100, or there about, for non-stepped headers per tube ($800 for a my '66 F100 when I priced last). I would think It couldn't much more than $400 to go from the ports to the "final" tube.
Just a thought.

But building your own would be more fulfilling.

Just drive on with the chopped together one...I'll need one too.

[kichigai]

Dont know how much custom headers would cost but if it is around $400.00 I would rather get me a Cope Stepped Prostock Pipe like on this GS. Its looks great and believe is functional. I have the Hayabusa header already being shipped so I think I will at least give it a try. Who knows, maybe it will work. I will post up either way of my findings.

[Guest]

I thought the gsxr ports were a little smaller. I know a guy who put an 86 gsxr 1100 pipe on his 84 750e and it fit but the 82 750 gs header would not cuz the head pipes had tooo large an od.
so the question I have is if they are smaller how much airflow disruption is there where you want it to be the smoothest.

and two.. can't remember where I read it but the smaller tube gsxr pipes don't work as well on the big gs motors. Crap! I wish I could remember what that was about.

ONe thought about the busa pipe. Isn't that a downdraft head? Aren't the exhaust ports at a much greater angle than a gs?

[tone]

To try & answer a couple of the questions posted here......

ive only ever put gsxr exhausts on gs's etc Not the other way round so have had no problems with the size at the head, no gas leaks either tbh i dont know if there's a size differance or not, ive never noticed

for steel gsxr type pipes i think you'd struggle kichigai, maybe gsxF pipes ?
its only the real top quality, very expensive pipes that are TI most are actually a cheaper stainless TI mix & will weld absolutely fine with stainless wire on a mig or even arc weld with stainless rods if you're good you can weld poor quality stainless with ordinary mig wire too if looks are not important or you are wrapping the pipes

bandit 12 4-1 pipes tuck up nicely on a gs for 4-2-1 its aftermarket pipes you will be looking for

yep busa's run a downdraft head the same as all the latest watercooled bikes, hence the pipes sticking out a long way from the head & not following the frame if you can get them on

Another option for getting the ground clearance back is a stepped top yoke !

hope it helps

[kichigai]

Tone, Well this sound promising. I do have a mig welder with stainless steel wire. Ok, so I know to look out for a GXSR 1100 stock header but what year bike? I think water cooled didnt come out till the late 90's so any air cooled header will do? Besides chopping down the down pipe, dont I have to have a collar and flange made by a muffler shop or get it off a doner exhaust to make it all work? Your knowledge here would be helpful.

[Mark M]

I think water cooled didnt come out till the late 90's so any air cooled header will do?

93 1100's were water cooled, 750's as well I think.

Mark

[tone]

Hi kichigai
in your case you will be looking for pipes from any of the oil cooled 1127's or the bandit 12 i believe the 750's will be too short, if you wanted twin silencers the slingshot models k-l-m (i think but pleas check)should work well & if you want a 4-1 i'd recomend bandit 12 all of the ones mentioned above split just after the collector so it makes life much easier when trying to get the secondry round the frame, footrests etc aftermarket pipes could be slightly different

most of the later stock exhausts have a collet & clamp arrangement at the head so you would need to sort your own clamps, ive never had to worry about this one yet as i had a pile of gs clamps from a defunct shop

not sure of the year when they went to water cooled as release dates differ in the us but i think it was 92 in the uk so you'll be looking at 89 to 91 model gsxr or 95 to 2001 bandit 12 models (check as it may differ on bandits too)

not sure if the earlier 86 to 88 slabside models will fit but they are steel 4-1 maybe worth having a look for a cheap aftermarket stainless one tho

phew my typing finger is worn out now