[GSX-S1K]

I waited and waited but a performance step header for our motorcycle never evolved. So... I made a custom step exhaust for my GSX-S1000.

The exhaust tubing is 18 gauge 304 stainless. I also have Akrapovic muffler, springs, and exhaust flanges.

The size of the tubing starting at the head and ending at the titanium/carbon fiber Akrapovic muffler is in this order: 1.5" to 1.63" to 1.75" to 2.38.

Each Primary tube slip fits into a collector and is held by two retaining springs.

I ordered some pre-bent and straight tubing. I did make a custom band saw and tubing holder to make all my cuts as precise as possible.

All of my Tig welds were completed with back-purged Argon gas.

As for the Akrapovic titanium/carbon fiber muffler, it fits a 2007 GSX-R1000. I cut 6" off the factory length to shorten it, and then I installed new pop rivets to complete its modification.

The total weight of my exhaust with the Akropovic muffler is 10.8 pounds. The complete stock exhaust weighed just over 22 pounds.

For a muffler installed exhaust, the sound is very deep and intimidating.

For an open header exhaust, the sound is very deep, very intimidating, and intoxicating. Goosebumbs and an "Ear-to-Ear-Grin" at 8,000+ RPMs! Just saying.

Now... I need a new base tune, because the A/F ratio is way off.

Next... I need a tune for my Nitrous. I cannot wait to get the motorcycle all tuned up.

Currently, I am undecided on installing the Akropovic sticker. I could have buffed/polish out the exhaust, but I don't see the point in a polished exhaust.

Thanks to "chr1s" for helping me purchase some Akropovic parts.

So far, my custom exhaust seems to be everything I wanted and needed for my motorcycle.

 

[nicka]

Wow nice work, I bet that took some time and patience, I plan on doing my own mods soon also but not to that extreme, I am planning to cut the cat in half and hollowing it so I have a two piece exhaust then it can go back together for now so I can build it over time from the cat back so I will not have to remove the headers again, I'm thinking of making a tubular muffler underneath in place of the big box and cat still using the original end can to keep it original looking so it looks like it still complies and so it's not too loud

 

[ESXB0Y]

Very nice! A lot of effort, but looks well worth it in the outcome. Keen to hear what your figures end up being once she's tuned!

 

[GSX-S1K]

Wow nice work, I bet that took some time and patience, I plan on doing my own mods soon also but not to that extreme, I am planning to cut the cat in half and hollowing it so I have a two piece exhaust then it can go back together for now so I can build it over time from the cat back so I will not have to remove the headers again, I'm thinking of making a tubular muffler underneath in place of the big box and cat still using the original end can to keep it original looking so it looks like it still complies and so it's not too loud

Thanks.

To build the bandsaw and tubing holder, mock up the pipes, and finishing the Tig welds took me one week to complete. I worked on this project everyday after work and and one full weekend to complete. 7 days from start to finish.

I built the exhaust for my True Street 1989 Mustang way back in 2003. That prior experience made building this motorcycle exhaust easier.

I was rusty on my Tig welding and I had to practice welding to remember the correct technique.

My custom bandsaw is small table top saw with a Milwaukee band saw bolted to it. I had to make a custom frame and drill the holes to attach the band saw to the table saw. I also made the custom tube holder to cut the tubing. The holder slides in the grove in the table top to keep the tubing square with the band saw.

The tube holder is adjustable and rotates complementary to the band saw blade to keep all cuts correct.

 

[GSX-S1K]

Very nice! A lot of effort, but looks well worth it in the outcome. Keen to hear what your figures end up being once she's tuned!

Thanks.

I'm also ready to see the numbers.

 

[rcannon409]

The talent level ..wow. How did you decide on dimensions?

I limit it to that one question out of the 50,000 Id like to ask.

 

[GSX-S1K]

I used a friends exhaust modeling computer program, and I did some research too. The program takes into account different factors about the engine/head/cam specs, header configuration, fuel octane, and if nitrous is used.

Once all the information is loaded into the program, it can calculate a recommended dimensions for the header, step tubing diameter, collector size, and more.

I don't mind sharing the calculated dimensions I was given.

 

[nicka]

I used a friends exhaust modeling computer program, and I did some research too. The program takes into account different factors about the engine/head/cam specs, header configuration, fuel octane, and if nitrous is used.

Once all the information is loaded into the program, it can calculate a recommended dimensions for the header, step tubing diameter, collector size, and more.

I don't mind sharing the calculated dimensions I was given.

I have calculated my build also but the formula is simply my ability

 

[Martin]

Awesome job... very talented, maybe you should go into production with them

 

[rcannon409]

Question 2........Based on what you had to do. The time it took, materials involved, etc.

If a person buys a full exhaust from Arrow Akra, etc, is it priced fairly? Figuring revzilla wants @ 1500.00 for what you've built. Yours looks better, but we'll pretend they are equal quality.

I wnays, your project depresses the **** out of me. Why cant I live next door to "guy who builds his own custom motorcycle exhausts?" instead of what I get.....

 

[GSX-S1K]

The aftermarket exhausts make about 5 - 10+ hp and they look/sound good. Akrapovic has an awesome Racing line of exhausts for about $1,400, but none of them fit our motorcycle. As for the current retail price & quality for an aftermarket exhaust for our motorcycles, I wasn't quite happy. I wanted a true performance exhaust at a fair price.

A lot of guys are happy with their aftermarket exhausts for our motorcycles. I wanted to buy a complete stepped tube exhaust, but I had to build it.

 

[rcannon409]

I dont mean to pester you, but the steps in the head pipes.....did you do that, or was it supplied that way?

I notice my Arrow exhaust has similar steps, but Arrow used different diameter tubes, then welded them together.

Yours is superior to that, and certainly looks better.

You shoudl have built two..one to use, the other to hang above the fireplace. If thats not artwork, I dotn know what qualifies.

 

[landy10]

I dont mean to pester you, but the steps in the head pipes.....did you do that, or was it supplied that way?

I notice my Arrow exhaust has similar steps, but Arrow used different diameter tubes, then welded them together.

Yours is superior to that, and certainly looks better.

You shoudl have built two..one to use, the other to hang above the fireplace. If thats not artwork, I dotn know what qualifies.

Dont you just hate talented people

 

[Mr Nice]

Nice job , I admire people with skills .

 

[m0bnd]

This is great, I know how 'difficult' welding Titanium can be with back purging of Argon or in a 'bath' of Argon being very important. I take my hat off to you and your excellent fabrication skills


Sent from my iPhone using Tapatalk

 

[GSX-S1K]

Thanks for the feedback.

The AF ratios with this exhaust are way too lean, but that is a good thing. I did run my Dynojet AutoTune riding on the highway/street for about 2 hours. With the new Map, the motorcycle is running much stronger. Wow! The bike has much stronger power wheelies. It does pull a lot stronger from mid RPMs and up.

I still see a lot of areas in the Tune map that need improvement, but for what I am experiencing now... the exhaust is all improvement.

No open header tuning till I get a "Muffler" tune first.

 

[rcannon409]

Ill tell you what...Lets look at the best, most famous painting in the world. Obviously, its the dogs playing poker.

I would remove said painting to be able to hang this exhaust on the wall.

The steps...you went out of your way to include them. Did you specify how much step you wanted, or how did that work?

 

[rcannon409]

Sorry to bump this old thread, but how about some pics of this exhaust, after its been used? I would love to see the colors....

I watched one of my customers working with some Inconel tubing. He welded it, then picked it up bare handed. I had that DONT!!!! reflex, but apparently that stuff sheds heat like no other.

I still wish you were my neighbor...Instead, I get to live next to "guy who collects stamps"....which is fine, but would rather live next to exhaust guru...

 

[mikstr]

wow, what an impressive project and build!!!!!!! I am green with envy at the building skills.

Ever get this baby on a dyno? Wondering how it compares to the Arrow set-up, for example.

 

[temporarykiwi]

exhaust dimensions

Thanks for the feedback.

The AF ratios with this exhaust are way too lean, but that is a good thing. I did run my Dynojet AutoTune riding on the highway/street for about 2 hours. With the new Map, the motorcycle is running much stronger. Wow! The bike has much stronger power wheelies. It does pull a lot stronger from mid RPMs and up.

I still see a lot of areas in the Tune map that need improvement, but for what I am experiencing now... the exhaust is all improvement.

No open header tuning till I get a "Muffler" tune first.

hi, nice job , i also like to mod stuff, ive found exhausts are one of the easiest ways to gain hp/torque, would you be able to specify the length of your headers to the collector, the std headers are too short in my opinion @455mm avg (and undersized)