Up for sale is my partial turbo kit for a GS500E. If you've wanted to go forced induction on your GS, this is your chance! I got started on this a couple years ago but lost interest after I got into motorcycle racing and picked up a racebike.

As the title indicates, this kit is incomplete and needs a few more items to finish the installation (see below)

What's included:
-Garrett GT15 turbocharger (an actual Garrett, not some cheap chinese knock off)
-Turbo mounts
-TIG welded turbo pipe
-Exhaust header
-Mandrel bends, silicone connectors, and t-bolt clamps
-Holley fuel pressure regulator
-Turbo oil supply and drain adapters/lines
-Turbo oil scavenge pump
-Turbo outlet flange and gasket
-A couple extra AN fittings and hose

































The turbo is mounted in place of the factory muffler. My plan was to use pre-turbo water/methanol injection via an air mist nozzle to provide detonation control. This type of setup uses boost pressure to push the MW50 out of the nozzle with little jets of air (like a HVLP paint sprayer) and provides proportional amount of MW50 to boost.











The system is designed for 10psi of boost (~75rwph), but can support more. I have the operating points are plotted on a GT15 map in excel, still trying to figure out how to post that.



What's needed:
-Sort out the airbox. The stock airbox will hold lower boost levels, but being plastic may limit things. The intake design of the GS is perfect for forced induction though, since the airbox is rigidly mounted to the frame. 
-Put a pitot tube in the boost line. This is how you make the carbs compensate for boost (read here:http://www.spartgsxrspecials.com/turbo%20do%20and%20dont.htm). The pitot tube applies slightly higher pressure to the float chambers to richen the air/fuel mixture under boost.
-Fuel pump and tank return (bulkhead fitting included)
-WMI system
-Muffler (optional)
-Dyno time


Don't skimp on the dyno time, it's the cheapest hp you will get, and it will save you a boatload of trouble in the long run when setting up a turbo (I have done a few, trust me).

I've got a lot of money into this since these are quality components, not cheap chinese junk. I just hope someone can use them.


$750 OBO, plus shipping

If you have questions, just ask!

Is there a reason you decided to keep the carbs.  i would have figured running injectors and a micro squirt system would make tuning easier.  Great kit...and very tempting.  Do you have any video or sound of your gs under boost.  choo choo. 

Quote from: mwe on March 14, 2016, 07:35:28 AM
Is there a reason you decided to keep the carbs.  i would have figured running injectors and a micro squirt system would make tuning easier.  Great kit...and very tempting.  Do you have any video or sound of your gs under boost.  choo choo. 

Carbs can be made to work well for low pressure systems like this and using them means one less thing to buy. If going EFI I would recommend installing that first and getting it tuned and running perfectly, then install the turbo system and tweak from there.

No video unfortunately, but blipping the throttle sounded nice  . Sort of a staccato turbo whistle. If I finished it there would have been no muffler. The turbo quiets the exhaust a lot, and I wouldn't want to lose that whistle. 

Like a baby Ghostrider noise eh?! Nice!

$650 OBO, I know someone out there is itchin' for some boost! 

$550 OBO plus shipping. Barely more than a full exhaust........ but can actually make real power!


Even Guy Martin has a turbo.....

would this be considered remote mount?  I have never seen a remote mounted turbo setup on a motorbike. Why did you choose to put the turbo so far out the back?

Yes, this is a remote or rear mount turbo setup. I did a rear mount for a couple reasons. I wanted to preserve the factory long tube header to improve off-boost performance. I see lots of turbo bikes where the builder chopped up the good flowing equal length header to make a log manifold  . Also, the turbo is smaller than the factory muffler, so removing the muffler provided a convenient place to mount it.

I would think that the gains saved from preserving "off-boost" performance would be greatly overshadowed by the downside associated with greater turbo lag.  Turbo lag can not only be annoying but downright scary on a motorcycle.  Don't get me wrong...I am interested and wouldn't mind boosting my GS, just not sure this is the way I want to go about that.

The increase in turbo lag with rear mount systems on cars is negligible. Look up installs by STS turbo to see for yourself. They actually did a rear mount on a CBR600RR a while back.

I understand the theory that if boost or exhaust routings are longer lag will increase, but in practice it is the inertia of the rotor system that mostly dictates the time it takes to spool, assuming the turbo is sized appropriately. If the turbo is too big the boost threshold will be high and the lag will be "scary" as you put it.


If this isn't the way you want to go about it, move along and get building. 

One last try, $500 plus shipping.

I really thought someone would bite on this, but maybe the world isn't ready for another turbo GS.

When I first saw you post this I thought holy crap that's neat!!!

It's something unique and that's right up my alley... I daydreamed about my dad and I (he's owned his own garage for over 40 years) messing with this turbo and having a blast figuring things out and getting the setup finished.

I am totally intrigued by this but with a full time job, home-ownership projects and a car that I'm about 5/8 of the way done with, my wallet nor the hours in the day make this a feasible purchase for me 

PS... have you tried listing this on ebay and/or the gstwin facebook page/group?

Quote from: ShowBizWolf on May 20, 2016, 04:07:16 PM
When I first saw you post this I thought holy crap that's neat!!!

It's something unique and that's right up my alley... I daydreamed about my dad and I (he's owned his own garage for over 40 years) messing with this turbo and having a blast figuring things out and getting the setup finished.

I am totally intrigued by this but with a full time job, home-ownership projects and a car that I'm about 5/8 of the way done with, my wallet nor the hours in the day make this a feasible purchase for me 

I hear that! I'm in the same boat, too many projects and other distractions.


To be fair it would take someone with shop resources like you to complete this project right. eBay and the GSTwins FB site are great ideas for getting these parts into the hands of an enthusiast, thanks for the tip!