Turbo

[drexer13]

I have a 1980 Gs 550. Last summer I re jetted it put on some higher flowing mufflers and replaced the air box with a single cone filter. This winter I was considering turbo charging it.
I was just wondering if anyone has ever put or tried to put a turbo on one of these bikes. It seems like a pretty good candidate with the low compression and all.

[Steve]

Suzuki hung a turbo on the 650 in 1985 and called it the XN85.

The tricky part of putting a turbo on a bike that small is finding the right size turbo, then deciding how to route all the plumbing.

There were kits for larger bikes, but they are VERY size-specific. You can not hang a turbo that is intended for a 650 on your 550 and expect any results, let alone good ones.

.

[Big T]

Blowerbike knows about it

It's really complex as a turbo can blow all the fuel out of your carbs

[Steve]

Blowerbike knows about it

It's really complex as a turbo can blow all the fuel out of your carbs

If it blows all the fuel out of your carbs, you obviously installed it incorrectly.

If you are going to blow through the carbs, you have to enclose the carbs COMPLETELY so the bowl vents see the same "atmospheric" pressure as the air that is getting ready to go through the throats.

It is much easier (in my opinion) to suck through a single carb and blow the mixture into a manifold.

Just slightly less easy is to set up a fuel injection system, but I would rather do that than try to enclose four carbs.

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[koolaid_kid]

The blow through method was called pressured carbs (on cars, anyway) and was a real PITA.
The suck through would be a lot easier, but a single carb would require a custom intake. Of course, you will also need a custom exhaust manifold to do it correctly. Lots of work, lots of money to get 750 performance out of a 550.
Factory turbo bikes of the 80s:
Suzuki XN85
Kawasaki GPz750 Turbo
Honda CX500 & CX650 Turbo
Yamaha Seca 650 Turbo

[drexer13]

I was thinking about using a single carb off of a 650 savage. and a turbo off of a 650 seca. I wasn't considering the blow through method, I have made pressure boxes for turbo projects before and they are a lot of work. The draw through method is much easier and more efficient. The draw back is you don't really have the option for an intercooler. I have had the carb and turbo sitting around for a while. I traded some work for them a few years ago. I was going to turbo my buddy's snowmobile but he decided against it when I told him it might blow it up.

[Steve]

I was thinking about using a single carb off of a 650 savage. and a turbo off of a 650 seca.

Since it appears that you have played with turbos before, you should know that they depend on proper airflow to do things right. Using a turbo that is designed for a 650 on a 550 engine, you will only have about 83% of the gas volume available, unless you spin the engine about 20% faster than the Seca. Since that's not going to happen, you will simply not have enough turbine speed to justify all the work to install it.

Not having an intercooler is not that much of a problem, unless you are going to Bonneville. You will not be able to stay on-boost long enough for it to really matter. If you want to cool it down a bit, you can over-jet it a bit or add some water or water/methanol injection to turn on while you are making some "horsepressure".

The carburetor might work, but will have to be re-jetted.

What happens if you don't jet the carb properly?


That's not from a GS, but it is from a mis-jetted carb on a turbo setup.

.

[drexer13]

That's funny, I have a 3 wrx pistons that look just like that.

As far as using the seca turbo, in the past I have been able to compensate for using a slightly over sized turbo by opening up the intake and exhaust. I dont know how restrictive the seca's exhaust and intake are but Im hoping this will give me the extra spool i need. I guess if I were really going to do it right. I should figure how much power I want to gain and then start looking st some turbo maps. But It sounds like you have done this a few times, and might be able to save me the trouble. Do have any suggestions for a more suitable turbo?
Any help is always very appreciated.

[Steve]

Sorry, my turbo experience is very limited, and no bikes were involved.

I know some general principles, but can't help you with details of what to look for.

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[drexer13]

No worries, You have helped quite a bit. Thanks for your information.

[blowerbike]

simple but can be expensive.
a b flow rajay is the turbo to use.
use it as a draw threw set up.
lot's of piping/header/turbo manifold/waste gate/oil feed-return/a mik hrs40 carb would be nice.
you will have turbo lag but that's just part of it.
your clutch will suffer.
your head gasket will suffer.
your cast pistons will suffer.
what is the fun if you have to run 5-6 psi..no fun really till above 10psi or more.
unless your a fabricator or have some favors owed you by one...
i would pass as the kit would cost 2-3 times as much as the bike is worth.
now on a 750 and bigger..
i would say go for it if you had the extra bucks plus there are bolt on parts out there for the 750-1150's.
i just shipped a bunch to south dakota.
there you have it.

[drexer13]

Thank you
That was very helpful. I really don't consider myself a fabricator but I should be able put together the intake and exhaust manifolds without much of a problem. My real concern was weather or not it would be worth all the effort. I have never put a turbo on a bike before.
From what I'm hearing the 550 just isn't big enough to make it worth my wile.
Thank you for all of your help.

[madjack57754]

By putting the carb in a pressure box the internal and external pressure in the bowl are the same. Carb doesn't know it's pressureized.
IHI makes some tiny turbos. That's where I'd start looking

[Agemax]

try this one, you may experience a bit of lag but once you get this bugger spinning.........HOLD ON!

[ClineDesign]

try this one, you may experience a bit of lag but once you get this bugger spinning.........HOLD ON!

I'd wear earplugs too cuz your going to hear a lot of screaming.