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Discussion Starter · #1 ·
I picked up this little gem to keep me busy this winter. I have a turbo thats been sitting on my shelf waiting for the right motor. Stock hp is 64hp my goal will be 100hp to the wheel with a weight goal of #400. Starting boost will be 7-8psi to get some base numbers then headstuds and 15psi and up till I make scrap.
 

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That sounds like a great plan turbo the little fucker till it blows up
 

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Discussion Starter · #4 ·
With the 9.8 to 1 compression ratio my guess it will explode around 25psi and it will definitely be piston failure due to detonation.
 

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Hack in a barn
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#114 CVMA/STTARS
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Hmm, I think this makes the 12th tiny motor turbo build I've seen attempted on here. They never finish them but it's fun to read.


It's not the head gasket that can't take it, it's the crank that will snap or the rod bearings that will get cooked and fail. Same issue the SV650 has when you try to add a bunch of horsepower. Only way to make it reliable is to buy an aftermarket crank and forged pistons.
 

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#114 CVMA/STTARS
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Honestly I dont care what lets go first. As for the size of the motor the fun factor increases. I dont want a 1000cc bike running a turbo its unusable power not logical at all. Be realistic here where would you ever use the power of a liter bike with a turbo?
Drag racing. But yeah I totally agree with you. Do you plan to rebuild the motor with stronger internals? The GS motor is not designed to have a 50-75% increase in horsepower. It could potentially pop on the first run. Would be a terrible waste of your energy. I think you can order custom cranks from Falicone if you wanted to do the turbo build right.
 

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Discussion Starter · #10 ·
I have a spare 83 850 thats sitting under my bench that might get freshed up after the 550 lets go. Im thinkin if the bike will take 14psi without major issues thats the way it will stay.
 

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UnicycleMode
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I have a spare 83 850 thats sitting under my bench that might get freshed up after the 550 lets go. Im thinkin if the bike will take 14psi without major issues thats the way it will stay.


Most Suzuki cranks are one piece units, not a big concern there, the valve trains are pretty much as tough as they come out of the box for the era, and there isn't much in terms of what the electrical system can't take in stride feeding a fuel pump and such.


The big problem is the pistons, and after that the rods become a weak link. You will burn a hole through one of them far before you actually kill any significant part of the engine. I am pretty sure it'll take 6-8psi developing about a 10-20% gain in power before you start having stresses that will eat up a piston top. And when that happens it happens right now, no warning, no tick, ping, knock, or rattle, it just makes this horrible "Foof, foof, foof, foof" noise as it winds down the revs blowing air strait into the cases through the massive hole in the piston top. :D


Bandit pistons from Andersbrink.se showing how far is too far with boost on stock Suzuki pistons. ;)



A set of forged pistons isn't too expensive and assures you will have a solid rotating assembly to jump off from. Wouldn't be much fun to destroy an engine on boost if it goes quietly into the night without so much as a crack in the cases. :D
 

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#114 CVMA/STTARS
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I have a spare 83 850 thats sitting under my bench that might get freshed up after the 550 lets go. Im thinkin if the bike will take 14psi without major issues thats the way it will stay.


I can't find a listing for forged pistons from Wiseco or JE. Maybe you could use pistons from a GS1100? There are a lot of hop up parts for the GS1100 and you could potentially buy pistons and rods from either company. That would give you a vast improvement over stock and avoid burning a hole through the stockers.


I'm not sure the crank diameter is anywhere near the same as the GS and even if you reused the stock rods I don't think the wrist pins are the same. I would call Wiseco and ask. I know the 550 was a very popular bike for Formula Twins racing back in the day before they came out with the SV650. It's very possible you could find some NOS parts floating around someone's shop.
 

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watches you sleep.
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Go for it. Yes. Are you not looking to throw a lot of money into the engine because honestly I agree with Ratfighter about stronger pistons and youre gonna end up spending quite a bit of money to complete and install a turbo setup on the engine anyways. If youre going through all the money and time and hassle you might as well spend more and dig into the engine, as fun as it sounds to just slap a turbo setup on it and see what happens lol.
 

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Discussion Starter · #15 ·
The biggest price of the build is the turbo. Which I have about 4 sitting on my shelf ready to go. Lc1 wideband, fuel pump and regulator is the only real cost to me as all then plumbing I have stocked in my shop. Total cost so far is $300 which is less than i paid for the bike.
 

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Discussion Starter · #16 ·
Anyone in the Wisconsin area is more than welcome to come out to my shop
Unlimited off road. The fridge is full of brew the bullshit is over the door come on it
 

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Discussion Starter · #19 ·
Lc1 wideband came today. Fuel pump and regulator will be in early this week. Changed my mind and opted for a vg1 turbo off a cx500. I have a gt12 in very nice shape thats listed on ebay if anyone is interested.
 

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