Predator 212cc engine with RHB31 VZ21 Turbo

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garagekart

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I just joined this forum so I could ask I question I can't seem to find an answer to. The RHB31 VZ21 is for engines that are 125cc to 600cc. There are only a small handful of builds using this turbo but none on a go kart. The only one I could find real details on was a 150cc scooter, and the turbo made 6psi of boost on it. Do you guys think it would work to use this turbo on a predator 212 engine on my go kart? Has it been done before? I don't expect anything ridiculous, just like 4 extra horsepower and a unique build. I think it would be better than having a stock 13hp predator because if I blow it up it costs $99 and a few hours time of replacing parts, not $350. What do you guys think?
 
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All reports of people trying to put turbos on their engines have always been failures. I have never heard of this one, so i cannot comment.

I would just get the stock 13HP
 
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garagekart said:
Has it been done before?
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Not that I know of...

garagekart said:
What do you guys think?
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I think if you beef up the internals (yes, it probably will cost around $350) it'll last a lot longer & add even more hp (we can add 2-3hp without even cracking the case). With a bit of luck & careful planning (& a few hundred dollars), there's no reason you can't double the hp
 
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It very possible but not very cheap. You need to either get a blow-threw Carb or use Ecotron fuel injection. Blow-threw carbs are not very easy to tune in such a small application but is the cheapest option. The problem you are going to have is getting oil to the turbo, you will need an oil pump and that requires extra plumbing and extra holes in your block(it can be done). All the builds you see don't work because they add way to much tubing. the exaust side has to be as close to the exausht port as possible. reason is because it takes 4 strokes to get a pulse to spin the turbo. the closer the better response. on the intake side Ecotron fuel injection will make it a not so simple, simple fix. It takes some decent effort to install it all and tune it properly. A supercharger on the other hand is the best option if you have the Ecotron kit it would be so easy to tune. The difficult part would be spinning the supercharger. it can be a Vaccum pump ***embly from any v8 engine. The difficult part would be making a drive train from the engine crankcase to the supercharger. you would need a sprocket attached to the flywheel attached to the supercharger pully. All in all it can be done but it won't be cheap. Turbo with Fuel injection your'e looking at a little over $800. Supercharged with Fuel injection around the same price reason is you need custom flywheel and pulley with chain or belt to run the supercharger itself.

and extra 4 horses is pretty crazy on one of these...I really would wan't to do this to my predator and I know I can but the cost has me brainstorming on fabricating my own methods. I get the 212's for 30-50 bucks here at local flea market so I don't mind blowing them up. They have Pallets and Pallets of these and I haven't been able to detonate one.
 
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garagekart

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I found the ecotrons kit which is the turbo kit (turbo, flanges, gaskets, etc) for $390 and an oil pump and oil cooler for $100. The EFI kit is just as expensive, so I planned on making a blow-through carb but I'm not exactly sure what that is. From my understanding you plug the holes for the engine and make the gas go through the turbo then to the engine. Or maybe the air. Something like that. What exactly would I have to beef up for this increase in horsepower and how much would it cost? I wouldn't think increased horsepower would be much of a problem, mainly increased RPM's, but again I'm new here.
 
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Get stiffer springs,hardened pushrods,hardened rocker amrs and forged piston rod. with upgrading that you can dump nitro-methane in it. Meaning boost won't blow it up! The springs you need for increase RPM and well Hardened pushrods,piston rods,rockers are for strength.
A blow-threw carb has to fight the positive pressure of the incoming air. Meaning the Turbos PSI going in will push against the Fuel coming into the carb so you need the Fuel to be pressurized accordingly as the boost increases. Boost goes up Fuel Pressure has to go up to compensate the amount of air being forced in the engine. Tune that ratio right and it will result in more power throughout the RPM range.

Ecotrons comes with it's own injector so it is pressurized p***ed 30lbs. Boost won't stop the flow of fuel like on a stock Carb. To make a blow threw carb you need a fuel pump and fuel regulator also something that regulates fuel pressure as boost increases I forget what it's called sorry.
 
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The first engine I had on my kart was an ungoverned piece of crap and I put the piston through the engine wall after like 10 minutes. Would I risk doing that after running all of these upgrades? I would leave the governor on mine and it is much higher quality, but I still think that much extra power could stress the small engine.
 
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If the thread was still open he wouldn't be "long gone" would he? Lol, would it make a difference? Yea, of course it would... o_O
 
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garagekart said:
The first engine I had on my kart was an ungoverned piece of crap and I put the piston through the engine wall after like 10 minutes. Would I risk doing that after running all of these upgrades? I would leave the governor on mine and it is much higher quality, but I still think that much extra power could stress the small engine.
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Depends on which upgrades exactly, intake, exhaust, and governor wont kill a motor, but stiffer valvesprings probably will without a flywheel and rod.
 
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