I am working on a go-kart/dune buggy project/monstrosity thing that is powered by an old 85 toyota mr2 4age motor...

I am kicking around the idea of junkyard turbocharging it, but I am unsure of the strength of the stock motors and the weaknesses of the fuel system... I am mostly familiar with hondas, but I wasnt sure how well a b series shift linkage would work with the engine behind the drivers seat, so I went with a drive train that was already mid engined...

any comment/help on turbocharging this engine would be appreciated (I really think a 200 whp go-kart would rule!)

 

Well, HKS makes a manifold for the 4a-ge that should fit fine, and it's not too expensive, either. Just do a search and that should be easy to find. The rods and blocks in the 4A series motors, in my experience, are strong as ----, the only thing I would worry about are the pistons.

There are two routes that you can follow to make your engine more boost-tolerant. One way is to get stronger pistons that also lower your compression. The other, and cheaper way would be to get a thicker head gasket to lower your compression.

All of the above is if you're going to even build the motor up. If your goal is 200 HP, you should be able to achieve it without going into your engine, but it won't be nearly as safe, and probably not as reliable.

Getting a turbo, manfold, intercooler, charge pipes, and all that ---- isn't really the hard part, the hardest part will be the engine management.

 

To add to what he said, if you can find a shortblock from a Supercharged MR2, that engine would be ideal for you. All you'd need is the intake manifold from a N/A engine (that you have), and the turbo components. The engine comes with reenforced rods and a 8:1 compression. From what I'm told the internals are supposed to be good for 35+ psi.

 

Absolutely! The 4a-gze (supercharged MR2 engine) is phenominal for handling boost. The pistons in them come from the factory FORGED and CERAMIC COATED!