Turbo charging cga3 v cg13

Im about to start building the exhaust manifolds for my turbo conversion in my mini clubman. I've already got the inlet manifold and bigger injectors sorted.

The plan was to use the currently fitted cga3 1348cc engine in stock form and run 4psi - 7psi with the GT1752.

However I'm a little concerned the coilpack piston ring lands and crown height don't seem as forgiving as the standard pistons in the cg13's. I'm a best sticking with the cg13?

I'm running DTA ecu so no difference in installation.

I'd appreciate your thoughts

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Club Member
pretty sure i ran coilpack 1.0 pistons matt, and they still detted the ringlands
this is cg13, cga3, corsa and lpg pistons eh

Thanks for the info. So the cg13 would be a better choice then?

How do the corsa Pistons work? I've got a spare auto cga3 engine for the long term turbo project.


Club Member
the corsa ones appear to be a lot stronger matt, i cooked mine when i ran out of coolant at mallory park, and the cyl that munched the big end left detonation pitting on the piston, yet the ringlands were still ok

As long as you keep the fueling and cylinder temps correct you should be ok. It's when things get too hot the issues are caused. You'll either melt the piston or more commonly the heat expands the rings past their gapped amount. When the ring ends meet it causes the ring to buckle, and the ringland breaks. With the correct mapping though I'm sure you'll be fine. The Nitrous guys file a slightly larger gap on some of theirs.


Club Member
nah, its not the ring gaps, its the peak cylinder pressures that collapse the ringlands
you can see here the huge ringlands on my 1.7 cdti piston compared to the cg ones, the diesel ones have to sustain over 2000psi peak cylinder pressure, the micra ones seem to fail at about 1000psi