Hello everyone,
I have a 1999 JDM spec Mini. I have removed the AC system from the car and changed the SPI intake system for a custom EFI setup using a sherryberg throttle body, a single injector, and bosch coilpack all controlled by a speeduino ecu.
I've been daily driving it with the current setup for about a year and am looking for my next project. I'm an engineering uni student so budget is incredibly tight... but I'm hoping to fit a turbo.
My plan is to use a clone gt15 turbo (mounted between engine and bulkhead) with a self built manifold/downpipe and a small front mounted intercooler. I want to keep my boosted brake servo and current efi system. Since the engine is still the stock 1275 A+ engine with a 10.1:1 cr (according to GuessWorks), my plan would be to remove the head and increase the combustion chamber size and possibly run a thicker head gasket to lower the cr. I don't want crazy power, I was thinking something around 80-90bhp running 5-7psi? What sort of cr should I be targeting?
My reason for going with the gt15 instead of something like the gt17 is because I want a setup that spools up fast and is fun for around the city. But please tell me if you think a gt15 is the wrong turbo!
I basically just wanted to check if this is something achievable? budget is around $1000-1500CAD
Some other things I am unsure of:
For the diff, would it be necesarry to upgrade to a x-pin? or just upgrading the single pin with a stronger one?
Could the stock gearbox/clutch handle this sort of power? I know the gearbox was overhauled and clutch replaced about 3 years ago by the previous owner.
Is it actually possible to lower the cr to a safe point by just increasing the combustion chamber size? I would love to go with a built engine with proper pistons, but budget doesn't allow.
I know this set up would probably end up being similar to the Jet motors kit, but I want something that I built and figured out myself and would also like to make sure the engine can handle it, as I understand the jet motors kits are intended as just bolt on with no engine mods.
Let me know if there is anything else I have forgotten to consider here.
Thank you!
