or am I best off waiting for a lil ole MPi???

spi = slow

mpi = fast

it depends how deep your pockets are??

The engine itself is VERY tuneable, and the difference between MPI and SPI is far more negligible than slow or fast. The bigger difference is high compression or low compression variants of the same engine.

The injection side of things though is more tricky, no more so though than MPI.

The engines respond very well to tuning in traditional areas, improving the breathing at both ends and flow through the head will give very good results, BUT as with any injection cars altering the fuelling requires more than a resistor of doom.

It can cost more to buy a good programmable throttle body and ecu setup than it does to go for a all singing and dancing racing engine build up :(. 150hp + is attainable out of the SPI engine once you ditch the injection setup. 130 is acheivable realtively easily. But the injection system itself is the limitation, jsut as it is on a MPI equipped car.

You would be hard pressed to get much more than 10-15% power increase out of either SPI or MPI considering the starting difference between the two is 1-2bhp and both systems need scrapping if you want serious gains Id say go with what youve got, (unless its a low compression engine).

The engine itself is superbly tuneable but the injection system is good only for mild tuning.

The ONLY advantages a MPI engine has over the SPI engine mechanically are slightly narrower valve stems and slight better port shapes, both of which will be of no benefit when you go for serious tuning anyway!

hmm- just asking as theres one on ebaynear me!

I need more cars:-)