Boyracer wrote:
That T piece with the green tags is not standard for an SPI. It should just be one vacuum pipe running down to the ECU. I wonder where the other line goes to? A vacuum gauge, maybe?
No it's standard. It's the "filter" that should be in the vacume line to the ECU to stops liquids going down the hose and fowling the MAP sensor inside the ECU. Short line from back of manifold to this filter which is mounted vertically next to the manifold, then a second line from there to the ECU.
As for the LCB's - go for it. I tried several combinations of exhaust diameters and mufflers - the only thing that made any noticeable difference to the performance was the LCB. It didn't do much for the middle/top end (maybe more economical), but made a big difference down low. SPi's seem to be a bit "sluggish" below 3k rpm, but the LCB improved the low end torque and made it a lot more pleasant to drive around town. Just mount the O2 sensor in the centre branch.