Putting the finishing touches on a 2.5 to 2.7 engine swap. Here are the important facts:
1) I am using the stock 2.5L wiring harness. to do this I had to change the coolant temp sensor and use the 2.5 exhaust so that the o2's would be in the correct place (may change to an aftermarket after I work out the bugs.
2)It will be a 5 speed as that is what the car (99 Boxster) came with and it makes for no pedal work.
3)I am using the throttle body and the intake crossover tube from the 2.5 as the front crossover tube (I've already cut the proper size reducer boots to make it fit) and the back crossover tube from the 2.7 with the butterfly valve removed and holes plugged. This is because I needed to retain the cable driven throttle body.
4)Stock DME 5.2.2
5)Using the 2.5L fuel rail as the 2.7 was returnless and I didn't want to even think of the nightmare changing the fuel system would have been.
6)Using the 2.7L injectors because I have been told they will work.
Questions:
Vac Ports: I am having trouble figuring out the vac lines. I understand that the 2 main vac sources are ports in 2 of the 4 Intake boots.
Which boots have the ports? I mixed mine up during disassembly. I believe they should both be on the front crossover (throttle body) as I think the changing airflow on the rear crossover with the butterfly valve would impact.
Fuel Rail: when bolting the fuel rail from the 2.5 to the 2.7 intake, the injectors don't line up.
if you put the injectors in then you cannot bolt down the fuel rail. off by about 10mm. What have people done in the past to overcome this? I'm thinking of grinding off the mounting brackets and re-welding them in the proper location where all will line up.
What have people done for the lower mounting of the throttle body as the tube is farther back than on the 2.5? I assume I will have to fabricate something.
See pic below -
Would assume that all of the vac lines going to the Vac Unit K would all be eliminated and H would plug into the 3rd port of G.
Where does E install? clip into the intake slot?
Feel free to ask questions as to why I am doing things this way. Mostly the answer will be that I want this to go together as inexpensively as possibly then put money into working out the bugs. I already think that once I know everything runs, I will reinstall the butterfly valve in the rear crossover. the an exhaust upgrade. car needs some body work too and am attacking one thing at a time.
Note: I know I am calling the front crossover the "rear crossover" and the rear crossover "the front crossover". just used to the throttle body being in the front of the engine of the stuff I work on usually. apologies in advance.