Ok, now I'm fairly good with my newer non fiero cars, but I just do not understand how you can figure out if a LS4 / 4T65E-HD Swap will fit in the Fiero and what modifications are needed. How do you do that ? Measure, cardboard templates ?
I think his question is more academic as to how did the first person figure it out? That is a very good question and I have no clue. It's one thing to copy someone else's install, but to figure it all out is really hard.
Most of the hard work has been done, knowing you can fit a small block chevy V8 with an adapter plate. Therefore anything the same size or smaller will fit.
-Will the engine bolt up to the original transmission? If not, need to create an adapter, or swap in the transmission the engine came with, which needs to be a transversely mounted unit.
-How was the original engine mounted to the donor vehicle? Need to fabricate mounts to sit on a Fiero engine cradle, and clear the trunk wall and frame rails. Otherwise need to modify these areas, which has been done, but requires far more fabrication time.
-How is the spark and fuel management set up? If these systems are tied to the rest of the vehicle systems, can these systems be integrated into the Fiero, made to run without being hooked up to anything, OR is there an aftermarket system that allows the engine to be run in another vehicle?
-If using a different transmission than stock, likely need to fabricate custom CV axles. Splines in the transmission compared to original Fiero, length of shafts, etc.
Originally posted by jscott1: I think his question is more academic as to how did the first person figure it out? That is a very good question and I have no clue.
As one of the pioneers of the LS4/F40 swap, it is rather simple. Don't ask if it will fit/work, ask what it will take for it to fit/work, then make it happen (which will often require modifying or building the parts needed).
It helps to focus on one aspect of the swap at a time, but you also must understand how interrelated many of the aspects are. For example engine placement impacts the design of all the mounts and it also has an impact of the clearance for the accessory drive... so it isn't uncommon for you to have to revisit and tweak each aspect to fine tune the needed balance between all aspects.
Whew, What I would really like is an LS4 in my formula. But sounds like I would have to fabricate alot of the mounts needed, correct ?
Nope, incorrect! You can buy most of the custom fabrication parts from members on here like FieroGuro or a vendor lol or West Coast Fiero. You can even buy the wire harness and ecm. Almost plog and play but all the hard to fabricate parts are done 4 u.