Hey there guys! I am new to this forum and had a question to ask you all. I have a 1985 Trans-Am with a tired 305 TPI. I am looking to upgrade to a 350 with either an underhood or rear mounted turbo system. I'm also contemplating going with a 383 but prefer to stick with a turbocharging. I was wondering if anyone out there has done a rear mounted or underhood turbo mod and what's all involved with it. I would like to keep the TPI setup but primarily looking for what's involved with the computer and fuel system modifications. Any advice would be greatly appreciated.

 

It is all going to depend on your skill and the size of your wallet. The computer is going to need to be reprogrammed to be able to handle the increase in the extra air. The MAF is not going to really like high boost applications so you will have to decide if you are going to stay within its limitations, swap to speed density or go to an aftermarket computer setup. The injectors are going to need to be increased, what size you will end up with will depend on your power level. You should upgrade your fuel pump. If you do not have an adjustable fuel pressure regulator, you should pick one up to fine tune what your engine will be looking for. The tank and lines will be able to handle the flow just fine. In regards to the turbo system you will need a bunch of straight and curved pieces for both the hot and cold side, you will either need v-bands or couplers to connect the pipes together. You should use an intercooler depending on amount of boost you are running. You will need a wastegate and blow-off valve. Headers will need to be figured out. Either make true forward facing headers or log style headers or modify factory manifolds to work properly. You will then need wideband sensor to make sure the tune is spot on or you will be buying a new motor to swap in as well. Lastly you will have to fabricate it all together.

Those are the basics, be prepared for scope creep. I am building a turbo motor and my scope has increased and my budget is getting close to $1K more than initial plan. I am not mad in the least with my creep because I would rather do it once.

Price will range from $1k-$5K and up and then double that and then add 15-20% extra. That will be the low end.