I decided to put this post out here because I am constantly see post on people who want to turbo but have not and are not sure wich way to go. This is more informational and something to consider than anything else. I have turbo'd 3 BJ70's and one BJ42 all having 3B engines of one type or another,and here is what I found.
AXT - A good turbo kit however has some drawbacks. The entry and exit ports are not in very good spots you will have to mess around with the inlet hose and it is very hard to get it in an ideal location on a 70 series (40 series not as bad). The exit port is horizontal and they include a header pipe with a 90degree bend however it is not bent enough to properly clear the firewall on a 70 series, also the compression flange setup to bolt it down is not very ideal. You really need to swap out most if not all of your exhaust if you are running the AXT (according to AXT as well as my own experience) you should run 2.5" all the way back to take advantage of the power from AXT and to help your EGT's. Other than those drawbacks I have found the AXT to give the highest potential output from a kit.
13BT turbo / Custom kit - This is a great setup with smoth power throught the power range. Drawbacks are cost is higher than AXT and availability, and if you are running a 3B you potentially will need to move the oil filter out of the way. On the plus side, it is all toyota and the manifold and turbo are bolt up to the 3b (and 3bII with adapter from luxury imports). Also the entry and exit ports are in a good place, the inlet has a great shot to the air cleaner while the exit port has a cast 90 degree elbow and has a vertical exit very simular to the stock manifold on 3B, flange is standard exhuast 3 bolt flange and you can choose to run near stock exhaust or go bigger. If you go this route you probably want to get a few other parts from a 13BT such as the thermstat housing (has water inlets/outlets for water supply to turbo). Great performance more mods and customizing, than AXT but better setup in the end.
Engine swap to 13BT - This is probably the highest cost depending on where you get a 13BT and what condition it is in. However if you are serious about turbo for you 70 series and plan on keeping it for a long time this option makes a lot of sence and gives you some great upgrades in the process. you get direct injection, turbo, and probably a better shape engine (or at least newer) that your 3B. You can retain your drive train and motor mounts where they are, and the swap is on the mild side compared to others.
Ok just for the really sick out there - 1HZ swap - I am pretty sure this will cost more than a 13BT swap especially if you go with 1HZ and turbo on that. You end up with a 6banger, more power, more torque, cool bragging rights. You will also need to swap out that H55F for another one with the appropriate input shaft, not to mention the motor mounts, fan shroud, and numerous other items. The down side is if you do a 1HZ and do not turbo it you will have the same issues at higher altitudes.
I am sure there are lots of home grown solutions to fit your budget and some work really well and some probably don't work as well as the time and effort that were invested in them. I think there is at least one other kit out there but I have no experience with it so I can not speak to it.
If you are not sure on the priorities of Turbo over lockers or what not just consider where you live, what you mainly use if for and that should help you decide. Always remember you don't need a turbo to wheel your 70
Cheers,
Michael
AXT - A good turbo kit however has some drawbacks. The entry and exit ports are not in very good spots you will have to mess around with the inlet hose and it is very hard to get it in an ideal location on a 70 series (40 series not as bad). The exit port is horizontal and they include a header pipe with a 90degree bend however it is not bent enough to properly clear the firewall on a 70 series, also the compression flange setup to bolt it down is not very ideal. You really need to swap out most if not all of your exhaust if you are running the AXT (according to AXT as well as my own experience) you should run 2.5" all the way back to take advantage of the power from AXT and to help your EGT's. Other than those drawbacks I have found the AXT to give the highest potential output from a kit.
13BT turbo / Custom kit - This is a great setup with smoth power throught the power range. Drawbacks are cost is higher than AXT and availability, and if you are running a 3B you potentially will need to move the oil filter out of the way. On the plus side, it is all toyota and the manifold and turbo are bolt up to the 3b (and 3bII with adapter from luxury imports). Also the entry and exit ports are in a good place, the inlet has a great shot to the air cleaner while the exit port has a cast 90 degree elbow and has a vertical exit very simular to the stock manifold on 3B, flange is standard exhuast 3 bolt flange and you can choose to run near stock exhaust or go bigger. If you go this route you probably want to get a few other parts from a 13BT such as the thermstat housing (has water inlets/outlets for water supply to turbo). Great performance more mods and customizing, than AXT but better setup in the end.
Engine swap to 13BT - This is probably the highest cost depending on where you get a 13BT and what condition it is in. However if you are serious about turbo for you 70 series and plan on keeping it for a long time this option makes a lot of sence and gives you some great upgrades in the process. you get direct injection, turbo, and probably a better shape engine (or at least newer) that your 3B. You can retain your drive train and motor mounts where they are, and the swap is on the mild side compared to others.
Ok just for the really sick out there - 1HZ swap - I am pretty sure this will cost more than a 13BT swap especially if you go with 1HZ and turbo on that. You end up with a 6banger, more power, more torque, cool bragging rights. You will also need to swap out that H55F for another one with the appropriate input shaft, not to mention the motor mounts, fan shroud, and numerous other items. The down side is if you do a 1HZ and do not turbo it you will have the same issues at higher altitudes.
I am sure there are lots of home grown solutions to fit your budget and some work really well and some probably don't work as well as the time and effort that were invested in them. I think there is at least one other kit out there but I have no experience with it so I can not speak to it.
If you are not sure on the priorities of Turbo over lockers or what not just consider where you live, what you mainly use if for and that should help you decide. Always remember you don't need a turbo to wheel your 70
Cheers,
Michael