Why swap an HR?
It’s not an upgrade you make cause you want a lot more power. You upgrade cause why would you bother putting another oil burning DE back in. Yes there is a decent power upgrade, (same car/dyno, FBO DE made 239 whp, stock tuned HR made 280), but it’s a much more reliable motor. You retain a fully functioning car with full OEM functionality and compatibility. There isn’t a bunch of fuss of getting a bunch of systems to work.
Just do an LS or 2J swap bro….
Fuck yeah, do it, but you better have deep pockets. You will be lucky getting out of it after $10k and who knows if you would have everything completely functioning OEM. It’s a much much more involved swap. The way we like to explain it, if you can swap another DE in, you have the skills to swap an HR in after we provide the wiring service. The harness will plug in just like it belongs there. Nothing else to do.
What do we need?
- 350Z HR engine harness
- Any HR ECU
- (optional) any complete HR dash harness to save yourself the $75 3rd ecu plug core cost
WE DO NOT NEED ANY OF YOUR DE PARTS. We use all new pins/wires/connectors to properly wire everything in. NO SPLICES!!!
We need an HR engine harness from a Z. I repeat FROM 07-08 350Z!!! We can do the service on an HR G harness, but it doesn’t fit in the Z33 and V35 as well, is more time consuming to complete, and requires more materials. For those reasons there is an upcharge for using HR G harnesses as a base.
What do you need?
- You need a full HR motorset from the engine to the transmission and everything between (flywheel/clutch/slave/starter). Don’t forget your starter/alternator power wire.
- Exhaust manifolds. You need to run HR/VHR test pipes or cats to bolt to the HR headers. You can technically run DE manifolds on your HR to keep DE test pipe/cats, but stock DE manifolds are a downgrade and restrictive. Aftermarket options apply, IE Z1 headers on HR will run DE test pipes still. Long tube headers will fit either as long as there is starter/steering clearance.
- Intakes. There are many intake options out there. Shorties, Long tubes, modified OEM. Take your pick, but your DE intake wont fit
- Coolant Reservoir. We’ve seen everything from a Jager bottle, to a custom aluminium, to a part store universal. It’s just a reservoir. An HR reservoir wont fit unless you also swap to an HR fan shroud (see below)
What don’t you need, but you can if you want to?
- Steering Rack – does not need to be changed but you can. It will just give you a little more starter clearance but dozens of swaps have been done without changing.
- Core support – A DE core support works no problem, just cut a hole in the passenger side for your intake if you please. HR Z core supports swap over to DE Z with no issue if you desire the full swap look
- Radiator – A DE radiator will fit/work with no issues. Just need to make a different upper radiator hose (an old DE lower works really well as a new upper). If your Z desires an HR radiator, it fits in both HR and DE core supports. G has no other bolt in options.
- Radiator fans – DE fans work fine with a DE radiator. HR fans work fine with an HR radiator, but will fit ¾ bolt holes of a DE radiator.
- HR Strut bar – The DE Z strut bar will fit over an HR engine as long as it has no engine cover. And HR bar will swap if you desire
- HR Hood – For a Z, an HR hood is only required to clear an HR strut bar. A DE hood will fit an HR motor with a DE strut bar. See above ^
- PS lines – DE lines fit no issues as long as you grind down that little tab
- Motor Mounts – DE and HR motor mounts are the same
- Transmission mounts – They are Z and G specific. Just match it with what your car is and/or use your old ones
- Driveshaft – No difference unless you are manual swapping
- Cluster – No need to change at all, but if you are wanting that full OEM look (just a different tach), an HR Z plugs right up into a DE Z. G has no other options.
- No modification needed to fuel lines, evap system
Small Details - Power steering reservoir – The DE power steering reservoir sits a little in the way of the passenger side intake. Just bend the bracket a little or make your own. Very simple.
- Brake booster vacuum line – DE vacuum lines come out the passenger side and loops around behind the false firewall. HR comes out the back and through the false firewall. Easiest thing to do is run a ⅜” hose from the HR intake to the side DE line.
- Oil pressure sensor – The Z runs a 3 wire oil pressure sensor. The G runs a one wire oil pressure switch. You can use your original sensor if it doesn’t match your car. If you are using a HR Z harness into a DE G, your oil pressure plug will be converted. If you are running an HR G harness in your Z, I hate you but it will be converted.
I’m manually swapping the car while doing an HR swap.
No problem. We just need to know beforehand to make a couple wiring changes. We can also assist you in what else is involved on your end of the swap.
Can you do an auto HR swap?
We don’t know, and we don’t want to find out that we can’t, so we just assume that we cannot.
I can’t find an HR Z harness!!?
Any HR Z harness. Even from an auto harnesses work. Even a JDM harness will work. Message us and see if we have any cores in stock. They go quick.
AC lines/compressor??
No matter your base HR engine, harness, or the car it’s in, you need to have an HR Z AC compressor. You also need the 2 lines that bolt to the compressor from any HR car.
The first line runs from the compressor to the condenser.
For the second line, If swapping into the G, you just need the short half line that goes from the HR compressor to the brake reservoir compartment. If you are swapping into a Z, the line is a single piece and you will need both halves from an HR car.
Can you swap a 3.7 VHR??
Technically yes, read this first.
Can you swap a 3.7HR
Yes! All the wiring and ECU is the same for a 3.7 block while running HR heads. It’s been done many times before