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| Shell modifications and clearance issues: The transmission tunnel needs to be modified to accept a VG five speed transmission. The shifter hole
must be elongated several inches and the tunnel needs two outward "dents" just forward of the seat
mounting rails. There are detailed photos of these modifications in the "Step by step installation"
section of this website. It is possible to modify a Z31 transmission so that it will fit without any
modification to a four speed 510 but it is quite complicated and very expensive. If you "have" to do a
completely bolt-in conversion and cost is not an issue we will fill you in on the details of these
modifications. If you decide to run the Z31 intake plenum the firewall must be modified for clearance.
For all other available plenums no modifications to the 510 shell are required. If you decide to run the
stock Nissan EFI system you will need to add a hole in the firewall so the ECU wiring can be routed into
the interior of the car. There is a minor steering clearance issue with the VG30 into 510 conversion. The
right side inner tie rod end hits the starter's mounting ear at a point near full lock to the right. This
is barely noticeable when driving a converted car but we want to make sure you are aware of it up front.
It is possible to almost completely eliminate this with modifications to the starter and steering idler
arm assembly. See our "Step by step installation" section for more specific information. All of our
conversion components can be used in right-hand-drive 510s if the stock steering box is eliminated. In a
RHD 510 with stock steering the right header and the starter hit the steering box. |
| Drive shaft modification The stock 510 driveshaft needs to be modified for use with the VG30 transmission. It needs to be
shortened and balanced and the steel dust shield around the slider yoke must be removed. For a sedan or
Coupe’ the driveshaft should measure 35 3/4" between U-joint centers. We highly recommend replacing all
of your U-joints when you install a VG in your 510! |
| Alternators We highly recommend upgrading to a late-model, internally regulated alternator when you convert your
510 to VG power. All VGs require an electric fuel pump and the EFI system (if used) draws some current
as well. The stock alternator simply will not be able to keep up. Any stock VG alternator should be
adequate. We recommend using the stock VG30ET (300ZX Turbo) alternator mounts. They fit most alternators
found in Nissans including the stock 510 alternator. These mounts locate the alternator on the passenger’s
side very close to where the stock one was so the wiring harness does not need to be modified. It is also
possible to modify the stock 300ZX alternator mount by cutting off all the extra junk (you'll see) and
bolting it to the passenger's side of the block. If you do this you will end up with approximately the
same mount as the 300ZXT unit. |
| Internally regulated alternator conversion A simple wiring conversion to use an internally regulated alternator can be done to any 510. First,
unplug the stock six terminal 510 voltage regulator and plug in a jumper wire from the WHITE wire to the
YELLOW wire in the plug where the regulator was connected. Next, plug in a jumper wire from the WHITE and
RED wire to the WHITE and BLACK wire in the same plug. Also, be sure that if your car has a choke heater
relay you unplug it from the wiring harness! If you go to a high-output alternator it’s also a good idea
to replace the charge wire from the alternator with one of heavier gauge. All that's left is to plug in
the internally regulated alternator just like the stock one. |
| Fuel pumps If you opt to run stock-based EFI in your conversion the best fuel pump option is the stock one found in
’89 and newer VW Golfs and Jettas with Digifant fuel injection. These cars have a very nice, compact
plastic surge tank with integral fuel pump mount. A surge tank is a near-necessity for any EFI equipped
510 to prevent fuel starvation under cornering forces, especially when low on fuel. This pump/tank
assembly can be mounted to the bottom of the trunk floor on the right side - opposite the muffler. The
stock fuel tank outlet can be plumbed to the surge tank input and gravity will keep the surge tank full.
If you decide to use a carburetor in your conversion the Holley "Red" pump and regulator work very well. |
| Rear differentials and half shafts No rear end changes are required for a VG conversion but we recommend using a relatively high-geared
limited slip differential. All VG30E transmissions have an exceptionally low 1st gear (3.321:1) so low
rear end gears actually make the car less quick. 3.7 and 3.54 are the most popular choices for VG510
gearing. Many people have had very good luck using Subaru R160 LSD units in VG510s. These diffs should
not be abused as they are on the weak side. If you plan to do lots of drag racing and/or you are running
a modified engine we recommend using an R180 LSD. If you like to do side steps, power shifts, or massive
burnouts an R200 LSD may be worth considering as they are virtually unbreakable. Replace your half shaft
U-joints and check the sliders for play before applying 3 liter V6 torque to them! Old half shaft U-joints
are short lived with the torque of a VG30. |