Begining with the 1994 model year Nissan changed their VG30DE(TT) VTC sprockets to a multi-piece unit with a separate outer drive cog. There is a misconception that these sprockets are better than the early models with respect to VTC noise, however, except for the substitution of teflon sealing rings, the internal mechanisms are the same. Most importantly, the piston return spring is exactly the same as that which was used in the early model VTC, and this spring is the primary part which allows VTC noise to occur.
At first glance the new VTC appear adjustable, similar to aftermarket Race sprockets, but the bolts used to attach the cog are located on the back making them completely inaccessible once the sprockets are installed on the cams. These adjustment slots are more of a production aid which allowed the assembly worker to align the timing marks faster during manufacture. However in doing so, the bolts are typically not centered in the slots and do not allow an equal amount of adjustment from either side of zero.
When BDE rebuilds late model VTCs, we set the bolts directly on center with the adjustment slot, allowing a full ±10° (crankshaft) of adjustment from either side of zero. Also, BDE relocates the adjuster bolts to the front of the sprockets making them truly user-adjustable when installed. Nissan has also offered this new style VTC as a service replacement with two different versions - one that will fit early (1990 to 1993) camshafts, and one that will fit only late (1994+) model camshafts. BDE has a limited quantity of cores for both versions, and these will only be sold as matched pairs. Please specify the version that you require when ordering. We prefer exchanged cores to be the same version as purchased, under no circumstances will early model VTCs be accepted as cores towards the purchase of late model VTCs.
Early style (1990-93 Original Equipment) BDE upgraded VTC gears are also available.
NEW 3rd Element Timing Ring
Camshaft degree-ing takes into account machining variations throughout the entire engine and synchronizes each camshaft's timing precisely to the crankshaft. In the past, after degree-ing with a traditional two element timing system, the end number on the adjustable pulley's timing scale would have no relevance to the now "degreed" camshaft timing and this could lead to a potential for confusion while tuning. Multiple camshafts, all with different final settings, tend to compound the issue even more.
The BDE 3rd element allows camshaft timing to now make sense after degree-ing so you can make tuning changes on the dyno and always know where your original degreed zero point was.
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