This isn't exactly about the VQ30DETT, but it is about the VQ series, and mentions a comparison to the Z32.Secrets of the VQ
[ http://www.freshalloy.com/site/features/interviews/vqengine/001/002-jimwolf.shtml ]By Joe Maserat Jim Wolf and Clark Steppler are big on the 350Z/G35 VQ platform. They see the potential of it, see it in its adolescence and are ready to kick it in its ass. If you have an adolescent, you know what I mean. I'm talking about the Jim Wolf Technologies Twin Turbo kit. This is going to be the clean setup to make good HP, and keep it running. But really, after talking to them at length one morning, seeing the design work and the product working well, I'm struck by this thought: If Nissan were going to offer a factory twin turbo setup, they could probably do no better than the Jim Wolf Technology kit. When you actually design parts for the manufacturer, you're able to offer an as good as or better than OEM setup. And the new car platforms are even better than ever. I think Nissan is going in the right direction, and offering fun and exciting products again, and seem to be ready to have fun at the corporate level. And it's great that tuners like Jim Wolf and Clark Steppler are excited about what's coming out, and want to bring things us a notch. FA: What do you admire about the new VQ series of engines?
Clark: The lightness of it. The lightness of the reciprocating mass, allowing for low vibration and increased responsiveness.
Jim: The micro polishing, the precision of assembly, the head flow design is much better, the mass flow is more proportionate, more efficient. There is a consistency in power output between motors in cars. This makes installing an aftermarket part more predictable. If it made X horsepower on this car, it will most likely make it on yours. Also the HP between brand new and broken is very close, sometimes only 1%
Clark: A lot of these changes have also been applied to many of the late model engine designs as well. They are becoming lighter, more compact with better power output. FA: What differences do you see between the VQ30 and the VQ35?
Clark: They've increased the bore and the stroke first off. It is very difficult to make these increases and keep it smooth. The VQ engine in general isn't as smooth as say an Inline 6 like the RB motors. You can make some changes to bore and stroke, but keeping it smooth is tough when the bore is increased. FA: Do you think they'll keep refining this motor or come out with an entirely new family of engines? Jim: They will keep this engine. There are more advances to be had with cam phasing, allowing more aggressive cam shafts. Also direct injection. Clark: There are already other displacements of this motor available in other markets around the world, with technology available here. I would look for advancements in the cylinder heads Jim: The 3.5 improved immensely on cylinder head cooling compared to the 3.0. The change of the plug design allowed for smaller bosses which in turn allowed for better cooling around the head. This reduces the chance of detonation, damaging the engine and increasing emissions. The next step will be higher volumetric efficiencies, which will allow for more HP. It will need to be more efficient to gain HP. Direct injection will allow more overlap of fresh air, without significant hydro-carbons passing through on the overlap. Direct injection promises higher volumetric efficiencies without the hydrocarbons. Clark: But you're going to need cleaner burning catalysts for that. FA: How does the cam phasing play a role in all of this?
Jim: The 3.5 Pathfinder was the first to use a pseudo open loop cam phasing, where the older VG30 used a cam switching. It was either Bang! ON, or Bang! OFF.
Clark: The Pathfinder was open loop, which is good, yet cruder than what is in the motor today. FA: So now the cam is infinitely adjustable?
Jim: Yes
Clark: Where it used to be a 20 degree switch, the cams can be adjusted anywhere along the path. FA: How much adjustment is built in now?
Clark: About 32 degrees, which is considerable. Also, once they were able to get the cam phasing, they were able to use it as an internal EGR (exhaust gas recirculation). At light throttle they are able to phase the cams to allow for EGR, yet at wide open throttle they are able to phase the cam for maximum power. Where they started with no adjustment, then went to the ON or OFF switching, the variable cam timing allows for lower emissions, better power and even fewer warranty issues not that there is no external EGR and the related parts to run it. FA: Do you think the factory will offer a forced induction VQ motor?
Clark: They already have a VQ turbo, just not here. FA: When do you think we'll see one?
FA: 2007 with the Skyline GTR.
Clark: The 3.5 would be the logical choice for that car. It's already setup for the V6.
FA: Would they put the 4.0 in it?
Clark: Maybe. There is some limitation to putting the 4.0 engine in. The rods and mains are bigger, the rods longer which means more height. Which is what you're trying to avoid in a sports car.
FA: it would most likely be too much modification to make it work.
Jim: Yeah, Nissan is all about streamlining right now. FA: What can you tell us about the JWT kit?
Jim: What we have put together is a kit that a guy can put on his with any stage of modification. It can be bone stock or already modified. You don't pull the engine, heck you don't even have to pull the radiator. We are using ductile cast manifolds; mandrel bent tubing and the latest Garrett ball-bearing turbos for near instant spool. They are sized conservatively for a big HP motor, but they are most appropriate for a high compression motor. But even if you went to low compression, the system as it is will supply about 530 HP. (More info here...) FA: Will you offer a 650 HP system like the Z32 Sport650?
FA: We intend to pursue that in the future, but right now we are just focused on fuel systems and control units.
Clark: One of our biggest concerns at the moment is CARB legality. It's been the primary focus of research. It would be easy to put a kit out, but designing it and tuning it to meet CARB rules is the hard part. FA: What is the ETA of the system?
Jim: Were still shooting for the first ΒΌ of 05, seeing as April is a week away, I'll say 2nd quarter of 2005. As soon as we have the exemption order, we should be good to go. FA: What is the difference in your opinion between the Z32 and Z33?
Clark: The Z33 is out of the box a great handling car.
Jim: If you put $5,000 worth of suspension on a Z32, you'd be to where the Z33 is.
Clark: With our turbo kit, the car finally has the power to meet up with the handling. If you had a 400 HP 300ZX, you had better have had some suspension or you could be in trouble.
|
