Bore and Stroke
Bore and Stroke
The Top Secret Team used a VQ30DET motor instead of our very own VQ35DE to produce 700hp. I remember something about there being a "better" bore and stroke.
VQ30DE:
Bore: 93mm
Stroke: 73.3mm
VQ35DE
Bore: 95.5mm
Stroke: 81.4mm
Smaller stroke in the 3.0, yet the twin turbo Z VG30DETT has a stroke of 83mm.
Would someone care to explain why Top Secret went with the VQ30 instead of our 3.5??
VQ30DE:
Bore: 93mm
Stroke: 73.3mm
VQ35DE
Bore: 95.5mm
Stroke: 81.4mm
Smaller stroke in the 3.0, yet the twin turbo Z VG30DETT has a stroke of 83mm.
Would someone care to explain why Top Secret went with the VQ30 instead of our 3.5??
Well, the shorter stroke of the VG motor will allow for a higher reving motor. The VG uses a stronger cast iron block vs. the aluminum block of the VQ. Lastely, there is a much stronger selection of parts and knowledge availible for the VG, so they went with what works...without reinventing the wheel.
At least thats my theory. ")
At least thats my theory. ")
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Joined: May 2003
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From: Illinois
Agreed; the shorter stroke allows for a higher revving, more usable powerband, but just imagine a fully built 4.3 L block with the AEBS stroker kit!! Damn!! It might not be abale to rev as high, but just imagine the torque increase!
-Justin
-Justin
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Joined: Aug 2002
Posts: 560
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From: austin
see my mathematical analysis of the engine bore/stroke and piston speeds/acceleration in this thread:
https://my350z.com/forum/showthread....threadid=90937
https://my350z.com/forum/showthread....threadid=90937
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Joined: Sep 2002
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From: So Cal
Originally posted by gq_626
Well, the shorter stroke of the VG motor will allow for a higher reving motor. The VG uses a stronger cast iron block vs. the aluminum block of the VQ. Lastely, there is a much stronger selection of parts and knowledge availible for the VG, so they went with what works...without reinventing the wheel.
At least thats my theory. ")
Well, the shorter stroke of the VG motor will allow for a higher reving motor. The VG uses a stronger cast iron block vs. the aluminum block of the VQ. Lastely, there is a much stronger selection of parts and knowledge availible for the VG, so they went with what works...without reinventing the wheel.
At least thats my theory. ")
Internet rumor. If this is the car with the custom stainless manifold, then it has been through three revisdions and has been in many mags throughout its progress. It is a VQ35, Super Street got it wrong and it just flew from there. Anyone who has seen a VQ30DE or DET can see it is not the engine used in the Top Secret Z car. Modified Mag had an article on the same car and got it right by calling it a VQ35. The VQ30DET TopSecret built is a single turbo unit they installed in a white R34 GT-R. This has been discussed to death in several other threads in the engine mod forum.
The shorter stroke doesn't do much by itself. Typically though, a shorter stroke allows a longer conrod, which allows a higher rpm by reducing piston side loads, all else being equal.
The shorter stroke doesn't do much by itself. Typically though, a shorter stroke allows a longer conrod, which allows a higher rpm by reducing piston side loads, all else being equal.
