i was just curious in what the differences were between say a 5th or 6th gen maxima with 260hp.... vs.... and 3.5 altima/3.5 pathfinder with 240hp... vs. the 350z w/ 280hp?. is it in the ECU w/ timing ... intake manifold design.... exhaust...? just kinda been in the back of my head for a while. thanks.

 

I know the diffrence between the maxima / 350 is the manifold and intake design... not sure if there is anything els....

 

Basically you answered your own question. Overall the engine is the same, but the ECU is different, the intake is different, and the exhaust is different.

 

how are they different... and are the parts inter-changeable.... ie.... putting a 350z intake manifold & ecu in say... a pathfinder

 

why would you do that ? its a pathfinder....

 

keyword - "ie"

 

it's done for marketing reasons, segmenting products for broader demographics. I've heard one reason for the extra 7 horseys on the Z vs the G35 (287 vs 280) is because of a bigger throttle body. The main reason why the Z is louder than the Infiniti.

STEVtec said the bore and stroke specs are different too in the Off-topic forum, accounting for a lot of the hp difference between the VQs.

 

Me and my dad drove a few different Infiniti/Nissans before he settled on his 04 Altima 3.5SE and me on my 99 Maxima SE. We drove a G35, 03 Maxima, 350z, and then his 04 Altima 3.5SE. Basically all the VQs felt the same when it came to power and refinement, which is one of the main reasons he bought the Altima over the 03 Max and the G35... same great power and almost as many options for much less money. I'm pretty sure the differences between them are mostly suspension/drivetrain configurations... the difference in power is barely noticeable and mostly marketing.

 

VQ30: 3.66in x 2.89in
VQ35: 3.78in x 3.20in

ALL of the VQ35s have the same internal configurations.

The VQ engine line is now in its 3rd generation. For the versions we've seen in the US, that can be broken down as follows:

1st Gen VQ
VQ30DE: 95-99 Maxima, 190hp/205tq

2nd Gen VQ

VQ30DE-K: 00-01 Maxima, 222hp/217tq
VQ35DE: 02-03 Maxima/I35, 02-current Altima 3.5SE, Pathfinder, 240hp/265tq

3rd Gen VQ
VQ35DE: G35s, G35c, Z, FX35, 04 Maxima??, 280-287hp/270tq


There were a lot of changes made between the 2nd gen VQ35 and the 3rd gen VQ35. Hotter cams, more flexible CVTC system (varies by 35 degrees vs 27), modified intake manifold, exhaust work, port modifications, and misc modifications to the block to reduce NVH. The intake manifold changes seem to be key because that has a very big impact on the power curve of an engine. The 3g VQ35 makes a ton more top-end power than the 2g does. The 2g VQ35 debuted here in the US in the Pathfinder, so naturally in a truck you want as much torque at the low-end as possible. The 2g VQ35 makes peak torque at only 3200 rpm which is ideal for that. It seems that Nissan stuffed basically the same engine into the Altima and 02-03 Maxima as well, but just rated it differently.

As for the 3g VQ35, Nissan is playing number games with this engine also. All of them seem to be dynoing about the same regardless of ratings. G35s 6mt has dynoed at about 227 whp, and the coupe the same. The Z dynos a tad higher (235 whp range) I guess because of the throttle body, and I think the intake plenum may be slightly different also but who knows. Tracking down exact data is very difficult. If Nissan is using the 3g VQ35DE design in the 04 Maxima (and the track results suggest they are) then the 265/255 ratings for the 04 Max are probably under-rated by a good bit.


References:
- SAE 940991 : Development of a New-Generation Lightweight 3-Liter V6 Nissan Engine
- SAE 2000-01-0668 : Second Generation of High-Response V6 Engine Series (3.0 and 3.5 Liters)
- SAE 2002-01-0450 : Third Generation of High-Response and High-Output 3.5l V-6 Engine

 

Great review!

But there is one more Nissan product using the VQ, the Murano. We have the 2003 Murano (our third VQ-- 95 max, 2000 I30 before) which I suspect uses the 2nd generation VQ35DE since it is rated at ~245 hp.

Of note, the Murano is the only US Nissan product to us a continuously variable automatic transmission (CVT). No shift points! The smooth 3.5 VQ with the CVT makes for very spirited acceleration, especially when the tranny is in sport mode.

 

Oh yeah, the Murano. I thought I might have been missing one.

Thanks

 

Uhh wouldn't that be

93.0mm x 73.3mm and
95.5mm x 81.4mm



Also the cam part numbers on the 2k2+ Maxima are identical to the cam part numbers on the 2k3 350Z so they aren't 'hotter'.

 

This is where my "2.5g" VQ theory comes in.

The "2nd gen" VQ35 described in these SAE papers by Nissan also says it has a 10.0:1 compression ratio when it's really 10.3:1 according to a few other sources. But then I thought I read that somebody with a shop manual said that that said it wasn't 10.3:1 but really 10.0:1. Like I said, exact data is tough to track down.

If the Altima also has the same cams and CR, then I think that would make the Alty/Max and possibly Murano engines "2.5g" VQ35DEs and then perhaps the Pathfinder is a true "2.0g" VQ35DE.

I wish Nissan would differentiate their engine codes a bit like Honda does. That would certainly help.

 

The 2k2 Altima data says 10.0 to 1 and the 2k2 Maxima is 10.3 to 1 however both spec sheets list the exact same compression pressure. The Nissan data isn't all correct because you can't have different compressions between engines and list one having better cams if internally they all share the exact same parts.
Now the 2k4 Maxima and 2k4 350Z do have different head part numbers from the previous engines.

 

I give up. Too much conflicting data.

This does however support the 2k4 Max = 3g VQ theory.