Decoupling a Q45 from it's tether??

How difficult is it to decouple a Q45 from it's electronics, wiring harness, and various nannies?

In other words, how difficult is it to work with as a motor donor?

What year?

Also, I bet the auto trans is the hard part. engine is probably just a megasquirt + tuning away from standalone. Heck, there may even be a plug in module for the megasquirt for auto trans control.

For mad-awesome excellence on the engine, go with 8 motorcycle carbs and megajolt (probably at a loss of HP though)...

I don't know the answer but I will try anything I can to help.

First off, you may want to define the model year of Q45
90-96 had a 4.5L (VH45DE)
97-01 has a 4.1L (VH41DE)
02-06 had another 4.5L (VK45DE) This time with a lot of "nannies" so my guess is this is the version in question.
https://en.wikipedia.org/wiki/Nissan_VK_engine#VK45DE

See the notes: https://www.youtube.com/watch?v=viubkqMCdRo
https://youtu.be/viubkqMCdRo

NICO section dedicated to 4.5L (more VH than VK but still source for VK)

At the beginning of the learning curve.

Honestly, I want V8 LS power in a car, but have been noticing a lot of cheap Q's on the market. I also see a ton of Caddys and Mercedes (but have no interest in playing with any of them).

I am looking for 350-400 hp RWD with a manual, but want good aftermarket support and reliability. It's a cakewalk with an LS, but the price tags are up a little (because everyone wants an LS).

I figure I should be able to find support, go-fast goodies (and a manual) from the Nissans, but teach me something. I would like to learn what I can.

Earlier ones are easier obviously but what are you trying to do with it? I know they have put a few into 240sx and the likes but the problem with them, like the Toyota v8 1uzfe is there isn't much aftermarket hot rod parts and the ones out there are $$$$. I hear the work well with a turbo strapped on, if you care there's a mighty car mods mini series on putting a vh41 into a stagea (wagon skyline) with a turbo and awd manual. Interesting build but it's just Nissan v8 fodder for you to get your jollies off on.

well, there is the whole OHV or OHC thing... the LS should be a LOT smaller than similar displacement SOHC or DOHC motors simply because of that. Sometimes the longitudinal motors can even be longer because of the drivetrain too. Lower COG by a bit with the OHV.

have space for DOHC?

Dunno about manual trans, that would also be the big sticking point of some of the other cheaper ones. Sure, can you fab something to work? Yes, but usually the easy button is to let the factory engineers do that for you for a minimal extra cost. At least with a manual trans you no longer have the problem of electronic trans control. And power transmission is starting to become a problem with cheap and available manual trans these days. (remember the vorshlag challenge car puking trannies a couple times because the budget could not afford the right trans for the job.)

The Achilles heal on the VH45 like I have in my Challenge Q45 is the knock sensors.
The knock sensor itself is a standard and inexpensive Nissan brand part used across many models.
The issue on the VH is that theses sensors are burried deep in the V of the engine. To get to them requires the removal of the entire plenum.

The plenum is this octopus looking thing.


To get this off, you will disconnect fuel lines, vacuum lines and coolant lines along with electrical connectors. And, that is where the Achilles heal lies because it is conventional wisdom that you can not remove this without damaging something and many of the specialty pieces are No Longer Available from Infiniti or aftermarket.
Full removal: http://www.q45.org/plenum.html

You will find many Q45's listed as, "needs a tune up." This likely means "needs knock sensor replaced" and this can very well mean, "car will never run right again and is headed to JY."

The VH was last sold in 1996 and at 20 years+ ago, this engine is pretty much unsupported by Infiniti.
The VK however is still Infiniti supported. Last offered in 2008 in the FX45 SUV.

In reply to JohnRW1621:

even better reason to megaquirt! Just make a tune that disregards the knock sensor signal.

I believe the z32 transmission bolts up but still takes some fiddling with flywheel and such. But really once you figure it all out, how much if any cheaper with a vh be all said and done when a 4.8 is 500ish or less and as long as you don't have to have a t56 there's a few other manual options. Then there is actually an aftermarket for them and as some have said, there's some nla parts on the infinity motor but not with the gm. I get how doing something different can be more interesting/ maybe cheaper. But there's a reason ls swaps are so popular.

The knock sensors are available on RockAuto.

Actually, I'm not that interested in just being different. Which is why I'd rather the LS.

But my standard method is to find a wrecked complete car with a running drivetrain then zero out the price in the budget by selling off the rest of the car. The Infinity offers good opportunities for recoup, unlike most GM products.

I would generally swap it in on its factory computer, get it running, then switch to MS later.

So, purchase price is better for the LS, but not once you recoup. A strong LS donor car may be $2500 or so, but sub $1000 Infinities are everywhere.

In reply to DeadSkunk:

Same knock sensor as Maxima. Cheap and plentiful.
The issue is that in the process of accessing the knock sensor, you will damage something or a number of things that are NLA.

I think the VH knock sensor job books out at 8 hours!

God mAn, make it easy! 1uzfe. Xcessivemanufacturing.com has the swap parts. Get a late (late 1994+) ls400 for 500$ for 300+hp stock. Or get a pre 1994 1uzfe from a wrecked ls400 for 400$ (like I did!) and turbo and megasquirt for 850hp and up.

Proof. https://m.youtube.com/watch?v=-eHRbes7fwE

In reply to Trackmouse:

Never said I was doing it. I asked about the difficulty, having seen available Q45s and their prices.

I am looking for easy. (Though I am not seeing cheap LS400s around here)

Try "ls 400" and "lexis" as craigslist searches. The methhead that sold mine to me had the listing as "lexis allis 400"

I know of (and I think SVreX does too) of a vandalized but running 02 Q45 (VK) that can be had for $50.

I think the attraction to this cheap is the reason for inquiries.

Trackmouse wrote: Try "ls 400" and "lexis" as craigslist searches. The methhead that sold mine to me had the listing as "lexis allis 400"

Try living in South GA for a while!

I don't need to search by brand. I can search by price only and find so few ads that it is pretty easy to read through all of them. Not too many here.

That sucks. I forget how spoiled I am here in the PNW.

Trackmouse wrote: God mAn, make it easy! 1uzfe. Xcessivemanufacturing.com has the swap parts. Get a late (late 1994+) ls400 for 500$ for 300+hp stock. Or get a pre 1994 1uzfe from a wrecked ls400 for 400$ (like I did!) and turbo and megasquirt for 850hp and up. Proof. https://m.youtube.com/watch?v=-eHRbes7fwE

But how many stock 1uz have you seen hold anywhere near that power? All I ever see is internet lore that they are amazing but everything I see where people actually put a turbo or supercharger on, they don't last long at all. Is your naturally aspirated? Have you dynoed it? I make more hp and torque with a mostly stock 4cyl than my friends sc400 with bolt ons does.

JohnRW1621 wrote: I know of (and I think SVreX does too) of a vandalized but running 02 Q45 (VK) that can be had for $50. I think the attraction to this cheap is the reason for inquiries.

Umm, nope. Clue me in.

JohnRW1621 wrote: In reply to DeadSkunk: Same knock sensor as Maxima. Cheap and plentiful. The issue is that in the process of accessing the knock sensor, you will damage something or a number of things that are NLA. I think the VH knock sensor job books out at 8 hours!

So, it sounds like you are saying if I get good at replacing knock sensors, I can buy all the sub-$1000 Q45's I can find, and sell them for $2500 after 8 hours of work.

Or learn how to flash the computer to ignore the knock sensor and make $1500 in minutes.

Details sent via PM.

The major flaw to the plan of flipping 90-96 Infiniti Q45's is that there really is nearly no one actively searching to buy one. These are significantly forgotten, overlooked and un-noticed cars.

All the better for me because I really quite like mine!

SVreX wrote:

JohnRW1621 wrote: I know of (and I think SVreX does too) of a vandalized but running 02 Q45 (VK) that can be had for $50. I think the attraction to this cheap is the reason for inquiries.

Umm, nope. Clue me in.

He might know a guy, that just may have one in his basement that he doesn't need or really want at this point.

That mess under the manifold is just a bunch of hoses and wires. If breaking those is your issue anyone who has owned a FD could probably offer you a solution to any problem you encounter.