hazesleepgod

My current build! Vq37vhr into z31 300zx

(Travelling from Zcar Forum)

(1/7/24)

Well, you've stepped foot into what my brain has been concocting since the purchase of my Z (welcome.), so let just jump right into the meat and potatoes.

I'm looking to swap my Z's overall powertrain, from the VG30ET/FS5R90A to the more modern 370z's VQ37VHR/CD009. While there are numerous reasons, I won't bore you with, the main reasons are, overall forged bottom end, fantastic base hp/lbs.-ft ratings as well as overall reliability and availability, but lastly sticking with the Nissan v6 mantra (and to save myself fabrication for more cylinders. we'll talk about that later.) I haven't fully decided whether or not aspiration is necessary, but with the numbers I'm looking for in the end, that's a bridge I can cross later. And the CD009 commonly used for drift setups with 2JZs and LS engines, again reliability WON'T be an issue.

The CD009 interestingly has a S1 sequential transmission kit directly off the prop cars in the latest FATF movies. I've been in the deep web looking for a set of straight-cut gears for future endeavors but came up empty-handed and likely will need custom made. As childish or corny as it may sound, we can all agree that the M3 GT-R with its transmission setup makes any and all listeners' fold. Forgive me for wanting this childhood dream lol. edit; I’m thinking to stick with the same r-end out of a 370z, however doing a little digging tells me that some Is300 differentials will give me a longer gear ratio. Again, all up to speculation, please correct me if I’m wrong.

Fitment with the general engine, transmission, and overall other parts to even have a working car, is a hurdle to overcome regardless of my situation. Were fittin' squares into circular holes here. So, to negate a lot of that, a rear mounted radiator setup, as well as an intercooler relocation. Battery, Fusebox, Engine Harness, and ECU with all working components will be cleaned up and refitted somewhere more accessible and manageable. Apart from the block and heads the only other things stuffed in that engine bay should be the air intake system, the fuel system, brake booster, and exhaust system. ((insert forgotten component here.)) Lastly in terms of fitment, I'm looking to extend the wheelbase by any means, 17" wheels 8.5F/9.5R with some proper spacers to account for the added width.

Ooookay, so as outlandish as that all sounds, I admittedly have been saving the more ludicrous bit for last. So, the entire from end from the tip of the front frame to the firewall will be cut off, as well as all trunk space, including the wheel wells, minus the top hatch. (I don't hate myself enough to figure that shit out.) Taking inspiration from Riley Stair and his Pontiac Trans Am, and Ken Blocks Hoonicorn, may he rest in peace, by making a custom tube chassis using what's left of the chassis. Why am I making this all the more difficult for myself you may ask. Well, it's my way cutting off the arm to save the body, more specifically to also make sure mounting and placement, are 100% manageable and accessible, while overall safety and rigidity of the chassis, there is some frame damage to take care of regardless. While opening up opportunities for mounting, that also gives me proper mounting for safety gear like harnesses and bucket seats but also should, theoretically of course, free up hundreds of pounds in the one-and-a-half-ton body alone. All Lexan windows, Door-cards, to Part relocation, every little bit will add up. Power to weight ratio is a keynote with a build of this type. I don't plan on pushing more than 450bhp but expect the chassis to total out around 2550lbs.

I should now probably state the general purpose for the build apart from it just being fun. I mean hell the car isn't even on jackstands yet. I'm personally hailing from Iowa, one of the few states on the map that doesn't really have a nationally recognized track, apart from Knoxville, with our dirt/sprint cars. No higher-class events further than that. But the point I'm trying to make is, our state regulations for street legal "restoration/hot rod builds" are shockingly, and I do mean SHOCKINGLY low. I am going to build the closest thing we can get to a street-legal, pro-am*, racecar to the point of teetering that line. Throw all comfort and practicality to the wind, if it's not required by state, then we consult the safety requirements on a track. In all honesty, I'm not sure the car will ever see a track in a competitive sense, maybe for a hot lap, but overall, this car is to represent my home-state, it's home, the spirit of racing, and just how batshit gearheads we really are.

Thanks for reading, will soon update with pictures. Follow along my journey, it's gonna be killer.

Much love,

Lennon.

(edit #1 ((3/5/24))

Hello and welcome back the pandemonium of inevitable self-destruction! So, the car is now up on jackstands, and I've made the plan for the upcoming summer, and figured I'd update any and all with the long-awaited photos I'd promised. So, the current plan is, do one last good tune up, and really just enjoy the car one last good time, before the summer either ends, I find the bits and ends I'm looking for earlier than expected, or lastly, send the 115k mile engine on its final farewell, as its currently leaking oil, and pissing gas on the cylinder heads. 

I'll be the first to tell you, that the more digging I do, (and throwing engine and transmission mounting out the window), the more realistic and feasible this is all turning into. 

First off, I'm currently on the hunt for 2 separate vehicles. First, a similar year, two passenger 300zx. Doesn't have to be perfect, or even running for that matter, but having a donor chassis, especially with some of the availability in the Midwest, a good deal shouldn't be too hard to come by. Second, I'm on the hunt for a '12-'18 model 370z. This will be achieved by going through salvage auctions and looking for a model with damage to the body. Hail, rear end, side impact, all perfect, so long as the engine and a code 'CD-8' CD-009 are intact, it'll be used. Just browsing the sites, I'm sure it wouldn't be a stretch to find a full powertrain in a salvage chassis for under 3 maybe 4k. So, let's do the math, a decent donor z31 for anywhere between 1-2k, and a powertrain donor for around 3-4. Worst case scenario, I'm paying a grand less for what the powertrain would cost me new all by itself. 

Now that we got the part sourcing out of the way, how in the hell am I going to fit the beast into the current chassis? The chassis itself, is fairly rust-free for being 30+ years old, only bits being a quarter side hole near the driver side floorboard, a patch growing near a hole on the rear hatch, and a bit of the frame is going to need some persuasion and reinforcements, all of which perfectly manageable with a sand blaster and a tig welder. It's going to be a mix of rag-tag, backwoods, redneck magic, and proper CAD software, and hopefully a couple gurus on sight to make sure I'm not actively making an ass of myself. The mounting of the engine and transmission are weirdly enough on the back burner, more-so how I'm going to mount the suspension, and make it play nice with the front axles and such. I can show some base sketches if you'd like but I'm going to preface by saying I'm not a professional and/or any kind of engineer by any-means, this is all a passion project. I figure I can fab up some kinda strut-plate through what would in essence be a fender bar/reinforcement, then making a strut brace off of that very setup. Another thing to take into account is how my exhaust setup would be, and there has been some debate in my shop what kind it should be. We ultimately settled on a x-pipe design straight from the engine to the side skirts, old-school corvette/'rat-rod' style if you will. Whether the exhaust tips should be a Nascar boom-tube or a large A/C Cobra tube on each side is still in the air (how subtle do I reeeeeally wanna be here? lol) 

I wanted to really kinda focus on the rear end as a whole here, as I planned on deleting the rear, more leaning towards the benefits of mounting with a tube chassis. But I'm stuck on whether or not ill still need a rear subframe, in which I could probably steal it off the 370z, or I'm told Silvia subframe fit better on stock chassis, but I also think I'm just confusing myself, and just need to make a proper cradle for the diff. The suspension however is a different question on the rear end. Since I'm not dealing with the common coil-over-shock setup (iykyk), does that mean I need to reconsider how my strut towers are placed? Or once again, will it even matter? One option I've actually been really considering, and an example of me being a glutton for pain, but configuring a rear cantilever setup, removing the need for stock chassis struts, and at the same time being a cradle for the differential. Logically speaking apart from a select few fabricated parts I'd need specially made, everything is made more accessible and, in some instances, a better ride for the bare road than stiff coilovers. Just a thought but please let me know your thoughts! I haven't really had anyone else to bring the matter to, all my friends are humble home mechanics as well.

Most of the electrical setup is gonna be the main challenge. It'll be as barebones as it can get, with a switch to power anything that needs electricity strictly. For obvious reasons, battery relocation either behind the driver seat, or somewhere close, and I picture the ECU remaining in the same location as the OEM 300's. Overhead switch panel, 2 kill-switches (one obvious, one hidden). Apart from some basic modifications to the engine in terms of minor, power, reliability, and accessibility, I'm hoping to be able to use either the stock wiring harness off the VQ37, or if I find an aftermarket one that's pretty plug and play, the better. I guess my questions lie in the realm of, how difficult are 370z electronics? (sorry I'm aware how bleak that question is...) and are there any hurdles I'm gonna need to watch for in working on these specific electronics. The final question is about the digital dash. I'm lucky enough to have found a model with a perfectly working digital dashboard, and a good part of me is sad to see it go, It's a part of the cars whole charm and aesthetic to me. I'm curious if the dashboard is accessible to be restored/modified to run properly with the new powertrain? Would it just be a matter in cracking the limiter, and programming it correctly, or would I be better off just upgrading to dials, or a newer screen.

Any and all other things of note, are going to be in the realms of bodywork, personal taste, and other comforts, as hypocritical that may sound with this build. In terms of body panels, I've been reading into laying fiberglass into molds and kinda designing from there. There are of course horror stories with self-made bodywork, but I'm a bit of a perfectionist, in the sense of if it doesn't look good, I won't be satisfied until it does. Interior will be about as racecar as you can expect it to be, no sound-deadening, not much of a dash, extremely cramped, but i'd like to make it at least comfortably accessible to a passenger. I'm likely gonna do a cast or something similar, of the original dashboard, the 2-dial design has been through about each and every Z generation, and I intend to keep it that way. Music while driving is questionable, the driver in my mind says just buy a decent Bluetooth speaker but the builder wants a full setup, custom build to the chassis. I'm taking away any and all comforts apart from an active heat-source, so let me have my music. The rest is just wrapping/paint, which the entire car will have a matte black base, then covered lettering, sprayed over by a glossy dark pearlescent British racing green. So, to recap, an American child wishes to take a Japanese sports car, inspired by GT Porsche of the time & modified for racing, and paints it British Racing Green. I don't see anything wrong with that, if you don't.

But that's about what I can rattle off the top of my head, as of now. Please let me know of any questions/comments/or concerns, I love hearing your guy's feedback, and it's all taken into deep consideration. Have a lovely day, and I'll update sooner than later.

Much love, 

Lennon