73 240Z VQ37VHR Swap Build Log

[Sanchez]

Front frame rail moving along. Driver side ready to be tacked and tweaked after getting a liberal amount of 2k Epoxy primer in it. I’m thinking given this frame rail had to be welded after the crossmember I will need to do a bit of bracing with thick square either inside the rail and weld to it or some angle iron on the outside for support.

Ford Performance trak-loc arrived, the pumpkin in my 8.8 currently is being really stubborn so I might need to take it to an axle shop to separate it from the housing. And I’ll be ordering more suspension parts from Apex Engineered at the next payday.

[Sanchez]

Been a hot minute since an update. Progress slowed due to life coming up. I haven’t had a lot of time to do the welding needed to finish repairing the front frame rails and test fit the engine because we've been pretty busy at our garage doing repairs and getting ready for hosting Boeing’s Annual Car Show. I also ran into an issue with those little pocket to access the front cross member bolts on the front frame rail curtain. I swear they used to sell them individually but I can’t find them anywhere and they appear to be 16ga which my cheap metal brake won’t handle. Ran out of welding gas and my local AirGas was back logged because they are supplying gas to the construction team finishing up the new soccer stadium here. Lots of road blocks.

 

What I have accomplished in this time:

- Getting the fuel tank hot tanked this weekend and getting a buddy going on installing a Holley Sniper Return Module fuel pump hanger. It looks similar to the Aeromotive Phantom unit but $150 less and no foam baffle. But while I can make my own little metal baffle box for a few dollars.

- Started welding some on the body panels, mainly rear hatch and the channel around it where some of the metal disintegrated.

- Radiator. The inlet and outlet on the VQ37 is reversed from the L24 so the options are buying a 240Z rad and having the bungs cut and moved, or some crazy piping. After a lot of measuring and cross referencing I found the radiator from a 70’s-80’s Jeep CJ has bungs correctly placed, has a 24”x15.7” (LxH) core, so almost identical to the Mishimoto/Champion Z rad with a little taller core but same overall height. I’m going to purchase a cheap Amazon one so I can test fit it, then get a higher quality Champion rad later.

Edited October 8, 2022 by Sanchez

[Sanchez]

Update video releasing on our YouTube channel soon, and…

 

 

 

 

Decided to get a little motivation to work faster on this project attached to my body

[Sanchez]

Pretty much all of my suspension from Apex Engineered has arrived. Just waiting on the coilovers which are shipped separately by Riaction. All the parts are quality made, but the only issue I’ve run into is that they sent me a L/R outer tie rod instead of the R/R outer tie rod. I ordered 2 standard thread inner tie rods from Zcardepot, but they claim they have them for the left side as well… I don’t know if that’s true or not because I heard these RareParts tie rods are only for the right side. Can anyone confirm if Zcardepot was able to source a manufacturer of left hand inner tie rods? Apex has been amazing about responsiveness so I have no doubt they’ll fix the issue for me with a new part if needed. Second small bit of confusion is I ordered the rear 370Z single brake caliper mount that should allow use of the drum-in-rotor parking brake, but some quick test fitting looks like there might be clearance issues with the parking brake hardware. I will update after some more in depth testing.

 

Still slowly getting my front frame rails together, taking my time to do it safely, strongly, and make sure everything is lined up very well. The Jeep CJ radiator looks like a great fit for a Z with a VQ in it. A little trimming to the radiator mounts that came on it and it will slip into place.

 

Been working on the fuel tank too with a Holley Sniper return style in tank module. My measurements are a little off and the area I cut put the top of the piece in contact with the rear frame by 1-2mm but I think that can be solved with the adjustment in the straps and some slightly thicker rubber isolator pads. Can anyone confirm that there is some adjustment in the straps using the J-bolt? Also building a small swirl/hallway baffle box for the pump to sit in. I think my design should allow plenty of flow even at a 1/8 tank (if I ever let it get that low) while stopping any slosh from starving the pump.

 

[Dat73z]

There is some adjustment in the Jbolted straps but tucked up like OE is better imo. My OE tank is cut and welded similar to how you have it up top for a fuel cell plate and the dimensions are similar to OE with the OE rubber pads. Since you are fabricating all of that as well see if you can match the OE dimensions, so your tank is appropriately level and doesn't hang low. 

[Sanchez]

@Dat73z

Thanks for info about the strap adjustment. Ideally I would like to avoid the tank sitting lower than factory. I probably should’ve done a few extra measurements while marking my cuts. I may be able to drop the plate I made another 2-3mm to make it work without using the adjustment in the J-bolt. Ideally this is only a temporary tank to get the car together and running first before I ditch it for a custom built aluminum tank, or I’ve even seen some companies making composite recreations of S30 tanks recently.

[Sanchez]

Realized it had been a minute since an update. Life and full time job getting in the way of doing serious work on the projects as you all are very familiar with. But I got some head way and updates.

 

Engine:

there is a company D&D Power Belts that makes a 31.75” outside circumference belt with 7 ribs that is a fit for the VQ37VHR with just an alternator and the stock tensioner. The part number is 310K7; however, they don’t have it in stock and it took 3 purchases from different suppliers who all sent me 315K7 instead before I finally got an answer that it would be a few months before they have it in stock. Would’ve been nice if they actually told me that before I had return multiple belts…

 

Body:

Driver front frame rail all welded in and started my cut for the patch on the passenger side. I’m going to do simple box tube to tie them together when done. Also started modifying the front front core supports to run the intakes for the engine up to the front out of the engine bay.

Apex Parts:

I’ve run into a few issues with the Apex Parts. They sent one of my rear knuckles which was welded to the coilover sleeve incorrectly causing the hub bolt to not clear. While they have been very responsive they still have not sent a working part out like they said they would. It’s been a bit frustrating, but I don’t exactly need the part at the moment and I understand they are busy fulfilling other orders… it just seems like this should’ve been sorted out a while ago and shouldn’t require me reaching out almost every week and still just hearing that they will get me a new one out.

 

 

Edited April 16, 2023 by Sanchez

[Sanchez]

Quick update: Belt

Finally found a place with the belt I suspected would fit perfectly. It’s a D&D Powerdrive 310K7. Perfect fit for no accessories. Haven’t run it yet but the tensioner marks line up perfectly and it goes in with no trouble or prying of stuff required.

[Sanchez]

So it’s been a while since an update. Progress stalled due a lengthy vacation followed by work being short staffed after I returned, followed by changing jobs which required opening and running a new facility, and finally an MG B that came to the garage for work that I ended taking on. A real whirlwind of stuff building up, but I’m ready to jump back on the Z now.

 

Apex Engineered got me a new rear knuckle to fix the issue a bolt hole being unusable so I’m hoping we will get a video of the kit up on our YouTube soon.

[Nismospek]

Have you mocked up the headers on yours? It looks like I am going to need to get the stock ones modified since they point towards the firewall. 

[Sanchez]

On 10/2/2023 at 11:06 AM, Nismospek said:

Have you mocked up the headers on yours? It looks like I am going to need to get the stock ones modified since they point towards the firewall. 

They do need to be chopped right at the down pipe flange and rotated to clear the transmission tunnel for any stock or stock-like aftermarket header. I may chop it and extend it to use v-band clamps instead. I still haven’t decided on it.

 

I just got back to working on it after a few months break to focus on opening a new laboratory facility at work… but in that time I came across a series 1.5 for a steal and picked it up. The unibody is pretty tweaked, but it has some solid parts, perfect glass, and I’ll probably end up parting most of it out and use some parts for myself.

Edited November 4, 2023 by Sanchez

[Gumiho3]

Hey Sanchez, how the build going?

 

My ECM decided to die on me and now I have a surging idle. I plugged consult in to do a idle relearn, but consult says I have a NG neutral switch. With it being this way I cannot start the relearn with consult.

 

Where did you locate the neutral switch? Have you ever heard of a vq37 with a surging idle? It goes from 800rpm to 3000rpm. It drops as it warms up.  When I unplug the gas pedal the idle stays constant but higher than normal(2k rpm)

[Sanchez]

16 hours ago, Gumiho3 said:

Hey Sanchez, how the build going?

 

My ECM decided to die on me and now I have a surging idle. I plugged consult in to do a idle relearn, but consult says I have a NG neutral switch. With it being this way I cannot start the relearn with consult.

 

Where did you locate the neutral switch? Have you ever heard of a vq37 with a surging idle? It goes from 800rpm to 3000rpm. It drops as it warms up.  When I unplug the gas pedal the idle stays constant but higher than normal(2k rpm)

The build is going slowly, work has been hectic, I’m buying a house, and family member health has me slammed. I still get a few hours of work in on Sundays and when the weather is nicer I can squeeze some time in on Mondays hopefully. I have nearly finished up the body work on the front half of the car since my last update. Just working on getting some crush sleeve installed at the sway bar mounts, then I should be ready to mock up engine and trans placement.

 

I haven’t fired up my engine in a while, but when I did it didn’t have surging issues. When I got my wiring and ECU modified by Hexa Garage they never connected the wire from my neutral safety switch to the ECU, so I had to go into the harness and make that connection. However; that caused “no start” logic so the engine wouldn’t even fire until it was fixed.
 

But I maybe able to help you diagnose with some knowledge I have from my RX8. When it gets cold and I haven’t driven the car in a while my idle surges at idle until I press the clutch and put the car into a gear. Then after some driving the trans warms up and the neutral switch stops sticking. Modern car logic has different idle speeds for different situations on cold starts, so neutral with clutch off it will high idle until up to temp, but once in gear it lowers the idle so you aren’t trying to shift into first at 1500rpm from a stop. The sticky neutral switch keeps pulsing the on/off signal to the ECU causing it to go from out-of-gear-fast-idle to in-gear-fast-idle. Add that to the fact you need to do an idle relearn and It makes sense why you are getting such a huge surge from 3000-800rpm.
 

If I remember correctly the neutral switch (and clutch switch which could also be at fault, so try the test on both) are just voltage on/off switches, so try feeding a 5-12v signal to those wires going to the ECU using a power supply or spare battery and report back if anything changes.

[Gumiho3]

That green wire was your pnp+ to the ecu?

 

The pic on page 4.

 

If so,  I'll try to add power thru that or just try to replace the switch

[Sanchez]

On 12/5/2021 at 10:35 PM, Sanchez said:

@Gumiho3

If you are referencing this picture then yes that is a green wire that supplies power for the PNP. In my case Hexa Garage never hooked up the wire running from my PNP to the ECU so I was powering that green wire at the plug but it never told to ECU to trigger a start signal and I had to borrow a snap-on diagnostic tool with Nissan protocols to see that, so you may want to bypass your PNP switch entirely and just run a signal directly to that pin on the ECU plug. I’ll check my FSM quickly and get that pinout for you. 
 

It is pin #109 (marked it on the image). Remember this pin out is from the harness side so it is as if you are looking through the connector when the wire side is facing you.

Edited March 1 by Sanchez

[Sanchez]

Progress has been slow as I’ve been working on a 76 Cutlass for a client to pick up some extra cash because buying a house with a 2 car garage ain’t cheap. Though at the moment we have a pretty cool piece of Z collector history come into the garage for some work before it goes to auction. A 280ZX-R. It’s got surprisingly good interior and mechanical wise, but the sunroof was unfortunate to see. Odometer says 930 miles but it has likely rolled over, been replaced, or is broken. We should have it up on BaT soon for those interested.