Project LSZ: Making it Run

Tom
Update by Tom Suddard to the Nissan 350Z project car
Dec 20, 2018

We spent the last installment bolting our LS1, Tremec Magnum transmission and accessories into our 350Z at the LOJ Conversions shop. Now that the drivetrain was installed, it was time to make it run.

First up: The cooling system. LOJ’s kit includes a custom C&R Racing radiator and the necessary hoses to install it. The cooling system bolted right in like a factory piece, taking a total of about 10 minutes to complete. We put the factory A/C condenser back on the car, too, since we’re keeping A/C for the time being.

Next: Clutch hydraulics. Since our 350Z originally had an automatic transmission, we needed to add a clutch master cylinder. LOJ’s kit included a nifty adapter to bolt an aftermarket Tilton master cylinder to the factory holes on the firewall, so we paired that with a stock clutch pedal assembly we bought used. We mounted a remote fluid reservoir near the car’s ABS pump, and just like that we had a clutch.

Cooling, clutch, next: Time to finish the oiling system. Space is tight in a 350Z, so LOJ’s kits use a remote oil filter. We installed the provided hose, fittings, and remote oil filter adapter, which puts the filter on the front of the driver’s side head.

We were ticking things off like crazy, so we moved onto the fuel system. A stock 350Z runs has a 52 psi returnless fuel system, which is no good for our LS1: It requires 58 psi. What’s the big deal? Lower fuel pressure means less fuel goes into the engine than the computer expects, making it run lean. There are a few ways around this issue. Some people address it during the tuning, opening the fuel injectors longer to make up for the lower fuel pressure. Some people completely replace the stock fuel system, going to a system with a return line and a standalone 58psi regulator. But neither of these solutions are great, so LOJ came up with a third solution: Their kits include an entirely-new drop-in fuel pump assembly, which lowers right into the stock tank and provides 58psi of fuel pressure without any other modifications. It’s a pretty darn clever solution to a problem that many swaps seem to overcomplicate. And unfortunately, this isn’t something that the average person can build at home. We installed the new LOJ fuel pump assembly in our stock tank, then used parts from the kit to hook our LS1’s fuel rails to the 350Z’s stock hard line. We did make one modification: We bolted a flex-fuel sensor to the firewall, so in the future we’ll be able to run E85 without any other modifications.

There was only one big thing left to do before our 350Z would run: Wiring. And yeah, we hit the easy button here, too. LOJ’s kit included a pre-made LS swap wiring harness, though they were kind enough to build it in front of us so we could see what goes into one of their conversion harnesses. We removed the factory engine harness, then plugged the LOJ one in its place. LOJ’s kit also included a CAN bus translator, which lets the 350Z’s body control module talk to the GM E38 powetrain control module that our engine would have been paired with in a Camaro. Why is the CAN bus translator important? Because it lets the stock 350Z electronic throttle pedal, climate control system, gauges, ABS and more talk to our V8’s computer while thinking they’re talking to the stock Nissan PCM.

After finishing up all of these odds and ends, we clamped the LOJ air intake on, hopped in the driver’s seat, turned the key… and HOLY CRAP THIS THING IS LOUD. With the help of the most extensive swap kit we’d ever seen, we’d successfully built a LS1-swapped 350Z. The factory gauges worked, the gas pedal worked, and it seemed to idle like Nissan had designed the 350Z like this from the start.

Next: Let’s see how fast it is!

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Comments
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EvilScientistMoose
EvilScientistMoose New Reader
12/20/18 2:06 p.m.

Soooo, what's the total cost involved for this swap?

Tom Suddard
Tom Suddard GRM+ Memberand Digital Experience Director
12/20/18 2:11 p.m.

This update explains the costs of the kit:

https://grassrootsmotorsports.com/project-cars/LS-Swapped-2003-Nissan-350z/project-lsz-lets-get-party-started/

This is absolutely not a down-and-dirty low-buck project compared to some of the things we've built over the years, but we think it'll be a great value compared to what it's able to beat on track.

EvilScientistMoose
EvilScientistMoose New Reader
12/20/18 2:15 p.m.

In reply to Tom Suddard :

Once labor is factored in, it's starting to look like a really-expensive way to build a Corvette.

Fascinating project otherwise. 

This reminds me of one hero car of mine, the Porsche 928. There are similar kits to fix and/or replace problematic bits and pieces with that car (okay, pretty much the entire drivetrain) by swapping in various Corvette odds and ends, including both a manual or automatic transaxle (ZO6 manual units are preferred). 

Small problem: The cost can run up pretty quickly, to the point where you can buy at least two C5 Corvettes for what it costs to do all of this. 

The bonus in all of this, however? I fit into a Nissan.

I don't fit into a Corvette. 

Tom Suddard
Tom Suddard GRM+ Memberand Digital Experience Director
12/20/18 2:46 p.m.

^Exactly. And we're already planning to run this car against our similarly-modified C5 Z06. They cost almost exactly the same amount by the time it's all said and done.

 

docwyte
docwyte UltraDork
12/20/18 5:38 p.m.

I LS swapped my Porsche 944 Turbo.  By the time I was done and truly had it completely sorted out, I could've easily bought a C5 Z06 AND had a TON of $$ left over in my account. 

I try to not think about it but I will *never* do another non-native engine swap again.  Most likely I'll never do an engine swap ever again period.

Dave M
Dave M Reader
12/20/18 6:39 p.m.

In reply to docwyte :

I dream of swapping my Solstice someday. Then I try to do something in the cramped engine bay and remember that a Vette is way cheaper.

docwyte
docwyte UltraDork
12/21/18 8:30 a.m.

In reply to Dave M :

I'm impressed with how integrated this swap is for the 350Z, that wasn't the case in my 951.  The LS doesn't fit all that well in the 951, it has a really narrow engine bay and not a lot of frontal area for cooling.  Those, in combination with the environment I live in (altitude and HOT during the summers) weren't good for how I used the car, which was on the track. 

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