Kyusha Beginnings: Introducing Project Natsumi

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Kyusha beginnings GReddy front

When we first introduced Project Natusmi a few months back, we hinted that we had something very special in store for S30 Fairlady’s and GC110/GC111 Kenmeri skylines. Here at Revmatch, we love all kinds of makes and models but classic j-tin hold a special place in our hearts. After going to shows like JCCS for years and getting to know how passionate the enthusiast base was, we knew we wanted to do something to help the burgeoning Japanese classic car community. So began our search for like minded companies that believed in the kyusha ways. When it comes to classic Japanese motoring, there are few companies that have been there since the beginning like Trust/GReddy.

Kyusha beginnings GReddy garage

Trust and its US based operations, GReddy, have been designing and engineering performance products since its founding in 1977, and many of the classic Nissan’s, Toyota’s and others roaming the streets of Japan at that time were running a variety of their products. When we presented our idea of injecting some classic JDM into their US line up of products, Trust/GReddy was more than happy to help us make this happen. After much discussion and planing, it was time to see some of the first official classic Trust products to make it to our shores.

Kyusha beginnings Natsumi intro

This was also the first time introducing a product feature on Project Natsumi, our own 1971 Datsun 240Z project car. I picked up this car a few years back in a very poor state but slowly nursed her back to running condition. Still running her numbers matching L24 and 4 speed trans, she has had a few reliability upgrades like a restored OEM braking system, Koyorad aluminum radiator, and synthetic gear oils. Unlike other project cars out there, where every modification is strategically planed out from start to finish, we wanted to keep the build a little more open ended. We felt that this would better reflect the average car enthusiast, where modifications are often times more opportunistic than systematic. You guys will see what I mean in a minute.

Kyusha beginnings GReddy R&D team

Now I have always been the “do it yourself” kind of guy, never one to let a mechanic work on my baby, but for some reason I felt I was in good hand with Aaron and the R&D team at GReddy.

Kyusha beginnings GReddy drift car

I mean, if this was indicative of what they work on daily, I guess they would be ok to work on her.

Kyusha beginnings Natsumi lift

By now I’m sure you guys are tired of all the build up and wondering just what the hell we brought over from that magical land of Gundam and Godzilla. Well…

Kyusha beginnings mystery box

In our talk with GReddy, we expressed that in the vintage Japanese car market there was a growing need for period correct parts, especially those of the performance variety. Unfortunately here in the states, many of those parts are either no longer available, prohibitively expensive or rusting back to their elemental beginnings. However in Japan, many of these parts are relatively affordable, widely available and in some cases, still being produced. Which brings us back to the big brown box you see before you.

Kyusha beginnings opening

This box had been sitting there a few days and everyone was pretty excited to see what was inside.

Kyusha beginnings plastic

Removing the protective plastic was like tearing off the last piece of wrapping paper on Christmas morning.

Kyusha beginnings TR NA Ex Manifold

Inside was a new, hand welded Trust TR-NA header. Not used, not old stock, but brand spanking new! I had seen pictures of this countless times in the lead up to this moment but nothing prepared me for how striking and beautiful made these Trust TR-NA headers were.

Kyusha beginnings for racing purposes

One of the first lessons you learn about the L series motor is that power is built in the head, so ideally that was to be our first big undertaking on Natsumi. But like I said earlier, many times opportunities arise that just can’t be passed up. While head work is still high on the list of upgrades, I wasn’t about to NOT run this blue steel beauty and come time for the port and polish, I’m sure it will help free up a few additional ponies.

So alright, header is here, the car’s on the lift, lets get this baby installed… eh not just yet.

One of the main reasons for our choice to bring over the Trust TR-NA header is that, like many other products, these were never intended for the US market and thus never officially tested on LHD configured cars. While many enterprising individuals have taken it upon themselves to test fit and run these headers, there was never an official stamp of approval from the manufacturers and left a lot of questions about warranty and support. Here at Revmatch we go the extra mile for our enthusiasts, so to remove any uncertainty, we wanted to get official approval from the horse’s mouth and worked with GReddy to test fit these on our LHD 240Z. However after looking at our stock 240Z system with all the outdated emissions equipment still intact, the install was looking to be a bit more involved than we originally thought and with Formula D Seattle just around the corner, we all though it would be best to reschedule on a day with a few less distractions. Not a problem.

Ok, Trust header install take two.

Kyusha beginnings GReddy Drift Seattle

About a week later we find ourselves back in the GReddy garage. Having just returned from a tough battle in Seattle, Ken Gushi’s Scion Racing FRS was already prepping for what would be an outstanding round in Texas. Its amazing how quickly these cars can take a beating and look factory fresh at every new round.

Kyusha beginnings Natsumi under

Getting the Z back on the lift, our first hurdle was to remove the exhaust system. With the factory system this would have been a straight forward exercise, but the vintage twin pipe exhaust system that came with the car posed a slight problem. The original factory system was sectional and, namely after the head pipes, could be removed in pieces to allow easy service and installation. However our vintage twin pipe required the installer to weld them to the head pipes effectively creating one giant exhaust system from the exhaust manifold back.

Kyusha beginnings Exhaust head pipe

Luckily for us, the Nissan engineers saw fit to design the exhaust manifold to separate from the head pipes saving us from having to wiggle or cut our way out. Just a few bolts up front…

Kyusha beginnings exhaust removal rear

… out back…

Kyusha beginnings Exhaust removal

…and out she comes…

Kyusha beginnings twice pipe crush bent

… in all her crush bent glory.

Kyusha beginnings Natsumi stock manifold

With the exhaust out of the way, it was time to for the real fun to begin.

Kyusha beginnings removal process

Our initial plan was to simply remove the stock exhaust manifold from below and slide in the new Trust one. Unfortunately the way the air injection ports wrap over the intake manifold meant the SU carburetors also needed to come out.

Kyusha beginnings coolant drain

And since SU’s are heated by engine coolant for air/fuel ratio consistency and improved fuel atomization, the coolant had to be drained as well.

Kyusha beginnings airbox removal

Drained of any interfering fluids, we got to work removing the SU’s

Kyusha beginnings intake close up

Since there were still a few things we needed to discuss about bringing these headers to the US, we left Natsumi in Aaron’s and Ben’s capable hands.

Kyusha beginnings Trust racing history

Making our way to the lobby waiting room, we find some of Trust/GReddy’s early racing milestones.

Kyusha beginnings Trust Porsche 962

Namely the Trust Racing Team Porsche 962C…

Kyusha beginnings Nisso Trust Toyota 92C-V

…and the Nisso Trust Toyota 92C-V, of which competed in one of the most grueling and highest forms of motorsports, The 24 hours of Le Mans. It was fairly common to see factory tuning shops like Nismo, Mazdaspeed, and TRD fielding cars at Le Mans, but very few independent tuners like Trust/GReddy had the guts to duke it out with the big boys. An amazing testament to their pursuit of performance and reliability.

After our tying up a few loose ends in our meeting and a quick break for lunch, we headed back into the garage.

Kyusha beginnings Manifold penetrant

Leaving the manifold to soak in penetrant, the guys got to work removing the antiquated air pump.

Kyusha beginnings air pump removal 1

Kyusha beginnings save the world

After 44 years of service, it was really just a loud noise maker and any claims of better emissions were dubious at best. Don’t worry though, it will be stored safely just in case we ever, to quote Aaron, “feel like saving the world through 1970’s emissions technology”.

Kyusha beginnings intake removal

With that out of the way, its was time to get my hands dirty and help remove the intake and carbs…

Kyusha beginnings air injection

…working our way down to the exhaust manifold. Just look at those air injection tubes! We were really surprised how far into the head they went. I’m sure that didn’t hamper exhaust flow lol.

But finally, we were at the moment we have all been waiting for. All the months of research and calls had all come down to this final question.

Will they fit?

Kyusha beginnings close fitting

Even though everything we found about these headers fitting were positive, we were still a little apprehensive. That steering column was looking mighty close.

Kyusha beginnings Steerng clearance

But we had plenty of clearance to spare.

Kyusha beginnings it fits

Looks like we are all good. Except for one little snag.

Trust TR NA Ex Manifold install clearance

Looks like we hit the very bottom of the thermostat housing by roughly a millimeter or so.

Kyusha beginnings measured modification

Nothing a quick shave couldn’t fix.

Kyusha beginnings gasket check

But not leaving anything to chance, we made sure the modification wouldn’t compromise the gasket in any way.

Kyusha beginnings shaved flange

A few passes with a grinder and…

Kyusha beginnings thermostat clearance

…no more issues. Despite this slight hiccup, we and GReddy were happy to catch this in our test fitting as things like this were exactly what we were testing for. We were able to relay our findings back to Trust Japan and now all TR-NA headers will come with this clearance ensuring a clean and easy bolt on install. Just another way Revmatch goes the extra mile.

Kyusha beginnings lower clearance

Underneath the Z, clearances were looking just as good.

Kyusha beginnings intake install

Wrapping up our install did present one more issue unique to SU users.

Kyusha beginnings SU return spring

Unlike Weber and Mikuni side drafts where the return spring is built into the carb body, SU’s return springs attach to the exhaust manifold heat shield. As the TR-NA header doesn’t provide any type of provision for these springs, the GReddy R&D team had to get a little inventive.

Kyusha beginnings airbox backing plate

Using the stock airbox backing, we decided to fabricate a few tabs to clip the return springs.

Kyusha beginnings the pain is real

The pain was real watching them punch two holes in the original airbox but sometimes sacrifices must be made.

Kyusha beginnings aluminum stock

Just a little aluminum bar stock….

Kyusha beginnings return spring tabs

…and voila! Two perfectly functioning SU return springs.

Kyusha beginnings install complete

All buttoned up. I love how those blue headers peek through from below.

Kyusha beginnings Natsumi TR NA header

This was a project that had been in the works for a while but it was well worth the wait. Even on our stock L24, the way the exhaust note crescendoed and opened up at higher RPM was addictive, made for a very entertaining drive back home. We would like to thanks Trust Japan and everyone at GReddy Performance Products for all their help in making this project possible. It was a real honor to work with an originator of classic Japanese car performance. It is our hope that having these here in the States will help breathe new life into these historic performance parts.

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