When something lingers in your mind, it’s probably doing so for a reason. In this scenario, there are 2 choices: ignore it and move on or take care of it. I yielded and opted for the latter.
All the new fuel lines I’m running are -6AN, which means they have an inner diameter of 3/8″. Attaching these lines to the smaller 5/16″ factory hardlines led to a predicament. The solutions appeared to be limited. One way was to cut off the barbs on the hardlines and install a compression fitting, but I was skeptical on how much pressure such an adapter could hold. Another method was to flare the hardlines further with a special tool. I wasn’t very enticed by either of these and they were both relatively invasive.
Finally, after seeking insight from 3 separate individuals, they all reported having simply double clamped the -6AN line over the hardlines. So said why not, and joined in.
At first, I double clamped my lines on and then decided to triple clamp them to help assuage my neuroticism. Fast forward to more recently, I was doing more research on other viable options out of curiosity (going back to the whole stuck on my mind thing), and ended up calling Flyin’ Miata. They offer a big fuel kit for Miatas and had everything figured out. Apparently, there’s ONE company (Aeromotive) that makes a special 5/16″ barb to -6AN male adapter. Finally, this was something that made a lot of sense.
I decided to buy 2 of these adapters from Flyin’ Miata and had them Express mail them to me. It was hard to suck it up and redo the lines at the last minute, but I knew it would be better to take care of everything sooner rather than later. I’m sure my triple clamping would have worked fine, but it bugged me because it seemed fundamentally wrong.
I undid all my hard triple clamping work, removed the Feed line, and bought the appropriate push lock fittings. I took the opportunity to redo the Feed line entirely because it was originally mounted to the secondary rail with a straight fitting, but I switched it to a 45* fitting instead to lessen the bend in the line.
On the other end of the Feed and Return lines, I pushed on straight fittings. I purposely chose Blue for these to add contrast down by the firewall where they will be attaching to the adapter and hardlines. I think I’ve gotten quite good at installing push lock fittings now. For the Feed line, I was able to do everything off the car on my workbench, but I left the Return line attached. This meant I had to push on the straight fitting without a surface to press against, and had to do it all against my palm.
Here is everything connected back up with the new adapters in place.
Now, instead of force clamping a 3/8″ line over a 5/16″ barb… I’m using a short section of 5/16″ fuel injection hose from the hardlines to the 5/16″ barb end of the adapters, which then converts and connects normally to the -6AN straight fittings. I also Express mailed new spring clamps from Mazda to help with the process. On the hardlines, I’m using both a worm gear clamp (with a smooth underside so it doesn’t cut into the hoses too much) and a spring clamp.
Talk about one aspect of the build being drawn out… but I knew I couldn’t shortcut anything, especially when it comes to fuel.
Earlier on, I brought my midpipe over to a local muffler shop to have a flex pipe welded on. I wanted this done to help relieve stress from the downpipe. This is what the exhaust system looks like hooked up.
With the V-Mount in place, it occupied precious real estate at the front of the engine bay. The Braille battery I had was too big to fit. I was against having to relocate the battery inside the cabin because A.) I think a battery should stay in the engine bay, and B.) I didn’t want to extend wiring or mess with the factory configuration. I bought a Rotary Extreme mini-battery kit as the solution, and luckily, it fit perfectly with the Defined V-Mount. My anticipations of having to notch or shave material proved to be premature. Cross product compatibility is quite the convenience.
Another item I checked off the list was the fuel pump’s rewire. Even though the car has a higher-flowing Supra fuel pump, it won’t be able to perform as intended if the power delivery is insufficient. The stock wiring to the fuel pump is a guilty area of voltage drop. This is due to the redundancy incorporated into the circuit relay, which taps power from an ignition wire.
By simply bypassing this wire and connecting it to a direct source of power (the battery), it has been shown to improve the fuel pump’s voltage by 2V. Another alternative is to go all out and completely obviate the stock harness by running new wiring front to rear, with the addition of a separate relay; however, I feel that this would be overstepping what I’m trying to achieve. And more relays equal more fail points.
Thus, I opted for the former method. I cut the circuit relay’s ignition wire and redirected it to the battery with an inline 20A fuse. At the battery’s end, I cut off the insulation from a ring terminal and then crimped + soldered it on. I finished it off with marine heat shrink (this stuff has adhesive inside for extra weather-proofing) and mesh cable shielding.
My categorical imperative for this build is to avoid cutting corners – at all costs. I was immediately dissatisfied by the push-through zip ties holding on the single fan to the radiator. I knew it was going to be a matter of time for the tubes to get worn down and spring a leak, especially because all of the weight of the fan is being hoisted by them. I decided I didn’t want to drive with the fan mounted this way, not even once.
What I needed was a custom bracket to hard mount the fan. How was I supposed to get this made, and quickly? I called Defined and opened my wallet. Thankfully, they were able to cook something up for me with a short turn-around time. In order to convince a busy shop to drop what they’re doing and focus on my job, I had to offer to pay double their work rates. Expensive, yes, but there is always an opportunity cost. At least I now have the fan’s mounting figured out and off of my mind.
I first mounted the fan to the bracket with M5 stainless hardware, and then the bracket to the radiator’s bungs (which were there for the stock dual fans).
And that is indeed a Chevrolet symbol. The fan I’m using is officially licensed by GM.
I haven’t posted any music in a while, so how about a touch of 90′s electronica? After all, older is better. I may have heard this track during my childhood somewhere. I am now an old man, so I like the entailing nostalgic feel.
With the Air Pump removed and the Greddy Pulleys installed, I picked up a Pineapple Racing Idler Pulley to fill in the gap. This pulley serves a simple but important purpose. Without the Air Pump in place, the leverage for the water pump pulley is reduced. The alternative is to compensate by over-tightening the belt, but this is a poor solution as slippage can still occur at higher RPMs. Secondly, you never want to over-tighten the belt because on top of reducing bearing life, it increases the stress on the crank pulley and by effect the eccentric shaft.
When the Idler Pulley came in, I had to take a moment to survey the parts more closely. I almost immediately noticed the superb level of detail and quality. Apparently, after talking with Pineapple, the machinist that makes these parts has a long track record and was even contracted to make pieces for a lunar project. It takes one to know one, in my opinion; most people who don’t work with cars to this depth probably wouldn’t give more than a second glance… yet this kind of stuff brings out my inner geek. Just check out the consistency of the nickel finish!
Installation was a straight forward bolt-on, but the space in its location was tight. In the end, everything went on just right.
With the Idler Pulley in place, you can see just how much more belt surface area the water pump pulley is able to obtain (almost quadrupled).
I adjusted the belt’s tension to have a deflection of approximately 3-5mm. Another good rule of thumb to go by: you should be able to grab a section of the belt in the middle and turn it a quarter-turn (until the ribs are facing you) without too much effort.
The way I came across this V-Mount was via a slight course of serendipity. Back when I was trying to sell my XD-9′s, I was in communication with another member on RX7Club who was interested in trading me a rear brake kit. The brakes ended up not being the exact ones I wanted, but during the process I discovered that he had a new Defined Autoworks V-Mount kit laying around. I think he went with an LSx swap and no longer needed it, so I bought it.
The kit was missing all of the small hardwares and radiator hoses. I had to piece them together myself through Defined and McMaster-Carr. In the end, it was still worth the effort and risk because I didn’t have to wait for the whole kit to be made.
I was pleasantly surprised with the design and fitment of the V-Mount, which made the installation uneventful, for the most part. Of course there were a few minor things I had to modify, like dropping the oil coolers’ hardlines to clear the radiator and trimming down the aluminum ducts.
Here is the Koyo radiator mounted, which is now positioned at a transverse angle in comparison to stock.
With this setup, I was forced to switch to a slimmer 14″ single fan. The stock dual fans were far too thick, and I probably would have had to run new oil cooler lines to fit them, as well as extend an outlet on the radiator to clear. Furthermore, the fans now sit on the bottom of the radiator, facing the ground. A thick fan would impede height clearance. The single fan is currently mounted with push-through zip ties, but I plan on looking into a hard mount solution in the future.
Once the radiator was situated, the intercooler then goes on. The assembly is connected together with a pair of steel brackets that sit on rubber isolators.
Next comes the ducting.
Here is a look at the “V” that is created, which maximizes air flow to both the radiator and intercooler.
It is plainly obvious why a V-Mount is superior to alternative setups. A Stock Mount just isn’t as efficient of a package and a Front Mount sacrifices radiator air flow plus requires long intercooler piping.
I’m still in the middle of making the intercooler piping, but at least the engine bay is now looking much more complete.
Included with my turbo kit was this 3.5″ stainless downpipe.
In an effort to reduce under-hood temperatures, I wanted to wrap the downpipe. I bought a roll of DEI Titanium exhaust wrap and locking ties. I’m not sure why I insisted on buying these locking ties, because I already knew from prior experience that they sucked…
The rolls only come in 15′ lengths. In combination with the 3.5″ tubing and a ~1/4″ wrapping overlap – I ran out of material roughly midway through and had to pick up a second roll.
Here is the end product.
Later when I tried installing the downpipe, it didn’t fit! I did a brief test fit in the beginning before wrapping, but that proved to be inconclusive. Once the v-band was hooked on, the other flange of the downpipe was pointing upwards at too much of an angle.
It seems like every part/component of this engine project ends up being a mini-project of its own. I unwrapped the downpipe and brought it over to FFTEC. In a very short time span, I’ve become one of their regular customers. The flange on the downpipe had to be dropped 1-3/4″ while still maintaing the same orientation and distance. The fabrication guru there was able to do all of this by simply making a measured cut and flipping around the tail section of the pipe. He left it tacked on so I could go back home to test fit before fully welding.
With the modification complete and the downpipe now fitting correctly, I rewrapped it again but used worm-gear clamps instead of the locking ties, which allowed me to get a much tighter wrap this time around.
Installed, plus a new Bosch O2 sensor.
After buttoning up the UIM, it was not long before I took it all back off again shortly after. Thankfully, uninstalling the UIM now is a far less intensive task. There are only 3 electrical connectors and about 3-4 vacuum lines hanging to it.
I was never quite happy with how the secondary rail to primary rail line was connected. The distance between these 2 rails were so short, the only possible way I could make it work was with a pair of 90* fittings and a hose that bent upwards. This was not exactly ideal. Secondly, I noticed that the primary rail to fuel pressure regulator had extra length in it, causing a superfluous bend in the middle.
I decided there was no skirting around the issue and set out to redo these lines. Initially, I planned on just optimizing the lengths and keeping the same routing… but then decided to cross over the lines instead. This would get rid of the extremely short and awkward connection between the secondary and primary rails, because the line now routes to the other side of the primary rail. I also tried using a pair of 180* fittings for this connection, and a short, straight section of hose in between. This ended up not working due to clearance issues and was extremely hard to install. I had to take off the primary rail and pre-install the line onto it, to even try the test fit.
Later, I made another line consisting of a 180* and a 90* fitting. Then another consisting of a 180* and a 120* fitting, which finally resulted in a solution I was happy with. For the primary rail to FPR connection, I used a short hose with a 90* and a 150* fitting.
Since it took multiple attempts and trials, I opted to forgo the circumspection of enlisting gym-going friends to help. By this point, I figured out the procedure of installing the fittings down to a science – which made pushing them on quite easy.
I went through countless different fittings and had to order another spool of fuel hose to finish the job. Needless to say, routing the fuel system was overall an overly tedious ordeal.
Before installing the UIM back on, I took the opportunity to wrap the lines in heat sleeves. This should help to prolong the fuel hose’s lifespan and lower fuel temperatures.
Another item that bugged me was on the UIM itself. One of the studs that held on the Accelerated Warm-up System broke off when trying to remove it. This meant I could install the block-off plate with only one bolt. It still clamped down well enough and looked to be sealing, but managed to linger in my mind. So, I took action and asked FFTEC to obviate the block-off plates altogether and weld-plug everything up.
The A-Spec turbo kit fit together within expectations. There were a few minor items that needed modification, namely the downpipe (discussed further in a later post). More focally, however, the crucial parts of the system went together like a fine watch’s clockwork and this alone appeased the long wait-time and price for me. When dealing with a niche car and handmade fabrications, there is a degree of leniency you have to uphold.
Here is everything all mounted up in the engine bay. The 5866 turbo is physically quite large. The clearance between the car body and LIM is tight, but just right. A-Spec did a spot-on job with this part, and it’s arguably the most critical. The short-runner design of the manifold sits the turbo low and relatively far back. This leaves ample room in the front, where a 5″+ air filter can be used.
And a closer look at the manifold & wastegates. I made sure to be thorough and invested in reflective heat sleeves to keep hoses in the area safe.
These are the dump pipes aimed and mounted. This party is about to get REAL loud.
In the picture above, with the pipe coming through the hole in the subframe near the control arm, you can see the 4″ extension I had to get welded on.
All this hardware is making the engine bay mesmerizing… occasionally, in between work, I find myself just standing and staring at everything for extended lengths of time.
I realize I never formally introduced or addressed what exactly it was I wanted to do with the engine – and that is go single turbo. That’s because up until now, I’ve primarily been preoccupied with waiting for the related parts to finalize and arrive in my hands.
Even if an individual does not turn a single wrench and is merely a credit card warrior, this still should not be seen under a trivial light. The fact is, even the task of picking and choosing what parts to buy takes skill and guile. This is compounded when you’re dealing with a more obscure car, as the options are more limited and require greater assessments.
For me, I wanted the best single turbo kit I could get for this car. One of the paths I could have chosen was to go with a Full Race manifold and then piece together the rest of the kit; however, I wasn’t too intrigued by their long-runner design. My priority is to maximize responsiveness and not necessarily power output. In the end, I decided to go with A-Spec Tuning from Chicago because they specifically offer a revised short-runner manifold. Additionally, their long history with RX-7′s and quality build materials have established a bit of a cult following.
There was, of course, a stipulation. As much as A-spec is known for their quality, they are just as known for the amount of time it takes to deliver a kit. This ended up being no exception for me…
I got the jump on this single turbo project early, and placed my order back in October. My manifold was supposedly already made at the time, but it wasn’t until mid-January that I received my first package. The turbo came separately about a week later. Then I discovered that I was given Precision wastegates when I ordered Tials… so that took a couple more weeks to sort out. Furthermore, the dump pipes were forgotten from my package and dragged out the waiting even longer.
While the experience was quite taxing and wearying, because a lot of money and time was on the line, it was a necessary deed. I like to anecdotally reference the Soup Nazi from Seinfeld… somewhat similar.
With patience and perseverance comes great rewards, and in this case, it came in the form of extreme turbo porno. A-Spec did eventually come through and deliver me my full kit.
Here is the ceramic-coated twin-scroll manifold with a divided T4 flange.
And the main show – I went with a state-of-the-art double ceramic ball bearing Precision 5866 turbo with CNC billet CEA compressor wheel.
The 5866 itself is an interesting setup and A-Spec helped recommend this to me to achieve my response goals. In comparison to a Garrett GT35R, the 5866 has a larger turbine but a smaller compressor. It is basically a hybrid of a 5876 compressor with a 7666 turbine.
For the wastegates, I opted to go all-out in this department. I am simply sick of boost creep issues with RX-7′s. On the stock sequentials, all it potentially takes is a removal of the catalytic converter to be stuck with uncontrollable boost. This didn’t exactly imbue a sense of confidence, I felt like the car was a time bomb and I never wanted to boost too much. Not the way a car should be driven.
To back my intentions of ridding this problem, I embodied the solution in a pair of 44mm Tial MV-R’s.
Lastly, here are the long-awaited dump pipes. The larger one fit well but the smaller one was way too short. It hung above the subframe when mounted, so I went to FFTEC and had them extend it 4″.
I took care of a few odds and ends by double checking the fuel pump and wastegates’ springs. Kind of boring, but this had to be done because these components are so crucial.
When I bought the car, one of the items on its rather minimal mod-list was a Denso Supra Twin Turbo fuel pump. These flow well past 400whp and significantly more than the factory RX-7 unit, which is insufficient for much more than stock power. There was no way I could overlook this, so I popped off the fuel pump cover and stuck my cellphone in to snap a few pictures.
I was able to grab the part number off the pump, and sure enough – Supra fuel pump confirmed.
Next, I double checked the springs on my Tial wastegates (more on these in a later post). I specifically requested to have 12 psi springs pre-installed and I will not be using a boost controller.
Blue and Black springs were in both wastegates, these are Tial’s current colors to denote a 12 psi combo. Check.
At one point, I was able to reinstall the upper intake manifold and hook up the fuel pressure regulator.
The fuel pressure gauge isn’t installed here, because I had to reorder one. I spent an hour looking all over my garage for the gauge… only to find it chewed up in my dog’s crate the next morning. He usually doesn’t touch anything in the garage, but the small size of the gauge must have made it look like a ball. Oh well.
And here’s the Greddy compression elbow, a staple of any RX-7′s engine bay.
Unfortunately, I wasn’t entirely happy with a couple of the fuel lines. One line had a bend I didn’t like to it, and the other was too long. So off came the UIM again. I’m still working on this part… to be continued.
It took me less than a month to grow tired of the Work XD9‘s that were on the car. They were simply too generic and lacked a certain element I was looking for. Picking the right wheels is extremely important, they can single-handedly transform your car. This is probably why it’s common to see people go through multiple sets of wheels – and it’s definitely not an area you want to skimp out on.
Aside from feeling that the XD9′s were bland, there was something off about their sizing to me. Maybe it was just the design of the face on those wheels, but in 18″, they seemed too big on the car. I’m taking the opportunity to step down to 17″ wheels. I think the larger sidewalls will balance out the proportions on this car when fit right, we’ll see how it goes.
I also wanted to find wheels that were more worthy, so I reverted to my short-list of favorites and picked the choice at the top: RegaMasters. I love the simplicity in their design, it’s almost utilitarian like. They are also more period correct to the RX-7 and have long been discontinued – which increases their rarity. This is a plus although adds to the challenge of sourcing them, as you’ll read…
I had to turn to looking overseas to find what I needed. I initially bought a set of 17×9′s from a seller in Japan. I really wanted 17×10′s but it was almost impossible to find a +40 offset for the fronts, so I settled on the 17×9′s instead. I had expressed this intention to the seller, and this lead to a tip from him a month and a half later. Apparently, as luck would have it, a 17×10 +40 pair popped up on a Yahoo Japan auction.
Since this seller wasn’t the cheapest (it would have cost me around $2500-2700 to go through him), I decided to take his information and go behind his back to save a few bucks. I had to work fast because the auction was ending soon. I did my research and quickly contacted Jesse Streeter, who specializes in proxy services. We moved fast, a bet was placed on the 17×10 +40 pair and another 17×10 +20 pair (for the rears). The next thing I know, my 17×10 RegaMasters were at my doorstep a week and half later.
I decided to spring for EMS shipping. The funny thing is, my first 17×9 set was shipped through a container, and didn’t arrive until almost a month later.
Forged in Russia, with love.
Note: Desmond made 2 types of RegaMasters, the Evo and the Marquis Promada. The former is slightly more rare but is not offered in many of the larger sizings. To tell the difference between Evos and Marquis Promadas (MP), look at the hub. MP’s will have a raised hub area for the center caps. Additionally, they also have a recessed groove that circumvent the inside edge of the spokes.
A few of the wheels had minor curb rashes, but curb rashes nonetheless. This meant that I couldn’t simply drop them off to the powder coaters to be repainted… they needed to be refinished first. I decided to keep to the color of the silver pair for the set (equivalent of Prismatic Powder’s Porsche Silver). This should help “tame” the car’s appearance, although I will miss the black on black look.
I chose Wheel Techniques in Santa Clara to do the refinishing, because they weld on new material to the curb rashes rather than simply fill them like some other shops do. Unfortunately, the refinishing process took far longer than anticipated. One of the wheels came out with a bad clear coat and needed to be redone, and I noticed minor inconsistencies on a couple of the other wheels. One thing led to another, it took over 4 weeks to finally get all of the wheels down to a satisfactory result.
I wasn’t in any rush so it worked out to that end. I’m appreciative that Wheel Techniques was willing to work with me and see it through by continuing to redo their work. They’re a busy shop, and Jeff, the co-owner, even personally extended an offer to redo a wheel, when I was about to just accept it and go… so I thought that was a classy act and gets major kudos in my book.
Let’s cut to the chase here…
Here’s a picture of both sets of my RegaMasters, with the 17×9′s in the foreground. You can see the small difference in the step lip depth between the 10″ and 9″. This difference was reason enough to make me buy 2 sets of these wheels.
Mounted on Hankook RS-3′s.
Whether I go with 17″ or 18″ wheels, one thing I will always keep is the fitment. I will continue to stay with a squared set up and with 10″ wide wheels all around with 255 width tires. I think 255′s on a 10″ is perfect. The pinch and stretch are just right. If the tires did not have a rim protector, the cross-sectional widths would basically be squared on the 10″ wheel.
Slowly but surely, I’m ticking off the items from a very long to-do list. I’m doing my best to approach this build as methodically as possible, I don’t want to rush. In abide by this ideal and still see a conclusion within a reasonable timeframe, I have to do or plan something daily.
Today, I pushed forward with the reassembly and took care of various tasks. I started by installing the HKS Twin Power unit.
Because I removed my A/C and Power Steering, a very prime location became available on the frame rail for mounting:
That spot was perfect, the piggy back harness was within good reach of the plugs and the box is relatively far from the engine’s heat. Furthermore, being down low and in an open area allows for increased air flow.
I also connected the Magnacore spark plug wires and buttoned up the coils. In my haste to get rid of the sequential system rat’s nest, I overlooked an important bracket necessary to mount the coil assembly (sold it away). Everything under there is intertwined with each other, and this bracket was actually an offshoot of the rat’s nest assembly.
This lead to a dilemma as I wasn’t sure how to find such a specific part. I called Mazda and they no longer carried it. I decided to try a Want to Buy ad on RX7Club’s classifieds. It was more or less a shot in the dark, but within a couple hours of posting, Ihor from IRPerformance came to the rescue. It’s a blessing that this car still maintains a strong resource-sharing community.
The clear braided hose in the picture below is a PVC Tygon line I’m using to vent/catch blow-by. I deleted the Positive Crankcase Ventilation (PCV) in the process. I may add in a catch-can in the future if the hose is not adequate and I notice excess oil in the intake tracts, but it shouldn’t be an issue in less than racing conditions.
I like to do my own work for a reason. It allows me to dictate full control of the operation and impart a more crucial eye. I feel that certain levels of attention to detail cannot be captured when you drop your car off to someone else – only unless you’re prepared to sign a big check.
For example, one of the benefits I’m able to enjoy is being able to handpick everything to my liking, down to even the replacement vacuum hoses. Even though there are barely any vacuum hoses left, it’s still an area that deserves scrutiny. Here’s a picture of a 3.5mm silicone vacuum hose I’m intending to use for the Blow-off Valve – the walls are nice and thick.
On the subject of vacuum hoses, I’m amazed at just how simplified the vacuum system is now. These are all that’s left:
- Wastegate Boost Pressure Sources (x2)
- Fuel Pressure Regulator
- Blow-off Valve
- Injector Atomization
- MAP sensor
- Check Valve (only Solenoid retained) -> Charcoal Canister