valley

iTrader: (1)

In my initial posts I’ll being going through some background and the thought process that pervaded the various steps and choices of my build. It will be rather text heavy. I’m posting this in the hopes that someone will learn from the mistakes and missteps that I made and maybe others will find something they like, or even don’t. I’m including my mistakes, missteps, and dead ends as they are a part of the learning experience (both personally and vicariously) and because they are the means by which I got to some ends. I feel that simply going over what I’ve accomplished (the ends) ignores this. Since I’m writing this primarily for those who haven’t done any major automotive work, or are just starting some, I feel it justified even though it adds quite a bit of text.

Throughout I’ll be reiterating advice/information that can be found elsewhere but that I feel is worth repeating. Some of it I’ve experienced personally, some of it I’ve read and followed (or not, mostly to my own folly).

I’ve owned and/or driven/ridden “fast” cars and motorcycles for most of my adult life. Prior to this build I’ve swapped a RB25DET into an ’89 240sx with reasonable success and attempted to do a bike build with a custom frame to great failure. This is in addition to having done most regular and irregular maintenance on my families, friends, and my own vehicles. I've attached a picture of the car as it currently sits in my garage. I've also attached the obligatory standing in the engine bay with the engine ou... wait... it's in... oh well. I think that's more a Nissan thing anyways.

First, some background:

It’s been a few years since I started my build and I’ve now “officially” gotten the car back on the road. It’ll be another week or three before I feel confident of it passing inspection, but, it moves on its own again and I’ve taken it on a low speed (like, 20mph max) shake down run and it didn’t fall apart, blow up, or leak any fluids.

I was given the car, a red ‘89 TII, as a roller, so long as I promised not to sell it or scrap it. I agreed on the condition that it didn’t have any bad rust. It was sitting in my friend’s driveway for ~7 years with a 350 that wouldn’t start (and a few years before my friend even got it). A few more holes in the floor than it should have (granny’s, not even once), a largish hole in the firewall to fit the distributor, assorted surface rust, dents, and dings throughout. Basically what I’d expect of a then ~23 year old car that I got for free. Oh yeah, and pollen that had caked onto the paint so bad I had to take a stiff bristle brush to remove it. Seriously, even goo gone and goof off didn’t work.

So, I had this car and a plan to get it moving… if only the engine would start. I did a compression test to find there pretty much was none and during the test there were problems even getting the tester threaded into the holes. Not to mention the water that came out of the open spark plug holes. In short, the engine was toast. I suspect that it was probably toast even before sitting for ~7 years. My friend, feeling bad about giving me a car he was sick of (but still wanted to see revived) with assurances that the engine was good went out and bought a 13bt from a local import shop and showed up at my doorstep with it. Yup, he’s one of those friends and I’m damn glad to have him (he actually met his to-be wife working on this build with me… strange world…).

Over two or so weeks we busted our asses to get the engine in the car. Disassembled many of the ancillary parts, including the turbo, cleaned, and reassembled them. On the day where we were close to being able to start it we had the brilliant idea to do a compression test. The 13bt was toast with no compression at all on the rear rotor. ****. The shop sold it “as-is” and later added after talking with the manager (owner?), “There isn’t anything you can do about it.” I later found out that as-is doesn’t actually mean anything if the expectation is that the item is in running/working order (“Oh yeah, it compression tested great!” [JEI, not even once]) and my friend could have sued the importer and won. You live and you learn.

So now, I had a chassis, two dead engines (350 SBC and a 13BT) and two unknown condition transmissions (T-5 and an R). Also, assorted motor mounts, tranny mounts, wiring, carbs, etc. What to do…

valley

iTrader: (1)

Like in any, imo, smart build you start off by setting an “end” goal. Again, imo, there is no better way to never finish a build than always have your “end” goal move. I’m putting “end” in parenthesis because even though it's called and end doesn't mean it's done. Just that it’s your main and primary objective before you do anything else too crazy. I actually have two “end” goals. The first was to get the car back on the road with most of what I’d need to accomplish my second goal in place. The second was a car that was to be as light as possible for as inexpensively as possible with ~400whp. Inexpensive meant, in a nut shell, nothing extravagant (like carbon fiber) and ~400whp I feel is a good power level for a car to do most things while still being “mild”. And inexpensive. I also tacked on that it must also be able to pass whatever inspection necessary to drive on the street and get on a track. Basically, a street legal track car. Why? Because I’m still young enough to not mind bad NVH (noise, vibration, and harshness) so long as I can get my kicks in too. This is where I made another mistake I didn’t realize for almost a year. This mistake almost never gets mentioned, imo, partially because it’s an almost intuitive thing with a stock car that you’re interested in racing and partially because most people that race, already know to take it into account.

My mistake was that I was building my car because I wanted to (and it “needed” it) and doing what I wanted without regard to what class the car would be in. Basically, I was building the car with a street build mentality when I also wanted the car to be able to fit in some class and have a chance at being competitive. In short, this should have been a part of my “end” goal and I’ve modified my car right out of most classes it would actually be competitive in.

Regardless, at the time, I had to choose an engine. At this point I was thinking of putting another rotary in it and then modifying that up to ~400whp. Or I could do a classic LS1 swap. I was skittish about the rotary route after the issue with the importer and “as-is” as well as reading all the swap guys bad mouthing the rotaries reliability while holding all other engines up as paragons of reliability. In the end, after doing a cost analysis on a rotary vs. LS1, they both would cost the same (at the time and for my specific plan of action) to get to ~350whp and depending on where/how I got my parts, probably to ~400whp too. Keep in mind that in the LS1 cost I’m including the cost of the swap.

In the end I chose the LS1. In my research (a fancy word for “reading with a purpose”) I found a few issues/areas that I would have to contend with. First, the issue of brake booster fitment. Also, this tied into the issue of a track car often running out of vacuum for brake assist since it’s at or close to WOT so often. Second, cooling, LSx swaps are fairly notorious for overheating issues. Third, LSx swaps add weight along with raising and moving forward the engine CG compared to a similarly modified rotary. Fourth, mounting and location of the engine/trans. Fifth, mounting and location of the alternator and tensioner. Sixth, ECU, engine wiring, gauges, dash. Seventh, interior, interior wiring. Eighth, the transmission. Ninth, the exhaust and intake. Lastly, things-I-learned/advice/whatever-you-want-to-call-it.

If I were a bit smarter I would have outlined these things in a more formal way when I set my “goal”. These were all sub-goals to get to the “goal”. Sure, I had ideas of what I wanted to do and why, but like with the “goal”, if you keep changing them then you’ll never get there. Granted, these sub-goals need to be flexible in case you think of a better idea, get a killer deal on some part, or just plain can’t or don’t want to do what you thought you did initially.

valley

iTrader: (1)

The first issue was brakes. Actually, more like the third, but I’m covering it first and the first few issues overlapped a lot anyways. The FC RX-7 uses an old (first?) generation of ABS with only 3 outputs. In short, especially compared to modern systems, it’s a piece of ****. Also, because of a few other choices and that it looked like I’d have to do a brake booster swap anyways I decided I’d do a manual brake conversion. I did some reading with a purpose and stumbled across this awesome thread which pretty much answered what sort of bore sizes I’d need to fun: https://www.rx7club.com/race-car-tec...brakes-940062/ . I also stumbled across this build blog which got me looking into ways to reuse the OEM pedals: Builds>> Rx-7 Time Attack Build Progress Feb 2011 - Speedhunters . Now I just needed to figure out my balance bar and its setup.

Looking into balance bars and setups I found a FSAE forum post about how the cheaper balance bars didn’t give consistent bias and, IIRC, it could vary as much as +-5% F/R between pedal presses. Not in my car! Not wanting to spend $1000+ for an awesome balance bar and pedal setup to use it I decided to design and build my own. I came up with, imo, a rather clever design that would be “simple” to build, not rely on “exotic” materials or treatments, use easily available off the shelf parts, and give consistent pressure all the time. IIRC, it also had a +-30% F/R adjustability. I ordered all the materials I’d need and started machining. Two drill bits, two endmills, and two “primary” parts later I realized two things. Despite having access to a mill and a lathe I did not have the power to machine just anything without all the ancillary things a mill and lathe needs to do so. I also realized I had destroyed, in parts/tooling, just about what one of those cheaper bias bars cost… In the end, yes in my car…

While this was going on I had also started to amass parts for a pedal assembly of my own devising. However, I kept changing small details about the pedal assembly and just couldn’t get satisfied with the design. After my dark eureka moment with the balance bar and all that wasted time on design and revision I had another right around when I found the speedhunter build blog. Why was I using all this time and energy to design something new when what was in it not only worked, but was actually pretty good? So, I disassembled the OEM pedal assembly, adjusted the pivot point (~7:1) and made a two-bolt (one bolt goes through the stock clevis point) and sandwich adapter out of some left over plate I had for the bias bar to fit on the stock brake pedal. At this point all I had to do was design yet one more thing to allow me to actually attach the master cylinders to the car. Keeping it simple I made an adapter plate so I could bolt some Wilwood master cylinders to the stock location.

valley

iTrader: (1)

A big issue for many LSx swaps is heat generation. The chassis I have came with a really big generic radiator that barely fit between the frame rails. I made and welded in a cradle for bottom and side support which I lined with some cut up rubber mat. I also made some really simple upper supports to hold it in place. I took some measurements and bought two cheap electric fans and that was that. Once the engine was in and located where I wanted it I was able to make some aluminum radiator lines that only needed hose at the ends. My thinking was that I didn’t want to have to spend a couple of days looking through radiator hose catalogs hoping to find something that might work. Also, since inexpensive is one of the primary concerns of the build I couldn’t develop the AN fitting fetish a good number of builds seem to get (that and they seem fiddly and take a lot of time to put together right)

Without any ducting or anything else the engine would stay at ~185*F just idling in a garage. Then I put the front bumper back on and added a heater core into the mix (I doubt this caused the issue) and all that changed... Or I still have a giant air bubble in the system. Hey, I said it’d be a few more weeks before I feel it’s inspection worthy…

valley

iTrader: (1)

The issue of weight. The start of many an online argument. Regardless of anyone else, my personal thoughts were that it needed to be addressed. I also had in my head the thought of “wouldn’t it be really cool to move the firewall like I’ve seen in some cars that run in the American Iron series? Because Race car!” Long story short, that’s exactly what I did. I moved the engine ~10” behind where the firewall sat and it sits really low. So low in fact that my 25% under drive pulley that doesn’t quite sit behind the steering rack is ~ ¼” away from touching it. Moving the firewall took a LOT of effort. I had to rework my gas pedal, throttle cable, speedo cable, etc. It goes without saying there was a lot of welding involved. In retrospect this was the defining feature that cause pretty much all the issues I had to later solve. By some miracle I can change all the spark plugs with the engine still in (although the rears suck) but it’s a PITA to put the engine back in by myself. One of my friends, a very eloquent fellow, asked me, “why in the hell are you moving the firewall? Isn’t that going to make spark plugs and pulling the engine a pain in the ***?” Well, pulling the engine isn’t the hard part anyways…

For welding in the new firewall I had some sheet metal laying around that was a bit thicker than the metal used for the firewall. I had heard of, and tried using the wood and cardboard mock up methods but they didn’t work so great for me so I went to the tried and true trial-and-error method. Around the edges where the new firewall met the old I overlapped the new, welded it inboard of the old (i.e. a lap joint, not a butt joint) and would then use my trusty 8-lb sledge hammer to shape whatever curve I needed. I love that sledge hammer and that method worked extremely well for some of the complex curves I needed to make. Later, for some patches I had to make for other areas, this was after I started following Aaron Cake’s videos, I used regular paper for mock ups (like he did in them) and it worked really well and took out a lot of the trial-and-error. Also, moving the engine played havoc with my driveline angles, mounts, and shifter placement.

valley

iTrader: (1)

There are a number of kits for LSx swaps, however, after moving the firewall, none of them would work (and they cost money). So, I had to make my own mounts. I could have done something convoluted and managed to use the stock rotary mount location. But, at the end of the day, with how far back the engine was, that was far from ideal. Actually, with the leverage the mount would have had, being so long, it would have been an absolutely horrible idea. So, simply enough, I took some plate I had laying around, cut it up into roughly the right shape, and welded a perch into the stock K-member. Unlike some other swaps I’ve seen that try to mimic the OEM LSx perch, which is tilted, I made mine flat. This is because I would not be using an OEM LSx motor mount. I made mine out of a round of 60A polyurethane I purchased on ebay. As most materials don’t like shear stresses it would have been foolish to make tilted perches.

Once the engine was located, the transmission pretty much located itself. I had to be, and was, concerned with driveline angles and with how low the engine sat it wasn’t easy to make them work out. I had to remake the transmission mount several times simply because the trans was sitting too low and the angles were horribly wrong (they’re a PITA to set when you don’t have a driveshaft). Since the trans was now so far back I could not really use the stock mounting location. Well, I could, but I didn’t feel comfortable doing so because of the length of the moment arm that would be created. I had several ideas, including essentially making a strap that would go around the trans, but in the end felt the simplest way was to drill a few more holes in the trans tunnel, reinforce said holes with a few, substantial, plates (I’m looking at you, granny’s) that I’d weld in place, and call it a day. And that’s what I did.

valley

iTrader: (1)

Once the engine and trans was located I could locate the accessories too. Well, accessory, the alternator. Because racecar! I wanted that fairly heavy chunk of copper, aluminum, etc. located as low and as far to the passenger side as possible. Since, when on a track you’re typically by yourself, and can weigh a not-negligible amount of the total vehicle weight I wanted as many “heavy” things on the passenger side to help ensure a fairly neutral L/R weight. That the alternator wouldn’t fit in the lower drive side because of where I had the engine helped make the decision too. With some angle iron I made a bracket that located the alternator low and on the passenger side. The bracket isn’t pretty, but it works pretty well.

LSx engines also have a problem with their belt tensioner. With fast RPM changes it is known to throw belts. The solution is to use a manual one. That I couldn’t use the automatic belt tensioner because of where I placed my alternator helped make this decision too. Using some square tubing, a machined adapter for the OEM pulley welded to it, and a few other parts, I made one. Making sure the pulleys lined up nicely and taking many measurements ensure this and made making these parts a several days affair.

valley

iTrader: (1)

I was originally going to use the OEM LSx wiring harness and ECU. However, in swaps without the clutch switch hooked up there is a known issue of intermittent stalling on clutch-in after deceleration. This, along with the fact that I didn’t feel like paying someone $200 for a mail order tune that I would have to pay another $200 for another mail order tune if I changed things didn’t sit well with me. So, I ordered an MS3 with MS3X expansion, wiring harness, and some other odds and ends and made my own harness.

It really wasn’t that bad of an experience. After carefully reading up on the how’s and why’s of the general harness setup it took me about a day of patient work, double and triple checking everything, to put the harness together. I put the ECU in a place where I thought it would go, pulled apart the different wires and ran them away from high voltage or other noise sources, grouped them together, and soldered them.

Wiring up gauges can be a PITA. Especially getting stock gauges to work with a swap. To do so you really have to know the how and why of the particular gauge you’re trying to wire. For things like O2 gauges it can get interesting when instructions conflict. For example, it’s not advised to have the O2 heater ground close to the ECU ground. However, you want the O2 gauge ground to be in the same place as the ECU ground. So what do you do when your wideband has them going through the same ground wire? I ended up just grounding it at a different place (although, I may run a wire between them and see what that does).

I originally wasn’t going to run a dashboard, because race car, or perhaps make my own. In the end, since I’m using the stock cluster and the dashboard doesn’t weigh that much I decided to use it after some modification. Also, since I wanted to reduce weight on the cheap, I’ve pulled out most of the interior. I had delusions of redoing the interior harness as well, again, because race car and also because since I was pulling out so much I wanted to simplify it. But, at this point it’s simply adding work.

valley

iTrader: (1)

Fitting the R-type transmission to the LS1 took quite the bit of work. Several iterations of both the transmission and flywheel adapter were made. In the end I am able to use the R trans for a fraction of what it would cost to purchase a T-56. That being said, it took a LOT of work and I don’t have a T-56, not that I think it would fit in the trans tunnel with how far back I moved the engine. I’m not going to go into excruciating detail, but I might, in the future, post up my CAD files relating to my adapters (assuming I can find them).

I speak a bit more about the trans in this thread towards the bottom of the first page: https://www.rx7club.com/v-8-powered-...ssion-1084499/

valley

iTrader: (1)

The exhaust was an interesting conundrum. I had little to no room on the driver side to route it and I would have had to use oval tubing, which is very expensive, if I wanted to route it there. However, I had a good chunk of space on the passenger side. I looked into a number of header options, including some block huggers but nothing really struck me as that good of a fit when I considered my placement. In the end, I used some LS6 headers, which I altered, to route the exhaust from the driver side under the front of the oil pan (I still need to put the heat wrap on that section…) to the passenger side, where I Y the headers together and have a single pipe going to the exit. Imo, it sounds very good. Although I think it being essentially a straight pipe has something to do with that.

In the same thread, I had several options of what to do with the intake. Long story short, I really wanted to use the TII hood scoop. Really, I was pretty fixated on doing just that. No other options seems all that great to me as getting nice, fresh, cold air from a laminar, attached flow region on the hood where I had no changc of accidently hydro locking the engine like most CAIs can. So, laying out the pipe and chosen air filter (after spending an hour or two cruising the auto parts air filter section for the biggest one I could find) I drew up the dimensions and welded it all together. Frankly, it looks like garbage as I hadn’t welded aluminum in a long time and had a lot of gaps to fill (pre-paper method). But, at this point in time, it’s all about getting it on the road, not making it look pretty.

valley

iTrader: (1)

Here are some things I would asked myself or problems I found myself running into during this and other projects I’ve had or simply points/opinions I feel like making. Feel free to agree or disagree with any of this. Discourse in these areas helps others at the least.

Can you build it?

If you don’t own, can’t borrow, don’t know how to use, whatever, a tool you know you’ll need (in my bike build, a welder), AND you don’t have a friend who isn’t flakey (what killed my bike frame) OR a lot of money, your build will fail. This one is pretty obvious until you get into “yeah, my good buddy said he’d do X for me.” Then never does. Or, “It should only cost X and take Y time.” It then costs 2X and takes 3Y time.

Should you build it?

Sometimes something is “great in theory” but simply won’t work out in practice. Sometimes it can be because you can’t do it right for some reason, the theory is incomplete, or there is actually a better solution out there. It can be hard to tell which, if any apply, but sometimes you have to cut your losses and go a different route. Experience will help with seeing the answer to this question before you spend money.

Should you do it?

During my build I made several choices that I had to go back and unmake. In particular, since Race car! I decided I was going to pull out the OEM seatbelt system and put in a 4 point system. I also did this to make room for the shifter input to come through the trans tunnel where I would then make a system, like in old F1 cars, that allowed me to relocate the shifter wherever I wanted. I later found a video about shortening the shifter location and decided to go that route instead. So I had to make a patch for the hole I’d cut while also relocating the bolt holes for the SRS system. In sort, I made more work for myself by jumping the gun and not fully thinking out how two different things would interact with each other. The moral of the story? Before you have to do something that is permanent (or will take a lot of work to undo) make sure it’s what you want in the end and put it off until that’s the part of your swap that you’re at.

Budgeting:

By the end of my swap I have very much so overshot what I thought it would cost. Those nuts and bolts you thought you’d reuse? Nope, they’re either “lost”, not quite long enough (or too long) for what you’re doing with them now, rounded off more than you remember, etc. Enjoy paying $1+ each. That took more Argon than you thought? There goes another $65 to fill your bottle. Wait, Argon shortage, $120?! A swap will nickel and dime you to death. Also, there is the old automotive Triangle Rule: Fast (speed), cheap, and reliable, pick two. However, there is also the build (any build, not just cars) Triangle Rule: Fast (time), cheap, and right, pick two. By doing also everything myself (cheap and right), even with my overshooting my budget, I’ve been able to fudge and extra half or so on the automotive triangle.

Reliability:

What I didn’t quite realize when choosing an engine was that any engine isn’t reliable if you don’t build it right. In retrospect, I think I paid too much attention to what the guys who built their cars and (unstated) hardly drive it were saying (“It’s the most reliable thing ever!”) when I really should have paid attention to the Camaro/Corvette/Firebird guys complaining about this coolant line, that oil pump, this excessive blow by, those shitty bolts, etc. The reality is that a Forum is where people go for help. So almost any forum will have the worst of the worst shown; until you ask about something “they” will get defensive over.
Imo, rotaries are a bit like of a “special butterfly” and if it gets treated like piston engines, which one should not do and expect it to last 100k+. I later learned of a few high HP rotary guys who think (and I agree with) water injection (or methanol) is God’s Gift to Rotaries and cast iron manifolds need to be tossed in the trash. Actually, these two things are true for any engine, but doubly so for rotaries.

Wiring:

IMO, it’s not super hard so long as you have a fairly well known engine/vehicle and whatever you’re wiring in supports it. MegaSquirt supports GM sensors pretty well, it’s a very live project, and the LSx family of engines is fairly well known. This made me more comfortable with going with a stand alone ECU.
I cannot recommend enough making soldered connections. Solder them and use adhesive shrink wrap. If it isn’t adhesive shrink wrap you’re just putting a shitty bandage over the connection. One that will get moisture and dirt under it and keep it there as opposed to keeping it out altogether. Some people recommend using a flux cleaning spray as flux can be corrosive. I have some issue with this as fluxes can have a wide variety of chemical compositions and a flux cleaner has to target that particular one. They also tend to work poorly without some sort of mechanical action too (i.e. scrubbing). So, if you’re not doing it right, it seems like a waste of money to me. I picked up this last tidbit from eevblog after looking into flux cleaners.

For important junctions, like your 5v+ power for sensors, make sure you get them from a single source and you branch the wire out at one place.

Cold rolled vs. Hot rolled:

If it’s going to be machined or cut and the final dimensions mater, use Hot rolled. I sort of lucked out on this one and my trans adapters were made with hot rolled because that’s what was available. Later, I learned that cold rolled tends to have issues with final dimensions after being machined. Seriously, look it up.

Bulkhead connectors:

They’re awesome and make taking the engine out that much easier. But, you have to cut a hole somewhere to fit them. They can also be a bit tedious to pin. In particular, with weatherpack connectors I’ve found putting the female pin on the “skinny” side (the side that has a guiding slope) is the best way. There is another problem with bulkhead connectors though. Shielding on shielded wire. What I ended up doing is running the shielding through its own pin such that it’s only unshielded for that small run through the connector.

Tools, tool placement, parts, and part placement:

As I’m sure you’ve experienced and/or read about, it’s a giant PITA to deal with misplaced tools and parts. It slows you down and on long builds you will end up wasting days worth of working time searching for tools and parts. Bagging parts, especially nuts and bolts is a GREAT thing to do. Until you lose that bag. I highly recommend having only one place you’ll stick particular things. So that labelled bag of bolts is in a box with all the other labelled bags of bolts. Those dozen tools you have out to take apart one thing? Only rest them by where you’re working or leave them in one area (not the tool box) otherwise. Mine was the drivers side windshield vent. Sure, there are issues with this too, but it’s better than all over the place. Also, avoid putting things in your pocket. I don’t know about you, but half the time I forget I put something in there since I normally don’t. It also sucks sitting down only to stab yourself with the screw driver you forgot was in there.

Labeling takes time. It can take a lot of time. But when you’re in a rush later in the build and the light at the end of the tunnel is visible is where it will save you time and make finishing the build that much faster (at the end).

clokker

iTrader: (2)

I'm a sucker for a well written thread, so I'm in.

valley

iTrader: (1)

Haha, thanks clokker.

I've done some small things this past week but very little is post worthy. That being said, I will add to the small pool of info relating to wiring of the stock FC (S5) wiper switch. As I was missing the harness that would normally go to the wiper motor, I had to "hard wire" it. To do so I used 4 different colors of 14ga wire I purchased from my local hardware store (Lowe's seems to have pretty good selection and at prices that often beat online distributors).

The first and second pictures are of the connector (the non-opaque yellow one in the gloved hand) to look for with some reference to where it can be found. In words, it's in the passenger side foot well and on a branch from that funny looking triple branch. The limb the connector branches off from is also the one that leads directly to the two green plugs that lead to the door switches, mirror, etc.

The wires share the same colors as those coming off of the dash surround wiper switch. Those colors being blue, blue red, blue yellow, and blue white. The wire colors are also consistent all the way to the wiper plug. The stock wiring appeared to be 16ga. The connector had them in two pairs of pins, each on either side of the connector (each pair had one on the "lower" and one on the "upper" part of the connector).

De-pinning them was easy using a standard jewelers flat head that was slightly smaller than the pin itself. If you look at the connector in the picture where I show the screw drive and the pin you can get an idea of where the wires are exactly by comparing it to your own connector. A way to check to be sure you've de-pinned the proper wires it to check the resistance at the wiper switch plug and at the pin. It should be >1 ohm. When I checked with a good solid connection at the pin (as opposed to from behind the plug like in the picture) I would get between 0.1 and 0.2 ohms.

At the wiper plug, the black wire needs to be grounded. I simply put a largeish ring terminal on it and put the ring terminal on one of the bolts holding the wiper in place on the firewall. I put it on the washer side, not firewall side such that it would touch bare metal (of the washer) and not paint.

valley

iTrader: (1)

Here I'm going to add some information about driver side blinker (turn signal) not working. In my case, and what seems most probable as a whole, is that one of the solder joints on the driver side relay wasn't given enough solder and eventually would crack and separate. I got the general idea on what was wrong from this thread: https://www.rx7club.com/2nd-generati...-does-1008753/
If you look closely at that threads first picture you can actually see the crack in the solder that was causing OPs issue.
If you, in general, know what's up and simply want to see the fix that worked for me, skip to picture 5 and see the joint I soldered (the joint my pencil is pointing at).
Anywho, on with the show.

The first picture is me holding the issue in question in my hand. You'll need to remove the plug (already off in the picture), the small screw in the middle (IIRC PH1 or smaller), and I recommend lifting the tab by my thumb first. After you lift that side there are two others as well. I lifted the one on the side next to the first, then the one on the opposite side last. The second picture is the board in question simply being slid out of its housing. If you want to check whether this is most likely your issue, do as the third picture shows and use a wire to jumper the green/black (bottom row first column as looking at the rear of the plug) and green/red (bottom row third column as looking at the rear of the plug) wires as pictured. Doing this jumpering will give you a constant on for the blinker and green arrow on the dash (assuming the respective bulbs aren't burnt up. Of course, you should probably do this before removing the board...

I examined my board and really couldn't find anything wrong with it initially. Sure, there was some crustiness which I mostly cleaned with a paper towel and rubbing alcohol but that didn't fix the issue. I then reflowed the joints that were initially crusty (i.e. put the hot soldering iron on them until the solder turned to a liquid) and that didn't help either. The caps were also in good condition. I found this a bit odd and traced out the power side of the relay circuit on a piece of paper and it's extremely simple. So... since I didn't have a magnifying glass I started poking around at the relay in question. I found that when I pushed it as shown in picture 4 that the blinker would work normally. Odd. Flipping the board over I found (picture 5) the solder joint my pencil is touching to be broken. My pushing on the relay was moving that side of it enough to make some sort of connection. At this point in time I added some solder to the joint and everything is back to working normally.

Hopefully this helps someone suffering from the same issue.


Unrelated to this but as a general update, I've messed with the car a bit more but in general have been swamped at work and was ill for a while which killed my desire to work on it. Once work lets up I'll post up an addition to the general knowledge base on the “proper” way to convert the FC RX-7 steering rack to manual.

2nd Chance

iTrader: (1)

Looks like a good thread, I've only read the first few posts but you've definitely given me some good things to consider with my build.

valley

iTrader: (1)

Thanks Chance. These next few posts will hopefully help you and others too.

This is done on a S5 TII steering rack.
Standard if you **** up your car don't blame me. I'm outlining what I had to do to get this to work for me. Your mileage may vary.
I decided to get this out of the way a bit earlier than I expected because reasons. This is not a step-by-step how-to but is more in line with a supplement to what everyone seem to read first, the miata version, and others threads with snippets of information and I even found a youtube video that was a good reference on what-you-need-to-weld.

I'll also preface this with the fact that this steering rack had been without fluid and unsealed for at least ~8 years prior to me tearing it apart. I highly suspect it has also been removed from the car a few times previously as I had to go so far as using a jewelers file to fix some things as well as the legitimate use on stomping on the rack (seriously, it was a last resort before I'd have had to weld stuff that shouldn't be welded to disassemble the damn thing). Basically, this was almost a worst case scenario in every way. Keep in mind, penetrating oils designed to make removal of rusty/corroded/whatever nuts and bolts help. A lot.

In this I used:
jewelers triangle file
jewelers screwdriver
regular flathead screwdriver
8lb sledge hammer
small benchtop vise (both on and off bench)
6ton (I think?) shop press (don't ever buy one of the A-frame ones)
vise grips
Large adjustable wrench
24mm socket
17mm wrench
14mm wrench
and probably a few things I'm forgetting

The picture order (unless I mess it up) is always left to right with the left most picture being #1 for that particular post. Now... here comes the fun!

Looking at the first picture you'll notice a bolt. There should also be a clip there (IIRC) but since this is a not unmolested car, I don't have one. Remove this bolt. The second picture is of the driver side rack mount/clamp being pried off. IIRC all of the bolts are either 14mm or 15mm and are accessed from the bottom of the car. Don't lose those bolts and remember the mount IS directional (IIRC the longer side in front).

For picture 3 you'll notice an upside down castle nut. Why you may ask. Well, if you don't have access to a pickle fork (which often destroys the outer tie rod rubber when used), or a proper outer tie rod separator, this is pretty much the next best way to pop the joint. Threading it on upside down protects the outer tie rods threads. You also need to have it far enough down so when you hit it with a hammer you don't mess up the ramparts. Now you just need to wrestle the wrack out of the car...

valley

iTrader: (1)

In picture 1 you'll notice I'm using a double wrench setup to loosen a nut that should not be this tight. The double wrench gives me much more leverage. Also, there is a very specific retorque sequence for this particular nut in the future so keep that in mind. Picture 2 shows whats under the upper cover/nut. Do not lose that spring as it is very important. In a later picture I've circled a part in green. That's what the spring places tension on which keeps the internal bits from wobbling around and the rack gears in mesh.

Also in picture 1 is a partially removed cover/nut. I used a 24mm socket on a 1/2” drive being beaten by a sledge hammer to removed that cover/nut. In picture 3 shows whats under that lower cover/nut. Picture 4 shows the removal of the end nut that holds the worm gear in place using a 17mm socket. May as well removed those inputs if you haven't already as shown in picture 5.

valley

iTrader: (1)

So you don't technically have to do picture 1. I did as I was replacing my outer tie rods anyways. Fairly straight forward, loosen the backing nut with (for mine) a 17mm wrench while holding the outer tie rod in place with the large adjustable wrench. Do make sure you're turning in the proper direction though. Some cars used a combination of right and left handed threads on the steering rack components. IIRC all of mine were right handed.

Now, picture 2 is supposed to show you the lovely small end of the inner tie rod to fit a crows foot wrench onto. I don't have any crows foot wrenches. If you look closely it also shows a damn small landing (flat spot) to put a wrench on so you don't twist the steering racks shaft too much and risk damaging it or its bearings. In picture 3 I put the teeth of the shaft in a vise, tightened it, put my adjustable on it and hit it with my sledge hammer. I could practically hear it laughing at me as it didn't budge at all.

Now, I know that some of you are cringing at the fact I have a rather important part in a vise, without protecting the teeth. It took me ~4 hours to get this desperate. However, I reasoned, the shaft is hardened, the teeth don't have sharp edges (i.e. the edges won't crack off), and this is realistically the only way I can hold it without welding something too it which I REALLY didn't want to do.

Eventually, what worked can be sort of seen in picture 4. I put the shaft in the teeth, used the sledge hammer to tighten the vise so it wouldn't roll at as it liked to do. Put that on the ground balanced with my adjustable wrench and stood on it. And it didn't move. Then I jumped on it and all was well in the world as that worked. For those who don't get why putting my entire weight on it didn't loosen it but jumping did, look up Jerk.

In the 5th picture you'll notice a small pin sort of poking out of the shaft by the flat spot. If you look even closer at the threads on the inner tie rod you'll notice a flat spot there closest to the hex. That pin is there to deform the threads somewhat to help ensure the inner tie rod doesn't prematurely come undone. Some genius crushed it until it was flat with the shaft...

valley

iTrader: (1)

Now that this is out of the way, let's return to the steering rack input. In picture 1 you'll see a piece of rubber that needs to be removed. I did it by slipping a jewelers screwdriver into the inner diameter of it (by the shaft, not the body), getting an angle on it, and prying it up just enough to attack it from the side. Your mileage may vary. Picture 2 shows it off and the C-clip you'll have to removed to eventually pop the input shaft. Try not to bend it too much... Picture 3 shows the bottom retaining bolt installed backwards. I tapped it lightly to pop the shaft after the C-clip was removed, then removed the nut and remaining assembly ones it was popped.

Picture 4 more or less shows the whole input assembly. Where I have the flat head you'll need to get that to come off. That piece that pops off I reinstalled (the one with the two black o-rings). Technically, you can probably get away with out it, but, I figured it made a good center support and reinstalled it during reassembly. Since mine has so many years of neglect I had to pop it off with a press as seen in picture 5.

valley

iTrader: (1)

Picture 5 of the last post shows my press setup that was able to removed it. Picture 1 shows what's under it. You'll need to removed that black clip and the 4 inserts it holds it. Picture 2 shows me using the press again to removed the pin that holds the input shafts two assemblies together. This should pop out with some light taps... again, neglect, mine didn't. These teeth are also what I had to fix with a triangle file. I would recommend putting something soft under (like a piece of wood with a hole in it) it as you'll notice I didn't... oops.

Once that's pin is removed you'll get picture 3 once you separate it. It just pulls apart. That middle piece does not go on. Reassemble it and press the pin in again and take a look at picture 4. There is a red circle. If you twist the two assemblies in your hand you'll notice it actually twists. That's because you're twisting that thin shaft the pin secures until what's in the red circle hits an edge. Weld all the way around being careful not to overhead the hole thing, especially the bearings. Naturally, don't forget to clean the weld site first. Picture 5 shows my weld on the two halves of the input shaft.

valley

iTrader: (1)

Now... back to the steering shaft. If you've removed both inner tie rods you can now easily do what's shown in picture 1. You simple twist that end and the metal rod gets spat out the window. Good luck reusing it on reassembly. I used some 3/32” aluminum welding rod in its place. You have to feed an end into one of the small drilled recesses, then twist it 360* on reinstall.

With that last part out you can finally removed the steering shaft and it should look a bit like picture 2. You want to keep the part with the black o-ring and cut off the one with the white. I used an angle grinder with a cut off wheel in a couple of places and then smacked it with a hammer. Picture 3 is what happened. While everything is out you might as well seal up the various holes as seen in picture 4. There are also the two on the main tube. At least 1 of these holes needs a hole drilled in it to allow pressure to move around. I chose the fitting more or less in the center of the main tube.

Picture 4 also has that all important piece I mentioned earlier in the green circle.

Now, make sure everything is clean and cool. Put some lube on everything and reassemble. Don't forget to give those PITA pins on the inner tie rods a squeeze like in picture 5. Also, you can put too much bearing grease on the parts. I personally put way too much in initially and had to remove some. A medium coating probably works best.

Notes:

Do not forget to look up the proper torque sequence for the steering input shaft. It matters a lot and if you screw it up your steering could be really sloppy with damage to the teeth or way too tight making all of this moot. Don't forget the C-clip or rubber cover for the input either.
On the passenger side steering shaft there is the support bearing and the end stop. Don't forget either of those.
When putting the rack back in the car I measure the racks movement from one extreme to the other (lock-to-lock) using calipers and two set reference points. One on the rack tube and one on the steering shaft. I then halved the measurement and put my reference points that far apart. This got rather close to centered. I then centered the steering wheel and gingerly attached the input to the steering linkage.
IIRC There is a torque sequence to the rack hold downs.
I could not find the inner tie rod torque spec in the FSM. I looked up other, similar cars and they seemed to range from ~55ft-lbs to ~90ft-lbs. Again, not having a crows foot I did the best I could and probably ended up somewhere in the middle of that. Again, your mileage may vary.
I bought and used a #53 power steering rack and pinion... etc. I found them on ebay and they seem to fit/work fairly well. Granted, I've only got a few miles on them.

This mod to this extent is not for the faint of heart. There are ways around pretty much all of the welding although if you're not welding the input shaft I'm failing to see the point...

Don't **** up your car. If you do, don't blame me.

It's "late" for me at the time of this posting. If I missed something or there are questions or additions/comments (about this or other stuff) feel free.

valley

iTrader: (1)

Had a smidgen of time and had a few parts come in so the ole' car got some attention.

I built myself a truly sealed battery box out of a 40mm ammo can. It fits my group 51 battery pretty well. I built it because I had pretty severe height/width limitations for the placement I wanted (behind the passenger seat). I was also fairly frustrated with the “sealed” battery boxes currently on the market. Since I'm not using a 100% sealed battery I made a vent (with loop) that goes through the passenger rear ABS sensor grommet. The loop is there to add extra protection in keeping liquids from being able to back flow into the box. Everything that goes through it has RTV on it for sealing and the lid comes with a rubber seal. It also serves as a much better firewall than anything I've seen inside a car. Yes, I could have made a box from scratch, but that's a good chunk on time welding and making sure the top seals, etc.

On that note, when you put your battery cables back on don't forget to tighten them down! I was messing with controlling my DR44 output with a PWM controller and I had an embarrassing moment when my alternator nut backed off just enough such that above ~2000rpm the cable would vibrate just enough that at times it would cause just enough of an open that the car and MS3 would lose power very briefly.

On another note, I've been meaning to post this and should have included it with my power to manual steering rack info. The last picture is the shifter grommet/seal from the Dorman 917-551 kit. You can buy them for ~$15 and it comes with a few other pieces you may be able to use. The catch is that the hole is just slightly too big. I put some RTV between it and the shifter and it's sealed. The new spring in the kit is pretty nice too and very firm.

I also purchased a set of steering rack bushings and I've been pondering making a mold out of them and seeing if I can make some useable delrin/acetal variants. I know a few members here have a fetish for delrin but I'm not convinced... Any delrin lovers want to chime in?

LargeOrangeFont

iTrader: (7)

I'm in for a set of delrin or aluminium rack bushings. I run a manual FC rack though.

Should increase the steering response a bit.

valley

iTrader: (1)

I said "**** it" and ordered some mold supplies and delrin. Once I have a bit more time I'll prep my bushings for making a mold from and see how it goes.

What exactly is the difference between the powered and manual rack as far as the bushings are concerned? I haven't been able to find it in a few cursory searches.

clokker

iTrader: (2)

Driver side bushings are the same, passenger sides are different (manual rack is smaller diameter tube at that end).