Recommissioning my 82 RX7

I have found no restriction with that muffler in a non turbo engine that meets your power goals.

It's quite a handful   I could imagine its power but shifted lower and with a softer onset.

You may find it difficult to get boost down with the stock turbo if the exhaust is not restrictive enough.  Mazda relied partially on exhaust restriction to reduce boost, a lot of people had to port their wastegates out to the point where the flapper had nothing to seal against, when these were commonly modded.

sevenracer said:

In reply to GasTungstenArc :

I am going to use the RB muffler with the TII motor. I am only looking for 220-ish whp, so I'll think it'll be ok.

Yeah, OK, good point.  One thing is for sure: you'll have an actually decently quiet rotary with a turbocharger and that muffler.  Will you be using only the muffler, or also the resonators from upstream?  If you use the RB muffler, plus resonators, plus turbocharger, I'd bet it would be factory quiet.  

I'm using an RB presilencer. I'm definitely curious to see how it sounds, I always liked the sound and volume level with that setup on my 12A, hopefully it's similar with the 13BT.

Pete. (l33t FS) said:

You may find it difficult to get boost down with the stock turbo if the exhaust is not restrictive enough.  Mazda relied partially on exhaust restriction to reduce boost, a lot of people had to port their wastegates out to the point where the flapper had nothing to seal against, when these were commonly modded.

Yeah, I'll be facing a big 'ol learning curve as far as tuning, I did port my wastegate, but nothing extreme. I'm hoping my stock injectors can keep up with whatever my boosts max out at, but I'm expecting to need some fiddling/upgrades to get it fully dialed in.

Another installment of what's happened over the course of the last year plus.

The underside of the car overall was I'd say in good shape with just a fair amount of surface rust that needed to be attended to. However, I discovered some trouble in the driver's footwell that had been concealed between undercoating and sound deadening.

Dealing with this took me forever, was quite a learning experience and highlighted the limits of my fab skills (and patience).

The patch below the throttle pedal was pretty straightforward, welding it to the channel below was a bit more of a challenge than I expected.

The patch below the dead pedal was a total pain. First, there was a rust hole in an angled wall of the outer "frame rail". It was a weird spot because it was angled but mostly vertical, so it didn't seem like water would have collected there vs the floor below. So, here's where I made my first mistake - I cut out way too much material. My thinking was that if it had rusted through in this unlikely spot, there must be a nightmare waiting behind it. Turns out, everything behind it (a small closed cavity) looked great. Argh, so instead of a couple of simple flat patches, I had to make a panel with multiple intersecting angles for this corner pocket of the floorboard. I tried making one single piece, but eventually gave up on that and formed 3 major pieces to patch it up.

The welds look terrible. I did a number of practice runs welding old metal to new metal on my bench until I got a fairly good result. And then it would be whole different ball game when I was hunched down in the floorboard. I used weld through primer for the first time, and my experience is that it made things worse. Anyway, it's not pretty but I banged around on it and I think it's solid. Some seam seal and paint, and enough of that mess.

Ok, this post is a status of where we are today. I had hoped to be a bit further along after several days off around the holidays, but some good progress was made. I continually find myself burning lots of time cleaning and painting parts/hardware because there's like zero chance I'll go back and do that after the car is running. Engine and trans are back in the car, steering box and front suspension mostly in (need to install radius arms, brackets and swaybar after paint) and I have mostly connected the fuel system. Next major task is installing the engine harness and getting that connected up to the chassis electrical system.

But the big news is that I have set a target date for a first start - Jan 14th. That's my birthday, and I have the day off and an appointment set with a remote tuner. This timeline will definitely be a challenge - there's LOTS still to do, but I've cleared my non-work schedule from now til then.

To keep my motivation level high, I am watching this every morning. The whole vid is a pretty decent comparison of a stock 12A to a stock S4 13BT, but the link should start at the key part - a run up through the gears with the turbo motor- I really just focus on the tach needle sweeping to redline. Yes please.

Decent progress last night, nothing really pictureworthy.

A couple of pics of engine and trans before install. and then in place

Fuel system is all connected except the 2 rubber lines to the engine. I had made up some NiCopp lines a while ago to connect up between the non stock pump and filters.

It's mostly hidden by the fuel pump bracket/plate in the picture, but the driver's side rear in front of axle is very busy. Fuel pump, feed and return lines, rear brake line, and e-brake cable all run through there. May need some adjustments to keep everything away from each other.

 EFI harness fished through firewall and laid out roughly in place, ready to connect up to sensors, batt, etc. Hole drilled and grommet installed for boost pressure hose

And as always some cleanup/paint. front sway bar was looking a little shabby and is not that easy to remove later, so I hit it with a bit of paint.

Before wrapping up, I spent some time organizing my parts bins to create a queue for the next most critical things to install. Focusing on the must haves for first start and things that require further thought/problem solving. Leaving more routine re-assembly tasks like brakes and suspension for later. Tonight will be mainly focused on wiring (and as always some clean up and paint of fasteners, brackets in parallel). 

Well, it's been quite a slog and not done yet. Not sure if I'll be able to do the first start on my birthday this Friday. Smart thing to do would be reschedule (I'm working with a remote tuner) for MLK's birthday , but the weather is supposed to be iffy this weekend with forecasts saying snow or ice storm possible. Can't really do the session if we lose power, and I also need to be able to roll the car out of the garage if there's any kind of smoke/fire event and that would be a cluster if it's icy out. So, I'm pressing on to try to make Fri happen.

front suspension is back in

brakes are in but still need bled

clutch hydraulics mostly installed still need bled

coolant system is partially installed

intercooler bracket riveted and epoxied back on

need to do some welding on the oil cooler brackets - I put a groove in the parts to get the bends that I wanted, and need to weld them up and maybe add some gussets.

tested fuel system tonight and have a couple of leaks that I need to tend to.

the EFI harness is in place and patched in to the car's wiring but still needs lots of tidying up and routing now that coolant and hydraulic lines are in place. The harness was made for a second gen and a lot of the wires are longer than needed, plus it has connections for things I'm not using like the MOP and AC, so those wires need coiled up and tucked somewhere.

a few pics:

I'm also at the point of dumb things making simple tasks take way longer than expected.

As I was trying to get the brakes back on, one of the rear rotors was missing - should have been on the car but nope. I turn the shop inside out wondering how I could misplace an item that big. The eventual answer:

It was stuck in the wheel. Because the brackets weren't in place, the disk was able to come off with the wheel and initiate an impromptu game of hide and seek!

Also, going to drop the upper intake back on and it won't slot into the big bracket and it's off by almost 1/2 an inch - UIM will not go on. half hour of head scratching to deduce that I bent the bracket when I hoisted the engine back in because I didn't install the intake elbow (in a hurry) and that elbow triangulates the bracket and prevents bending when lifting. Dumb mistake trying to rush, yeesh. Evidence of the bending where the paint cracked off:

Quick update. My target of starting the car on the 14th (my birthday) came and went, lol. Not a huge deal, I knew it was going to be tough to finish everything by then. I was actually at a point where I likely could have had the key components "ready enough" if I had done a late night on the 13th and a few hours in the morning of the 14th, but the weather was beautiful on the 14th with cold winter weather moving in on the 15th, and I had the day off. So, I pushed off the car work and went mountain biking instead. No regrets.

When I got back to it, I spent more time than I expected resolving small fuel leaks. I also had a bit of a hiccup when pressure testing the intake tract. Wasn't expecting problems with this since it is all stock past the turbo inlet, but had to order some new grommets for the fuel injectors which took a few days to get. Also, have been sorting lots of little things.

Current status:

Wiring is in and connected up for first start. Will be tidying things further and adding loom once I verify everything is working properly. I should have all the factory gauges functional. Planning another iteration later on with a small panel near the battery to mount circuit breakers and the fan relay - haven't found the parts I need for that just yet. 

brakes are done

trans and driveshaft done

battery tray and battery installed

fuel system is done

cooling is done

oil system is done

Air filter, BOV, and intake done (though there will probably be a version 2.0 later on)

exhaust is done (just need to swap the block off plate for a gasket at the downpipe exit.)

Major things needed before first start now scheduled this Friday:

deal with a bracket that is interfering with the intercooler - it's bent, but hard to see where and how to fix.

final install of upper intake, throttle cable and intercooler (after I do whatever is needed with the bracket)

quick pressure test then remove the blocking plate from the exhaust

connect up the interior switchgear and make sure all is working

make sure no wires will be too close to hot, spinny bits

get the car down off the dollies

throw the driver's seat and steering wheel in

move all the crap off the roof

A couple of random pics though doesn't look much different:

BOV to intake: needed to reduce from 1" to 3/4"and use an elbow to mate things up. So many hose clamps!

Block off plate to test for boost leaks - never found an engine position where intake both combustion chambers were sealed

Wheels on!

sevenracer said:

Every.  Time.

Awesome!   I might have missed it but what ECU are you using?

Thats fantastic!

Seems to be a good week for long dead project cars coming back to life!

In reply to Greg Voth :

I'm using a Haltech Elite 1000. Original plan was to use stock S5 ECU and harness. I had gathered all the stock parts, but the more I researched it, the sketchier it seemed as far as controlling fuel and timing with added boost.

Since I've never messed with aftermarket ECU's, I bought a package deal with a remote tuner for a first start session, a tune update based on road logs, then a dyno session. Incremental cost over just a dyno session was well worth the money.

The first start session had a couple of hiccups but overall went really well.

IAT sensor didn't connect to the ECU, so I plugged in a spare sitting in free air to get a close-ish reading.

I had not fully tightened one oil line connection, so I dumped about a quart of oil on the ground.

The motor is a JDM unit that was rebuilt with new rotor housings. Tuner did a zoom session and ran my PC to upgrade to latest firmware, load his base tune, and set all configurations. Car fired right up on first try (video above was the actual first start). We got idle dialed in and timing dialed in. All my gauges are working except fuel gauge which has a small wiring issue. I was honestly shocked how well it went.

Need to get insurance and a tag, put the nose panel and bumper on and get some break in miles logged.

Congratulations!

sevenracer said:

In reply to Greg Voth :

I'm using a Haltech Elite 1000. Original plan was to use stock S5 ECU and harness. I had gathered all the stock parts, but the more I researched it, the sketchier it seemed as far as controlling fuel and timing with added boost.

Since I've never messed with aftermarket ECU's, I bought a package deal with a remote tuner for a first start session, a tune update based on road logs, then a dyno session. Incremental cost over just a dyno session was well worth the money.

The first start session had a couple of hiccups but overall went really well.

IAT sensor didn't connect to the ECU, so I plugged in a spare sitting in free air to get a close-ish reading.

I had not fully tightened one oil line connection, so I dumped about a quart of oil on the ground.

The motor is a JDM unit that was rebuilt with new rotor housings. Tuner did a zoom session and ran my PC to upgrade to latest firmware, load his base tune, and set all configurations. Car fired right up on first try (video above was the actual first start). We got idle dialed in and timing dialed in. All my gauges are working except fuel gauge which has a small wiring issue. I was honestly shocked how well it went.

Need to get insurance and a tag, put the nose panel and bumper on and get some break in miles logged.

 

I've been having the same ECU concerns with a turbo swap (Series 4 NA, want to go to a Turbo setup). My plans are still off in the future as I accumulate parts, but the plan is to just go standalone and not even try with the stock stuff.

When everyone says it's easy and to just use the stock ECU and sensors, they neglect to talk about how the stock ECU has zero learning functions, stock maps above 8psi are sketchy since they were never meant to be used, fuel cuts at 8psi without a FCD, and nearly complete lack of engine protections (knock sensor and nothing else). And you need to keep the MAF.

Basically the stock ECU is okay for stock applications. Then you need to hunt down an rTek (no longer made), SAFC (works but has no timing controls), or whatever other sketchy piggyback is required. And all on a rotary which can die from one big ping. A standalone is the only way that makes sense anymore.

Cool project, I'm eager to see more updates as you go :)

EDIT: Oh, and just to add to the existing sketchiness, rTeks are programmed using a Palm Pilot. Meaning you need to track one down or figure out how to emulate one.

Didn't do much car stuff the rest of the weekend but did do a lot of cleanup and organizing in the garage. I'm flat out terrible about cleaning and organizing as I go and I usually have a few parallel activities going at once. So, a reset was needed.

A low point a day or two before the first start:

And from Sat evening (no pic, but I cleared the work surfaces Sun):

And a random shot from Friday, just cause I like the composition or something:

I got insurance and a tag today, then bolted the nose panel and bumper back on after work.

Took it for a spin - about 3 miles total. Good thing it was under the cover of darkness - lots of smoke. I had started the car and let it idle for about 2 minutes to check for leaks, and it didn't seem to be smoking at all. But plenty for my entire test drive just after that. My street still looked foggy when I got back, lol. Hopefully, it's still burning off assembly lube? It is dripping an oily mixture out of the flange between the midpipe and muffler. I undid the tube between the turbo and intercooler, and it was dry. Tomorrow, I’m going to see how it looks in the downpipe and midpipe and maybe clean those out if there's a lot of residue.

Other than that, it runs great. Started easily and holds a rock solid idle at 1000 rpm. Drove fine.

In reply to sevenracer :

Is the turbo known to be good?  It could be oil being blown out the rear seal of the turbo into the turbine housing.  

There's going to be lots of oil smoke until you burn it all out of the exhaust.

Check the PCV setup too. I thought I had blown a side seal when mine was just vented into a can temporarily.

Stock FC setup sucks air through the charcoal canister into the nipple on the center iron below the fill neck. Then the fill neck itself has a nipple that is the outlet, which goes to the PCV valve and then out to the intake. Then a smaller vacuum hose goes from PCV valve to intake on the back side, which keeps the valve shut below 2000rpm.

I've found if you want just a simple vented setup / catch can, you need BOTH those nipples vented. One is not enough. Although nothing beats the stock setup IMO

Thanks all. The turbo is an unknown but should have <60k miles. I honestly had not considered crankcase venting too much, I guess I should do a catch can.

I pulled the exhaust this evening and the turbo housing, exhaust wheel and O2 sensor were dry. The outlet of the downpipe and midpipe had oil residue collected at the bottom of the pipes that was leaking out of the flanges. I cleaned them out with degreaser but didn't attempt to clean the muffler or pre-silencer. Based on the turbo being dry I am optimistic its just residue in the exhaust burning.

I buttoned it up and took it for a slightly longer drive.

The good news: it started out smoking similar to last night once warm, then reduced but did not totally go away.

The bad news: The car died on the test drive. I had brought a flashlight, but no tools or spares or documentation or anything, lol. It would crank but not fire. Luckily, it didn't take long to realize the fuel pump wasn't making any noise. A 20A fuse in the Haltech fuse block was blown, so I stole a 30A fuse from the stock fusebox and was back in business!

I headed home, total of about 6 miles covered. The Haltech has a relay for the fuel pump that supports 15A but the circuit has a 20A fuse . I have a lift pump which should draw less than 5A and the high pressure pump - not sure what it pulls, but I would not have expected to blow a 20A fuse due to load. Will check things over tomorrow, and make sure the wiring isn't damaged.

Overall, it didn't have to come home on a hook, so a successful outing. I guess I'll put together a tool roll and spares box. And maybe join AAA.

I think I may have a bad stock fuel pressure regulator.

I was hoping to put quite a few break in miles on the motor this weekend, but my fuel pump started making a squealing noise right out of the garage this morning. The fuel pressure reading shows way higher than it should - peaking over 120psi.

Symptoms/clues:

1. Popped a 20A fuse on last outing - circuit is running a lift pump (<5A) and a high pressure Walbro style pump (amps unknown, but seems these should pull 6-9 amps max at 40psi.

2.  High pressure pump starts making loud squealing noise this morning.

3. At idle, Fuel pressure reading goes through a repeating cycle: Spikes up to ~130psi then drops down to 12-15psi over maybe 5-10 seconds, the car almost stalls, then the pressure spikes back up to 130 and repeats.

Incidentally, I did drive the car about 3 miles and put another 5 gallons of gas in to make sure it wasn't just a low fuel issue. It didn't drive terribly, a little weirdness at very light throttle, but pretty much ok. I think the weirdness was happening when the fuel pressure bottomed out.

Here's my theory:

FPR is sticking and only opening at very high pressure (130psi), then sticking open until a lower than normal pressure (12-15psi).

Fuse blew because pump amps spiked under high pressure.

Pump noise is a symptom of high pressure, or pump is damaged due to high pressure.

This all assumes the fuel pressure reading from the ECU is correct - I don't currently have a gauge to test this.

Does my theory hold up? Can a FPR fail in this way?

Exciting fuel pressure video: