If your cruising at 70 then ai isn't even being used...

 

Take the car out to Steve Kan in Texas (I think thats where he is) and all your problems and worries will go away. For the money you spent on the car and worry about it happening again, its worth the drive I would think.

thewird

 

You can get the Datalogit from RX7.com so you can pull the map from the ECU directly. They are rather easy to resell if you decide you don't want it later. At least this puts you in control of access to your car's maps and tuning to get help on here.
Rotary Performance | FD ECU

Alternatively, try and find a local guy with a Datalogit who is willing to pull /download the map from your ECU for you.

 

If the engine ran fine for 8k miles it certainly wasnt the build that was the issue. It was the tune or an issue with an injector or other issue with the car. If the engine made it 8k miles it doesnt just decide to shoot an apex seal. Also, were you really just cruising when the seal broke? Not calling BS but that is really really rare and usually only on high mileage motors that have been beaten for years and have old brittle seals.

Ceramic seals......pure waste of time for a boosted street car.

Water/meth injection......if you arent using it you are taking an unnecessary risk. No need to tune for it but it is a great tool for preventing detonation, mental stress and lowering intake temps. Its simple, no need to over engineer it. It just works, plain as that.

Tune/Tuners....The tune is likely the cause but no way for any of us on here to know that for sure. All tuners have a lot of blown engines accredited to them, even the biggest names out there. If you arent trying to set records on a track somewhere or street racing for big money it is best to ask for a conservative tune and then install water/meth injection after for your own piece of mind.

Apex seals.....Tons of choices here. It all depends if you want to stay super conservative on your tune and boost settings and use seals that will not prematurely wear housings but have higher chance of breaking under detonation. Or, you can choose something along the lines of E&J Apex Seals(ALS), Rotary Aviation Super Seals, Goopy Seals which all hold up great to detonation but likely wear housings faster than OEM, Ceramics or Atkins seals.

Their is no definite answer to your issue or to the best choices moving forward. It would be difficult to point the finger at the engine builder though if you made it 8k miles without issue.

 

Could also be a bad engine harness or injectors. Have the injectors ever been cleaned and flow checked?

 

That popcorn sound is knock and if you ever hear any hint of it lift immediately and find out why you are running lean.

I suspect you have a fuel delivery or fuel injector problem.

The engine is likely fine and the tune is likely fine.

I'd start with wiring to the secondary injectors since it happened with the stock ecu as well.

 

Thank you all.

I will be going down the list of things to check this coming week (harness, injectors, and get a datalogit)

Honestly, I was just cruising. 4th gear at 70mph.

I suppose the turbo would attest to that, being that the turbo is okay and didn't eat any broken seal pieces. (Correct me if I'm wrong, but wouldn't that imply no boost?) simply asking..I'm NOT trying to sound like a smarta$$

I had the injectors cleaned and flow tested, But I know when the engine first went back together...the car wouldn't start.

The builder told me that the injectors were "sticky" and "sometimes that happens when they come back from the cleaners." (I don't know since I've never sent injectors out for cleaning, but is this true?)

Also, I'm seeing that lots of people think the ceramic seals are rubbish. Are they something I should worry about too?

Since ceramics are in the car...what can I do to ensure their longevity.


Thanks

Jay

 

For all I know, the motor could have been assembled perfectly.

But, I'm a CNC programmer/machinist by trade, and my company CALWIRE manufactures medical device components that go into your heart. My point being...everything that leaves my shop is inspected under microscope and documented for obvious reasons.

When my motor blew I went to the builder and asked them for any type of documentation they had..measurements or flow test charts for the injectors...They had nothing. (In hindsight I should have done this from the beginning)

So I guess these people are just throwing these engines together with out any type of clearance or flatness measurements.

I'm just spinning my bearings here..

Thanks

Jay

 

Ceramics aren't rubbish. Just the wrong choice for a turbo application. At your power level they shouldn't be a problem and should give you a long life. BUT your car needs to be working properly.

As I've said before, the problem isn't the engine. If there is something wrong with the build, it will show itself VERY quickly. These motors are really simple, it doesn't take an engineer to put them together.

thewird

 

I'm betting a problem with the fuel system or tune. If you lug the car on the highway at low rpm, it is possible to build boost in cells that normally don't see boost, especially with twins. If this isn't tuned for, it can cause a problem. That's why when we tune we make sure to at some point put the car in 5th gear at low rpm and load it up so we cover all those weird areas in the map that normally don't get utilized. If fuel injectors stick after cleaning, then most likely they sat too long. I don't send injectors out to be serviced until I need them. I also always apply voltage to them immediately when they come back to make sure they fire. Like others mentioned, ceramics are a waste of money for your application. You already have them, so might as well run them. There is nothing wrong with them except they cause a lot of damage when they break because they shatter. That being said, they will not break if you don't detonate. Did the builder use new rotor housings with the ceramic apex seals? If not that canl be another issue because they don't really wear in. You are better off with RX Parts, ALS, or Goopy seals. 14k is a lot of money for a stock build. I'd be curious to see the list of parts that went into the motor or an itemized invoice. what is the condition of the engine harness? How is the fuel pump? I had a car that would just shut off randomly and it ended up being a fuel pump that would cut in and out. I'm not very familiar with shops in your area, but PRT (Steve Kan) and Rotary Performance are in the west. You also have BDC over there. Not sure who else. Or send me the car and I'll gladly fix it. I did one for a customer in California last summer and shipped it back to him.

Ihor @ IRP

 

I had a bad tune from Nelson. Was lucky I didnt blow my engine. He had the timing way off.

 

I would like to consider myself a bit of an authority on tuning. And I think you should put your car back to the way i was when the first motor blew. Put a stock ecu, stock fuel pump, etc. stock tune is the safest there is as long you don't mod the car much. And it is rare for the second engine to ever last nearly as long as the original.

 

For cars with simple bolt ons, is a tune really necessary?

Before I went single turbo, I ran the base maps on my power fc with an bosche fuel pump, intake, exhaust, downpipe, and intercooler and daily drove my car for over 30,000 miles (after that I went single turbo) without any issues. I was running 91 octane gas (crappy CA gas) on a mazda reman motor and even took my car to the track several times on this setup with no problems.

 

Crappy 91 octane my ***. OP you don't need any bandaids (water injection) with 91 at your power level. What you need is a proper full map tune. Here in west Texas 91 is all we get. Back in 2007 I was a parts manager at Mazda. We had this one modified twin turbo Fd that I got a chance to work on. Even though I was in parts, I worked on this particular car because the regular mechanics knew nothing about fd's. Anyways the chassis had 180k on it. After doing my repair, I took it for a test drive and was amazed at how well the car performed. She was only making 12psi and about 320rwhp and ran flawless. I was assuming recent rebuild so I contacted the owner and we had a nice conversation about the car. I asked him how long ago was the engine rebuilt and he told me back when it had about 90k. I was like are you serious? He's was like yes. It also has the factory 3mm apex seals. I then asked him who built and tuned the motor and he told me Rotary Performance.


So the moral of this storey????On one hand you have a rebuilt engine making 100 more hp and has lasted nearly 100k with no water injection and just simple 91octane while you have your rebuilt setup barely lasting 10k on lower power levels???

Find a reputable shop and have them go through your entire setup and retune everything.

 

You will always benefit from a tune. A base map may get you by but it is not ideal. These cars don't compensate whatsoever under boost. They read fuel and ignition straight off the map.

 

I think you meant to say a GOOD tune.

A crappy tune is no benefit.

 

Bad gas is just poor excuse for something is wrong with the car. It's an easy escape coat that people use to wash their hands. If something fails, ITS BECAUSE SOMETHING WAS WRONG. They're is a reason to everything, this isn't magic. I constantly look for the answer to the Why question when I fix someone's car.

thewird

 

too bad you don't open a rotary repair shop. I'm finding most shops don't give a rats *** about finding the real cause of a problem. A long as they can get "close" with how it is supposed to run I guess they figure they've done their job! Bullshit....

 

Again this isn't the tune or the engine.

It happened with the stock engine and ECU the exact same way.

He heard the infamous popcorn sound (big time knock) both times so he ran lean. It's a fuel delivery problem.

Hopefully he will post with an update once it's fixed

PS Stock PFC map is good. Good mileage (so a little lean) but the timing is silly safe. His car was probably getting great mileage LOL

 

Missed the part about the stock ecu. Base map on the PFC is decent, but it can be made safer/better. I'd also look into the engine harness. A lost crank angle signal can blow a motor.

 

Yep that's my 1st guess as well. I'd start with the engine harness and secondary injector wiring.

 

I don't recall OP indicating any kind of signs of knock when the first engine blew (obvious audible noise). It sounds like it was ~20 years old and it let go. To me it sounds like it blew up because it was old, and the second time because of any number of reasons.

 

Let's take a look at the provided dyno sheet. The first thing I see is that the car never made 232ft/tq, it made 204tq with spikes around 80 and 95 mph on the run 001.



Spikes like this are caused by a slight jerking motion of the tires on the dyno rollers, this can be caused by a misfire or detonation or loose straps. Unfortunately the AFR's were not logged so determining what was actually going on is very difficult.

From experience of tuning so many cars on the dyno, every FD that has produced such low HP numbers that would pull to redline (with a healthy engine and turbo) always had an ignition issue. One car the customer had relocated the coils to the CC area and the leading was arcing to the mounting bracket, on a different car the owner had installed J&S knock control unit, then removed the controller without reconnecting the signal wire to the leading, another had a fried igniter that only fired the trailing coils. Ever one of these cars were down around 100rwhp, similar to the OP's car. We have tuned many stock FD's with similar basic mods (DP, CB & PFC) the cars make around 300rwhp on a Mustang dyno.

Now let's look at fuel Inj Map



What I can see from the Inj Map is that the tuner removed 10% fuel from nearly every cruise cell 1600-4K RPM from 0psi to max vacuum, problem is we do not know what the actual base fuel map looks like, if it is the stock Apexi base fuel map, it would imply that the tuner was having an issue with a very rich cruise area. This again would be a sign that the ignition system was not functioning 100%.

A secondary injector issue does not allow the car to make it into positive pressure or WOT.

The first thing I would be doing is checking to see if there is spark at each plug.

 

With all the blown motors I've seen over the years (7 being my own when I was inexperienced and learning) I have only heard audible knock once. These cars are generally too noisy to make out knock before it is too late. The stock knock sensor is worthless as well. Banzai brings up a good point. I had a car that was running on trailing ignition only. It took forever to diagnose because the leading appeared to be sparking, but the coil was in constant dwell. Basically the coil was constantly charging and then discharging. This was a car that I built and set up that ran great for over a year. Then the customer brought it back saying it was down on power. The turbo spooled super fast, and the afrs were about a point richer with nothing else being changed on the car. I also noticed that the egts were super high. We found that an issue developed in the body harness. There was no signal between the ecu and igniter for the leading trigger wire. We ended up switching to the Sakebomb ingnition setup with the IGN-1A coils and wired them directly to the ecu, by passing any issues in the body harness. This particular car the customer believes an acquaintance sabotaged. It may not be a bad idea to pull down the fender liners and look at the body harness. If the wrong wheel/tire sizes were run or the car was lowered too much, the harness could be rubbed through.

 

That is just all wrong... Bad gas can and will cause a component to fail.....