1992 RX-7 FD. A tale of two Rexes and several engines...

1992 RX-7 FD. A tale of two Rexes and several engines...

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4star

331 posts

194 months

Monday 23rd May 2016
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Absolutely top thread and a stunning example, I'm a fan of anything from the land of the rising sun, but FDs (and rotary Mazdas in general) are among my favourites.
Keep up the brilliant thread.

Vitorio

4,296 posts

142 months

Monday 23rd May 2016
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Looking good Nik! Love Ralph the bridgeported RX4 by the way, looks/sounds mental!

and the rotor shaped alternator pulley is pure brilliance!

AH33

2,066 posts

134 months

Monday 23rd May 2016
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Love the RX7.

I was slightly amused that your number plates are BOT and PAP.

Im a 5 year old.

Chris Stott

13,185 posts

196 months

Monday 23rd May 2016
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I have no real interest in RX7's, but this is a cracking read... a few of my colleagues have been wondering what I've been quietly giggling at the last hour biggrin

Really well written.

gregs656

10,818 posts

180 months

Monday 23rd May 2016
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Good read this one. Thanks.

chuntington101

5,733 posts

235 months

Monday 23rd May 2016
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Without trying to sound like everyone else what a cracking read! Your writing style and honesty makes you want to keep reading! Please keep it coming.

Nik da Greek

Original Poster:

2,503 posts

149 months

Tuesday 24th May 2016
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OK then biggrin

[quote="Lucky"]http://www.youtube.com/watch?v=NM6i4_Tsoq8&feature=plcp

IT LIVES! Mwahahahahaha bounce

This, it's fair to say, was one of the happiest days of my life. Well, the birth of my kids, my wedding, discovering two-girls-one-cup... all the usual major things we all go through... but this was a close fourth.

http://www.youtube.com/watch?v=7B90hiCXfNA&fea...

You can hear the uneven idle of a ported rotary really clearly in those vids, the burp-burp-burp sound. A bridgeport is often referred to as a "brapper" because of the distinctive "brap-brap-brap" noise they make.

Sounds awesome enough to me cool

http://www.youtube.com/watch?v=Chk7BbtmFKI&fea...

It wasn't all totally smooth going, of course. When you change that many components, you have to expect things won't all work perfectly out of the box. Actually, that's not true at all. The ONLY problem we had was a boost leak. Which frankly, was unbelievable. To have one minor problem and only one, well it was more than either of us could have hoped for. The boost leak was easy enough to trace by the simple expedient of listening to the exhaust. The wastegate was stripped and we found;



wedged in the piston was a shrapnel piece of apex seal from the engine that had blown up and I'd bought the turbo kit from eek

This is the little critter. This is all it takes to wreck an entire rotary engine and turbo



And this huge teetering pile of stuff is what you have left over when you build up a single turbo RX-7 from a twin-turbo one



And just as well it was all being got rid of; check out the state of the manifold for the twin turbos!



No, all those cracks aren't meant to be there nono That's what a couple of decades of rotary furnace heat does to cast iron! The double-edges sword of rotary life is that the frequent power "strokes" mean you can get ridiculous power from a 1.3, run huge turbos and all that, but the downside is that the associated heat and gasflow problems cook everything in the engine bay to destruction and require excessive exhaust plumbing to cope with them.

And it's funny really; there's so much work in that pile of stuff - nigh on four years of mods and polishing and changing hoses and fabricating ducting and god knows what else. All just a complete waste of time. This is what I mean when I say I could have saved so much time and effort and money if I'd just gone straight A to B instead of Z and back again. But, je ne regrette rien as the song says! It was a wonderful trip and I learned a hell of a lot on the journey. And hey, dudes, it's about the trip, not the destination, yeah? hippy

So, that's it, happy days then?



yeah, all I had to do was a thousand miles running in, and then map the ECU properly and it'd all be gravy. Finished. You can all stop reading and go home then.

.... nahhhhh, you know it's not gonna work out that way hehe

Nik da Greek

Original Poster:

2,503 posts

149 months

Tuesday 24th May 2016
quotequote all
So what was I waiting for? I got right on with the running-in. At first it was horrible, limited to 4,000 rpm and keeping off-boost altogether but as the engine loosened up and bedded in it got more pleasant to drive around. It was still frustrating as hell, but I kept myself motivated by the thought of how fantastic it'd feel to finally unleash the beast and feel that turbo hit for the first time. To keep the passion alive, I parked her up against a pretty background and took some "money shots" against the obligatory graffiti backdrop;









I was feeling pretty smug looking at those, and knowing the potential of what was lurking under the bonnet. At last I could sit back and go "Dang!" for the right reasons!

It seemed the best way to run it in was to go to as many shows as possible, so that's what I did, and the car never missed a beat. The culmination was the Seven's Day London run. This is the 7th July, long celebrated in Japan as being the RX-7s special day. It's got a special meaning to me as a train driver as well, since it's the anniversary of the bombing atrocities in London on the Tube and the one bus. In Japan they meet in the reststop under the concrete roads in the sky and look at each other's cars. Here in Blighty we decided to commemorate Sevens Day with a run through the Smoke. We persuaded a reporter from Japanese Performance mag to come along for the craic, and set to

pack of FDs plodding along the A40 overpass
http://www.youtube.com/watch?v=2lin-mwdQ-A&fea...

and a walkabout parked up in Westferry
http://www.youtube.com/watch?v=9tci89ONl0c&fea...

Plus some photos from the night, hope you agree a whole phalanx of FDs makes quite a sight (and noise, lol)

starting at the Ace




along the Embankment


and finally Docklands




and home over Tower Bridge


The article in Japanese Performance came out pretty cool as well







and that was it, run in. Time for the moment of truth. I wanted to get it done NOW because Rotorstock was fast approaching and It'd have been nice to make the UK's only specific rotor show with the car finished. Unfortunately, J couldn't fit in the mapping because his dyno operator of choice was in the middle of moving premises. So I took it to a mate on the forums who does mapping and indeed does it extremely well. His own drag car is running the frisky side of 550 bhp so I knew I'd be in safe hands.

Strapped her down, run her up and let her rip





all was going well, here's a quick vid of one of the early runs

http://www.youtube.com/watch?v=wShdpdXwwA0&fea...

and it even managed to climb a bit above that, this was the best graph I got out of the night;



and I was thinking "Jeez, it ought to be good for a bit more than that!" but then things seemed to be going really wrong. All sorts of rough running crept in, and as you can see the AFRs were all over the place. The dyno guy and mapper started fiddling around under the bonnet trying to cure it. The boost controller was a suspected culprit, so they tried to re-plumb it to the wastegate to gain more control. Before you knew what was going on, there was a boost spike of well over two bar, just for an instant, but long enough.

http://www.youtube.com/watch?v=cXAArwNw0Yo&fea...

Now it sounded sicker than ever. The guys persisted trying to sort it, but it got worse and worse. Eventually around midnight we had to call it a day. Ignition breakup was diagnosed as the problem, and they handed the car back to me with the warning it'd probably run really rough because the plugs were now fouled. I got in to drive back home as their van disappeared into the night... and straight away knew there was something badly wrong.

Yep, it had dropped an apex seal. The engine was ruined.


This, it's fair to say, was one of the low points in the story weeping

LincolnLovin

2,732 posts

217 months

Tuesday 24th May 2016
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:'(

Vitorio

4,296 posts

142 months

Tuesday 24th May 2016
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Ouch Nik

I saw the "shortly before it dropped an apex seals" in the description for the penultimate video and new where it was heading...

Lovely write-up nonetheless, this thread is pretty much the highlight of my work day

LaurasOtherHalf

21,429 posts

195 months

Tuesday 24th May 2016
quotequote all
Absolutely love the thread Nik as I've always wanted an FD RX7 since they first came in the scene.

As enjoyable a read as this thread is however, it just proves to me why I've never bought one-I just couldn't be arsed with the monumental amount of faffage running one takes-I'm way to lazy for all that toot.

Fastdruid

8,623 posts

151 months

Tuesday 24th May 2016
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I have to say much though it didn't work and went pop that is an absolutely beautiful power graph in terms of feeling fast, almost vertical in the middle. I loved the RX-8 but I can totally see why people *really* love the turbo'd rotaries (despite the tendency to go pop)!

Daston

6,074 posts

202 months

Tuesday 24th May 2016
quotequote all
Great read dude, you have now made me want to get the old polishing kit out and get stuck into all my intakes and Upper manifold!!!


TacoExcellence

62 posts

107 months

Tuesday 24th May 2016
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I love RX7's, but it seems like the same story with every car. I can handle a car being unreliable, but not replace-the-whole-engine unreliable.

Yours is lovely though and I'm really enjoying this writeup.

Nik da Greek

Original Poster:

2,503 posts

149 months

Tuesday 24th May 2016
quotequote all
Sorry, been trying to post again for ages but some kind of bloody adblocker thing kept screwing the site up furious




Well, needless to say, I missed Rotorstock cry

My previous post sounds bad, but it's not meant to. I don't blame the guys who blew it up on the dyno. You can't, can you? No dyno operator runs a car without you signing to say its at your own risk, so even if I wanted to shout and scream about it, it wouldn't have helped. Don't get me wrong, I was pissed off, more angry than I've been about almost anything else, but it was no help. It was done.

It's a terrible situation to be in though, caught between Scylla and Charybdis, to quote ancient Greek proverb lol. The engine builder says "well what do you expect if you boost it two bar above where it should be?". The dyno operator says "why did you bring us a car with flaws like that in it?". The mapper says "the ignition was breaking up long before it overboosted".

Who's right? They're all right. To this day it's never been conclusively proved what killed the engine first, or why the faults developed... although later events would shine some further light and show the way forwards...



So there's li'l old me stuck in the middle sucking on it. I drove the car home that night so angry I've almost no recollection of the journey. For those amongst you who've never had to drive a rotary when it drops a tip, my advice would be; "don't". It'll barely idle, it's got random compression, its throwing neat petrol out through the exhaust... it's terrible. The only way to keep it running is to keep it spinning fast when centrifugal force almost overcomes the worst of the damage by flinging what's left of the apex seals outwards towards the housing. I got it well over the legal speed limit on the way home, and I was so angry I never once thought of calling recovery, or even of the added damage it was doing to the motor.

And that's the catch-22 of a rotary. So fragile in some respects, then quite able to add 20mph onto the national speed limit... with only 50% of its engine working rotate Fickle bloody things.

Once I'd calmed down I drove it up to Super 7. J was more gutted than I was if anything, after all he was the one who'd put in the hours with the die grinder porting the engine and sticking it all together. But there was no sense in crying over exploded apex seals, we had to strip it apart and find out what was left

back to square one



it was literally like tearing your heart out. The strip-down revealed the expected carnage. This is the tip that went, the pesky li'l critter. One of the ends is supposed to be missing; the tips are two-piece with a triangular section at one end for sealing purposes. The other end isn't supposed to be missing irked



There was no sign of the missing bit, but you could easily trace its progress around the engine by the scrapes in the rotor housing...



...the nicks where the rotor had bounced over it...



...the chunks taken out of two of the rotor faces...





...the horrendous gouge in the housing where it had got trapped under the rotor edge before exiting through the exhaust port...



...and of course the nicks taken out of the turbine wheel blades as it made its final bid for freedom through the hot wheel...



Dang!

I really can't pay enough respect to J over his attitude. He was gutted, clearly, but as a businessman, he didn't need to take responsibility for the disaster. There was no proof anything he'd done had led to the destruction, indeed it seemed as likely if not more that the boost spike is what done the deed...and that was probably down to the dyno guys meddling with the boost controller. I was certainly not going to try getting into legalese about it because that would have been a nightmare for everyone involved and probably would prove nothing. He stepped up to the plate and offered to rebuild the engine for the cost of the parts alone, and I don't think anyone can say fairer than that.

So hey, ho, it's running in (again) we go rolleyes

Nik da Greek

Original Poster:

2,503 posts

149 months

Tuesday 24th May 2016
quotequote all
J was as good as his word and re-built the engine for the price of the parts. It was back in and running within a couple of weeks. A few things got changed along the way, since some weak spots had been identified during the previous running-in period. In particular, I got a set of uprated MazdaSpeed spark plug leads as there was a question mark about the ignition side of things contributing to the blow-up. The coils were tested and appeared to be absolutely fine, but I had Magnecor plug leads that were a nightmare for seating properly. The boot formed a vacuum when you pushed them on the plug and even when they seemed properly seated the electrode sometimes wasn't in proper contact. The Magnecor were red, which matched the colourscheme and the MazdaSpeed ones were a fetching shade of turquoise, which didn't, but you can't have everything!

The little Blitz dump valve had proved to be feebly inadequate to flowing the amount of shunt the new turbo was pushing out, and a GReddy Type R was pressed into service instead;



The pulley setup had been chafing slightly on the oil cooler lines, so a bag-load of cable ties sorted that little problem before it led to disaster!





The fuel pressure regulator was a secondhand one of unknown provenance, I think it was a Nissan one of some sort. Since there was a question over the fueling too, it seemed prudent to change the poor little thing



Rotaries simply cannot take being run lean, because of course that makes the chambers hot. Then carbon deposits form localised hotspots and then they get hotter and hotter. The mixture pre-ignites before ignition. Yep, that's good old-fashioned pinking right there. A piston engine will tolerate a certain amount of detonation like this, but a rotary will just blow itself to bits; it breaks apex seals and in extreme cases even puts dents into the rotor faces. So, the moral is, don't let it lean out. Ever. With this in mind, I sourced a nifty SARD fuel pressure regulator which should be more than manly enough



and the injector system was double-checked and refreshed. Here's the end of the billet rail with ballast resistor load-protected injector gubbins



That was pretty much that, normal service was resumed. Even from the word go this engine seemed a lot more tractable than the last, even with the limits of 4k rpm and no boost imposed again. Not sure why really, it was just smoother and more pleasant to drive on. And so I did, racking up the miles. I was pretty broke by now, as you can imagine, so there wasn't much budget for any new toys, though I did manage to score a MazdaSpeed alloy rear strut brace to replace the standard steel one and to match the front



That's my cuddly lucky Cthulhu there as well, he's been in the car since the Montego Blue one. I'm not actually convinced he's really all that lucky, to be honest, but you never know, perhaps things would have been worse if he hadn't been there rofl . Not much else to report, except I stickerbombed the battery box in a moment of extreme boredom



I also managed a swap for some wider spacers because the ones I'd bought proved to be slightly too bi-curious to really fill the arches as I'd hoped. Fortunately, a fellow FDUKer had some wider ones that were too manly, so we exchanged. Much better;



Except now the rear wheels rubbed heinously on the arches grumpy I thought about getting all ghetto on they ass with a scaffold pole but the way my legendary luck was running in 2010 I thought that might well end in disaster. So I rented a proper arch roller and got a brave mate round for moral support...



I know he looks a bit like a monkey with a jar of peanuts, but this is my bezzy mate Ada without whom none of this would have been possible lol. Whenever the lurrve for the car flagged and I felt like chucking it in he'd show up and just attack whatever the problem was full-on. Sometimes everyone needs a mad mate to kick them up the backside. Metaphorically.



What a clever doobrie these are, too. Even our hamfisted efforts worked wonders, one rolling the arch and the other keeping a heat gun aimed to soften the paint and prevent it from cracking. All these years later, it still hasn't cracked. Winner! Encouraged by our stance-stylee success we threw a bucket of elbow grease over the engine bay, along with a few litres of autosol







As summer drew to a close, I had well over a thousand miles on the car and things were looking up. All summer I'd also been working through the death of my old man and trying to settle his estate, but this was now drawing to a close and the money we inherited took some of the strain off the finances. It incidentally meant that my long-suffering wife sent in the builders to start work on her long-awaited loft conversion and kitchen extension. Then...

...riding home on the bike, all of ooooh, ten miles an hour ...if that... across a roundabout in town, some wizened arthritic old pensioner decided she was far too important to give way to the right on a roundabout .... BAM! she just drove right over me. The bike was wedged under her front bumper, right under the number plate. Oh goody, haven't done any upside-down riding in ages.

She was very peeved to be so rudely inconvenienced by my inconsiderately interfacing with her car just because I clung to tedious out-dated notions like right of way and my liberty to go about my lawful business without being assaulted by fking idiots. She was in a hurry. Her passenger would miss his train at this rate. As you can imagine, I was very sympathetic to their plight and showed my understanding by not beating them both to death with my bare hands.

However, she had managed to rip out my cruciate ligaments, tear the cartiledge off in the knee joint, pull my shoulder joint apart, all sorts of fun things like that. Amazing. Chuffed. rolleyes

So I finished the summer stuck living in a building site, no roof on the house, every room torn to bits, building dust everywhere, on crutches, unable to walk let alone finish the car. (It took something like two years to get the claim settled by the way... despite her admitting 100% liability and the police thinking about charging her with dangerous driving. The law's an ass. My recovery took half as long, mostly because I had to have an operation to put my shoulder back together. Don't do it, kids, stay rubber-side down lol).


You gotta say one thing for my luck, it's consistent banghead


My incapacity wouldn't necessarily have been a problem in as much as there was no time limit on running-in... except... I'd put the Rex forward as a decent car to feature in Japanese Performance magazine. The editor had written an editorial appealing for more street-driven cars than the track fare they'd been focusing on and buoyed on the success of the tunnel run feature I'd sent in some details. Out of the blue, an email... can we feature your car? Errrr... that'll be the one that blew up and that I can't drive cause two of my favourite limbs no longer function, then. Dang!

I had no choice but to ring Super 7 and plead with them to map the car up at short notice, it would have been rubbish to try and sell a piece on a car that wouldn't rev above 4,000 rpm and couldn't boost. Jason stepped up once again and took it away to map. By now it had well over a thousand miles on it, so it'd all be fine. Nothing could go wrong, could it?


Could it? scratchchin

WaferThinHam

1,680 posts

129 months

Tuesday 24th May 2016
quotequote all
Still a great read Nik. When's the next installment?! smile

Nik da Greek

Original Poster:

2,503 posts

149 months

Tuesday 24th May 2016
quotequote all
Round about...


...now!



Of course it was all fine tongue out Gahh, what you'd think there'd be any problems after all that? I was due some good luck, surely confused



three hundred and ninety-six very real and emotional horses. How d'ya like them apples! Felt like all the hard work had been vindicated, just a gnat's short of 400bhp from a 1.3 litre twenty year-old car. What a result. J delivered it back to me the night before the day the photoshoot was scheduled. It was filthy, and the morning dawned freezing cold. I couldn't wash it; the hose had frozen. I could hardly stand anyway. I drove it up to the local Polish car wash. Their pressure washer had frozen. Went to the automatic car wash. Yeah, that's right banghead Out of order due to freezing temperatures. Does no-one lag their goddamned pipes nowadays!?

Went home in a massive strop and phoned Ada for help. He came straight round off a night turn without having any sleep and we managed to fake the car into being shiny. We literally were just finishing when the reporter and smudger turned up.

The photoshoot was a strange affair, I didn't really know what to expect. We tried to find somewhere nice for the pics, the photographer had an idea of getting onto the beach since we were by the sea, but in Darkest Worthing it's not that easy as it's all high promenades. Eventually we tried the council. Yeah, they were happy to let us get onto the beach. A fee of £300 ought to cover it...

We bade them a fond farewell rolleyes and eventually wound up on the waters' edge on Littlehampton's west beach. Scary. It ain't called L.A. for nothing, you know. Still, I thought the location came out OK in the pics (these are stolen from Ada as I was too busy being a helpless cripple and telling the reporter my life history to take any photos)





my sad story being taken down by the inestimable "Carolgees"



Adam's T-Rex watching the proceedings



Snapper doing shapes and colours lol



Still talking rubbish.... note how I spent the time sat down, even driving was a bit painful. I was crippled by the end of the day!





Right, that's enough of that. Safe to say it all felt like another vindication. I took Carolgees out for a blast up the bypass in the car and it blew both of us away, to be fair. It was soooooooo fast now, as you'd expect in a 400bhp car weighing just over a ton. He left muttering about having to get one of these, so I felt that was job done. Even if we did nearly get rear-ended by some dappy old geezer in a Punto who hadn't noticed the traffic had stopped in front of him eek Fortunately the squeal of brakes ended with him stuffing it into the central reservation rather than right up our arse.

Y'know, that sorta thing happens around me all the time rolleyes They never published the article in Japanese Performance either, after all that. The editor changed and the new one thought the location wasn't dramatic enough in the photos to use. That's about right for my luck, then mad

Anyway, once my leg and shoulder had healed up enough for me to drive again I got on with enjoying the fruits of my labour. Figured I'd earned it. Of course, it was the depths of winter by now, so it wasn't as much fun as it could have been (or more, depending on how much fun you consider total lack of traction to be). Still, the li'l 'un enjoyed it



"I love Daddy's car cos it goes really fast and makes whooshing noises " Bless him, he was only 3 1/2 at the time laugh

It was beginning to dawn on me that this wasn't the most ideal form of winter transport, however. Since the Mister Two was dearly departed (I actually offered it to We Buy Any Car and they came back with an offer of £50... rather less than weighing it in at the time rofl . Eventually I gave it to Jason as a sorta "if you can get it running, you can have it" deal. He did, and the little Toyota gave sterling service for years as a courtesy car. I had loads of people from FDUK say to me "I had your old MR2 while my FD was in Super 7 and it was great... dunno why you hated it so much!". Must be me, then laugh) and the bike clearly not an option because it was still being fixed, I had no choice. It's no fun starting the car at three in the morning and seeing water and air intake temps on a running engine of;



but what choice did I have? I'd made my bed, ploughed everything I had into the car, and now I was stuck with it for better or worse. I only had enough money to buy a cheapy set of spare Volk splitrims on winter tyres and bung them on to save the GT-Ps from rotting in the road slurry.

You want pepper with that salt?



Gahhhh, just think what this caustic cack is doing to our lovely paintwork yikes



Fortunately, the problem of paintwork wear and tear was solved for me on the way up to Milton Keynes for a FDUK meet-up and dinner.



The car blew up again weeping














Yep, you read that right. It blew up. AGAINfurious


Open road from Dunstable, out of a roundabout, second gear... short shift at 6.5k (it's one degree above freezing, after all)...third gear... go for gearlever at 6k.. BOOM!

Night sky lights up with sheet of flame from exhaust...Car loses way immediately... Starts rattling... running rough as a three-legged dog... won't rev... oh, no, not again, come ON you evil, vicious bh... please don't be dead again.. drop to second.. give it a big bootful... BANG!.. more flames... engine stutters...

...and dies.

coast to halt at roadside. Get out in forlorn hope it's blown the vacuum line off the MAP sensor, they run rough like a dropped tip if that happens. My mate Andy who'd been following pulls up "What happened? I saw the flames! How's it blown up, you weren't even caning it..."

Map sensor's still plugged in. I've killed it. Again. Get her started after ten attempts. Idles like a tractor, shaking to bits. Limp the last few miles to the pub. Car dies again and won't run at all.

Call RAC



the driver's a great guy, a Caribbean fella who's been all over in the Army and has a hundred great stories to tell. It's just as well, he's my company for the next four hours as we totter along at 55mph all the way back to the South coast



I'm happy to listen, he's a great storyteller and to be honest, I don't really feel much like talking anyway. Get home at two in the morning.

Drop the car on the drive, crawl into bed. The wife's watching from the window as we unload it. She doesn't need to say anything. It's all been said before.


Edited by Nik da Greek on Tuesday 24th May 18:04

baptistsan

1,839 posts

209 months

Tuesday 24th May 2016
quotequote all
Really feeling for you at this point.

Brilliant write up and am looking forward to the next installment.

WaferThinHam

1,680 posts

129 months

Tuesday 24th May 2016
quotequote all
Dunstable's a hellish place, maybe it blew up in disgust? :P