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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Nik da Greek

Original Poster:

2,503 posts

151 months

Wednesday 25th May 2016
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So the great resurrection shuffle began again. The first thing we needed to eliminate from our enquiries was the wastegate. If you remember, it had come from a car that had blown up whilst mapping, and when we bolted it to mine we found a bit of apex seal still trapped in it. I'd had boost issues on the dyno to the point the mapper thought the boost controller had been plumbed wrongly. All this pointed to the wastegate perhaps not being all it could be. I was through taking risks on secondhand stuff, this was going to be done right this time.

A dude in FDUK imports bits from all over, mostly the Americas. He did me a mates rates deal on



a Tial v60 60mm wastegate cool It's a wee bit lovely, innit?



Right, moving on the next thing was I needed a manifold to replace the cracked cast one. Enter stage left...



A tubular stainless Trust/GReddy manifold. It was used,but that was OK cos we'd need to cut it about a bit anyway to fit with the rest of the gear. At least it was sound. The next major link in the chain was the wiring. About the time I was still having loads of problem with the rat's nest while on the twin turbo setup, the engine horse-shoe loom had been replaced (it runs round the engine bay in a big "U", hence "horseshoe"). It feeds sparks to all the engine ancillaries so it's rather important but the wires suffer from being cooked by turbo rotary heat and mine was 17 years old by then.

Of course, the replacement was designed for the twins and had loads of now obsolete wires and connectors hanging on it. Plus, it was getting as crusty and brittle as the last one. Since electrical issues could well have been to blame for the engine blowups, the loom had to be changed. And not for another manky used one, this time the only real way forward was making a one-off bespoke loom from scratch.

Which led on to the ECU. The Apexi had had its day as far as I was concerned. It was OK at running the car so long as everything was purring along, but it was just too numb and too slow to react to sudden mutant problems. More to the point, you had no way of interrogating it after the event to find out what had failed or why. It was time to move onwards and upwards, to be exact, a Link G4 rotary specific ECU. To my knowledge, the first on a UK street rotary.

They have a great rep amongst the Scooby boys,and are so much more advanced than the Apexi; packed with features, extra resolution, datalogging, ancilliary control (it'd even run the Oil Metering Pump that injects oil into the housings to lubricate the rotor tips). Yeah, it was twice the price of the Apexi, but hopefully it was twice as good.

Oh yeah, I almost forgot, I'll be needing one of these



Mmmm, nice, eh? Ed, the purveyor of fine wastegates to the stars also sorted me out with a cut-price Brazilian hehe



Brazilian-made turbo, that is. It's an MPT64 with .70 on the front and .96 on the back on a P-trim. Or roughly a bit bigger than a T04R. Hmmm. Gonna need bigger engine porting.

An exhaust was flung together from a stainless Dragon mid-pipe with tiny silencer, and a very dirty and disreputable-looking Kakimoto Red Label. Which is supposed to be a competition-only exhaust. It's loud. Full circle, it's as loud as the first blue Rex was on the hilariously named "silent" Hi-Power rolleyes



The parts were assembled (again), would it work?

Place your bets rofl

Nik da Greek

Original Poster:

2,503 posts

151 months

Wednesday 8th June 2016
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Sorry about the delay, my computer committed suicide irked ! Rememeber, kids, always back everything up eek


Well, there's not much I can add to previous pics to be honest. I'd sorta had my fill of documenting engine rebuilds and that. Also, I'd just got a camera and had no idea how to use it, so a good percentage of the photos I did take turned out properly st! *ahem* The porting was made about as big as it can go without having to go to a bridgeport, to make sure we were flowing enough gas to spool up the bigger turbo. There was a bit of an issue with the turbo being too big and the manifold had to be cut and re-welded to get clearance from the strut turret, otherwise the turbo housing wouldn't fit!

The new Tial wastegate hung a bit too low at first as well, but the modification to the mani lifted it off the floor enough to clear speedhumps



The engine looked a fair bit scruffier; a few bits had to be forced to fit slightly, and at the last minute I realised I hadn't even thought of things like an airfilter, so an eBaytastic bit of rubbish was furkled out of a back shelf in the garage and pressed into service.



I'd polished the water filler neck as well, since it was now all exposed and looked rubbish compared to the rest of the polished stuff. Of course, there's always something else that's made to look rubbish, the more you make the stuff around it shiny. Now it's the lower intake manifold. One day...

In all honesty, I couldn't face polishing up the turbo this time. It was such a humongous amount of work, and having wasted hours on the last one just for it to end up as an ornament in scrap metal... well, I guess my faith had been tested just a bit too far.

The turbo was mounted further forward than it had been, and it was too damned big to clearance the idler pulley where the airpump had been, so that had to go. The belt for the waterpump would just have to cope with the decreased contact patch. On the plus side, I got the last pulley I needed in purple from DM-Motorsports, cos they'd finally started making the idler pulley for the PAS/aircon belt



Sadly, there's no way of getting an alloy pulley for the aircon pump itself, as it has a bloody great electromagnetic clutch in the middle of it. That would just have to stay black scabby paint and rust coloured. Dunno why I even kept the aircon... it didn't work and never had. The clutch seemed to struggle to close, and I often meant to get round to having it sorted but there was always something more pressing to fix. The system held pressure so it seemed like it might be something worth sorting out one day.

Here's a sneaky peek between the upper inlet manifold and strut brace. You can see the billet fuel rail and the ballast for the injectors. The braided stuff is the new bespoke one-off engine loom that J made. He swore at the time he'd never do another, not that he didn't enjoy the challenge but more that he has a business to run and the sheer amount of time it took was uneconomical. I left him to it, sparks are one thing (of many, lol) I can't get my head round at all.



I was also now on my third set of GReddy gauges after the last lot had started to fail. You have to be able to trust gauges, that's the entire point after all, so they got sacked out in favour of some of the newest electronic peak/memory ones



Eventually the water temp one went mutant AGAIN, so as soon as I recovered enough money from the constant rebuilds I resolved that they all going to go, I'd had enough of them. They look lovely and they're so easy to read at a glance, but they just break all the time and it's annoying as hell. I quite liked the idea of replacing them with a Link display unit. The new ECU was a lot cleverer than the old Apexi, but one score the Apexi definitely had was the Power Commander display widget. It was handy having the ability to display engine parameters exactly as the ECU was seeing them, and the Link version was an option. An expensive option. But I quite liked the idea of having all the information in one place, rather than strewn all over the place. Excep for a boost gauge. Gotta have a good old-fashioned turbo meter biggrin

So, here we go, I guess this is sorta MkIV



As to what caused all the engine blow-ups? We're pretty sure we found the culprit. It was the alarm.

Yep, that's right, the aftermarket Clifford alarm that's been fitted since the word go. It was done by a nationwide but extremely poorly-reputationed installers who I won't give the publicity of naming. I guess they'd do it pretty much how any other installer would, maybe. I dunno. What was certain was, as J found when he started doing the loom, the alarm cut into the ignition circuit of the car. The ignition on an FD is massively heavy-duty, it has to be to make fat, hot sparks that won't blow out in the stress of a rotary power plant. The alarm was cut in using wire that would have struggled to be man enough to run a doorbell. Seriously, it seemed thin as a hair compared to the ignition circuit it interrupted.

We're pretty sure that it could cope up to a point but when under load and demand the current was simply too much, and it led to ignition breakup and that was that. So maybe the dyno guys who blew it up were right all along, but for the wrong reasons. Who knows? Not me. But it makes sense, when the engine grenaded the second time it was hardly under serious load, and the only thing I can think of that fails when it's not either on full load or returning from it is electrics.

What's certain is the alarm has since been re-wired in a way that doesn't intrude into the ignition. Obviously I'm not going to go into detail on an open forum lol, but it still immobilises the car... but safely

Wow, that was a lot of fairly boring writing, sorry. Here, lets lighten the mood with a photo of some nice efini-logo fuse box covers I got from the Welsh fella off eBay



Well, I set off on the third lot of running-in in about a year. Actually, that's a bit of a fib, I couldn't face it. I'm not saying I kicked the doors in every time I drive it, but I certainly didn't really stick to any rev limit or even keep off-boost nono I just drove it as I saw fit lol. Maybe that's the key, treat 'em mean and all that!

I did have one horrible moment on the Brighton top road bypass when it sneaked onto boost and then there was a horrible PHOOOOOOooooooom! noise and all the boost trailed off. For a moment I thought I'd blown it up again and my heart was in my mouth. But it was still driving OK and you could hear the turbo spooling (it sounds like a jet engine with that ported shroud. Which I guess in a way it is). Fortunately all it had done was blow this bodged pipe off, which had been pressed into service at the last minute when we found the old one wouldn't fit the new setup. It looked rather like a zombie's cock so I wasn't too upset about the idea of replacing it



In a way, once the initial trauma faded I was quite proud that ol' Ruby had blown off the pipe, despite having replaced all the old jubilee clips with proper Mikalor ones! That's my girl, this build showed promise cool

One rather better boost coupler later



we were back in business. As you can see, I also had to get a GReddy Airinx filter to replace the manky eBaytastic one. Annoyingly, you can only get them in blue or yellow. Grrr! HKS ones come in red, but they're too small. Typical





....incidentally, why is the car called Ruby? Well, obviously people who don't name their cars are weird and far too serious about life, but in this instance she was actually named by my wife. Partly because it was red (clearly) and also because, as she said "you ought to call her Ruby after that Siouxsie and the Banshees song... 'cos it's always sulking in the garage broken. Y'know, like 'Ruby, can you come out to play'?"
"Would that be Dear Prudence then?" I replied. "It's 'Dear Prudence, can you come out to play?'. And Siouxsie only covered it, it was the Beatles."
"Yes, that's right," says she blithely. And it's been Ruby ever since. Personally I think she was probably thinking of the Kaiser Chiefs all along anyway, which I find slightly upsetting.....



And after what may have been a thousand miles but was more likely to have been about 800 (I dunno for sure, the odometer panel had stopped working rolleyes It's a common FD fault). It went back for mapping. I didn't go, I literally couldn't stand the idea of watching, and I was like an expectant father till I heard the good news



Well, that'll do then. The turbo is a bit more laggy than the old setup, not surprisingly, it's a good deal bigger, but when it hits it hits HARD!. (ignore the rubbish AFR trace, it's been smoothed since this graph) and just look at the way the graph heads for the skies... and this isn't a full power run to the redline either. It stops at 6500 rpm, a good 2000 revs short of the top end.



I once had the privilege of blagging a go at the GT40 owners club trackday at Goodwood through a mate of a mate... no, really, look;



and the heavenly shove of a GT40 is the closest feeling I've had to equate to the feel of this turbo kicking you in the ass. It's like the invisible Hand of God just hurling you up the road evil It's certainly a bit addictive.

Huh? Moar GT40s? Oh, go on then, just a couple...






Right, enough of that. Back on-topic. I fitted a diffuser to the rear. Well, I say fitted... It was an RE-Amemiya "Street" replica by Shine Auto Project, who usually have a good reputation. Not this time, they must have been having a long lunch the day they made this one cos it fitted like a prick in a shirtsleeve. Which is to say, not well irked

Which was irritating especially as I'd spent ages rubbing it down, priming it;



that's the li'l un "helping" by leaving fingerprints in my fresh primer lol. Then several coats of Ford Graphite Grey to tie it in with the wheel colour of the car, and loads of rubbing down



only to find it fitted in like Camilla at the Queens' karaoke nights



Dang!

In the end, after much scratching of heads and help from Ada we conceded defeat. Without a million years of titting about cutting and re-'glassing it was never gonna fit right. So we went for the macho caveman technique



of cutting it up and boshing the old Abflug spats back on at the ends



which kinda works and most people don't notice unless I point it out. All up together with re-mounted foglight and suchlike;



And that was actually that. I just got on with enjoying the car. That was what it was all about in the first place, after all. I never set out to build a stupidly fast single-turbo RX-7, nor to make it antisocially loud and anarchic (my mate was gutted after we convoyed to Japshow that year because his little boy pointed out he could hear my turbo over the noise of his dad's car smokin ). All I wanted was my car... only working. For a while it was exactly that, and I loved it all over again. We went to shows...



club meets


tunnel runs
http://www.youtube.com/watch?v=4GRNyb5s3qU&fea...

and generally just had an immense craic. As I said before, the magazine feature never happened. I eventually got in touch with the new editor, and he explained the pics just hadn't been good enough for a feature, which was a real shame. The car did get a spot in the reader's rides section, which was a bonus, and I managed to persuade him to come along to one of our meets, the feature from which ran to four pages of rotary righteousness, including a spot on my car, so that mollified me a bit. I can't find the pics right now, you'll have to take my word for it lol



At the time, I naively thought the car was finished, but of course they never are, are they? For the meantime, have a few arty pics of the then definitive iteration;



















The one thing that did go wrong and need a change was the clockset. When I renewed the insurance they asked for the mileage to log the limited-mileage part of the policy and rather than just lie or make up a number, I stupidly said "Errrr, dunno, the odometer stopped working ages ago". Doh! So then I needed a complete set of clocks (farrrrrrr easier than changing just the digital element) in a hurry before the insurance lapsed.

I went to see my man Martin at Speedline Imports and blagged a set of clocks from him. Since he hadn't had a chance to test them I even managed to browbeat him into giving them a test fitting to check everything worked laugh Which meant he had the job of stripping the clocks out of the console and if any of the notoriously fragile little clips and tangs snapped it'd be down to him. Not that I'd have kicked up, but it would have been funny at least biggrin

Here he is gingerly taking the old ones out, miraculously without breaking anything



Not the prettiest place to be, behind an RX-7 fascia. Made worse by loads of aftermarket gauge and stereo wiring bodged in there



And they all work! Hurrah! I had a working odometer again. The beauty is that it's a later clockset which had slightly clearer dials and black bezels rather than chrome. I think it looks a lot neater.
New;



Old:



And a night-time shot of the new ones. The gauges are a legendary weak spot on FDs. The solder and tracks seem to just degrade with time and you start getting all kinds of spurious readings. The digital mileometer panel packs up (like on mine), the speedo stops working and the rev counter needle flicks and flaps around at random. At the moment (until spares start to dry up and get prohibitively expensive) it's easiest and cheapest to swap rather than try to fix them.



Stay tuned for the next thrilling installment, groovers smile

Edited by Nik da Greek on Wednesday 8th June 10:49

Nik da Greek

Original Poster:

2,503 posts

151 months

Thursday 9th June 2016
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SebringMan said:
I am surprised that you came over to this side wink, it doesn't seem your thing! But welcome and as always it is great to see a fellow petrolhead on here.

On the basis I know a couple of tales about the car I shall stay quiet and enjoy smile.
Hey dude, wassup! I like the nice places on here and try to avoid the worst of the hate and rage hehe People were asking about the RX so I thought I'd bung a thread up, is all. Time to move on to the other one soon...

Nik da Greek

Original Poster:

2,503 posts

151 months

Thursday 9th June 2016
quotequote all
Vitorio said:
A whole post where nothing blows up Nik!

Looking good!
It did happen from time to time rofl Who knew something as overlooked as alarm wiring could cause so much hassle? It's especially annoying as I've always hated the damned things with a passion. They do nothing to deter theft or vandalism, all they do is cause endless irritation for the owner irked