Anyway, sod the aircon, whats it like after driving it for a month? The answer is....much better. I like driving it much more now; the gearing has been the making of it, and the mapping is much better as well. Starts on the button hot or cold, and is amusingly bad-tempered when its cold (wants revving to pull away, vibrates a lot, like it has a hangover and wants you to bugger off and annoy someone else). Its fine within a few minutes of driving (or let it warm up a little at tickover) and drives fine. Also, you can start it when its been sitting for an hour or so, when its between warm and hot, and its fine; it used to be a pig - hunting and trying to stall. Mapper guy Greg - recommended.
The engine is much better; linear, without the big wodge of torque and breathless afterwards, like the LS2 was. This cam is great. I have a usable 1st gear, and the rest are spaced well; it pulls them just fine. Anyone doing this conversion; make the effort to lose the Mazda diff. Its a different car now. Been to and from Birmingham a few times since (details to follow) and at 1750rpm its doing 80 on the motorway and averges 26mpg over the journey; better than the LS2 and purely down to the gearing I would think.
As the recent picture showed, I have a new petrol/volts gauge. The petrol side is a pain in the arse, if I'm honest. Flicks about constantly, and there's no way to damp it. Under about 25% (you can have it in litres, gallons, or percentage, which is nice) it flicks to empty constantly around corners and such and I've ended up disabling all the alarms (either a flashing light, or the entire gauge can flash; doubly annoying!) and simply ignoring it most of the time. Craig programmed it but after a battery change I had to do it again, which was annoying. I googled 'RX-7 FD3S petrol tank capacity' and found lots of things saying 76 litres. So off down the petrol station I go, after first running it so low I was scared I'd run out; after it said zero per cent I did another 15 miles or so. So.....there are 6 calibration settings; 0 (empty) and 5 (full) then 1, 2, 3 and 4 inbetween (20, 40, 60 and 80 per cent). Set 0, then put in 15 litres (1), then 30 (2), then 45 (3), then 60 (4) then.....CLICK at 62. b
ks. The japs get a smaller petrol tank, and my googling showed the US version. Sod it. So I set 62.5 litres as FULL and start to understand why, when I got the car back from Craig, it started at 100% when full up then, after about 15 minutes driving, dropped to 80 without anything inbetween, then started counting down in a linear fashion. Maybe they got caught out the same way? I must ask. Anyway, it seems its a 65 litre tank, and I still had 2.5 left when I went to the petrol station! There's a drain plug underneath, but I just get the feeling its one of those things that if you ever touch it, it weeps for ever. Or you strip the thread. Its under a ton of underseal and just seems like one of those things you shouldn't screw with.....
Anyway; start of August was the Goodwood sprint run by the Brighton & Hove Motor Club. I generally do alright here but god I'm rusty, and the wet practice didn't help. I haven't driven this car in anger since the previous august and it shows; my slowest ever time! I warm up slightly for the 1st timed run, and win the class by about half a second on the 2nd timed run, but I'm still 2 seconds off last year's (LS2) time and 3 seconds from my best ever (as a rotary, but I'd done every sprint there that year and was totally 'on it'. Its the last sprint of the year at Goodwood, so.....next year I'll do them all and see if I can get in the 80s.
I bought a new set of 888s especially for the sprint, and didn't want to waste them on a trackday. At a thousand sodding quid for the set, I may even take them to bed with me! They are being saved for sprints and Nurburgring trips, so are tucked up nicely in the house (less heat cycles than in the garage!).
With that in mind I got the 3rd set of wheels I own (nasty cheap 'Work' ones I got off the forum for £200 years ago and have only ever used once) out of the shed, strangely finding a pair of only half worn rear 888s as well in there (bonus!) and bought some slicks off eBay. When they arrived they looked alright, but when I took them to get them fitted the tyre guy pointed out that the DOT numbers on the side told me that two were from 1993, one was 1994, and the 4th one was 2004. Oh. Well what the hell, they had no cracks on them (I've seen one-year-old ones in worse nick) so we fitted them anyway, and was told that they'd most likely be awful for a few laps (they are Dunlops, 235s all round, from a touring car, so should last whole sessions) but may be usable after that, but be careful and don't expect much. Oh, and you might die, said the tyre guy. Pffft. Wuss.
So.....1st trackday. Rockingham, mid August. I fitted the 'death slicks' before I even went and stuck the car on the trailer, taking the 888s as backup. Guess what? The slicks were great, and worked within one lap. I guess they'd been used very little, and dry-stored out of the sun all this time. Having 235 all round (normally 235 up front, and 255 at rear) was entertaining; the hairpin was a giggle; OK, I could destroy ANY tyres round there in 2nd, but these in 3rd gear were brilliant. Turn in late, plant foot on floor, and the back comes out just a little, but I barely have to counter-steer - it doesn't come right round on you. It comes out of the corner four-wheel drifting, the rears spinning and pushing the front slightly, and leaving two dirty great black lines all the way up the track, which drew admiration from the drivers behind. Top fun. The Pif-Paf chicane could be done flat in third, drifting through the whole thing, smearing the tyres front and back. Brilliant. This is the car at its best. Very little got past me. Max was there in his Manthey-tweaked GT3 and we had a great few sessions swapping the lead, until I cleared off a little. Should have kept the Rex and gone V8, Max..... I just remembered, for those building one of these; we could not stop the radiator fan being on all the time. The ECU was switching it on and we don't know why. But my fancy gauges also have outputs.....so now at 90C water temps, the fan comes on, and I can change this any time from the gauge. Nice It was at 97, but I want less temps in the car (a recurring theme.....) so I set it lower.
Temperatures though. Still an issue for me, but there are two 'usages' here that are different. One is Track, the other is Road.
Track first; even with the new, larger oil cooler, I was hitting 120C oil temps almost immediately during sessions. Not so the first session, but subsequent ones (where the car hadn't really cooled down after the previous one; 20-30 minutes is not enough when a car has no way of losing oil temperature apart from airflow while moving, and the moving is done while flat out on the next session). It would then creep up by a few C per lap, and I was doing slowdown laps when it hit 130C. Then someone overtook me and I just had
to go after them....the most I saw was 134C. I consider this too hot, though several people have told me that with modern motors and oils, it isn't really (Aston Martin run their race cars at 140+ for eight-hour endurance races). Either way, it would continue to climb if I let it. Its worth mentioning here that Taz, a mate with another Craig-built V8 Rex, has no oil gauge whatsoever, and merrily does sessions all day (and did, at Bedford on the same hot day), completly ignorant of what I imagine is his engine screaming for mercy beneath him. Maybe I think too much. Water temps seemed fine, under 110 most of the time, and only climbing to 115 when the oil was around 130 for any length of time. At the end of a session I had to come in and leave the car running until the water gradually came down to under 100; the one time I just came in and turned it off at 115 it spat some water back out of the reservoir in the inner wing (the standard Mazda one which is still there). Started car again and it stopped as the temps came down. All good. Worth mentioning that it did want some water after that trackday; in the bottle by the engine as well as the inner-wing reservoir. Not much, but hot running will boil some away, it seems. Something to check with the oil, before and after track days (and during!).
I'd like to see lower oil temps, or at least it staying static, rather than climbing. Looking at the front of the car its plain that air going into the side pod is hitting the power-steering cooler first and thats covering half the oil cooler really, and that half the air may well be missing everything anyway, and whistling off past the front wheel (the arch-liners are knackered; something else on the list....). Two things to do here; one is to duct the air from that side pod purely into the oil cooler and move the power-steering cooler from in front of it, and the other is giving the car some way to lose oil temps after it stops or is moving slowly. So, off to Birmingham for the day and the power-steering cooler is moved to the other side, next to the air filter. The side pod is ducted on both side and the underneath (we left the top). Then the radiator fan from an Aprilia Tuono (V-Twin 1000cc motorbike; the V-Twins always get hot....£25 from eBay) is attached to the back of the oil cooler. I was going to attach this to the Oil Temp gauge and control it from that (as I did with the rad fan and the water temp gauge) but that would mean the dash coming out AGAIN and its already getting bloody awful with its rattling, so I just said 'balls to it' and ran it off the radiator fan wiring. So at 90C water temps the radiator fan comes on, and the oil cooler fan as well. Just static testing this (leave car ticking over for half an hour....) showed the water and oil stopping at around 95-100 with the bonnet down and around 95 with it up. Putting your hand behind the oil cooler with the fan on....well, you can't leave your hand there. That fan fitted exactly over half of the cooler......so I ordered another and will run them both. We'll see what this has done next time on track.
Now for Road; and this is a very different set of needs. Having driven the car a fair bit now (back and forth to Birmingham, around Peak District, motorways, town stuff (whether stuck in traffic or not)......I now know that if the water or oil temps go much over 90 then the car is a much less comfortable place to be in. I also know the cut-off point for climbing temperatures; its about 40mph. Above that oil and water temps will start to fall, below that (just driving in town, moving around normally) they will start to rise above that. Bear in mind the fans come in at 90C and its plain they are fighting a losing battle. OK, I have no air-con as yet, but I think more can be done. Oil cooler gets two fans, above. But the water temps are the issue; they just keep climbing. So I've ordered some ridiculous rad fan from the states. Next time I'm in Birmngham that and the other oil cooler fan go on and we'll see where we are. Bear in mind the car will not overheat; the most I've seen after getting utterly stationary for half an hour, was 109. But its horrible in the car, so I am trying to get it lower from a comfort point of view, not a 'health of the car' reason. If i can maintain 90 oil and water at a standstill, I'll consider that a personal victory. It may never happen.
The Zircotec coating.......was it worth it? I think if it was cheaper, yes, but I don't know if I'd do it again. £1000 for.......temperatures in the car simply climbing more slowly. It hasn't fixed anything, its a sticking plaster. Spend longer than 20 minutes in traffic and its simply not nice in there. Without the coating it would probably be 10 minutes?
While I'm at it, I'll put my hands up and admit I may well have been wrong about the gearbox. All day on track and the car like a sodding bonfire inside and......shifts the same as when its at normal temperature.
The big thing here is; once it gets hot it takes HOURS of driving on the motorway to get the chassis cool again. Yes, the actual body of the car, the tunnel, the floor, the roll cage, get warm. Not sure I'll ever beat this to be honest, but the aircon will fix it I guess.
The battery? My £180 dry cell Optima thing had been screwing me around for a while (going flat every few weeks last year, though strangely behaving itself perfectly for Craig throughout the 4 months it was in Birmingham this year, the b
d) and the afternoon before the track day I find the car absolutely dead. Great. Stick a charger on it and the alarm immediately goes off, and there isn't enough power in the car to tell it to stop. Even better. Yank the battery terminals off and the alarm keeps going off. Charge battery for 10 minutes with alarm going off, while still unplugged. Plug it back in and manage to tell alarm to shut up. Zoom down to local motor factors and try to find something vaguely comparable to the 750 cold cranking amps that it claims to have. Oh, and will also fit in the same hole (the passenger-side rear seat) and still allow my rear-seat unit thingy to fit. End up with the battery from a 2.5 diesel transit. 650 CCA. Also test the dry cell and find it outputting 5 amps, they guy says its knackered and offers to throw it away, but I decide to take it home and stick it on the Optimate and leave it.
Transit battery is perfect, and its nice to have something trustworthy. Also, it seems that I left the lights on. Doh. Now the dry cell (and the car) acting so strangely when I hooked the charger up makes more sense. Oh well. On the plus side, the Optimate has apparently brought the dry cell back to life completely, green lights abound. Which is good, as I must have a dry cell for Sprinting (wet cell must be in a box, and I haven't the room for one). So i guess thats going back in soon.
Wow, I've been typing for about two hours. That'll do for the moment....