Renault Safrane —
the flagship, in two V6s

What are the specifications of the Safrane's Z7X 722 and 723?
Vehicle B544, engine Z7X, suffix 722 or 723: bore 93, stroke 73, 2,975 cc, compression ratio 9.6 — a full point and a half above the 8.6 of the GTA's turbocharged Z7U. Gearboxes PK1 and PK7 manual, AD8 automatic. Injection multipoint Siemens with richness regulation, ignition M.P.A. with a knock sensor. Idle 700 ± 50 rpm between 80 and 100 °C and CO 0.5% maximum, both marked “not adjustable”. Fuel: Eurosuper lead free 95, and a line worth knowing — minimum permitted octane rating: 91. Fuel pump in the tank, 12 V, 3 bar, 80 l/h; pressure regulator 3 ± 0.2 bar at zero vacuum, 2.5 ± 0.2 bar under 500 mbar. Idle regulating valve Hitachi AESP 207, single winding. Three computers, all Bendix: S101 722 101 for the manual 4×2, S101 722 102 for the manual 4×4, S101 722 201 for the automatic. Air and water sensors Bendix, NTC type. Oxygen sensor NGK, heated: at 850 °C, 625 to 1,100 mV rich, 0 to 80 mV lean. Three-way converter marked C20, under the floor. Safrane M.R.302, chapter 12.

What is in the cooling circuit of a Safrane V6?
Three calibrated parts that no catalogue photograph will show you, and one figure to check before buying a cap. The circuit carries a restriction Ø 3 mm, a by-pass Ø 8.5 mm and a nozzle Ø 22 mm, besides the engine, the radiator, the heater matrix, the water pump, the thermostat, a bleed valve and a temperature switch. The expansion bottle is a “hot” bottle with permanent degassing, and its valve is set at 1.2 bar. Set that beside the catalysed R25 V6 Turbo, whose “hot” bottle valve is blue and set at 1.6 bar: four tenths of a bar apart, on two cars of the same era and the same engine family. A cap is not a universal part, and fitting the higher-rated one “to be safe” raises the pressure the whole circuit has to hold. Filling: bleed screws open, fill through the bottle, close each screw as soon as liquid comes out in a constant jet, then run at 1,500 rpm and set the level by overflow after about four minutes. Bleeding: run 10 minutes at 1,500 rpm, until the fan cuts in — the time the automatic degassing needs — and check the level is near Max; in capitals, never open the bleed screws with the engine running, and retighten the expansion bottle cap once the engine is warm. Sealing test (kit M.S. 554-05): replace the bottle valve with adaptor M.S. 554-01, warm the engine and stop it, pump up to 0.1 bar below the valve setting (the A610 and GTA manuals say 0.1 bar above) — the pressure must not drop; decompress slowly and refit the valve with a new seal. Valve test: a valve that has let liquid through is replaced; on adaptor M.S. 554-06, the pressure must settle at the setting, ± 0.1 bar — brown plastic valve 1.2 bar, blue plastic valve 1.6 bar. Antifreeze (Glaceol AL type C): 35 % for −23 °C, 50 % for −40 °C, and protection falls again above 60 %; checked with hydrometer 778A or a refractometer, the table values being valid for liquid at 40 °C. The manual's example: a 6-litre circuit reading −15 °C needs 0.7 l of mixture replaced by pure antifreeze to reach −23 °C, 1.9 l to reach −40 °C. Safrane M.R.302, chapter 19 · Technical note 1558, folio 19-1.

What rev limit does a Safrane V6 have, and when does its injection warning lamp light?
Rev limit, before injection cut-off: Z7X — 6,300 rpm in 1st and 2nd, 6,200 rpm in 3rd, 4th and 5th; J7R and 12-valve J7T 6,350 rpm; J7R and 8-valve J7T 6,000 rpm. The Alpine A610's Z7X stops at 6,100. Warning lamp: on the Safrane it is used — unlike the A610 and the catalysed R25 V6 Turbo, whose lamps are not connected — and, depending on the seriousness of the fault, a voice synthesiser message may go with it (if fitted). It lights for a faulty absolute pressure sensor, throttle potentiometer, oxygen sensor, vehicle speed sensor, idle regulation valve, primary ignition circuit, injectors, or TDC sensor connections reversed. And with the electronic anti-theft: if the decoder's signals to the computer are interrupted while running, between idle and 1,800 rpm the lamp flashes, with a voice message. Vehicle speed: an impulse generator in the speedometer cable, under the dashboard at brake pedal level, on the right — wire A + after ignition (after fuse), B speed information, C earth; the signal reaches computer track 3. The manual's warning: no speed information can explain an idle regulation that misbehaves — road test with the XR25, # 18 must match the speedometer, and right-hand bar graph 9 must stay out. One more practical rule: erasing the computer memory cancels the auto-corrections, so drive the car about 5 minutes before handing it back to the customer. Safrane M.R.302, chapter 17 · Alpine M.R.297, folio 17-3.

How many knock sensors does the Z7X V6 have?
Two — one per cylinder bank. A direct consequence of the V layout: a single ear cannot listen to six cylinders spread over two banks. Both are read on gate 13 of the XR25, which gives the total engine noise picked up by each. The Alpine A610's Z7X also has two, in the V between the banks, under the intake manifold — which has to come off to remove them; the catalysed R25 V6 Turbo's Z7U has only one, on the cylinder head under the fuel pressure regulator. Renault Safrane phase 1 M.R.302 workshop manual, chapter 17 · Alpine M.R.297, folio 17-3 · Technical note 1558, folio 17-1.