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Fiat 131 Abarth

                                  
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FIAT 131 ABARTH RALLY CORSA

Markku Alen won Rally of  thousand lakes four times.                                                                                                                

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13. October 1975 400 vehicles were made for FIA homologation, from those 50 were given to Abarth for competition use. At beginning 35 were actually used. Rest were test/proto cars? No wonder Fiat used great deal of money for rallying. They used as much money for rallying as Ferrari for F1 those times!

Full modifications at Turini factory in Italy (preparazione corsa) to g.4 by Abarth cost 33.000.000 liras + 9.086.000 liras for standard 131 Abarth body (2d 131 with 1,3 engine was 2.296.000 liras)!!

How many you would like to have, sir?

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Engine

Motore 232 CIG

Snow, gravel and safari engine. See the large airfilter. Engine had also milder camshafts than tarmac version.

Tarmac version. See straigh rampipes. Engine had wilder cams than the other version.

Head engineer at Abarth, Lampredi, insisted that all race engines are tested up to 9000 rpm before taken use!

Oil pan was protected by large aluminum shield,5 mm thick, weight 5,8kg. (131 RC. 02.83.1)  125 970 lit

131 abarth g.4 had two kinds of crankshafts. Normal four counter weight crank and this eight counter weight crank.

All belts were toothed. Here is picture of water pump pulleys and belt. 

Early version

• compression ratio 10,7-1
• Bosch-Kugelfischer mechanical fuel injection, first version had DCOE type throttle bodies and manifold.
• Larger oil pan, 6,6 liters oil, normal type oil pump
• 215hpDIN (158 kW) at 7000 rpm 
• 23kgDIN (225 Nm)  torque at 5600
• oil cooler mounted beside radiator
• flywheels were two kind, both weighted 7,3kg with 230mm clutch, difference between them?
• clutch was mechanically operated as in street version
• nitrited crank
• 84 mm pistons                                  no. EM 939          price 44 460 lit
• Abarth valve springs,                      no. 06.131.83     price    7 752 lit
• Abarth oil filter                                 no. 90.131.00     price    5 244 lit 
• cylinder head gasket 86,5 mm     no. EM 876          price 41 838 lit
• intake valve 35,5mm                       no. EM 937         price 44 232 lit
• exhaust valve 30mm                        no. EM 938        price 44 232 lit
• engine gasket set                              no. EM 952        price 15 390 lit

7/77

• dry sump lubrication system in use (three pumps in same unit), 15 liter oil tank in trunk, Valtaharju drove (test) car which had it in Thousand lakes -77. Car had better engine than others too, "about 15 hp more than other factory 131", he says. Thats the first time they used that 230 hp engine
• CR 11.0-1
• 230 hp (172kW) / 7500 rpm
• torque 166 lb-ft (225 Nm) / 5750 rpm
• It was propable that this version was the first one to use slideplate throttlebody. There was two types of them. First version had problems, it sticked open. Later version was otherwise similar but had needle bearings inside. Guillotine was first used at San Remo 1977
• Early engine used normal ignition with breakers, but later version had transistor ignition, Im not absolutely sure when it was first used

1/78

• new dry sump pumps, Im not sure what was the difference to earlier

8/80

• new dry sump tank, 8 litres

Later 

• at least in Rally of Thousand lakes 1979 they used "circuit" engine that produced 235 (236?) hpDIN, Markku Alen said that "it had psychological effect mostly, because it went really up, but torque was no good". Markku won that rally. Actually Markku won Thousand lakes four times, only once he drove off and interrupted. 

Performance

• with 230 hp engine, 4,88-1 final drive, straight V gearbox, Pirelli P7 205/60VR-15. First results are from Car and Driver 5/80, second results are from Road & Track 5/80. Those were not the same cars C&D had registration plate 8009 E (Jim Walkers car at that time)  and R&T had 8009 A (Dan Goodwins car). Both were late models with larger rear lights.

                            0-30 mph (48 km/h)         2,7 s        (2,6 s R&T)

                            0-60 mph (96 km/h)         6,6 s        (6,9 s R&T)

                            0-100 mph (160 km/h)  17,5 s        (18,8 s R&T)

                            top speed                          115mph (184km/h) / 8000 rpm   (113 mph (180,8km/h) 7500rpm)

                            1/4 mile (400 m)               14,7s / 94 mph         (15,2 s R&T)

                            braking 70-0 mph            249 ft

• late -78 Autocar tested works g.4 131 (ex. Salonen, Alén, Verini), different ratios or wheels, see top speed

                           0-100 mph (160 km/h)  17,5 s

                           top speed                          102mph (163km/h) 8000 rpm

                          1/4 mile (400 m)               14,6s

Exhaust system had 4-2-1 exhaust manifold. Though after getting to one pipe it split  to two different pipes under the co-drivers seat and went to end in two pipes. Some versions two pipes got to one before rear silencer under floor.

There was also engines for customers, without injection. These engines used downdraft carburettors. Im not sure if they had drysump systems, but its possible that some had some didnt.

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Electrical system

1976                                                                                    product number                            price with tax

• Battery was 12V-24Ah-150A                             (Cat. 6.FC.17)                                      97 356 lit
• faster windshield wiper motor (80 al m/´)     (Cat. 5040704.1)                             116 280 lit
• starter was 12V-1,2kW                                        (Cat. 5023181.1)                             509 580 lit   
• Coil, "Super Bobina" with resistore, good up to 8000rpm.  (Cat. BZR.204.A)          7 296 lit
• Distributor, specially manufactured for rally use                   (Cat. s.144.PA)           85 500 lit
• Alternator, six diod version produced 12V-1000W              (Cat. 63303425)     117 420 lit 
• Voltage regulator, electronic version                                        (Cat. RTT.110.B)        16 530 lit
• "Abarth" spark plugs                                                                       (Cat. 7024041)        45 030 lit
• All of these were made by Magneti Marelli

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Transmission/clutch

• Transmission was Colotti T.209 (it is possible that they used T.247 too)
• There were few different ratios
• Transmission was straight gear dog-clutch (gear can be changed without clutch)
• in T.209 gears were in normal places, in T.247 reverse was on N:1 place, N:5 on reverses place
• All later versions were made by CIMA. Actually Colotti boxes are pretty rare. Early versions had many problems with gearboxes, that problem was quickly cured, maybe moving from Colotti to Cima?

Colotti T.209 

1. 2,156     2. 1,565     3. 1,242     4.  1.000    5.  0,802    R.  2.666     (4/74)

1.  2.021    2.  1,537    3.  1,185    4.  1.000    5.  0,876    R.  2,666     (4/74)

1/77  They made new homologation. Text from papers show; "Instead of the following ratios (text shows 2.021 1st gear specs) recognized on page 9 of the recognition book, the third series of applicable ratios is the following".

1.  2,654    2.  1,895    3.  1,568    4.  1,244    5.  1.000    R.  2,671    (1/77)

Here is CIMA gearbox casings.

CIMA mainaxle with dog rings.

Gear shifter mechanism. Have nothing common with later 131 Racing type.

I found this from one source showing Cima type numbers and ratios.

Type 163 with ratios 2.156, 1.565, 1.242, 1.000, 0.802

Type 164 with ratios 2.021, 1.537, 1.185, 1.000, 0.876

Type 165 with same ratios as 164

Type 168 with ratios 2.654, 1.895, 1.568, 1.244, 1.000 (Direct Drive top)

8/80

• new model "clutch cover" to transmission, starter motor from passenger side to driver side

Clutch had original style pressure plate but three wing "copper" plate.

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Rear axle

Ratios were;

• 6,83       =    41/6
• 6,42       =    45/7
• 6,143    =     43/7
• 5,375    =    43/8
• 4,875    =    39/8
• 4,625    =    37/8
• 4,444    =    40/9
• 4,3        =    43/10
• 3,9        =    39/10
• 3,63     =    40/11

1/81

• new reinforced differential mounting bracket

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Brakes

4/76

• Bedal box assembly at engine bay
• Front: 300x11,8mm disc with two piston caliber, 48mm pistons
• Rear 252mm disc with two piston caliber, 38mm pistons
• early version had little drums inside disc for handbrake !

    First version of brakes. 

7/76

• Front: Lockheed four piston, 38,1mm 
• Rear: Lockheed four piston 38,1m
• for some reason they used same type Girlings too, though them had different pads
• two kind of handbrake; hydraulic two piston 38mm, mechanical one piston 31mm
• handbrake had its own calibers

   

   

10/76

• brakes were moved closer to wheel, by new reinforced front suspension steering knuckle post.

1/77

• in some cases they started to use smaller front disc; 275mm
• new type of hydraulic handbrake handle

1/78

• again new type of hydraulic handbrake handle (hydro mechanical ?!)

1/79

• braking regulator to rear brake line

8/81

• new handbrake handle and cylinder, now working at rear brake line without own reservoir, liquid from pedal box went through brake line in handbrake cylinder, and through it to rear brakes.

5/80

• Road & Track test car had these brakes;
• 274mm ventilated front discs (guess those were Ate too)
• 254 mm rear discs with Ate calibers, Brembo hydraylic handbrake calibers (I have heard that those were from Moto-Guzzi  motorcycle !!)

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Steering

4/76

• faster steering 2,85 rounds, absorbed

10/76

• reinforced steering rods

turning circle was 10,3 m

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Suspension

• Bilstein shocks with progressive springs
• If someone knows rates for those, let me know! (one type rear shock was 220/110lbs)
• All mountings and joints were Uniball

10/76

• new stronger front steering knuckle post
• reinforced upper front and rear shock absorber seats, uniballs
• reinforced lower front suspension arm, uniballs
• reinforced rear suspension arms, uniballs

1/77

• reinforced front wheel shaft hub

8/77

• again new reinforced steering knucle posts to front and rear

10/77

• again new reinforced lower front suspension arm, uniballs, adjustable from both ends
• reinforced upper mounts for struts (thicker metal to body) to rear and front, they were also little higher in body. Maybe they started to use longer shocks or they wanted body go lower.

5/78

• again new lower front suspension arm,  adjustable from other end only

8/78

• again new reinforced rear suspension arms (little shield for wheel side uniball included)

AVR(?)/80

• movement limiter for front shock absorbers (for asphalt use?)
• again new reinforced rear knucle posts
• two new front and two new rear absorber struts

1/81

• again new reinforced rear suspension arms

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Cockpit

4/76

• lighter dashboard for competition use
• roll-bar (early type only on top and behind of drivers!)
• not homologated but they used fire extinguishing system (automatic?)

7/76

• new transmission cover (and quite long stick!)

8/79

• new dashboard, little differently positioned gauges

Dashboard had tachometer to 10 000rpm, oil temperature, oil pressure, water temperature, fuel level, ampere and fuel pressure gauges. Co driver had flexible Lucas map lamp, pair of Halda twinmaster to measure distance and two Heuer stopwatches. And lots of fuses, relays and switches.

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Body/colors

• Weight balance 50/50% with driver on.
• wheelbase 2489 mm
• track, front 1461 mm
• track, rear  1397 mm
• length 4181 mm
• width 1720 mm
• height 1372 mm
• ground clearance in gravel 216 mm
• fuel capacity with "abarth" tank 59 litres 

Abarth build three different body types, light to tarmac, middle strength, and heavy strength to Safari and such. Early middle models weighted 980 kg, late middle models "dry" 953 kg and in "use" 1026 kg.

7/76

• three holes homologated to front spoiler (for disassembling oil sump protection bolts)
• bigger air cleaner for dusty areas (for engine)
• modified firewall (near distributor, dont know why (?))
• removable air intake cover for fitting the car ventilation air filter (no modification of car body outline) they didnt use this in all cars
• extra locks for front and rear bonnet

1/78

• Reinforcement rods for engine compartment were homologated. There was two models, one for carburated car, it had rod between struts positioned so that downdraft carbs had room to be. Another was for injected models, this was straight rod between struts. Both had samekind of pipes from struts to front betweem bonnet hinges.

6/78

• new rear lights were homologated

At least in some cars they used aluminum doors, or aluminum outer panel and persplex sidewindows.

Sometimes they used big lights in middle, some times small lights middle (Not Racing grille!). Front mudguard flashes were rectangle on top of fender, or small round located more front.

Tarmac cars had different mudguards, little more round shape and quite a bit wider too! 

Different fenders than usually!

FACTORY TEAM USED THREE MAJOR BODY COLORS 

 "OlioFiat"                                                     "Alitalia"                                   "Wreath Fiat"

They had few different light attachements. Here is some samples of them.

First version had 4x5" lights, square flashers and one pair of extra lights. This one is with narrow mudguards. 

This is the same except only holes for extra lights and wider mudguards for asphal. I think this was -76 version and used in 215 hp cars.

This is the same except this have new smaller side flashers. I believe this means 230hp version, first time used -77

This Alitalia painted is with small side lights, narrow mudguards.  Used since -78. Now they started using bigger lamps in light grille. 

  This is the same but with larger mudguards.

Last type, need of light. Double extra lights since -79. New lught got on flashers way, so new round flasher is little more up. This have larger mudguards. These mudguards were common on these "wreath" Fiats.

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g.4 REGISTRATION PLATES

Im trying to find out how many 131 g.4 cars was built..

Thanks to Mike Hollander,FIAT 131 mirafiori Club Holland!!! We had own lists, and when we put them together....