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)!!
Car specific info (links):
- G1 TO?
- G? TON 19169
- G? TON 19171 (M2)
- G? TON 67714
- G? TON 72918
- G? TON 72919
- G? TON 72920
- G3 TOK 95989
- G4 TOP 06217
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Engine
Motore 232 CIG
Safari and Acropolis engine. See the large airfilter, it was used in long travel suspension bodies. It was seen also in some gravel rallies. But cause they didnt drive long travel suspensions on tarmac, this variation was not used on tarmac.
Short suspension body engine version. See straigh rampipes.
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
- engine gasket set no. EM 952 price 15 390 lit
Early Kugelfischer injection with DCOE style throttle bodies.
7/77
- First version of 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. The first drysump version had different type of oilpump, and different type of aluminum front plate to install it to the engine. 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. The last version ignition was Magneti Marelli Raceplex ignition. Raceplex was first used on F1. With knowledge Magneti Marelli got from Raceplex system, they started to make Dinoplex ignition for various different cars. Forexample Lamborghini Countach uses Dinoplex which looks pretty much the same than Raceplex.
1/78
- New dry sump pumps. This is the mostly used system. The pump had large aluminum block which bolted to the engine with four bolts. It had oilfilter housing and pump in same unit. Unit had different Kugelfischer front mounting plate cause the oilpump didnt need external mounting anymore.
8/80
- new dry sump tank, 8 litres
Later
- at least in Rally of Thousand lakes 1979 they used “circuit” engine that produced more hp, 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
Raceplex ignition.
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Transmission/clutch
- Transmission was Colotti T.209 in early version. (it is possible that they used T.247 too)
- There were few different ratios used.
- 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 are CIMA 168 gearbox casings.
CIMA 168 mainaxle with dog rings.
Left one is Cima, right is the std Fiat. Differences are easily seen. The Fiat part has Fiat partnumbers, Cima donthave anything in the place.
Main casing looks the same, only the text has been removed from Cima.
On bottom there is extra oil drain plug in Cima, though not in all Cimas.
Selector rod area is a bit different in Cima, there is more room grinded in the area.
Layshaft thrustplate has a bit different motion machined. Left is Cima and on right Fiat.
Third casing, the one before bellhousing has different numbers, left Cima, right Fiat.
Selector area is more different, thicker on left is Cima and thinner on right is Fiat.
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 (All photos of gearboxes are from 168)
G.4 guibo. The flange at left is bolted to output shaft of gearbox. The propeller shaft will go inside the third part in the picture. There were few different lengths of the propeller shaft flange.
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
First version used the same drive shaft flanges as the Stradale. Later versions had larger flanges and larger CV joints. The LSD and the ring/pinion is the same in every version. Here are some pictures of late type differential.
These dates are propably maintenance dates. There were different dates in other LSD.
All diffs I have seen had different badges on them. Most of them have text showing ZF LSD and all have ratio stamped on them.
There are different markings painted on the casings. As you can see some have blue/yellow dots, some have blue white dots. And then on the other side there are painted markings, they are also stamped under the text as you can see from the pictures.
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: 300×11,8mm 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
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 COLOURS
1976
1976 colours had some specialities. The driver / co-driver names were on the rear mudguard, only one name on a side. Small Oliofiat stickers on front mudguards and square flashers in the middle of the front mudguard. Though, they did use Fiat 124front flasher in some rallies, like in Morocco and here in the Thousand lakes, car is TON 94414
Here you can see the same TON 94414 with square flashers and wide mudguards.
1977
Yet again the TON 94414 in this picture, though in New Zealand plates in NZ -77. You can see the new painting for 1977. Large Oliofiat sticker on front mudguard and small Fiat 128 flasher in front corner. The driver names are now in the doorr.
This is very special livery at 1977. Salonen at Quebec having a variation of next year main sponsor Alitalia and -77 main sponsor Oliofiat in same car.
1978
TOP 35975 in the Portugal 1978. This is the classic -78 ALitalia livery. Note also the larger inner lights they started using at -78. The yellow lights are some Portugal special, they were used only in this rally. Note the wide mudguards, compare to next picture.
1979
And here is the same car again, TOP 35975. Now with narrow mudguards. The difference in the 1978 and 1979 colours is easily recognised by the ASA sticker in front door. In otherwise there is practicly no difference.
1980
TOR 92448 in 1980 Portugal, driven by Rohrl. The “wreath” type of painting on the car.
1981
And the TO 92448 in 1981 painting. Alen winning the Thousand lakes, again. There were two types of front mudguard decals, other type had FIAT and other Abarth 131 decals. Those seem to have no rule which were used.
There were also some special coloured cars. More of those later.