Turbo Race Cars

[Roy]

The last few nights i have been reading thru some old magazines i have, and thought others may be interested in some of the turbocharged race cars from yester year.

Dauer 962LM Porsche , 1994 Le Mans winner.

Engine configurations - flat six, (935-76)

Displacement - 2994cc

Turbo/s – 2 x kkk turbochargers

Inlet Restrictors – twin 37.1mm

Hp – 620hp @ 8,000rpm (1.0bar)

Weight – 1025kg

This car gave Porsche its 13th victory at Le Mans. As per regulations the Porsche was a homologated road car with Dauer car being shown at the 1993 Frankfurt Motor Show and resceiving homologation in March 1994.

IMSA Cunningham Nissan 300ZX

Engine configurations – VG30DETT (V6)

Displacement – 3.0L

Turbo/s – 2 x Garret turbochargers

Inlet Restrictors – twin 37.1mm

Hp – 650hp @ 7,500rpm

Weight – 1181kg

From a chassis perspective the IMSA cars share very little with their road going counterparts, using a chrome moly tube frame. Using double wishbone suspension and four piston calipers gripping 355mm rotors. Bodywork consisted of 5-pieces, much like you see on sports sedans in Australia, made from carbon fibre with localised kevlar reinforcement. At 241km/h the IMSA 300ZX generated 408kg of downforce, 80% of which was concentrated on the rear.

[Roy]

Bugatti EB110S LMGT1

Engine configurations – 60 deg V12

Displacement – 3499cc (81 x 56.6mm)

Turbo/s – 4 x IHI turbochargers

Inlet Restrictors – 4 x 25.8mm

Hp – approx 640hp available from 5,500 - 7,500rpm @2.1bar

Weight – 1370kg

Homologated from its 4WD road car derivative (maintained 4WD for racing), with the addition of splitter and slighlty modified bodywork to allow for larger 18” wheels and carbon-carbon 355mm discs. The front wishbones were operated by pulrods. Its carbon composite monocoque was rated at 2000kg/m/deg, so fitment of the roll cage was for compulsory safety rather then torsional reasons. Engine performance was considered well down on its potential with the engine being largely std with the exception of the fitment of competition standard forged pistons.

TWR Porsche 96 Le Mans LMP-1 winner

Engine configurations - flat six,

Displacement - 2994cc

Turbo/s – 2 x kkk turbochargers

Inlet Restrictors – twin 33.2mm

Hp – approx 520hp @ 2.0bar

Weight – 891kg

Entered into the sports-prototype class, the TWR ran Porsche won on its race debut. (Alex Wurz was one of the drivers) The Porsche shared components with the TWR built XJ-14. Two cars were entered with one car suffering a drivesahft breakage in the 24th hour whilst in the lead, handing victory to its sister car.

[Roy]

Ferrari F40 LMGT1 (1996)

Engine configurations – 90deg V8

Displacement - 3600cc (85 x79mm)

Turbo/s – 2 x IHI turbochargers

Inlet Restrictors – twin 37.5mm

Hp – 640hp @ 7,300rpm (1.8bar)

Weight – 1112kg

The F40 had a tubular steel spaceframe chassis with bonded carbon-fibre composite panels. It differed from the road car derivative in it had been bored and stroked, used a 6-speed sequential dry sumped gearbox. Body and susp remained largely as per the Ferrari factory had intended with the production of the Evolution F40s.

GT-1 Porsche 96 Le Mans GT-1 winner

Engine configurations - flat six,

Displacement - 3164cc

Turbo/s – 2 x kkk K27 turbochargers

Inlet Restrictors – twin 36.6mm

Hp – approx 590hp @ 7,200rpm (1.1bar)

Weight – 1053kg

Car destroyed all other GT-1 entries in the ’96 Le Mans including our beloved Skylines’ and Supras’. Porsche GT1s' finishing 2nd and 3rd behind the TWR Porsches’. Its TAGtronic engine management system had lambda exhaust sensors and cylinder selective knock control. Its 4 valve per cylinder engine with chain driven camshafts was water cooled and shared much with the road going Porsche engine.

[Roy]

Sard MC8R (1996)

Engine configurations – Lexus V8

Displacement – 4.1L

Turbo/s – 2 x KKK turbochargers

Inlet Restrictors – twin 36.6mm

Hp – 600hp @ 7,000rpm (1.68bar)

Weight – 1061kg

Looking like a coked up MR2...this car gets my vote, the SARD MC8R used an MR2 monocoque lightened using thinner gauge steel. Keeping in line with its Toyota heritage the MC8R used a twin turbo version of the Lexus V8 mated to a March 5-speed gearbox. It had earlier used a Hewland 6-speed but was 15kg heavier then the 5-speed March box.

Nissan Skyline GTR LM (1996)

Engine configurations – inline 6 RB28DETT

Displacement - 2795cc

Turbo/s – 2 x Garret turbochargers

Inlet Restrictors – twin 41.0mm

Hp – 600hp @ 7,500rpm (2.4bar)

Weight – 1282kg

Essentially a modified JGTC car the LM GTR RWD, dry sumped and stroked which allowed the crankshaft centreline to be dropped 30mm, th engine was also moved 30mm further rearward. They used 5 speed H-gate boxes as losing a gear in a sequential box would have the car out of the race as was the case in 1995, but in H-gate box would allow the car to limp on. The car used 4-spot AP Racing carbon fibre brakes.

Two cars were entered by the factory NISMO division, with one car being the epitome of reliability all through qualifying and the race up until the 23rd hour when a driveline vibration was detected. The gearbox and propshaft were repalced in 34minutes with the car going on to finsih, the second car suffered a brake failure and crashed out of the race.

[Roy]

Nissan R390 GT-1 (1997)

Engine configurations – 90degree V8 (VRH35Z)

Displacement – 3.5L

Turbo/s – 2 x Garret turbochargers

Inlet Restrictors – 2 x 35.7mm

Hp – 600hp @ 7,000rpm

Weight – 1000kg

Built by TWR but entered in the '97 Le Mans 24hr by Nismo, the R390 sported a composite monocoque similar to that used by the Jaguar XJ-15 also built by TWR for a failed one make series. It was powered by 3.5L twin turbocharged DOHC 90deg V8, that in similar guises had seen use by Nissan in GroupC racing, and aslo in NA form in the Indy Light series. Drive was thru a sequential 6 speed gearbox which was designed and built by TWR in conjunction with X-Trac.

At pre-qualifying prior to the ‘97 Le Mans the R390 qualified quickest, but had little in the way of comprehensive testing between pre-qualifying and the actual 24hr race. Come the race they were gridded 3rd, 7th and 12th, due to a change in rules prior to the race the car would not race in the trim it pre-qualified.

The FAI decided that homologated cars required luggage space be provided on the car so concern centred around the temperatures that the gearbox was being run at as the gearbox cooler were removed in order to provide the required luggage space. Two of the 3 cars suffered gearbox temp woes during the race, resulting in the retirement of one car, whilst another suffered underside damage after an off track incident. The3rd car finished the 24hr race 12th overall.

Toyota Supra GT-1 (1996)

Engine configurations – inline 4 cylinder

Displacement – 2140cc

Turbo/s – 1 x turbochargers

Inlet Restrictors – 1 x 52.5mm

Hp – 650hp @ 7,500rpm (2.1bar)

Weight – 1141kg

Like the GTR the Supra entry was a JGTC car tweaked to allow for the different FAI regulations. Using the 3SGTE engine as its basis, the Supra was stroked as the larger displacment did not incur any weight penalty as per the JGTC. Bodywork relied heavily on Kevlar and carbon fibre, whilst the chassis was essentailly as per the TRD built JGTC cars.

In 1995 the Supra had the highest BHP/litre of all LM GT-1 cars at 303.73. Even with still one of the highest BHP/litre cars in '96, cars like the GT1 Porsche and McLaren F1 had moved the goal posts out of Toyota’s sight in the GT class, so with Toyota interest in the the class starting to wain, in 1997 and onwards they would be looking to compete in the LMP class.

[Roy]

Toyota Celica – Millen Pikes Peak Car

Engine configurations – inline 4cylinder 3SGTE

Displacement – 2.14L, 89 x 86mm

Turbo/s – 1 x Garret turbocharger, with external gate and 60mm compressor

Inlet Restrictors – free

Hp – 930hp @ 8,900rpm (4.06bar) at sea level. 600lb.ft between 5,000-5,500rpm

Weight – 1134kg

Don’t ask me the sort of fuel or compression ratio this thing runs, as I havent been able to find out, but the Garret turbo seems to be efficient at that boost level. The Celica uses a 5-speed non-synchro box which drives the front/rear wheels with a 50/50 torque split. AP 4-piston calipers grip 304 x 27mm front rotors and 276 x 23mm rears. The body is moulded glass fibre replica of the production ST205 shell, with the floor being formed by carbonfibre/aluminium honeycomb underwings front & rear, with the rear incorporating ground effects tunnels from the centre of the car rearwards.

[hippy]

whats "homologation" mean?? and why is the skyline rwd??

[Roy]

whats "homologation" mean?? and why is the skyline rwd??

Speculation...others might know the actual reason.

Im guessing it was because the FAI stipulate minimum weight classes that dictate the size of inlet restriction the car must be ran with. With the 4wd in place im guessing the weight put it well over the minimum weight. Combined with the length of the Le Mans track and the fuel cell was only allowed to hold 100L, then perhaps the added weight of the 4WD system did not offer a significant enough improvement with respect to tyre durability or traction to justify using it.

'Homologation" typically means approved/sanctioned modifications that allow a car to race.

[Guest INASNT]

Toyota Celica – Millen Pikes Peak Car  

Engine configurations – inline 4cylinder 3SGTE

Displacement – 2.14L, 89 x 86mm

Turbo/s – 1 x Garret turbocharger, with external gate and 60mm compressor

Inlet Restrictors – free

Hp – 930hp @ 8,900rpm  (4.06bar) at sea level. 600lb.ft between 5,000-5,500rpm

Weight – 1134kg

How long would this engine be able to run before rebuilds?

[Guest RedLineGTR]

one race...??? dam crazy shit..

[Genesis®]

thks roy.

lemans .... ahhh..... :drooling:

[Roy]

Imagine the power figures some of those cars would have if not for the pesky restrictors they have to run with...

Maybe not a race car, but one of my favourite turbo cars of all time would be the '88 Corvette Callaway Sledgehammer.

Engine : Twin turbocharged, twin intercooled, 350 cubic inch V8, Chevrolet Bow-Tie block, Brodix 2V heads

Bore x stroke : 4.0 x 3.48 inches

Compression ratio : 7.5:1

Power :880 bhp @ 6,250 rpm @1.5bar

Torque :772 ft-lbs @ 5,250 rpm

Weight : 1575kg

Transmission : ZF 6-speed manual

Turbo/s : twin Turbonetics T04B

ECU : Zytec engine-management system

Top Speed : 409km/hr

0-100km/hr : 3.9 seconds

1/4mile : 10.6 @ 127mph

It had a custom Callaway SledgeHammer Aerobody whilst the old pushrod 350 Chev had 2 x Turbonetics TO4B 60:1 turbochargers, Cosworth crank and pistons, dry sump lubrication system, Hand-crafted 321 stainless steel headers and exhaust, M.S.D. ignition system, higher flowing fuel injectors, specially designed Centerforce clutch system, 5-point Simpson safety harnesses, 4-point leather-padded roll bar, fully-functional heating, ventilation and air conditioning, Racequip manually operated Halon fire extinguisher, selective ride control (1989 FX-3 option) and Delco/Bose audio system.

The tune was considered to be conservative, with even more being able to be extracted if desired and due to careful sizing of the turbos and camshaft, there was a claim that lag was non existant. Suspension was also heavily modified with special Koni shocks.

The later version that used the LT-5 quad cam engine is even tastier, but old Reeves Callaway decided to use the 'SuperNatural' ie NA LT-5 Lotus designed quad cam 350 in its Le Mans entries.

[51jay]

Roy

Very interesting read ....thanks a lot...

[cul202]

first time i've see the old sledgehammer aero mentioned for years. the original write up i read (motor in around 1990) put it at around 1000hp. i'd say the info you have is more accurate as motor's info was rather brief.

didn't look like much but it was a bloody awsome car! cheers roy for the info

[gtstcruiser67]

That was a great read Roy.

I went to LM 2004 and made it past security to mulsanne straight for some unbelievable moments. And its on video..

Thanks

[AMS]

That was a great read Roy.

I went to LM 2004 and made it past security to mulsanne straight for some unbelievable moments. And its on video..

Thanks

haha get out that shovel!

[Quinny]

There has been quite a few turbocharged cars/race cars in general that have done quite a bit.

One car that has not been mentioned is the Jaguar XJ220 (twin turbo 3.5L V6), which held the "official" production car top speed record for a little while.

The Callaway Sledgehammer was an absolute weapon. 898rwhp, and they used to drive it to and from the track, and down the shop to get breakfast. Not bad for a 410km/h car. I find it funny that the Sledgehammer was genuinely fast, very streetable, and it was built in 1988, nearly 20 years on, Ferrari, Lamborghini or Porsche can't seem to better it.

No-one has mentioned the 2 Bathurst wins for the R32 GTR, or the Ford Sierra or Nissan Bluebird turbo (which held a lap record at Bathurst for a while).

I also believe that there was a category in Japan for production cars in 1990 or 91, in which all 29 races were won by a GTR.

Another interesting statistic is a VC Commodore, 372ci twin turbo V8, 1470.8rwhp on pump fuel, street registered. Apparently that is the highest HP figure for a car on pump fuel in the world.

Edited June 8, 2006 by Quinny