Engineered rule bending

[mrmr96]

Chassis 33 said:

JR told me of one of the Tuscans in the old RV8 days of the series that had a straight line advantage over the other cars in the series, cant remember who's car but I could take a guess , spent the season trying to figure it out and eventually ended up lining all the cars up for a photoshoot only to find the fast car had a higher bonnet line...with a double skin underneath it creating a ram effect into the carbs at speed.

Oh, and then there's Audi in the 1992 DTM where the cranks had to be production items, when asked by the powers that be why they were using a flat plane crank as opposed to a cross plane, they replied (hopefully with a Michael Palin-esque smirk from the Dead Parrot Sketch) that is was a production crank, just un-twisted. Which in effect was true, they'd missed out a stage in the forging of a production crank. http://www.youtube.com/watch?v=p4amaa6MpVY

Regards
Iain

Edited by Chassis 33 on Tuesday 5th July 13:13

Interesting stuff. I wasn't aware of the difference between a cross vs flat plane crank. Turns out the cross plane one is better balanced, but heavier so slower to rev (think Lazy Yank V8) and needs a more complex exhaust. Whereas the flat plane one is lighter but not balanced (so needs balancer shafts) with simpler exhausts (think Ferrari). More info on Crank designs here, which also makes reference to the Audi DTM story above! http://en.wikipedia.org/wiki/V8_engine#Crankshaft_...

[ZeeTacoe]

motorsportbeng said:

apparently the rs500 touring cars used to have a cage inside the boost pipe on the inlet side which would be filled with some sort of dry ice for the race. the first handful of laps the charge temps would be around single figures obviously equalling more grunt, come the end of the race it just looked like some sort filter

Would you really want to be adding CO2 to the intake of an engine?

[Chipchap]

ZeeTacoe said:

Would you really want to be adding CO2 to the intake of an engine?

The local hero Sarel Van der Merwe had a few guest drives in a 944 Turbo in the International series and was always really fast for a few laps. Dry ice froze the wastegate closed for 2 laps until it melted and normal performance resumed. Then all that was needed was to maintain the gap.


A

[stinkysteve]

rev-erend said:

Bespoke race cylinder heads lurking under a standard rocker cover .. can't say where as it's still being used

I bet there's more than one! Try any one make or controlled hatchback series......

[Ranger 6]

mfmman said:

This was on the Ivory Coast Rally of 1985, it was more of an open road event than a conventional stage rally and chase cars followed essentially the same route as competitors

Gotcha - feasible then and a quick google suggests there is a story behind that one

[n3il123]

There was a case of a car that when the headlights were on it seemed to be much quicker than all of the others around it, seemed that when the headlights were on it (illegally) changed the ecu map to non standard.

[Slinky]

n3il123 said:

There was a case of a car that when the headlights were on it seemed to be much quicker than all of the others around it, seemed that when the headlights were on it (illegally) changed the ecu map to non standard.

Wholly feasible to do this, and maybe, just maybe, if you press, say, a couple of buttons on the dash, you could, potentially, scramble/delete the extra map..

but this is only conjecture..

[MrKipling43]

I can't believe the Toyota restrictor plate fiddle only got a cursory 'they had one, and got banned from motorsport'.

It's one of the cleverest cheats ever.

The cleverness was in the fact that when the airbox was opened for inspection, the modification that bypassed the restrictor plate literally hid itself thanks to a spring loaded mechanism that snapped the gap shut.

They only got found out because they got greedy at the Safari Rally (do you also remember when the WRC was not some soft-cock mince about on a couple of re-run stages?) and were clocked at silly top speeds.

Diagram of the widget:

[bobthemonkey]

Does the Ilmor 500I belong here?

At the time, Indy 500 rules allowed for a maximum capacity of 2.6l for racing engines, or 3.4l if you used a single cam, pushrod block. This was to encourage use of production based blocks.

Ilmor however, went and produced a custom pushrod racing V8 in complete secrecy, with a near 200bhp advantage over the rest of the field. This was a custom engine for a single race, and the engine was banned for the following year.

[thunderbelmont]

Wikipedia said:

As with most successful racers, Yunick was a master of the grey area straddling the rules. Perhaps his most famous exploit was his #13 1966 Chevrolet Chevelle, driven by Curtis Turner. The car was so much faster than the competition during testing that they were certain that cheating was involved; some sort of aerodynamic enhancement was strongly suspected, but the car's profile seemed to be entirely stock, as the rules required. It was eventually discovered that Yunick had lowered and modified the roof and windows and raised the floor (to lower the body) of the production car. Since then, NASCAR required each race car's roof, hood, and trunk to fit templates representing the production car's exact profile.
Another Yunick improvisation was getting around the regulations specifying a maximum size for the fuel tank, by using eleven foot (three meter) coils of 2-inch (5-centimeter) diameter tubing for the fuel line to add about 5 gallons (19 liters) to the car's fuel capacity. Once, NASCAR officials came up with a list of nine items for Yunick to fix before the car would be allowed on the track. The suspicious NASCAR officials had removed the tank for inspection. Yunick started the car with no gas tank and said "Better make it ten,"[3] and drove it back to the pits. He used a basketball in the fuel tank which could be inflated when the car's fuel capacity was checked and deflated for the race.
Yunick also used such innovations as offset chassis, raised floors, roof spoilers, nitrous oxide injection, and other modifications often within the letter of the rule-book, if not the spirit. "All those other guys were cheatin' 10 times worse than us," Yunick wrote in his autobiography, "so it was just self-defense." Yunick's success was also due to his expertise in the aerodynamics of racing cars.
Yunick also built a 1968 Camaro for Trans-Am racing. Although Yunick set several speed and endurance records with the car at Bonneville Speedway, with both a 302 cubic inch (~4942 cubic centimeter) and a 396 cubic inch (~6489 cubic centimeter) engine, it never won a race while Yunick owned it. It was later sold to Don Yenko, who did win several races. In typical Yunick fashion, the car, although superficially a stock Camaro, had acid-dipped body panels and thinner window glass to reduce weight, the front end of the body tilted downwards and the windshield laid back for aerodynamics, all four fenders widened, the front subframe Z'ed and the floorpan moved up to lower the car, and many other detailed modifications. The drip rails were even brought closer to the body for a tiny aerodynamic improvement. A connector to the engine oil system was extended into the car's interior, to allow the driver to add oil from a pressurized hose during pit stops. In order to allow the driver enough freedom of movement, the shoulder harness was modified to include a cable-ratchet mechanism from a military helicopter. In 1993, Vic Edelbrock, Jr. purchased and restored the car. Contrary to popular opinion, Yunick designed the first "safe wall" in the early 1960s using old tires between sheets of plywood but NASCAR did not adopt his idea. Also Yunick developed air jacks for stock cars in 1961 but NASCAR did not deem them appropriate.

The TWR Built Volvo 240 Turbos had wider rear bodywork than standard, they were modified from the rear light right back to the bulkhead so they looked standard. That information came from someone who drove in the ETCC at the time.

[Silent1]

WHat's the benefit of being able to add oil during pitstops in the above smokey yunick bit?

[ZeeTacoe]

Silent1 said:

WHat's the benefit of being able to add oil during pitstops in the above smokey yunick bit?

You wouldn't have to spend time opening the bonnet during the stop.

[Silent1]

ZeeTacoe said:

Silent1 said:

WHat's the benefit of being able to add oil during pitstops in the above smokey yunick bit?

You wouldn't have to spend time opening the bonnet during the stop.

So it was common to add oil then?

[skwdenyer]

Chipchap said:

The local hero Sarel Van der Merwe had a few guest drives in a 944 Turbo in the International series and was always really fast for a few laps. Dry ice froze the wastegate closed for 2 laps until it melted and normal performance resumed. Then all that was needed was to maintain the gap.


A

That 'solution' was rife in R5 GT Turbo racing in the '80s IIRC.

[skwdenyer]

Re TWR, a former colleague of mine used to work on TWR Le Mans cars. Allegedly, his job at the first pit stop was to swap the extra-heavy 'scrutineering' fire extinguishers for the regular ones, and to reverse the procedure at the last pit stop before the finish....

[Mr E]

MrKipling43 said:

I can't believe the Toyota restrictor plate fiddle only got a cursory 'they had one, and got banned from motorsport'.

It's one of the cleverest cheats ever.

The cleverness was in the fact that when the airbox was opened for inspection, the modification that bypassed the restrictor plate literally hid itself thanks to a spring loaded mechanism that snapped the gap shut.

They only got found out because they got greedy at the Safari Rally (do you also remember when the WRC was not some soft-cock mince about on a couple of re-run stages?) and were clocked at silly top speeds.

Diagram of the widget:

The Grp-A 'dodge' wasn't actually found to be in breach of the rules...

....just the spirit of the rules, hence the two year ban...

Edited by Mr E on Wednesday 6th July 10:29

[Ahonen]

thunderbelmont said:

The TWR Built Volvo 240 Turbos had wider rear bodywork than standard, they were modified from the rear light right back to the bulkhead so they looked standard. That information came from someone who drove in the ETCC at the time.

The Volvo 240 Turbos weren't built by TWR. This is the second or third time someone has mentioned the TWR 240s, which is a bit puzzling. Volvo's motorsport department (such as it was) supplied teams with parts and had its works teams, such as Eggenberger, RAS Sport and to a lesser extent Ulf Granberg's Magnum team, but not TWR. TWR ran the Jaguars and the Rover Vitesses and spent most of the '85 and '86 seasons protesting the Volvos at every opportunity.

[Ahonen]

StevieBee said:

Think this one's been proven wrong though.

Was privy to discussion on the subject some years back with a couple of auto blokes who pointed out that a) there was (and as far as I know) only small number of companies that make automotive glass so finding one willing to be complicit in the ruse would be unlikely, and b) the cost of tooling and manufacture to accommodate a very small run of glass would be been prohibitive.

This would also have applied to front and rear light clusters that would have looked odd but didn't.

I don't agree with the 7/8ths car thing, because that would be stupidly expensive and a tad obvious. The massive Volvo 850 road car suddenly becoming half a metre shorter would be noticeable even to Father Dougal:



Screens, however, would be pretty straightforward to get made and pretty cheap. Around £2k for the tooling, then £250 or so per unit (heated, too) for glass ones. I've had them made in the last 6 months for two different cars. If you want a sooper dooper Isoclima heated plastic screen then the costs are obviously considerably higher, but in factory BTCC budget terms it's still bugger all.

[IanUAE]

n3il123 said:

There was a case of a car that when the headlights were on it seemed to be much quicker than all of the others around it, seemed that when the headlights were on it (illegally) changed the ecu map to non standard.

Corvette in the USA? Didn't they flash their headlights when entering the pits to switch back to a legal engine map. not sure how but they got caught.

[thunderbelmont]

IanUAE said:

n3il123 said:

There was a case of a car that when the headlights were on it seemed to be much quicker than all of the others around it, seemed that when the headlights were on it (illegally) changed the ecu map to non standard.

Corvette in the USA? Didn't they flash their headlights when entering the pits to switch back to a legal engine map. not sure how but they got caught.

It was an in-depth check of the ECU. I was offered a Lingenfelter tuned Chevy V8 from a SCCA Trans-AM GTA car two years ago, that had an ECU with another/second map in it selected by pulling an un-used pin up to 12v which lifted the output of the motor from it's restricted 430hp to 500hp (dyno sheets were seen).
That could be done with a latching relay - energised by flashing the headlights, or flicking the rain light, etc..