Without restrictors?

[DanJR1]

How much would a prototype like a dallara Judd or Audi R8 produce without the restrictors? I know the size of engine decides what restrictors you'll use but i just wondered about the approximate figures.

[Rhino]

I'm sure the Judd people reckoned theres could produce just over 1000hp, and still last 24hrs.....

[jhansen]

Mulsanne's Corner has a write up on the Judd GV5. It says about 800 horsepower at roughly 10,000 rpm unrestricted. Or 600 horsepower at 7,800 rpm restricted.

http://www.mulsannescorner.com/juddgv510.html

[pirenzo]

I think 800 is more likely, for a 4 litre engine.

Perhaps the Audi's might get a little more, but the trouble is making them last a 24 hour distance.
I would like if just once someone took their restrictors off and did a lap of Le Mans just to see how quick they might go.

[Bob Riebe]

With the blowers, the Audis could easily top 1,000 hp.
In sprint form I am sure they could pull a safe 1,200 hp but the fuel mileage would be abysmal, which is why for an enduro they would be tuned down to a level where speed and mileage were a best compromise.

Bob

[Félix]

The power curve you see before the restrictor acts would stay the same, but you'd have to adapt the engine to support higher speeds. The Audi engine can take 9000 rpm for brief moments, but it would have to be developped to do it consistently. The turbo pressure would also be freed up. The turbo Group C engines made a 1000 horses at 8000 rpm with big boost for qualifying, but the strains that puts on an engine for a whole race must explain why Nissan, for example, didn't do anything good out of 7 starters...

[Adam43]

In terms of reliability, I think even if the engine can take the increase in power other components, like the gearbox, may not be able to.

[Edmonton]

The engine in the corvette should be good for at least 800hp or more.

[Splatz the Cow]

I don't think this is true at all.

What's being talked about here is engine remapping and upping the boost, that has got no relevance to just removing the restrictors.

Example 1, the BMW S70/2 GTR engine in the McLaren is good for 680 bhp as it is in the F1 LM, but the 1995 Le Mans restrictors meant it only pulled 640bhp. Its creator, BMW engine designer Paul Rosche, meantioned in an interview that if modified the engine was good for 850bhp but at much higher revs. Does this mean we should consider that its power potential?

Example 2, the 3.6litre Tipo engine in the Ferrari F40 GTE II made 660 bhp at Lemans in qualifying but was reduced for the race. These cars are usually refered to as being capable of 720bhp when for sale or auction. Engine craftsman Willy Koenig however easily pushes Ferrari F40 LM engines 1200bhp, however this is not with the same turbos or boost, so common sense suggests that 720 should be the benchmark quote.

Example 3, the Viper GTS/R was capable of 700bhp & 880Nm for sprint events in the 1996 BPR season, howevere this drops to around 650bhp & 850Nm for endurace races (Brookspeed Racing quote 650bhp & 854NM). Viper tuner Hennessey can get 800bhp max for the road with every last bell and whistle installed and I've seen one genuine reference to just around 1000Nm.

Lastly, that old Panoz beast is good for some 900ftlbs torque, but simply to just go racing with the race motor and its restrictors removed and rev limitor raised would probably not make much difference to its normal performance.
If we assume it makes 620bhp with the restrictors at approximately 7000rpm, I would guess it might be able to go to 9000rpm max, similar to the nascar engines because they are somewhat similar. But I don't think it will really make much more power in that 2000rpm because there will be so much torque drop-off that little power will be made for the increase in rpms. My guess is about 720 - 760 bhp.

[TheNewBob]

all that said, examples given are older cars, I do wonder what they'd manage to get out of a new car like the Maserati or Aston? Considering technological advancements and abilities since the 90's...

[Bob Riebe]

Originally Posted by Splatz the Cow

I don't think this is true at all.

What's being talked about here is engine remapping and upping the boost, that has got no relevance to just removing the restrictors.

Example 1, the BMW S70/2 GTR engine in the McLaren is good for 680 bhp as it is in the F1 LM, but the 1995 Le Mans restrictors meant it only pulled 640bhp. Its creator, BMW engine designer Paul Rosche, meantioned in an interview that if modified the engine was good for 850bhp but at much higher revs. Does this mean we should consider that its power potential?

Example 2, the 3.6litre Tipo engine in the Ferrari F40 GTE II made 660 bhp at Lemans in qualifying but was reduced for the race. These cars are usually refered to as being capable of 720bhp when for sale or auction. Engine craftsman Willy Koenig however easily pushes Ferrari F40 LM engines 1200bhp, however this is not with the same turbos or boost, so common sense suggests that 720 should be the benchmark quote.

Example 3, the Viper GTS/R was capable of 700bhp & 880Nm for sprint events in the 1996 BPR season, howevere this drops to around 650bhp & 850Nm for endurace races (Brookspeed Racing quote 650bhp & 854NM). Viper tuner Hennessey can get 800bhp max for the road with every last bell and whistle installed and I've seen one genuine reference to just around 1000Nm.

Lastly, that old Panoz beast is good for some 900ftlbs torque, but simply to just go racing with the race motor and its restrictors removed and rev limitor raised would probably not make much difference to its normal performance.
If we assume it makes 620bhp with the restrictors at approximately 7000rpm, I would guess it might be able to go to 9000rpm max, similar to the nascar engines because they are somewhat similar. But I don't think it will really make much more power in that 2000rpm because there will be so much torque drop-off that little power will be made for the increase in rpms. My guess is about 720 - 760 bhp.

US V-8s can pull 2 HP per inch, on a single carb. easily; the Trans-Am engines were at 650+ HP on a single carb, the NASCAR engines, are listed at 800 HP on a single small carburettor.
While fuel injection does not up the horsepower simply because it is fuel injection, if unrestricted, it would have air-horns considerably larger than the carburettors used in either TA or NASCAR and would therefore breathe better and pull more horsepower.
US small-block V-8s are reliable to the mid to high, 9,000 rpm range.
The huge 815 in.cu. IHRA drag racing engines, ten years ago, had a 7,700 dyno red-line, and went higher in a race.
Figuring a conservative 2 HP per inch, any 427 inch engine will pull over 800 HP.
Bob