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F1 engines were running at 17:1 CR some time back. DO they still run this high a CR?

Will turbo engines be anywhere close to this? typically they were around 10:1

WilliamsF1 wrote:F1 engines were running at 17:1 CR some time back. DO they still run this high a CR? Will turbo engines be anywhere close to this? typically they were around 10:1

CR will be higher than 10:1. The new turbo engines will be managed throttle less and have injection at the end of the compression phase. The old engines were port injected with toluene fuel to avoid knocking. Nowadays they achieve the same thing by injecting very late and with super high pressure in the compression phase.

Static compression will have to be somewhere around 9 or 10 to 1 at max.

strad wrote:Static compression will have to be somewhere around 9 or 10 to 1 at max.

Very unlikely. The Ferrari 458 Italia engine spec. Btw. this is a direct injected engine:

Engine
Type V8 – 90°
Total displacement 4499 cc (274.5 cu in.)
Maximum power 570 CV (425 kW)** @ 9000 rpm
Maximum torque 540 Nm (398 lbs/ft) @ 6000 rpm
Specific power output 127 CV/l
Compression ratio 12.5:1

^^ odd choice for a comparsion, as the 458 has a N/A engine not a turbo.
Perhaps a Porsche Cayenne turbo (10,5:1) or BMW N74 (10:1) is a better choice.

Good info WB.

WhiteBlue wrote: According to latest info they will have one unit which will have a compressor, a turbine and an MGU on one shaft. The MGU will be allowed to feed electric power to the rear wheel MGU but not to the battery. It is not clear if the turbo MGU is allowed to use battery power to spool up the compressor. That may come at a later time.

I think the only reason to make the compressor, turbine, and MGU on a common shaft would be if the battery pack was allowed to spool the shaft via the MGU. In the absence of that, why would you use a common shaft? Wouldn't it just be an awkward turbo with lots of inertia and lag?

Intercooling will come back, any thoughts on this? Will we see air-to-air, fluid-to-air, or something else?

747heavy wrote:^^ odd choice for a comparsion, as the 458 has a N/A engine not a turbo.
Perhaps a Porsche Cayenne turbo (10,5:1) or BMW N74 (10:1) is a better choice.

The Honda Ra-168-E already had a 9.4:1 CR twenty five years ago and the Panamera turbo with old FSI technology has 10.5:1. This leads me to believe that F1 state of the art engines with superior efficiency requirements will have nearer to 12:1 CR. We will see.

What are the petrol LMP sports cars doing in that regard. I'm not very familar with those engines.

It may not be as high as 12.

These engines have to be severely mellowed out turbo charger and compression ratio wise to be revving to 15,000 rpm and yet have 750hp and run only 28g/s of fuel.

I easily see a 10.5:1 compression ratio as standard.

No need to be any higher, when it actually takes work from the engine to compress an already compressed volume of air.

Concerning KERS it will be the same as today's. Teams have so many problems already with the current units, i don't think radical energy recovery will be welcome.

Renault Sport's managing director Jean Francois Caubet told AUTOSPORT: "We have had a four-cylinder [powerplant] on the dyno and the sound is nearly the same as the V8 running at 12,000-14,000rpm. With the V6, with one exhaust, the sound will be very good."

"The rules look like they are heading towards a rev limit of 15,000rpm, and the fuel flow limit is intended to drive the operating speed of these engines up towards the upper end of that range, rather than the lower," he added.

"There is a detail in the rules that makes it interesting for the engine people to push the rpm up above 10-11,000rpm, where the engines would have perhaps naturally ended up in the previous incarnation of the rules.

from: http://www.autosport.com/news/report.php/id/92873

makes you wonder what this "detail" will be, a gradual fuel flow limit or a boost limit perhaps.

Increasing compression ratio will only make the engine more efficient in the no-boost rev-range.

Will these engines even be in that range very often?

Does anyone have good sketches of the R18? This engine was a V6 single turbo, would like to see how the engine exhaust intercooler is packaged

WhiteBlue wrote:

747heavy wrote:^^ odd choice for a comparsion, as the 458 has a N/A engine not a turbo.
Perhaps a Porsche Cayenne turbo (10,5:1) or BMW N74 (10:1) is a better choice.

The Honda Ra-168-E already had a 9.4:1 CR twenty five years ago and the Panamera turbo with old FSI technology has 10.5:1. This leads me to believe that F1 state of the art engines with superior efficiency requirements will have nearer to 12:1 CR. We will see.

quote]
There are limits to the amount you can compress the mixture without detonation that have nothing to do with what year it is.
Ringo is correct.

747heavy wrote:

Renault Sport's managing director Jean Francois Caubet told AUTOSPORT: "We have had a four-cylinder [powerplant] on the dyno and the sound is nearly the same as the V8 running at 12,000-14,000rpm. With the V6, with one exhaust, the sound will be very good."

"The rules look like they are heading towards a rev limit of 15,000rpm, and the fuel flow limit is intended to drive the operating speed of these engines up towards the upper end of that range, rather than the lower," he added.

"There is a detail in the rules that makes it interesting for the engine people to push the rpm up above 10-11,000rpm, where the engines would have perhaps naturally ended up in the previous incarnation of the rules.

from: http://www.autosport.com/news/report.php/id/92873

makes you wonder what this "detail" will be, a gradual fuel flow limit or a boost limit perhaps.

Hmm, they said the fuel-flow limits remained the same that were written for the inline-4. So I think we'll have boost limit.

strad wrote:There are limits to the amount you can compress the mixture without detonation that have nothing to do with what year it is.
Ringo is correct.

You obviously do not understad that they use direct injection where the compression happens 95% before you inject. The injection is so late that you practically compress only air and no "mixture".

The year is relevant, because spray guided combustion is a recent invention which wasn't around before 2006.

you don't understand that the mixture still get compressed no matter when you put it in..otherwise the engine wouldn't work..static compression can only go so high to allow for a much higher number under boost...if you started with 17:1 after ,,oh pick a number...14 lbs of boost..what is your compression ratio? at 9lbs? at 24lbs? I say static coompression will not be over 10.5:1