[WEC] Rebellion Racing

[knighty]

warning - nerdy engine stuff coming up.....well that engine started life as a 3.5 Litre IRL engine with a mandated 93mm bore back in 2003, which was reduced in capacity for the old LMP regs to 3.4 litres, I honestly dont know if this was done with a stroke or bore modification........the IRL engine would have been built to the 2003 regulations which mandated everything, so the stroke, bore, bore-spacing, crank height and so on, were all mandated, I honestly cant remember the sizes, but I do remember they were very generous, I seem to remember the bore spacing was 110mm, so there is plenty of scope to grow things.

so lets assume Toyota kept the stroke and changed the bores and pistons, as thats what I'd do if I was creating an air restricted engine for 2010-2013 rules, as these are the shortest lead time parts and the piston is most important for getting the compression ratio absolutely correct......so working the numbers backwards that equates to a stroke of 64.4mm and a bore of 91.66mm for a 3.4L engine......so lets say they stretch the bore and stroke in equal proportions to obtain 4.4 litres for a V8, which is a 22.72% capacity increase, lets say half for each so 11.36% bore increase, 11.36% stroke increase....so 4.4L version would equate to a stroke of 71.71mm and a bore of 98.81mm

So on the bore the cylinder to cylinder gap will reduce by a similar amount as the difference between the 2 bores, which is 7.15mm.......the stroke needs to increase by a total of 7.3mm, which is the distance the deck height of the cylinder block will need to lift by, and half that amount (3.65mm) when you look at the radial swept increase in the crankshaft area, this can normally be contained with a smaller big end bearing design.

So to conclude, increasing the capacity of the 3.4L unit up to 4.4L is not a big challenge, but the cam-drive syetem will be a sea of precision cut gears and that will need a total re-design, plus new cams, crank, rods, piston, overall the engine would need just about everything new, apart from the sump, cylinder heads and valves & rockers.......but my overall point being this should not impact the new chassis design in a big way, hardly at all by the looks of things, I will be surprised if they have to modify the chassis to bring the mounting lugs upwards & outwards by 7.3mm mm due to the cylinder heads lifting, but hey what do I know!!!......also, sorry to correct you, but Rebellion are not "clued up"

[J Jay]

Don't worry about nerding out, it's all informative for someone with no experience or knowledge beyond changing oil, belts and fuses. However, I am slightly disappointed by Rebellion's lack of knowledge in this area. Assuming they have at least anticipated the need for a new engine the R-One should be designed accordingly. It would be great to see a Judd back in the top class too.

[knighty]

the trouble is Judd have recently significantly damaged their reputation over the past 2 years, firstly the 3.4L DB V8 LMP1 performance in the back of the Oak and Pescarolo + Dome cars in 2012 LeMans, it was an utter shambles......then the complete FUBAR IRL project for Lotus, whereby it was hopelessly uncompetitive.......also the 4.5 Litre Nissan LMP2 engine is just better than the 3.6L BMW engine, because of more torque if you ask me, but i would day that.......also Zytek hardly have a great reputation for flawless launches of new LMP1 engines, they blew up quite regularly!.....so any new prospective buyer of the 4.4L V8 options from Zytek or Judd is probably asking themselves ......"how many times is it going to blow up before it shows any signs of reliability"

[madfast]

Originally Posted by knighty

I can understand your logic, but if a "leg-up" equates to only 2 seconds per lap, they are still going to be hounded all the way by the LMP2 runners and the works LMP1 teams will just steam off into the sun-set.......I have reason to believe that Rebellion have a very significant budget and are not doing this on a shoe-string, despite what they say publicly, have you seen the cost of a typical rebellion watch? a crap one is $10K!....an average one $50 - 100K......a real funky one £930K!!!!!.......all they would need to do is sell about 10 average watches and that would pay for the engine upgrade no problem!.......from what I hear through the grapevine Rebellion just dont have the depth of knowledge to understand the basic powertrain requirements.........Even Judd and Zytek have pushed 4.4 Litre 2014 LMP1 V8's for the past 6 months (links below), you would have thought that rebellion would have taken the hint back then, but they didnt......dont get me wrong, I think they are a great team and deserve credit for going the LMP1 route as a privateer, especially in the face of such competitors, so overall good luck to them, but they will be on the back foot with the old 3.4 engine due to a significant torque deficit, which will also not help their fuel economy due to its very high revving nature, going the 4.0L+ route would have significantly helped both torque and fuel economy.

Personally I would not be surprised to see one of the new Rebellion cars running one of the Zytek or Judd 4.4 litre units in the not too distant future after LeMans, as they are in for a rude awakening on the engine front, the 3.4L unit is the wrong tool for the job in 2014.

http://www.autosport.com/news/report...?source=latest

http://www.engdev.com/engines/db-4-4-l-lmp1-v8/

i was wondering when zytek would offer a "off the shelf" hybrid system. once these become more commonplace, hopefully the privateers can be competitive enough to somewhat battle the factory teams...

[Maelochs]

To be fair, Judd's Indy engine was never properly developed because it was never properly funded ... not indicative of what the company could do.

I forget, but I thought the issue with the Judds vibrating so badly at Le Mans 2012 wasn't the motor but some other issue, but I can barely recall two years ago ... Sunday is lost in the fog and this morning is a little hazy.

I don't know much about it but I have never gotten the impression that rebellion's race team were dumb or something. Bart Hayden always struck me as on top of things.

Probably the watch company doesn't give more money to the racing team when it sells more watches, it gives more money to its top management. Probably, like Toyota, Rebellion allots a certain amount of cash each season and says, "Do as well as you can."

[JoestForEver]

Originally Posted by madfast

i was wondering when zytek would offer a "off the shelf" hybrid system. once these become more commonplace, hopefully the privateers can be competitive enough to somewhat battle the factory teams...

They do actually. The plan of Zytek has always been a 4.4 engine plus the Kers used on GT300 Honda CRZ and GT500 NSX

[Articus]

***The Rebellion R-One Toyota, which makes its Le Mans debut in only the LMP1-L car’s second-ever race, shares a handful of parts from other winning prototypes, including the headlights from the Peugeot 908, which claimed overall honors here in 2009.

Hmm

[TF110]

Engine issue on the #13. One driver didnt do his night laps!

[deggis]

Originally Posted by Articus

Hmm

Recycling parts, now that must be green. (Rear wing ended up on the Peugeot Pikes Peak car)

[Koenigsegg]

From Dailysportscar.

DSC has learned that a current (and as yet unidentified) LMP2 team has entered into discussions to purchase a Rebellion R-One to contest the 2015 FIA World Endurance Championship.

Rebellion is understood to be open to other offers for the purchase of one of their existing cars post-season, or to allow the construction of this and further new customer cars. “We simply want competition,” said a team source, “and if that has to come from a rival team racing a Rebellion car then so be it.”

Interesting.

So which current LMP2 have the resources to buy and race an LMP1 car? KCMG perhaps?

[TF110]

Wonder what engine they would go with if they choose not to go Toyota.

[Koenigsegg]

The clever choice is probably a V8 engine. Since the Toyota engine is also an V8. We all know what happened to Lotus when they switched engines from a V8 to something else.

[carbon_titanium]

Originally Posted by Koenigsegg

From Dailysportscar.



Interesting.

So which current LMP2 have the resources to buy and race an LMP1 car? KCMG perhaps?

SMP is one of the richest team, but they are already involved with their own lmp2 project, another rich team is signatech... maybe their deal with alpine will expire at the end of the year so they can be free to run in lmp1.

[JoestForEver]

Can it be Jota or Greaves racing with the Caterham livery? After all Fernandes must have been tired of burning cash in F1.

[Salamus]

A very impressive effort by Rebellion finishing 4th! Congratulations to them. This R-One is very pretty and very reliable.

[J Jay]

Originally Posted by Salamus

A very impressive effort by Rebellion finishing 4th! Congratulations to them. This R-One is very pretty and very reliable.

That it is. Unfortunately it's missing that one "very" that every race car needs...

We'll see how much quicker a more developed R-One is, but I'm with knighty on the engine - they need something better and they need it quickly.

[FIRE]

Nice to see them in 4e spot.

Good debut for the R-One.

[carbon_titanium]

agree, the consumes of the r-one are really bad... doing a quick calculation, in a stint with an average laptime of 3.35, the car could do barely 11 laps with 6.4 liters consumed per lap. (at le mans the r-one had a 72L fuel tank and basicly no limits on fuel flows)

[dbagtbag]

Originally Posted by FIRE

Nice to see them in 4e spot.

Good debut for the R-One.

Rebellion

[FIRE]

Originally Posted by dbagtbag

Rebellion

Yes

Hopefully next year some competition from other LMP1 privateers.

[Brownj]

Also nice to see them manage a 3:28.466 lap during the race.

[Deleted]

Heidfeld and Prost have behaved rather well on twitter after the Chinese debacle got sorted out so I'm sure they'll be fine for the rest of the season.

I'm bad at spotting tiny modifications, but looks like the lovely coupes remain relatively unchanged (well apart from L EoT) for the weekend

[TF110]

This is a "preview" of the high downforce nose


On the picture above, you can see the split feet on the front floor like the TS040.

[chernaudi]

Actually, the Le Mans Prototypes blog as a better illustration from the side, and the splitter feet there actually look more like what the Oreca 03 LMP2s run. After all, that's no coindicence, since Oreca helped design and are the manufacturer of the R-One.

[Deleted]

Originally Posted by Chiana

Heidfeld and Prost have behaved rather well on twitter after the Chinese debacle got sorted out so I'm sure they'll be fine for the rest of the season.]

All fine here too