[WEC 2015]Nissan GT-R LM NISMO

[langwadt]

http://www.motorsport.com/lemans/news/m ... or-nissan/

Mission accomplished???? That's just sad Nissan.

completing the Le Man with all cars is an accomplishment in it self, if they didn't have a working hybrids system it is no
surprise they couldn't keep up, the question is where a working system will make them fast enough and/or save enough
fuel stops to make them competitive

[Cold Fussion]

if you go off on Mulsanne you'll mostly likely slide along the rails, if you go off in the Porsche curves you'll hit the rail hard

You can have a brake failure before Mulsanne corner, you could hit a car approaching Mulsanne corner (like Anthony Davidson in 2012).

[Earnard Beccelstone]

So, they ran a compromised concept and it was an almost total bust. As I understand it, Nissan were forced to be completely reliant on FWD and was without hybrid power during Le Mans. The twin flywheel system wasn't working and almost all the braking energy was going through the front wheels. Apparently they had to go from 16 inch to 18 inch wheels just to get large enough brakes.

I wonder where they will go from here?

If they get their concept actually working - with the front-wheels powered by the ICE and the real wheels powered by the hybrid energy systems - the car just might be competitive. The again, it could be a lost cause that will never be better than 10-20 seconds of the pace.

My feeling is that Nissan will continue the insanity for at least another year, hopefully with the benefit of 12 months experience and a lot of lessons learned.

I really want them to get this working. Forget about all the marketing rubbish but this is actually an interesting concept.

[ChrisF1]

Are Nissan scheduled to enter the other WEC rounds remaining?

[machin]

If they get their concept actually working - with the front-wheels powered by the ICE and the real wheels powered by the hybrid energy systems - the car just might be competitive. The again, it could be a lost cause that will never be better than 10-20 seconds of the pace.

Just doing some real quick simulations suggestions that if they'd had an additional 2MJ of KE per lap (but otherwise identical) it should improve their lap times by about 2 seconds (moving up to the 8MJ class doesn't give you 8 seconds per lap, since you have less fuel per lap in the 8MJ class). I think if they have four wheel drive (as intended) they would improve by a few further seconds... but that only gets them to around a 3:32~ish lap time at best.

Add some more downforce (if the front engine allows?!), develop the car a bit and move up to the 8MJ class if they can (without going above the minimum weight) and I think they can be fairly close in qualifying performance to Porsche/Audi.

My calcs say that biasing the CoG too far forward isn't the best way to get the most out of the tyres, and this indicates they will always have a little disadvantage on lap times (although that could be overcome by being superior in other aspects), but tyre longevity could be their problem...

[Tim.Wright]

My calcs say that biasing the CoG too far forward isn't the best way to get the most out of the tyres,

I assume that the deficiency you see is in traction? I don't believe you can make any assumptions about the CG location's effect on lateral grip without more detailed tyre model...

[BanMeToo]

Are Nissan scheduled to enter the other WEC rounds remaining?

I am wondering too. You'd think they would at least participate in one more for testing/data purposes.

[Samraj_official]

Are Nissan scheduled to enter the other WEC rounds remaining?

I am wondering too. You'd think they would at least participate in one more for testing/data purposes.

isn't the GTR-LM a LeMans special?

[BanMeToo]

Yes but that doesn't mean they can't participate in the other WEC rounds... just that they would (presumably) be even farther off the pace than they were last weekend. If they just want to use one of the later rounds as a test to try out some changes / try to get the hybrid system working correctly then who cares if they are last in class again.

[machin]

I assume that the deficiency you see is in traction? I don't believe you can make any assumptions about the CG location's effect on lateral grip without more detailed tyre model...

The tyre model I'm using is detailed, but of course (unless I'm very lucky!) isn't going to be 100% accurate. The same could be said about the suspension kinematic model, the aeromap, the turbo lag characteristics, the polar moment of inertia.... etc.. etc.. all I can say is that I'm really pleased with the tyre model I'm using (and the other factors), and when used to do a blind prediction of performance has always come out suprisingly accurate...

...Bowlby claimed his simulations showed the car would do a 3:20... I didn't ever think that sort of performance was on the cards.. although I didn't think it would be as bad as 3:38 for the fastest one of the three either... so I still maintain that with 4WD, more downforce and some development this thing can be pretty close to the class front-runners...

[wesley123]

Yes but that doesn't mean they can't participate in the other WEC rounds... just that they would (presumably) be even farther off the pace than they were last weekend. If they just want to use one of the later rounds as a test to try out some changes / try to get the hybrid system working correctly then who cares if they are last in class again.

I'm certain they'll be better off relative to LM24 as they'll find pace and experience in running the car. Maybe they'll actually use the hybrid system(which was present, but not ran at LM).

It'll certainly be good for experience.

[henra]

Add some more downforce (if the front engine allows?!),

That is actually my concern with the car. There is not much space for large air extraction openings and channels behind the front wheels which are normally used to create a front diffuser effect. I'm wondering how they want to create meaningful front downforce with this design?! In my opinion aerodynamics (not min Drag but max negative Lift/Drag) is possibly more of a stumbling block than the FWD itself. A 400kW electric Motor will put much more peak load on the tyres than a 550HP ICE

[wesley123]

Add some more downforce (if the front engine allows?!),

That is actually my concern with the car. There is not much space for large air extraction openings and channels behind the front wheels which are normally used to create a front diffuser effect.

They do, just not in the normal sense. The front diffuser vents in the large tunnels that are made possible because of the lack of radiators in that area.

I'm wondering how they want to create meaningful front downforce with this design?

A gurney on the rear deck could possibly improve flow through the tunnels and improve some downforce. Other than that, they are seriously limited on the front diffuser because of the engine and radiator package in that area.

The car also lacks a few details seen on the other LMPs, like the Vg's behind the front tire, and vanes in the diffuser area.

[wesley123]

In slightly different news, some more great words on the project:
http://sportscar365.com/lemans/wec/cox- ... amentally/

The one we weren’t expecting was the inability of the car to run the harsh curbs, which meant we had to keep the drivers off the curbs. You lose a significant amount of time not able to do that. But it was the right thing to be conservative as we didn’t want all three cars to be out with suspension issues early on.

This makes me wonder if there is anything that actually works on this car.

[machin]

I wonder what caused the "inability to ride the curbs"... Fragile suspension parts.... or insufficient suspension travel.... Or insufficient compliance.... Or.....????