DPX Concept

[Clark]

Turbos are better for producing more power but at the cost of driveability and throttle response.

 

[Murcie_LP640]

I'm using 2 superchargers. Can that be done?

Koenigseggs from the CCR to the CCXR "Edition" have used twin Rotrex superchargers. The Agera however moved to twin-turbos.

 

[Luminis]

355 tires (does Falken make these? they're my new fav tire brand, their cars look awesome)

I wouldn't base that choice on what the cars sponsored by a given brand look like - that's only going to compromise the outcome. Anyways, 355 section tyres aren't exactly common, so it would mostly depend on who's offering a performance tyre of that width in the first place. I do know that Pirelli offers the P Zero Rosso in that size, though.

I'm undecided about the engine. The 4RR (4 Rotor Rotary) was good for the DPX because the HFC (Hydrogen Fuel Cell was originally going to be in the back, along with the large fuel tank, with only the battery in the front. But the DPX-II'll have the tank & cell in the front, so there's room for a massive engine. Still undecided. I've always like rotary engines. My grandfather said they're good because pistons must keep changing direction, whereas rotarys just go around. Piston engines would be more avaliable too. Perhaps we could use 2 like the veyron?

The Veyron only uses one engine.

And rotaries could - theoretically - achieve insane RPMs due to the mass not needing to change direction. Same as a turbine, really. Thing is, this is only a theoretical thing. The friction generated at high RPMs is still limiting the red line on rotaries. The materials available wouldn't be up to the heat and the forces involved.

Piston engines, on the other hand, don't need to achieve such high RPMs, though. As you might have noticed, they're producing considerably more torque at low RPM, which then means that similar power can be achieved without revving as high. Which is one of the reasons why you'd potentially be able to get better fuel economy out of apiston engine. But I really am not that knowledgable on the whole topic. You might want to ask Scaff on that - he's a much better source for automotive knowledge than I could ever be. Or Famine, as I'm convinced that he's basically knowing anything

I'm using 2 superchargers. Can that be done? Would turbos be better? I personally prefer superchargers.

I can't think of a reason to use two superchargers, as there seem to be better options. Either try compound chargin the car, which would consist of a supercharger for low-RPM boost and a turbo charger for high-RPM boost. Or a set of turbochargers with variable turbine geometry. Porsche uses this technology to counter turbo lag on their cars.

Compund charging (also known as twin charging, I think) was used on some of the Group B rally cars of the late 80s, like the Lancia Delta S4 - to great effect. With technical possibilities like VTG that seems like an unecessity nowadays, though. Turbochargers do tend to be heavier and to make less power due to requiring power from the engine via their belt drive in the first place.

Now, I know that my suggestions are driving you away from your original concept more and more - I'm sorry about that. That's not my intention, really, I'm just trying to provide my thoughts on what seems to be the best option, to me

 

[HDT Commodore]

Pirelli P Zero Rosso 355 tires then for the DPX-III.

The first Veyron (16.4 I think?) had two V8s joined together.

I'll contact Famine for engine help. I went to Scaff's page, the last message was when I tried to contact him ages ago, so I won't bother with him.

The supercharger + turbo idea is a good one, could it be coupled with VGT tech? Or should we go one way or the other?

I don't mind at all how this is changing. Its constructive criticism! If there's a way to improve this car, then I'm willing to listen. I don't care how many changes I have to make. Remember, the idea was to make a car as fast as possible, with all the best tech. The evolutions following the original don't even need to resemble it!

"If you believe something will happen, it WILL happen." -Jeremy Clarkson

 

[Luminis]

I guess that's one way to describe a W16 engine, yes

As for the twin charging, I don't think VTG would be a necessity if you had a supercharger supplying boost at low RPM. But I've gotta ask this: By "as fast as possible", do you mean "highest top speed possible" or "fastest lap times possible"? Because, personally, I'd tackle both of these tasks quite differently - the latter mostly with low weight and high downforce.

 

[HDT Commodore]

Well, both really. That's why I used active aero. It's good for top speed, but when you want to corner just use the spoiler.

Picture of DPX-III is there. If we need to modify the body before it's ready, we'll just make a DPX-III P1 (DPX-3.1)

I'm also working on a more practical car.

 

[HDT Commodore]

if famine can help us with the engines, then i'll just tidy up the exterior for the p5, then i'll send it Nissan first? they seem most likely to listen 💡

 

[HDT Commodore]

famine remains silent. boxor, h or x engine, i think. They're most compact, meaning more cylinders can be fitted.

x is too unreliable. boxor is best up until 12 cylinder, from which h is more compact. H16, or two boxor8s?

diagram of you might assemble one:

you could join 2 flat8s. porsche or jabiru?

also, can anyone here reliably type in japanese?

 

[Luminis]

Hm, have you specified the displacement of the engine? Personally, I'd only go with such a complicated layout if I really had to. Plus, an engine that huge would be insanely heavy. The more I think about, the less I see a rewason to go with something like an H16 engine. AMS gets Nissan's VQ38 V6 (stroked to 4l of displacement) to produce somewhere around 1700 HP. The 2JZ and RB26 engines have been tuned to produce more than a thousand HP for years now.

So, yeah, I'd focus on an engine that can reliably sustain very high boost and heat by using top-notch materials like titanium alloys and carbon fibre, then compound-boost the hell out of it. Light engine + light chassis + boost = great power to weight ratio + great cornering.



Quite a good example of what I think is a good concept if you want to go really fast. Maybe not in terms of top speed, but in every way else.

 

[1stlsx]

Do you really need 4 Nos tanks? Seems a bit extreme considering Nos isn't road legal(at least in the US).

1st there is no need for 4 nitrous tanks. A normal nitrous tank holds 10lbs of nitrous. I believe that 4lbs of nitrous use per minutes is equal to roughly 100hp increase for a 1 minute period, no reason I can think of you would need more than a few seconds here or there on a road car with a single tank lasting you plently of time.

As far as the legality of it, I'm not 100% sure on this. I have nitrous in my car. It is licensed and registered and, until recently, driven on the street on a regular bassis. As you can see from the below picture, I have 2 nitrous tank mounting points. Back back clearly seen in the back window and hidden in the wheel well. I have been stopped numerous times with the visible tank in the car and hooked up. Not once has a cop said a negative word about it what-so-ever. I've also heard its illegal, but I nor any of my friends running it have ever been given a ticket for having it on the car and hooked up. As far as the emissions concern. If the car is setup correctly, I do not see why this is a concern. Nitrous would only be active for a VERY short period of time under 100% load. Im not 100% familiar with the federal emissions testing, but I doubt they are running cars at 100% throttle for exended periods of time.

The issue more comes if to dynamically controlling timing with the injection of nitrous and, if running a dry kit, the additional fuel required to be injected through the injectors. Also plug selection becomes in issue depending on the amount of nitrous being used and how a colder, if needed, plug would effect emissions of the car under normal operating conditions...

Edit: Also, if a nitrous system were to be used on a prodution vehicle, a system would need to be put in to place to eliminate the addition of fuel if the tank were to "run dry". Also as the amoutn of nitrous in the tank gets lower pressure usually drops leading to unreliable injection. A lot to think about on something that woudl be production, but I dont see why it couldnt be done...

Legality in Texas (my state):


Nitrous Systems
Texas Health & Safety Code, Chapter 485, includes nitrous oxide under its list of so-called abusable volatile chemicals, though it states a person commits an offense if one "inhales, ingests, applies, uses, or possesses an abusable volatile chemical with intent to inhale, ingest, apply, or use the chemical in a manner ... contrary to directions for use, cautions, or warnings appearing on a label of a container of the chemical; and ... designed to: (A) affect the person's central nervous system; (B) create or induce a condition of intoxication, hallucination, or elation; or (C) change, distort, or disturb the person's eyesight, thinking process, balance, or coordination." It goes on to state that an offense under this section is a Class B misdemeanor. It would seem from the wording of this provision that use of nitrous in a vehicle's engine does not create a violation, but again, there is still the question of permits in Texas.

 

[HDT Commodore]

Luminis, i cant believe a v6 can produce 1700hp! i had no idea. we definately won't need a h16. the reason i wanted h is because I just thought that you can have double the amount of cylinders if you place one boxor on another. also i already had the h16 lego model on my computer so don't think i wasted all my time. i'll get back with more reseach soon.

can someone help with aerodynamics? i've been trying to base my designs on a teardrop shape which i've head is the most aerodynamic shape possible, with downforce incorporated. Is it good? or does anyone have any tips? i hear the saleen s7 is exteamly aerodynamic, or does it just have heaps of downforce?

i might call #4 the GTPlanet C3 (combination coupe concept) dual power experimental makes one think it's designed as a fuel efficient car, but thats not it's main purpose.

just watched the lotus vid. shocked. we need that man.

did you mean vq37vhr? the vq40de looks compact, and 4.0 should be enough. it should be quite ideal.

best overall track performance is the goal. top speed perfection is kind of tedious. the veyron is really only good for straight line speed. this car needs to be good on the track.

how about optional nos? depending on whether it's legal in your place and some people might only ever use it for track anyway.

what department of nissan? should i go into the dealer and ask who to send this to? i wouldn't give it to our dealer, they probably wouldn't care. (i live in rural australia so it probably won't reach nissan jp.)

 

[Luminis]

Well, the 1700 HP that AMS coaxed out of the GT-R is obviously pretty extreme and it'll be hard to get anywhere near that while providing decent reliability. The GT-R's engine is the VQ38DETT, the 3.8 litre twin turbo V6. AMS strokes it to 4 litres, I think. If you want to go with something like that, I'd suggest getting in touch with AMS Performance.

However, I do know that there are some other engine builds that are just as crazy, if not even more crazy. There's Nissan's RB26DETT engine, a 2.6 litre straight six. Someone went and welded two of those together to form a 5 litre V12 that can reliably push out 1,000 HP.

One of the most mental things I've read about is Chris Rado's Supra, though. It uses Toyota's 3UR-FE engine, a 5.7 litre V8 usually found in the Toyota Tundra. In that Supra, it's stroked to 6.2 litres, set up to rev to 10,000RPM and sustain 50lbs of boost. It provides 2,500 HP, though. A more moderate setup could run with less max RPM and bosst to provide more reliability, but still get up to 1,500 HP, I'd think.

NOS depends on where you live. It's illegal in Germany, I know that much. Wouldn't incorporate something like that if you want to amrket it globally. A water-based anti-lag system would be nice with a turbo charged setup.

Now, what I'd do to get the fastest possible track car: Get an intelligent AWD system like the one found in the Nissan GT-R, couple that with a mid-engine layout and a titanium alloy/carbon fibre version of the 3UR-FE, a twin turbo setup with variable valve timing, water based anti-lag system, carbon fibre monocoque with titanium frame parts and a dry carbon exterior.

Tear drop design provide very little drag, but I'm not sure if they produce any sort of downforce. Personally, I'd think that the Caparo T1 has a great design if you're jsut going to try and get the fastest track car ever.

If one was somehow able to couple such a design and super light body with an intelligent AWD system and an engine as described above, you'd have something that should be able to brake all kinds of records, at least as far as road legal cars go. Well... Thinking about it, you shoudl create this:

A real life version of the Hot Wheels Shadow Jet, hust at a front wing

 

[HDT Commodore]

wow! ^that's perfect! i'll draw it later. remember, i have no money to build this obviously (i've said that before) but nissan does. if they actually made this, it would cement them as the best supercar manufacturer in the world. The only problem is cost. it would end up like the veyron. costs more than anything else and still sold at a loss.

 

[Exorcet]

The "tear drop" is a low drag shape, it provides exactly zero downforce (when parallel with the ground).

You still want a similar shape for a downforce producing car though. The secrets are camber and angle of attack.

That airfoil makes no downforce, but like most airfoils, it's very low in drag. You can greatly increase the downforce simply by tilting the back up. This puts the dotted line (the chord line) at an angle, which will cause the flow to change direction and generate a force on the airfoil.