Ah yes, the DeltaWing...

[Jersey Tom]

I recall when this concept was first announced and they had the complete BS assertion that it would be "inherently stable on braking."

First hour of Daytona 24.. locks up brakes and spins out

[Lycoming]

Did Ben Bowlby say that? what made you think that it was BS? How does it feel to be right?

[MOWOG]

Perhaps Bowlby MEANT to say: "When done properly, the Delta Wing will be inherently stable on braking." ?

[Jersey Tom]

BS either way, IMO. You spin out trail-braking by running out of rear lateral. The moment generated from lateral forces that far from the CG dwarf whatever "inherent stability" effect you might think you have with braking forces and yaw. I'd guess by immense amounts.

You can get braking stability in any car - DW included - by dialing in front brake bias.. which is commonly known. No magic in DW's layout.

[Andres125sx]

BS either way, IMO. You spin out trail-braking by running out of rear lateral. The moment generated from lateral forces that far from the CG dwarf whatever "inherent stability" effect you might think you have with braking forces and yaw. I'd guess by immense amounts.

You can get braking stability in any car - DW included - by dialing in front brake bias.. which is commonly known. No magic in DW's layout.

Yes, no magic, just a backward CG that actually provides some inherent stability when braking

Your statement is like saying F1 cars brakes sucks because you´ve seen some F1 cars going too long on some corners.... Is not possible for you to think DW may have some brake problem?

Like any 911, when the CG is backwards, on braking the mass transfer (I think this is the term, sorry for my english) makes it more neutral. When it´s neutral by design, the CG goes too far forward on braking so the rear end will always loose much more grip.

This is a fact, you can´t have a perfect mass distribution between both axis both when turning and when braking, you have to choose your preference. Some designs are better for turning (most cars) and will lack some grip at the rear end when trail braking, and some others are better for braking and accelerating (Porsches and DW) but willl lack some grip at the front end when turning. I guess DW tried to solve this problem with that weird design, but don´t know the result, they claim they don´t have too much understeer problems, but don´t know for sure...

[autogyro]

The DW should not suffer from grip problems under trail braking.
The secret to cornering ability for the DW is the torque vectoring differential.

[countersteer]

The torque vectoring differential was abandoned on the "original" developed by Bowlby. I don't know if Nissan has pursued it in their version. Have you seen any reference that they have? Thanks...

[autogyro]

The torque vectoring differential was abandoned on the "original" developed by Bowlby. I don't know if Nissan has pursued it in their version. Have you seen any reference that they have? Thanks...

I believe the reason for the removal was a control issue.
In such a layout with the narrow front track vectoring torque on the rear drive axle would have to be precise.
The delta design IMO will never reach conventional layout cornering potential.

I would guess that at this time the lower cornering potential compared to a conventional layout is a trade off against the improved aero from the design.

I still prefer a car based on the tadpole layout three wheeler, with rear steer, rear wheel lean, FWD and vectored torque front diff steering.

[Jersey Tom]

Yes, no magic, just a backward CG that actually provides some inherent stability when braking

Your statement is like saying F1 cars brakes sucks because you´ve seen some F1 cars going too long on some corners.... Is not possible for you to think DW may have some brake problem?

Like any 911, when the CG is backwards, on braking the mass transfer (I think this is the term, sorry for my english) makes it more neutral. When it´s neutral by design, the CG goes too far forward on braking so the rear end will always loose much more grip.

Eh.. I still don't think rear CG gives you any inherent braking stability, certainly not on a circuit racing car

A few topics to clarify here though, and not that I'm trying to make this into a pissing contest. Not trying to offer this one case as some amazing "proof" or a "ah-ha! gotcha!" I just found it amusing.

Now as for rear CG cars and straight line braking, on a car with the same tire on all four corners if you have the CG rearward enough to equalize vertical load on a braking event - yes, that would probably give you the best straight line deceleration.

Braking stability though - as in yaw stability under braking (be it straight line or cornering) is going to be all about tire lateral forces. Yes - a car can have some tendency to lose stability on decel because of forward load transfer, but this is regardless of CG location. If you tune the car to be perfectly neutral at constant speed, front CG or rear CG will both lose yaw stability and move toward some amount of oversteer with forward load transfer.

I'd say a major contributor to any consumer car braking stability is just the brake bias - which I would wager is considerably further forward than you'd have if you wanted to take the same car build and port it to a race application.

[Andres125sx]

Braking stability though - as in yaw stability under braking (be it straight line or cornering) is going to be all about tire lateral forces. Yes - a car can have some tendency to lose stability on decel because of forward load transfer, but this is regardless of CG location.If you tune the car to be perfectly neutral at constant speed, front CG or rear CG will both lose yaw stability and move toward some amount of oversteer with forward load transfer.

Yes, any car will suffer that problem (unstability under braking), but if the CG is backwards the problem will be smaller.

My english sucks (sorry if my previous reply didn´t look kind) so I´ll try it with an example. Imagine a car with a rear CG, the mass distribution will be around 40/60 at constant speed, and when braking it may be 60/40 (just a guess). Now another car with a neutral CG, 50/50 distribution, so when braking it will be 70/30. The car with the neutral CG will be more unbalanced under braking, its back side will be lighter (wich is the reason any car is more prone to oversteer under braking), so it will be more prone to oversteer, less stable.

A rear CG means more load on the rear side, and that´s good for braking because the unavoidable unbalance will be smaller. Obviously a car with a rear CG will suffer on other aspects, but for braking I think it´s much better

[Pierce89]

Braking stability though - as in yaw stability under braking (be it straight line or cornering) is going to be all about tire lateral forces. Yes - a car can have some tendency to lose stability on decel because of forward load transfer, but this is regardless of CG location.If you tune the car to be perfectly neutral at constant speed, front CG or rear CG will both lose yaw stability and move toward some amount of oversteer with forward load transfer.

Yes, any car will suffer that problem (unstability under braking), but if the CG is backwards the problem will be smaller.

My english sucks (sorry if my previous reply didn´t look kind) so I´ll try it with an example. Imagine a car with a rear CG, the mass distribution will be around 40/60 at constant speed, and when braking it may be 60/40 (just a guess). Now another car with a neutral CG, 50/50 distribution, so when braking it will be 70/30. The car with the neutral CG will be more unbalanced under braking, its back side will be lighter (wich is the reason any car is more prone to oversteer under braking), so it will be more prone to oversteer, less stable.

A rear CG means more load on the rear side, and that´s good for braking because the unavoidable unbalance will be smaller. Obviously a car with a rear CG will suffer on other aspects, but for braking I think it´s much better

He's not talking about straight line braking capacity. Any car will spin if you overload the rear tires braking capacity while trail braking. The delta wing guys claimed their car would not, which defies physics.

[gixxer_drew]

Marketing people love to hear stuff like that being discussed and then push for it to be repeated because it sounds good to non engineers. I dont see how you can even discuss its truth/untruth without understanding what he meant exactly when he said that. It could be anything frankly. Seems JT doesn't think much of the car though

The thing I liked about the car frankly, was firstly that it was different and nobody is doing different anymore everyone is doing "to spec" these days. I also enjoyed it let you pick out straight away which guys dont really understand vehicle dynamics... when they didn't understand how it works.

[SectorOne]

His statement is absolutely correct as some have pointed out already, the only problem is he and you JT are talking about two different sides of the same coin.

It´s a truthful answer but not the whole answer.

[G-Rock]

The Deltawing concept is the dumbest car design I"ve ever seen. It disgusts me.
The fact that the rear is wider than the front should have sent the designers back to the drawing board. It makes contact accidents violent and unpredictable.

[munudeges]

This is what happens when you get a standardised racing formula and why Indycar has become a dangerous joke. When you're not pushing the limits and truly understanding what your chassis is doing and it's not designed with a specific purpose in mind then you get idiocy like this and how we've come to have the deaths and accidents there have been.

But, some people want to view Indycar through rose tinted glasses....