99th Indianpolis 500 - May 24th

[mustafur]

There is nothing to suggest to me that they can't hit that speed and still be safe it's just Chevy seems to have made an Aero kit with major lift of in reverse.

Easiest way to ensure safety Imo would be to go back to last years oval spec.

I think Honda would still be pissed that it would come down to that though as they have likely spent big money in their kit and then to throw it away because of a circumstance not linked to their own design.

Letting Chevy resign their Aero kit is also a massive dilema as it also gives them an advantage for having a bad design, it's a complicated scenario to say the least.

It also should be noted that whilst Aero knowledge today is quite intensive it's still has a very unknown side to it and things like these are envitable when you allow such freedom on development.

 

[IforceV8]

There is nothing to suggest to me that they can't hit that speed and still be safe it's just Chevy seems to have made an Aero kit with major lift of in reverse.

Easiest way to ensure safety Imo would be to go back to last years oval spec.

I think Honda would still be pissed that it would come down to that though as they have likely spent big money in their kit and then to throw it away because of a circumstance not linked to their own design.

Letting Chevy resign their Aero kit is also a massive dilema as it also gives them an advantage for having a bad design, it's a complicated scenario to say the least.

It also should be noted that whilst Aero knowledge today is quite intensive it's still has a very unknown side to it and things like these are envitable when you allow such freedom on development.

The topic of switching to the Dallara bodywork came up yesterday on twitter with the Indy Star's Curt Cavin and ESPN's John Oreovicz and the opinion of those two Indy Car writers is that the cars engine packaging

The '96 record-setting Reynard 96i had a simple Cosworth turbo engine of ~750hp

It was a 95i actually.The 96i only ran in CART.

Not exact but.
http://smg.photobucket.com/user/indypete/media/projects/DSCF0048.jpg.html

The problem could be the lack of end fences on the wings. http://espn.go.com/racing/indycar/story/_/id/12904775/indycar-facing-major-problem-third-car-flies

And the delay in release,and the lack of on track testing,and too much focus on CFD.

 

[Dotini]

Not exact but.
http://smg.photobucket.com/user/indypete/media/projects/DSCF0048.jpg.html

NO venturi tunnels, NO wing profile under tray. I think this may be the answer.

 

[Earth]

My scientific analysis is that the DW12 is an abomination. The delta shaped underbody has caused lift issues since its debut in 2012.

 

[spacecowboy73]

NO venturi tunnels, NO wing profile under tray. I think this may be the answer.

They had venturi tunnels. It's hard to tell because they are in the black area. Look on either side where the diffuser in an F1 car would be.


Here's a quick photoshop I did to enhance the tunnels:

 

[LMSCorvetteGT2]

My scientific analysis is that the DW12 is an abomination. The delta shaped underbody has caused lift issues since its debut in 2012.

That's not at all scientific...

 

[catamount39]

Why didn't Dallara give the car a flat floor? Just curious is all.

 

[spacecowboy73]

Probably because it's not mandated by the rules and it's faster to have ground effects. I'm not really sure though.

 

[LMSCorvetteGT2]

Why didn't Dallara give the car a flat floor? Just curious is all.

Why would you want a flat floor...which I'm guessing by your understanding is just a plain flat undertray and diffuser at the end?

 

[catamount39]

Why would you want a flat floor...which I'm guessing by your understanding is just a plain flat undertray and diffuser at the end?

No I was just curious because F1, LMP, and GT cars have that arrangement (spliter, flat floor, diffuser)...and I'm sketchy of ground effects anyways. I'm not criticizing Dallara I'm just asking is all.

 

[G.T.Ace]

A flat floor would make blowovers even worse.

 

[MustangManiac]

A flat floor would make blowovers even worse.

No, it wouldn't, what we have now is a reverse wing that creates down force instead of lift except when the car goes in reverse it turns into a wing and does the opposite creating lift instead of down force which is exactly why the cars are getting airborne.

 

[G.T.Ace]

No, it wouldn't, what we have now is a reverse wing that creates down force instead of lift except when the car goes in reverse it turns into a wing and does the opposite creating lift instead of down force which is exactly why the cars are getting airborne.

If you'd add a flat floor to the current chassis, the cars would sail through the air.
Remember the CLR, 911 GT1 and most recently, the GT-R GT3 blowovers? They all flipped thanks to their flat underbodies. The whole car needs to be changed, a flat floor would make the whole thing just more unpredictable.
You would create an air pillow.

 

[MustangManiac]

If you'd add a flat floor to the current chassis, the car's would sail through the air.
Remember the CLR, 911 GT1 and most recently, the GT-R GT3 blowovers? They all flipped thanks to their flat underbodies. The whole car needs to be changed, a flat floor would make the whole thing just more unpredictable.
You would create an air pillow.

Yes, you would need holes and/or some kind of flap system, but running a reverse wing is just asking for trouble. Not sure what they can do with just a week to go before the race. This obviously was not tested properly beforehand and will need extensive testing before the next oval.

 

[Dotini]

Perhaps a simple cigar shaped car (like Clark's '67 winner) with no real extensive floor area would be most stable going backwards?

The big problem about testing these things is persuading your test driver to spin backwards at 230mph and see what happens?

 

[catamount39]

IIRC the Deltawing received a flap in its diffuser so that when it spun it'd be fine. Basically when the car went backwards the flap would close the diffuser and render it neutral or something.

If you'd add a flat floor to the current chassis, the cars would sail through the air.
Remember the CLR, 911 GT1 and most recently, the GT-R GT3 blowovers? They all flipped thanks to their flat underbodies. The whole car needs to be changed, a flat floor would make the whole thing just more unpredictable.
You would create an air pillow.

Yeah they flipped with flat underbodies because the manufactures were idiots and they had almost no downforce for crying out loud (the Mclaren, Nissan, Toyota and Panoz GT1's had no issue). When was the last time a GTE car blew over? When was the last time a LMP1 or LMP2 car blew over (without contact and being thrown in the air)? When was the last time an F1 car blew over? And the GT3's that have blown over are unbalanced aero wise (Nissan).

 

[spacecowboy73]

Did they ever figure out what caused Loic Duval to get airborne at Le Mans last year?

 

[catamount39]

Did they ever figure out what caused Loic Duval to get airborne at Le Mans last year?

From what I can gather I think the curbing and grass caused the aero to be "upset" and launched it and then it flipped.

 

[LMSCorvetteGT2]

No I was just curious because F1, LMP, and GT cars have that arrangement (spliter, flat floor, diffuser)...and I'm sketchy of ground effects anyways. I'm not criticizing Dallara I'm just asking is all.

No they don't F1 has stepped floor or double floors, LMP has various set ups like stepped floors (without wood planks) and or aero gates. I don't know for sure about GT cars though but seeing as then and LMP have more liberal use of aero and more surface to do it with, you can creates items like louvers, inner body ducting aero and what not to aid in minimizing to eliminating front end lift and rear end lift.

However, in any high speed situation where there is aero loss, or placing aero in a position where it can't function as intended, you've basically made the car a wing for lift. So flat floors in these situations would be far worse because it would only help give into the turbulent airs flowing above and beneath the car at the different pressures and then take off.

DP, LMP, GT, F1, Indy, NASCAR it doesn't matter. You put these cars on tracks and allow them to do 200+ and when they crash at that magnitude of velocity they're going to take off like a plane because they're all essentially aero tools like a wing in varying degrees.

Rather than make the cars have less drag, giving them more downforce for now and slowing them down is the best option because it makes the situation of them being placed in a crash where such violent loss aerodynamics less than if they were in the low drag trim. The danger will always be there and will on cease when they stop racing cars at Indy, one can only try and minimize it from happening so frequently.

 

[prisonermonkeys]

Ryan Briscoe has been called up to replace James Hinchcliffe:

http://m.speedcafe.com/2015/05/21/ryan-briscoe-to-replace-hinchcliffe-in-indy-500/

 

[CAMikaze]

I'll just leave these PDF links here.

Starting Lineup - The 99th Indianapolis 500
Starting Grid - The 99th Indianapolis 500​

You can add these to the OP post if you want.

 

[spacecowboy73]

IIRC the Deltawing received a flap in its diffuser so that when it spun it'd be fine. Basically when the car went backwards the flap would close the diffuser and render it neutral or something.

I think these would be a great idea. 👍

 

[Earth]

Weather forecast looks good

prerace show in 15 minutes

The race starts in just a little over an hour

 

[Whodoyouthink]

Isn't it more like 75-90mins? We Americans LOVE to do 131343442342 things for pre race rituals before we actually go racing. And then the actual podium takes a while as well.

I know rightly so the race won't happen at 12pm EST. Even with an hour long pre race show.

 

[IforceV8]

Hopefully this will work during the race since ABC will have no idea what is going on for the majority of the race. http://www.livetiming.net/firestone/

 

[TDZdave]

They on track yet?

 

[LancerEvo7]

They on track yet?

National Anthem.

 

[IforceV8]

They on track yet?

Singing now.

 

[TDZdave]

http://www.wibc.com/listen

Here's a radio stream

 

[MatskiMonk]

Come on Juan