Acura/HPD's future plans - Page 135

TF110 · 11 Mar 2015, 22:46 (Ref:3514305)

Do they not rely mostly (all?) on cfd for car design?

J Jay · 11 Mar 2015, 22:54 (Ref:3514308)

From the MWM episode that has just been broadcast, they have built small scale models to verify the numbers in the past (Hindhaugh said he has seen this on a previous visit). So it implies that CFD takes the lead/majority of the design process but not the entirety of it.

Regardless, the reliance of CFD at the expense of physical testing has apparently come back to bite Wirth again.

TF110 · 11 Mar 2015, 23:23 (Ref:3514323)

Thats what I thought. They take the lead with cfd and its only small scale tunnel-testing to try and verify their findings.

Maelochs · 11 Mar 2015, 23:23 (Ref:3514324)

I had heard that none of his designs ever went to a wind tunnel. Not sure if its true. Pretty sure it never will be again in any case.

Articus · 12 Mar 2015, 00:52 (Ref:3514345)

Well that's a silly rumour. I think the amount that Wirht research does in CFD tends to be overstated. And why not? CFD isn't imaginary. It's using basic principles of fluid mechanics. It's not perfect but it's getting there.

Also CFD is only used for aerodynamics. Has there been any word that that the aero on this car is way off and that's why they are closing the curtains on this season?

I'm not sure how you guys have crucified CFD as the reason for the car's failure when they have not made any specific claims as to what is unsatisfactory other than they want to improve some things before they have to homologate.

In case memory does not serve you all well, Wirth research has been dynamite with all of it's previous LMP2 cars (especially the 07-08 era with the Acuras. And that was heavy CFD and proven on track).

The problems with the car could be any number of things not limited to aero. Could be bad suspension geometry, overweight (fact), and so on.

Let just leave it at that and that all is not what it seems here please.

Maelochs · 12 Mar 2015, 03:55 (Ref:3514377)

Well, I'd rather not leave it at that

I had heard that the ARX-02A was done entirely on computer, and I know it was great right out of the box (only trouble was the power steering couldn't cope with the front tires.) Don't know where I got that idea but it was from some source besides my imagination, or 10/10ths.

As for the 4b, it was overweight at Daytona, but I am not sure that was its only flaw. I read a post by a person who saw the car in testing at Sebring said they were changing some parts of the sidepods and/or aero bits and he speculated that front-end aero seemed to be an issue.

As for what I know, I know that I wanted the car to do well and I am bitterly disappointed that it didn't .. I also know no one can tell me not to talk about something I want to discuss. Obviously you are emotionally/personally connected to the car or program, and that's great, but that doesn't mean people cannot talk about it, or even criticize it.

However it was designed, it doesn't work. That's absolutely undeniable.

I made a complete ass of myself over on some IndyCar boards telling everyone what great cars Nick Wirth penned, and that the Honda aero kit was sure to be great. Now I wonder if the Indy work took too much of the firm's time.

I still hope to see the 4b run later this year. It is a weird but beautiful car, and the only HPD prototype that isn't a winner ... yet.

Articus · 12 Mar 2015, 04:07 (Ref:3514379)

Quote:

Originally Posted by Maelochs

Well, I'd rather not leave it at that

I had heard that the ARX-02A was done entirely on computer, and I know it was great right out of the box (only trouble was the power steering couldn't cope with the front tires.) Don't know where I got that idea but it was from some source besides my imagination, or 10/10ths.

As for the 4b, it was overweight at Daytona, but I am not sure that was its only flaw. I read a post by a person who saw the car in testing at Sebring said they were changing some parts of the sidepods and/or aero bits and he speculated that front-end aero seemed to be an issue.

As for what I know, I know that I wanted the car to do well and I am bitterly disappointed that it didn't .. I also know no one can tell me not to talk about something I want to discuss. Obviously you are emotionally/personally connected to the car or program, and that's great, but that doesn't mean people cannot talk about it, or even criticize it.

However it was designed, it doesn't work. That's absolutely undeniable.

I made a complete ass of myself over on some IndyCar boards telling everyone what great cars Nick Wirth penned, and that the Honda aero kit was sure to be great. Now I wonder if the Indy work took too much of the firm's time.

I still hope to see the 4b run later this year. It is a weird but beautiful car, and the only HPD prototype that isn't a winner ... yet.

I am in no way tied to the program, physically or emotionally

I didn't mean to say no one can talk about it. Just take a step back to see the way it's being talked about is a bit narrow minded.

You said "02a was designed entirely on a computer". What you meant to say was the aero package was designed on a computer (and that's the only abnormal thing about it compared to everyone else. Everything else about the car being designed on a computer (Suspension, Chassis, steering wheel etc) is standard fare in this industry and many others.

But again that's how everyone seems to be talking about these Wirth cars, like they are no good because they have "been designed on a computer", without elaborating on what they mean or even understanding what they mean, further spreading misinformation.

I did say however that the last couple of post accuse the car of having failed (whatever that even means) because the Aero was designed in CFD entirely. Having no inside knowledge of the car or program how can you talk about it like it is fact or truth?...

I mean yeah anyone can say whatever they want on a forum but they should realize they are spreading misinformation and it's in no one's interest so why bother?

Articus · 12 Mar 2015, 04:11 (Ref:3514381)

Quote:

Originally Posted by Maelochs

Well, I'd rather not leave it at that

I had heard that the ARX-02A was done entirely on computer, and I know it was great right out of the box (only trouble was the power steering couldn't cope with the front tires.) Don't know where I got that idea but it was from some source besides my imagination, or 10/10ths.

As for the 4b, it was overweight at Daytona, but I am not sure that was its only flaw. I read a post by a person who saw the car in testing at Sebring said they were changing some parts of the sidepods and/or aero bits and he speculated that front-end aero seemed to be an issue.

As for what I know, I know that I wanted the car to do well and I am bitterly disappointed that it didn't .. I also know no one can tell me not to talk about something I want to discuss. Obviously you are emotionally/personally connected to the car or program, and that's great, but that doesn't mean people cannot talk about it, or even criticize it.

However it was designed, it doesn't work. That's absolutely undeniable.

Wow, that's a whole lot of reading into nothing. The car ran laps did it not? Small issues can make a racing car look very bad. Just because the aero is wrong doesn't mean the braking system is wrong and vice versa. I just think you are overstating how "off" the car is. Maybe I'm just reading too much into what you are saying.

chernaudi · 12 Mar 2015, 05:06 (Ref:3514383)

It's none the less obvious that the car has some fundamental issues that can't be resolved quickly, hence, why ESM has reverted back to the older 03 model.

I can't say for sure what the problem is not being in the know, but CFD being the main source for aero data does seem to be problematic to rely on, just like any other simulation programs. Hence why Audi, Porsche and Toyota design stuff in CFD and do testing simulations, then do wind tunnel and on track testing to see if what the simulations say are backed up/are able to be replicated in the real world.

It was hinted a while back that HPD/Wirth were having some major issues with the 04, though it was never stated exactly what those issues were, but it's obvious that something's still amiss big time for ESM/HPD to ditch the car for the time being.

TzeiTzei · 12 Mar 2015, 05:58 (Ref:3514392)

The racer.com article did say:

Quote:

With the ARX-04b's aerodynamics said to be at the heart of the gains to be made

These things can happen, but I'm still quite disappointed. Isn't the 04b based on the LMP1 coupe that was never built? If it is then atleast the aero package would seem to have been in the making for long time. Or are the aero regulations different in LMP2? I can admit that I don't know.

The car was late. It should have hit the test track last fall so that they could have identified possible problems and fix them before the first race. It's quite bad PR for HPD and Wirth that they have to pull out for the entire season because of problems like these. With all the problems Dome and HPD have had, it kind of makes you appreciate what Onroak achieved with the Ligier.

Christian Mogami · 12 Mar 2015, 06:27 (Ref:3514401)

ARX-O4b was totally done on CFD,Wirth doesn't believe in the wind tunnel(cost too much) and because the Tubs were made so late in the game,HPD didn't have time to bring it to their wind tunnel in America to check the numbers before the first test and race at Daytona.

From day one it had no front downforce,much lower than even the old ARX-O3.

Also it couldn't keep a trans working(bad chassis rear end design that flex the trans case?),they been going thru them like butter!!!

So the only fix for it is for HPD to take it to their wind tunnel and redesign the whole areo package.I'll almost bet this the end of the ARX-04b because of cost and the new rules in 17.....even if they get it fixed....who is going to take a chance on it for just 1 or 2 years!

templer · 12 Mar 2015, 08:40 (Ref:3514425)

Quote:

Originally Posted by Articus

Wow, that's a whole lot of reading into nothing. The car ran laps did it not? Small issues can make a racing car look very bad. Just because the aero is wrong doesn't mean the braking system is wrong and vice versa. I just think you are overstating how "off" the car is. Maybe I'm just reading too much into what you are saying.

I have said it that it seems the car has aero poblems at the front. Racer Magazine did say the car has aero Problems. If you look at the Marshall Pruett pics of the Sebring tests you see teh car in several different aero configurations. Some show a low downforce configuration, some a high downforce package with double dive-planes, gurney on the tail and so on. If you make the pics a bit brigther you see some work on the leading edge of the sidepods. The original ARX-04b has a closed sidepod with a rather small outlet for the front diffusor and one turning vane. It is a similar design to what we have in 2000 to 2003 on Audi, Cadillac, Bentley and so on. Now they have opened the bodywork with seperate front Fenders and a much larger diffsuor Exit. So why did they try it. First Intention they have a Problem with the front aero. Am I wrong? I don't think so as Christian Mogami said the same and he knows it.

Of course only mentioning a car is entirely designed on the ciomputer is wrong as all design work is done by CAD and CAM.
The question is is CFD the right tool to design a car's aero. Some People say yes, some other say no.
Why did they say no. They think there are some parts on a modern racecar you cannot simulate properly in CFD ( for example the interaction of the exhaust flow on your airflow pattern) so you need wind tunnel to refer it.

Wirth Research did a great Job withe the LMP2 cars battling against Porsche and latter with the LMP1 Version 01e. The 02a was also a good design but this car was tested in a wind tunnel as well. Not too Long but they tested their whole car to refer the CFD results.

BTW if HPD take the cars back and published it when can be sure the car has Major Problems not only the front aero, as it is a PR Desaster for Wirth Research and HPD.

I have also heard rumours that the car has had problems with ist bellhousing cast and flexing parts. But I don't know it

J Jay · 12 Mar 2015, 09:51 (Ref:3514437)

Quote:

Originally Posted by Articus

Maybe I'm just reading too much into what you are saying.

Pot, kettle, black.

Regardless, the 04b does have aero problems. Of course there are other issues, but the closest we get to insider information (Pruett's Racer article) says that the aerodynamics represent the biggest performance gain. It's not a huge leap to then point at how the aero was designed as a factor in the car's withdrawal.

Edit - Christian, are you sure there was no wind tunnel input at all? (sorry if this seems like a redundant question, but I want to be sure!). The late tubs really haven't helped in this case, surely the 04b would have been sanity checked in the tunnel even if Wirth isn't a fan.

Jack Spratt · 14 Mar 2015, 01:23 (Ref:3514966)

Quote:

Originally Posted by Christian Mogami

Also it couldn't keep a trans working(bad chassis rear end design that flex the trans case?),they been going thru them like butter!!!

Not true.

Quote:

Originally Posted by templer

I have also heard rumours that the car has had problems with ist bellhousing cast and flexing parts. But I don't know it

Bellhousing issue yes, that was stated in earlier reports. Flexing of any kind, no.

Christian Mogami · 15 Mar 2015, 23:13 (Ref:3515634)

Quote:

Originally Posted by Jack Spratt

Not true.

Bellhousing issue yes, that was stated in earlier reports. Flexing of any kind, no.

So 'why' is it going thru trans? Jack did you you do something wrong like bad engineering???!!!

Jack Spratt · 19 Mar 2015, 23:22 (Ref:3517277)

Quote:

Originally Posted by Christian Mogami

So 'why' is it going thru trans

It wasn't. The rest of your comment is ignored.

Christian Mogami · 20 Mar 2015, 04:06 (Ref:3517327)

Quote:

Originally Posted by Jack Spratt

It wasn't. The rest of your comment is ignored.

Marshall Pruett reported that ESM went thru something like 10 trans at Daytona(practice,qual and race).

Is that wrong info told to Pruett that came direct from Sharp?????

You HPD guys need to start pulling your weight or HMC is going to shut you done or AHM/HNA is going have you guys helping out at Raymond mowing the lawn.

Maelochs · 20 Mar 2015, 16:40 (Ref:3517471)

In any case ESM is doing well at Sebring. Hopefully we get to see the 04b run later this year.

**joeb** · 20 Mar 2015, 17:35 (Ref:3517483)

Quote:

Originally Posted by Maelochs

In any case ESM is doing well at Sebring. Hopefully we get to see the 04b run later this year.

They should know more about the future of the project by the end of April:

http://sportscar365.com/industry/hpd...n-for-arx-04b/

Bobby_status · 20 Mar 2015, 18:16 (Ref:3517498)

Quote:

Originally Posted by Christian Mogami

Marshall Pruett reported that ESM went thru something like 10 trans at Daytona(practice,qual and race).

Is that wrong info told to Pruett that came direct from Sharp?????

You HPD guys need to start pulling your weight or HMC is going to shut you done or AHM/HNA is going have you guys helping out at Raymond mowing the lawn.

Wirth Research did design the chassis so I wouldn't place all the blame on HPD. Why is HPD so fixated on Wirth Research? There are other more established chassis companies they can partner up with. I really hoped it would be Dome due to their relationship with Honda Racing in the past (lmp2,GT300,GT500). Since Toyota is now majority owner of Dome, chances are slim to none. I thought you were a HPD fan? Beside it not like their Japanese brothers from Sakura (Tochigi, Japan) are doing any better haha.

Starfish Primer · 20 Mar 2015, 19:38 (Ref:3517529)

Quote:

Originally Posted by Bobby_status

Wirth Research did design the chassis so I wouldn't place all the blame on HPD. Why is HPD so fixated on Wirth Research? There are other more established chassis companies they can partner up with. I really hoped it would be Dome due to their relationship with Honda Racing in the past (lmp2,GT300,GT500). Since Toyota is now majority owner of Dome, chances are slim to none. I thought you were a HPD fan? Beside it not like their Japanese brothers from Sakura (Tochigi, Japan) are doing any better haha.

Have you heard of the latest Dome P2?

TF110 · 20 Mar 2015, 19:53 (Ref:3517542)

Toyota didnt buy most of Dome, they bought their tunnel in Japan.

Bobby_status · 20 Mar 2015, 23:57 (Ref:3517644)

Quote:

Originally Posted by Starfish Primer

Have you heard of the latest Dome P2?

The S103 has its share of problems and keeps on getting delayed. But Dome's racing history is way more abundant that Wirth.

Bobby_status · 21 Mar 2015, 00:07 (Ref:3517646)

Quote:

Originally Posted by TF110

Toyota didn't buy most of Dome, they bought their tunnel in Japan.

Oh I thought Toyota bought Dome, I stand corrected. But why did Dome break ties with Honda? Dome Honda in Super GT were my favorites.

MagVanisher · 21 Mar 2015, 01:18 (Ref:3517656)

Dome is pretty much busy making Mother Chassis tubs for GT300 teams aside from the Strakka project.

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