Vehicle modding

Trae00
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Trae00
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April 28th, 2016, 8:42 pm #1

 Vehicle modding discussion.  
Last edited by Trae00 on October 27th, 2016, 9:12 am, edited 3 times in total.
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Ziggy Moonglow
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Ziggy Moonglow
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April 29th, 2016, 5:25 am #2

Thx for the link! I tried it but still no mirrors. I change from DX7 to DX8 and can see the instruments, which have black stripes look different. Like a reflection layer might be missing. They also need to be stock, but I'm not too worried at the moment.

Do you happen to have an Nvidia card? I have an ATI so I'm wondering if it's got something to do with the rendering. Your screen shots are better than I can get maxxed out.

I've got most of the pits and garage issues worked out.

Benny Parsons talks about the Wood brothers' fuel stop to be around 25 seconds while everyone else would take around a minute. He also says teams would have to stop 5 or 6 times a race for fuel so around 4 MPG. - American Stock: The Golden Era Of NASCAR Vol. 3 (46:46).

There is a video out there of a pit stop challenge and Bobby Allison's Coca-Cola crew wins but I can't find it anymore. There might be a link here I need to look for! LOL

Things tested, in need of more testing and tweaking - Along with some wish list/expectations
Engines - 426 Chrysler, 427 Chevy, 427 Ford, 429 Ford with real torque curve numbers. No limiters or modern stuff, between 590 and 600 HP, 7200 red line, 7500 "BOOM". Need to work on mileage, durability, heat and inertia. Still not sure how to calculate inertia.

Transmission - Stock and option gearing per make, any rear end ratio.

Correct weights for all cars, 3900# with fuel, without the 176# driver. 4076# ready to race. rF weight is with driver and no fuel so 1789.13 kg. (note - it's written a current 12 gallon gas can weighs 81# but 22 gallons of fuel only weighs ~60# so the can itself weighs 50#?).
F-R Weight distribution - 54 to 50 front (looking for article where Darrel Waltrip mentions it..)

Front spoilers for all cars. Daytona and Superbird adjustable rear wing.
Aerodynamics of the car based the coefficient of drag (Daytona .29, Charger 500 .37).
Wheelbase - 115" minimum, 1/2" tolerance from stock. Chevelle is 112" stock so would be stuck at 115" for all tracks. The tolerance could be an upgrade if not available in the garage.

Tires - Should last 500 miles in a Road Runner at Talladega per Ramo Stott's win at the Vulcan 500. He says in the post race interview that they didn't change tires all day and the car ran just as strong at the finish as it did at the start.
3 tire types, soft for short tracks, medium for speedways and hard for Talladega (Darrell Waltrip - Taking Stock: Life in NASCAR's Fast Lane)

Ride height minimum of 6.5" on the left and not more than 2" higher on the right, up to 8.5".

Wedge - Not sure it was adjustable during the race except for guys crawling under the car to pull or insert spring rubbers?

Spring rate - Not sure how long it took to adjust the screw jacks but Joey might know! He can make jumping under his Charger part of his workout routine! ;-)

Here's a link to the rule book - http://aerowarriors.com/rules/nosearch/70nrS20-1.html

Sound - I'm using the corvette 427 sound from the Historx mod right now.
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Trae00
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Trae00
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April 29th, 2016, 10:55 am #3

Ziggy Moonglow wrote:
Thx for the link! I tried it but still no mirrors. I change from DX7 to DX8 and can see the instruments, which have black stripes look different. Like a reflection layer might be missing. They also need to be stock, but I'm not too worried at the moment.
Hmm ... I'm sure you already know this, but just in case ... I believe you can toggle the mirrors on/off in the in-game graphics settings, worth double-checking.  Not sure what to say on the instruments, no issues here.
Ziggy Moonglow wrote:
Do you happen to have an Nvidia card? I have an ATI so I'm wondering if
it's got something to do with the rendering. Your screen shots are
better than I can get maxxed out.
Yes, nvidia card here, don't recall the model.  I'm taking my screenshots with Fraps.
Ziggy Moonglow wrote:
I've got most of the pits and garage issues worked out.
Awesome! 
Ziggy Moonglow wrote:
Engines - 426 Chrysler, 427 Chevy, 427 Ford, 429 Ford with real torque
curve numbers. No limiters or modern stuff, between 590 and 600 HP,
7200 red line, 7500 "BOOM". Need to work on mileage, durability, heat
and inertia. Still not sure how to calculate inertia.

Transmission - Stock and option gearing per make, any rear end ratio.
I think I've found most or all of the production gearing info.  I'll compile it all and post up later. 
About the only thing I've been able to find regarding "real" torque/HP curves are close approximations based on (what appears to be) manufacturer published data.  This site has that for about any production car you can imagine.  Obviously the max HP and RPM are off, but I will take a look and try to come up with a decent way to create a new approximated curve.  I've looked into the engine files before, so I may even do some in-game testing with it. 
Ziggy Moonglow wrote:
Aerodynamics of the car based the coefficient of drag (Daytona .29, Charger 500 .37).
Curious where you found those numbers, the Charger number seems pretty low to me.  The site I linked above also has Cd approximations, note the Daytona is the same as your source:
1969 Chevelle ... 0.491970 Chevelle ... 0.481969 Charger 500 ... 0.451970 Charger R/T ... 0.501969 Daytona ... 0.291970 Roadrunner ... N/A (0.50 should be a good approximation, based on the '69 Coronet)1970 Superbird ... N/A (0.30 - I've read that somewhere, just slightly more than the Daytona)1969 Torino ... 0.531969 Talladega ... 0.451970 Torino ... 0.501969 Cyclone ... 0.531970 Cyclone ... 0.50
1976 Corvette ... 0.40
Ziggy Moonglow wrote:
Wheelbase - 115" minimum, 1/2" tolerance from stock. Chevelle is 112"
stock so would be stuck at 115" for all tracks. The tolerance could be
an upgrade if not available in the garage.
I can get the production wheelbases too, if you don't have them already.
Hope this stuff helps! 
Last edited by Trae00 on April 29th, 2016, 6:35 pm, edited 3 times in total.
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Ziggy Moonglow
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April 29th, 2016, 8:13 pm #4

Hi!

Automoblie-catalog is where I get most of the data for starters. Then I go around looking for more from more reliable sources like http://aerowarriors.com/sss.html

Since the automoblie-catalog site (great site, I LOVE it!!) estimates the cd, I look for articles or videos of guys talking about the specs.

.37 was the starting point for the 500 since I read the .45 number but then read an article about how they had to lower the cd 15% to .29, which would make it .34. He could have meant lower it from .45 to .30. But, another article, about the Talladega, talked about it's cd being .34 to .36. Nothing in stone about those numbers.

Engines - I don't use stock numbers since they lie. I get onto Hotrod magazine or other sites and look for dyno run numbers. Not just peak, but the curve. http://www.hotrod.com/how-to/engine/mop ... dyno-test/ is an example and what I used for the Hemi.

I've got a lot of torque curves for a lot of engines. Either somebody tests an old NASCAR engine or I find one that is close and use it's curve. If the HP is too high, I'll adjust it. Just to get good curves instead of the ones the 'physics editor' gives. Will work on fuel mileage, heat and other parameters as testing goes along.

I've got the wheelbases, track, length, width, height and all that good stuff. What I don't have are the center of gravity, roll center and all the goodies that are used to make up the suspension files. All of the T/A suspension files are the same, as they are in many mods, and I'm not sure how that effects the cars. Being that the suspension points are located in the same place on every T/A car, using that file, I'm not sure how it would convert to a bigger car. That is something I need to read up on and learn more about. I think the suspension file that comes with the mod now is from the T/A mod.

Right now though, I'm giving the mule a break for a bit.

Wheelbase - The Chevelle will also need the suspension modeled so that the wheelbase from the door pillar to the front wheel is stock and the extra 3 inches are added at the rear since that's where the 3" had to come from. This is the suspension stuff I'm not 100% clear on yet, along with the locations of all the 'stuff'.

Center of drag/aero forces is another that's hard to find, but I have found some articles that talk about how much downforce was provided at what speeds. Just a matter of figuring those numbers into the game.
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Ziggy Moonglow
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April 30th, 2016, 9:50 pm #5

After watching some video and reading some stuff, we should never be able to hit 200 MPH at Talladega.
With all the cheating that went on, I'm wondering if going by the rule book is realistic!    I'm hearing all kinds of guys saying they'd drop weight during the race, lower the car and do all kinds of other things and I'm thinking that, most likely, when Buddy Bake went 200 MPH during the tire test at Talladega, he probably had the car lower, lighter and they might even have played with some other things to make it faster and handle better.  199 is close enough.

As far at the Trans Am mod goes and using it as a base...   What was the best lap at Lime Rock Park when we raced there?  The real poll speed was 59 seconds and my best lap was 1:06.  I'm not Mike or Donnie or Parnelli, but that's a lot of time difference. Like, 1967 lap times.  How fast did Mike and Donnie go?  That's how far off those cars are from reality.  Looking at their drag, they have spoilers that create downforce and no drag!!  Neat trick.  Also, the rear wings create lift instead of downforce, which could explain why the rear is so tail happy.

Just got word from Papaw that wedge adjustments were done by a crew member crawling in the side window and adjusting the right or left screws from there. Thinking it should take about 12 seconds or so to climb in, adjust and get back out?
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Ziggy Moonglow
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May 1st, 2016, 6:34 pm #6

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Trae00
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May 2nd, 2016, 8:19 am #7

Ziggy Moonglow wrote:
.37 was the starting point for the 500 since I read the .45 number but then read an article about how they had to lower the cd 15% to .29, which would make it .34. He could have meant lower it from .45 to .30. But, another article, about the Talladega, talked about it's cd being .34 to .36. Nothing in stone about those numbers.
Cd isn't really a percentage value ... I regularly use numbers around 1.2 and above in my daily work. 
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Trae00
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May 2nd, 2016, 8:20 am #8

Ziggy Moonglow wrote:
As
far at the Trans Am mod goes and using it as a base...   What was the
best lap at Lime Rock Park when we raced there?  The real poll speed was
59 seconds and my best lap was 1:06.  I'm not Mike or Donnie or
Parnelli, but that's a lot of time difference. Like, 1967 lap times.
 How fast did Mike and Donnie go?  That's how far off those cars are
from reality.  Looking at their drag, they have spoilers that create
downforce and no drag!!  Neat trick.  Also, the rear wings create lift
instead of downforce, which could explain why the rear is so tail happy.
Here are last year's Lime Rock race results
Looks like Mike's fast lap was 64.2s, yours was 65.4s, and Doni's was
66.2s, so 8-10% slower.  Of course, you have to wonder about track and
surface accuracy as well, and Lime Rock seemed to be rather slippery.Comparatively, the pole speed for the 1970 T/A race at Road America was 151.0s by George Follmer.  In last year's DTAC event, the best laps were 154.4s (Mike), 154.5s (ZM), and 154.7s (Jimmy).  So only 2.0-2.5% slower.
Possibly
related ... you said something about hitting 199 at Dega with your test
engine & gear files.  I tried them in a Superbird and only hit 191,
but I was losing a decent amount in the turns - could be
differences in the track versions we're using.
Ziggy Moonglow wrote:
Just
got word from Papaw that wedge adjustments were done by a crew member
crawling in the side window and adjusting the right or left screws from
there. Thinking it should take about 12 seconds or so to climb in,
adjust and get back out?
12-15s seems reasonable to me.
Last edited by Trae00 on May 2nd, 2016, 8:35 am, edited 3 times in total.
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Ziggy Moonglow
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May 2nd, 2016, 7:15 pm #9

Trae00 wrote:
Ziggy Moonglow wrote:
.37 was the starting point for the 500 since I read the .45 number but then read an article about how they had to lower the cd 15% to .29, which would make it .34. He could have meant lower it from .45 to .30. But, another article, about the Talladega, talked about it's cd being .34 to .36. Nothing in stone about those numbers.
Cd isn't really a percentage value ... I regularly use numbers around 1.2 and above in my daily work. 
Yep.  The guy said "we had to drop the drag 15% or find another 85 HP.  I guess I should find the link - http://www.caranddriver.com/features/ae ... les-page-1
I never said it was a percent.  I said that I took the number they came out with (.28, .29, .30, depending on source) and came out with .34, which seemed way too low to I cranked it up a bit.  I then made the statement that maybe the guy meant to drop it from .45 to .30 by losing .15, which he referred to as "15%", just like redneck math takes the 10 degree banking of the apron and the 26 degree banking of the track to say "Bristol has 36 degrees of banking!"

The article says "These changes not only reduced the Charger's drag coefficient from 0.37 to 0.30 but also transformed the 1969 race car's slight lift into modest downforce."
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Ziggy Moonglow
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Ziggy Moonglow
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May 2nd, 2016, 8:16 pm #10

Trae00 wrote:
Ziggy Moonglow wrote:
As
far at the Trans Am mod goes and using it as a base...   What was the
best lap at Lime Rock Park when we raced there?  The real poll speed was
59 seconds and my best lap was 1:06.  I'm not Mike or Donnie or
Parnelli, but that's a lot of time difference. Like, 1967 lap times.
 How fast did Mike and Donnie go?  That's how far off those cars are
from reality.  Looking at their drag, they have spoilers that create
downforce and no drag!!  Neat trick.  Also, the rear wings create lift
instead of downforce, which could explain why the rear is so tail happy.
Here are last year's Lime Rock race results
Looks like Mike's fast lap was 64.2s, yours was 65.4s, and Doni's was
66.2s, so 8-10% slower.  Of course, you have to wonder about track and
surface accuracy as well, and Lime Rock seemed to be rather slippery.Comparatively, the pole speed for the 1970 T/A race at Road America was 151.0s by George Follmer.  In last year's DTAC event, the best laps were 154.4s (Mike), 154.5s (ZM), and 154.7s (Jimmy).  So only 2.0-2.5% slower.
Possibly
related ... you said something about hitting 199 at Dega with your test
engine & gear files.  I tried them in a Superbird and only hit 191,
but I was losing a decent amount in the turns - could be
differences in the track versions we're using.
Ziggy Moonglow wrote:
Just
got word from Papaw that wedge adjustments were done by a crew member
crawling in the side window and adjusting the right or left screws from
there. Thinking it should take about 12 seconds or so to climb in,
adjust and get back out?
12-15s seems reasonable to me.
It's probably the tires.  Which track are you at?  The tires in the mod as it comes are wrong.  He's got the same compound on the front and a different compound on the rear instead of having the soft grippy tires on the left and hard durable tires on the right.  I took the tire from the Historx mod and turned them 'sideway' putting the rear on the left and front on the right. Then I changed the diameter, width and heating properties to get them to be good hot or warm, depending on the side, psi and all that stuff.  They have a low rolling resistance number so that probably had a big effect.
I used the plate tires that come with the rf stock car and they were super sticky and I think I was turning 194 and on the red line.  Again a pretty high rolling resistance.
The grip levels of the Historx tires is 1.12xxxx and 1.16xxxx while the GN mod as it stands has super grippy 1.4xxx tires.

The road course tires will be the left side short track tires, soft.  Then, a little harder and hotter would be the short track rights, intermediate.  A little harder and hotter for the speedway lefts, hard.  Then the Talladega tires which would be really hard, not up temp until they are going 185 or more and such.

I've got feelers out for some period type tires.  A guy at HSO has got some and I've asked to try them, along with a chassis he's working on for a Ford Torino.

Joey?  Do you have a tape measure and a couple of pieces of cardboard?  

Thinking out loud..
Aero stuff - Need to figure out how to get the Daytona to go fast but have the drag of the wing and front spoiler while making the Charger 500 go slower without the drag of the wing.  And if a Daytona gets in a wreck and the nose comes off (not sure if it ever happened), it will to produce more drag, like any car with the nose knocked off.
There can be a front wing (nose cone), difuser (front spoiler) and rear wing (rear wing/spoiler) and all of those will provide downforce and drag.    
Every car would have a front wing which would count as the grille/nose.  Drag reduction would go away if you pop the nose too hard or lose the 'front wing'.
Every car would have a front spoiler (difuser) which would produce downforce and drag.  Lose it and you get lift but less drag
Every car would have a rear wing which would provide downforce and drag,  Lose it and you get lift but less drag...
For the wing of the Daytona and Superbird, there would be a base, constant drag for the tails, sideforce and then downforce and drag being produced by the angle of the wing.

What work are you doing where you get to work with F1 cars?!     It sounds fun!!  Why am I trying to do the math when you probably already know these formulas?!  

I've got some articles that talk about how much downforce was created by the wing and how much body lift the nose removed from the Daytona - http://www.allpar.com/model/superbird.html

"1200# at race speeds" I take to mean around the 190 MPH mark.  If the Charger 500 had 1200# of lift at 190 MPH, I wonder how to put that into the file.  Then make the nose (front wing) have -1200# of lift at 190 so they cancel each other.  Add the front spoiler to provide the downforce the overall car actually had and then take the bodyaero and adjust it to get the desired top speeds...?   Thinking out loud.

Thx for the lap times!  I tried the mule at Riverside and I need to make up 10 seconds.  Mostly the tires need more grip (bet you never thought you'd hear me say that!).  
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