The online racing simulator
VHPA v3.1.4 [updated 26/03/10]
(613 posts, started , go to first unread)
#76 - axus
No, he means:


neutral
|U | O|

understeer
|U | O|

oversteer
|U | O|

#77 - JTbo
Oh, I like my version better, there can be then nice colorful bars :lovies3d:[etals:]
I have to agree, the display format isn't ideal, I just emulated what Colcob used in his suspension spreadsheet. I agree there is still some ambiguity.

I will adjust it to JTbo's suggestion, I think that will be nice and clear. Anton - with your suggestion you might not see the bar as I wouldn't want to draw it more than 1 pixel wide, otherwise it's less precise.

How does a gray (grey?) background sound with the bar extended towards oversteer, coloured red, or extending towards understeer, coloured blue, sound?
^ Yup, JTbo's suggestion is probably the easiest to understand. It would be the same as the current ingame damage indicators but with different colours
#80 - JJ72
this is really amazing, a huge step up from the excel spread sheet back in S1 (which was wonderful itself, I use it till today), it helps drivers like me who don't have a clue with the numbers, who can only adjust by the seat of the pants feeling create precise and consistent setups.
The program works perfectly with me and is so useful

now my suggestions:
  • ability to watch acceleration time in a custom speed range.
  • zoom-in graphs with values on axis for precision reading, and keys.
  • more help for ackermann setup, what is the optimal corner radius the current ackermann setting set up?
  • a global over/understeer diagram which takes in account all elements
  • what do the dots represent in the springs tab's bottom graph?
and the questions:
  1. I've noticed that the springs stiffness influences the aero force distribution. May I conclude this distribution takes in account the car pitch?
  2. Is it normal that undertray's ground effect forces are not affected by car pitch and ride height? (not implemented yet I think?)
Suggestions:
* Custom acceleration times can, for now, be found from the CSV data outputs, or slightly more conveniently from the real time acceleration viewer (not released yet).
* Graphs cannot be zoomed, but I've added a new resizeable graph window that can display any graph. Keys I should probably add at some point, for now the (unreleased) manual covers the colours.
* Steering analysis is yet to be added
* Not sure on the global over/understeer diagram

Questions:
* The dots in the springs tab diagram represent the CoG, and where applicable, undertray and wings
* Car pitch didn't really affect aero distribution until I coded dynamic wing angles the other night, so I'm not sure what you're seeing there. It should be very small, whereas now it should be quite pronounced for cars with downforce
* Undertray is not affected by pitch or ground clearance in LFS, thus I have no data with which to build my own model. I will it add when LFS does.
Future releases sound better than I thought what a great program

Quote :Car pitch didn't really affect aero distribution until I coded dynamic wing angles the other night, so I'm not sure what you're seeing there. It should be very small, whereas now it should be quite pronounced for cars with downforce



It's the FXR. The slider range can be exaggerated, but we can see that it affects the forces.

Quote :Undertray is not affected by pitch or ground clearance in LFS, thus I have no data with which to build my own model. I will it add when LFS does.

I didn't know that ground effect in LFS works like this. It's quite a disappointment, it's so sensitive in the reality.. But your program is coherent with LFS, that's most important.
OK, I think this makes sense. While in your copy the wing angles are static, the level at which their force is applied, relative to the centre of gravity (CoG) height, is not. The force on the tyres, due to downforce, comes from two effects. First, the downward force generated by the wing, pushing on the tyres. Secondly, the drag created by the aero device, when not at the same height as the CoG, transfers force between the front and rear wheels. Thus the total amount of downforce did not change with pitch (the relative vertical force figure is constant between those images), but the heights do as the vehicle pitches, hence this weight transfer can be altered. That is the effect which you are seeing there.

This also applies slightly with roll for cars with a non-central left/right CoG position, as roll alters the height of the CoG, but not of any of the aero components, thus this drag induced weight transfer changes.

--------------------------------------------

Anyway, it just so happens I'm happy to release another update (nearly a month since the last, didn't realise it would take so long).

So, go download it! - link removed, please see first post

Updates since the last preview version:
* Fixed bugs to do with springs inside the acceleration/deceleration loops
* Added dynamic wing angles (with body pitch, from both springs and tyres)
* Reworked all the graphs, now lots of shared code, should look a toucher neater too (some graph types have changed more than others)
* Added resizeable graph window which can display any graph from the program (balance diagrams excluded) and updates live, press Ctrl G or use the menus
* Add real time acceleration viewer, still more work planned for this later but you should get the idea, accessible from the acceleration tab
* Added analysis of dampers, springs no longer instantly deform during the acceleration run, actually oscilate now (until dampers stop the movement)
* Other small changes dotted all around

Other requests people have been made are noted but I'm still concentrating on finishing off the main content first.

The manual is coming along but not anywhere complete enough to be worth releasing at this time (although it's already 20+ pages)

Go play.
now THATS what I am talking about, top notch work Bob!!!!

Any chance we could be able to maximise the window? would be nice to get the whole springs window without having to scroll up and down it.

Also, I get quite a bit of "lag" on the sliders, I think maybe the force diagrams are updating all the time you move the slider bar and cause the lag, any chance the force diagrams can be redrawn once you have de-clicked the slider bar?

Also again.........any chance of being able to input numerical values aswell as using the slider?

Also part 3..........for some reason, everything seems to be on the "H", spring rates, frequency, dampers etc etc everything seems uneven from left to right, i.e. with all the same settings left to right I have bump ratio 60.1% left rear, 61.1% right rear shouldn't they be the same?
I found a bug in the latest version (not present in previous release):

- live settings like throttle, brake or lateral acceleration doesn't seem to have any effect on springs deflections
- live setting default throttle is now 0% (used to be 75%)
Quote from Bob Smith :Heh, that's funny, I was using my own "made up" code in GRC, but now I've switched to the same code as LFS runs, thanks to a helpful Scawen. So, they should match.

I had noticed it giving some funny results though but hadn't got around to chatting with Scawen again, letting him have some time away from LFS at xmas.

Just to bump this up... tyre stiffness has still quite a big difference between your calculated values and the output you can read from LFS itself.
Quote from danowat :Any chance we could be able to maximise the window? would be nice to get the whole springs window without having to scroll up and down it.

I'm not keen on the idea, tbh.

Quote from danowat :
Also, I get quite a bit of "lag" on the sliders, I think maybe the force diagrams are updating all the time you move the slider bar and cause the lag, any chance the force diagrams can be redrawn once you have de-clicked the slider bar?

It's intentionally like that, I like everything moving as the slider is dragged. Try disabling on-the-fly calculation of deceleration testing to reduce the slider lag. The lag should then be quite minimal on any PC capable of running LFS well.

Quote from danowat :
Also again.........any chance of being able to input numerical values aswell as using the slider?

For all sliders, or just a few in particular? There's little room left in the interface to add more text boxes, between dragging the slider and using the scroll wheel I can usually get to any specific value pretty quick, an exception being gearing where there are 7000 different settings per slider, more than any other. If you could let me know which would benefit from it the most, I'll see if I can squeeze them in.

Quote from danowat :
Also part 3..........for some reason, everything seems to be on the "H", spring rates, frequency, dampers etc etc everything seems uneven from left to right, i.e. with all the same settings left to right I have bump ratio 60.1% left rear, 61.1% right rear shouldn't they be the same?

Yep, that's right, on the road cars, the CoG is not in the centre, rather slightly off to the left due to the drivers position. On formula cars they should be equal.

Quote from flyby3d :
- live settings like throttle, brake or lateral acceleration doesn't seem to have any effect on springs deflections

Aha, thanks, not sure how that got broken. I'll fix and re-upload later today.

Quote from flyby3d :
- live setting default throttle is now 0% (used to be 75%)

Yep, that was an intentional change.

Quote from flyby3d :Just to bump this up... tyre stiffness has still quite a big difference between your calculated values and the output you can read from LFS itself.

I'm still waiting for Scawen to get back to me on tyre vertical stiffness issues, I might drop him a reminder soon. Don't want to pester the guy.
Quote from Bob Smith :I'm not keen on the idea, tbh.

Fair enough, it's your program matey


Quote from Bob Smith : It's intentionally like that, I like everything moving as the slider is dragged. Try disabling on-the-fly calculation of deceleration testing to reduce the slider lag. The lag should then be quite minimal on any PC capable of running LFS well.

I am running on a core duo 3.4ghz with 2gb ram PC, it's quite bad, gawd knows what it's like on something slower, it can make making small adjustments a pain in the neck.


Quote from Bob Smith : For all sliders, or just a few in particular? There's little room left in the interface to add more text boxes, between dragging the slider and using the scroll wheel I can usually get to any specific value pretty quick, an exception being gearing where there are 7000 different settings per slider, more than any other. If you could let me know which would benefit from it the most, I'll see if I can squeeze them in.

Springs and dampers mainly


Quote from Bob Smith :Yep, that's right, on the road cars, the CoG is not in the centre, rather slightly off to the left due to the drivers position. On formula cars they should be equal.

Yeah, never thought of that, Doh!!!.

BTW, love the little "drag run" simulation
#90 - JTbo
At springs page there is this graph that shows unloaded and loaded springs length (green/blue bars) with RAC two of bars are just thin green stripes at bottom and no setting seem to be changing that. Also spring deflection seem to be 0m even my setup is rather soft, maybe this is related to what flyby3d mentions about live settings.

Edit: Oh, I found out why this was such, when I load RAC setup front spring length is 0, program seems not to read this information like planned so perhaps it is one bug to kill?
OK thanks for bug reports so far, the spring loads bug reported by flyby3d and the RAC spring length bug reported by JTbo have both been fixed and the zip reuploaded. Download the file again to get the bug fixed version.

danowat - did disabling on-the-fly deceleration calculations help? That's usually the main candidate for causing lag.

Edit: just tested on my spare PC, Athlon XP 2100 (1.75GHz) with 512MB of RAM (not that should make a difference), and it is a touch sluggish with deceleration calcs on auto, when on manual it doesn't lag at all. So the program doesn't need that much raw horsepower to run smoothly.
Yeah, that helps , nice one Bob
Short progress update:

I got the steering analysis working about a week ago but I'm holding back on an update until the manual is ready.

I've been taking screenshots of everything for the manual and have made a glorious collage. Just thought it looked cool to see everything at once.
Looking good Bob, I am waiting the update, loving this utility, massive help with making setups for me
WOW WOW WOW WOW

I just discovered this... and WOW, what a program. What an amazing piece of work. You should be bloody proud of urself Bob, bloody nice piece. Any ideas when it'll be finished? {drooooo}

V
danowat - thanks

Venus - "finished" is an interesting term. That's unlikely to happen for quite some time. I've a big sheet of extra features I want to add at some point, however I will consider it to be in a public, releasable, non-preview state once the analysis is finished (it is in my version) and there's a comprehensive manual (still in the works).
I'm hoping to have the bulk of the manual work out of the way in 2 or 3 days, tops. So I'll release then, and then I can update the manual to answer any questions you'll all bound to still have for me.
Well the program has pretty much reached a feature complete stage, in that all the analysis tabs are there.

I still have two pages of A4 covered with things to add, mostly at a later date, so don't think I've forgotten about everything that's been mentioned in this thread.

Download RC1 - link removed, please see first post

Changes since 'DamperTestRelease':
Added steering analysis
Added manual
A few small things, like updating about box, the odd bug fix, etc
Nice Bob, looks like you have but a HECK of a lot of work into this, it is a tool that I have used alot, and will continue to do so.

So it's two thumbs up from me
Nice work bob, but unfortunately I get a bad error.

run time error 11

division by zero

This happened when I loaded a set, went to deceleration, and selected coast down only.

edit:
Besides that bug, this app really rules, so a big to you
Great tool Bob! I often use sets that I have to mod because of my driving style. This utility has taught me much about driving with a stiffer rear end than I ever thought I could.

VHPA v3.1.4 [updated 26/03/10]
(613 posts, started )
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