Tony Posted March 12, 2009 Report Share Posted March 12, 2009 I dailled in -4 degrees front and rear (max allowable) for a giggle. It was horrible, understeer, snap oversteer, no traction or grip at all. The contact patch is to busy...... think "tyre saturation grip limits" Quote Link to comment Share on other sites More sharing options...
CIH Posted March 14, 2009 Author Report Share Posted March 14, 2009 Does extreme Camber make the contact patch smaller ? Or recuce how much migration is possible ? Had a good day in work today, incidentally. Two BMWs; one axle lift, only got 2 minutes but enough to restore to OEM-target and a 98 Civic. My work times took a nose dive after I first found WIM (ignorance was bliss) but they're heading back up again. Quote Link to comment Share on other sites More sharing options...
Tony Posted March 14, 2009 Report Share Posted March 14, 2009 Does extreme Camber make the contact patch smaller ? Or recuce how much migration is possible ? Had a good day in work today, incidentally. Two BMWs; one axle lift, only got 2 minutes but enough to restore to OEM-target and a 98 Civic. My work times took a nose dive after I first found WIM (ignorance was bliss) but they're heading back up again. The SR is about the same, what changes is the amount of weight that patch supports..... Nice to read your "applying calibration" times have reduced, this is good for all involved and keeps grizzly off your back. Quote Link to comment Share on other sites More sharing options...
CIH Posted March 15, 2009 Author Report Share Posted March 15, 2009 How does the amount of weight differ ? The weight of the car hasn't changed ? Quote Link to comment Share on other sites More sharing options...
Tony Posted March 15, 2009 Report Share Posted March 15, 2009 How does the amount of weight differ ? The weight of the car hasn't changed ? The weight is the same, it's the concentration that's changed. Think of zero camber, the SR has a proportional share of the weight meaning the tyres saturation limits are very low. If we tilt the camber weight is added to the SR generating more conical compression and friction... now the grip limits has raised. The holy grail of chassis dynamics is to know how much camber and whether or not to add additional angles like toe and castor. Quote Link to comment Share on other sites More sharing options...
CIH Posted March 15, 2009 Author Report Share Posted March 15, 2009 Ah I see. So by incrrasing camber it puts more weight to the SR. Is that true across the whole camber range ie; 0 to -whatever or just at exteme settings ? I guess it's across the whole range, to some degree or another. Quote Link to comment Share on other sites More sharing options...
Tony Posted March 15, 2009 Report Share Posted March 15, 2009 Ah I see. So by incrrasing camber it puts more weight to the SR. Is that true across the whole camber range ie; 0 to -whatever or just at exteme settings ? I guess it's across the whole range, to some degree or another. Yeah.... everything we do is to manipulate the contact patch, what's in it, where it is and how busy it is. Camber is our most powerful tool, toe is our least. Like a doctor you listen to the complaint.... read the modifications then analyze the intentions, it's all on the fly, there's no template to go by so it's you and whatever data displayed on the screen. Scary... nah. Geometry calibration has the same global ingredients whatever the car, it's how you mix these ingredients that results in a successful calibration. If i could define my tools geometrically it would be "understeer, oversteer" every calibration falls into this realm. Quote Link to comment Share on other sites More sharing options...
CIH Posted March 28, 2009 Author Report Share Posted March 28, 2009 'ave been at it with Forza again, this time a 350bhp NSX. IIRC it's on -2.8 camber rear, -2.4ish front, no toe and 7.0 castor. That's on race suspension with very stiff springs, semi-slick tyres and minimal ARBs. Has really nice slow corner turn-in but can be a little edgy on the fast constant state turns and a little over-steery generally. Quote Link to comment Share on other sites More sharing options...
Tony Posted March 28, 2009 Report Share Posted March 28, 2009 Soften the front ARB. Quote Link to comment Share on other sites More sharing options...
CIH Posted March 29, 2009 Author Report Share Posted March 29, 2009 It's as soft as the game will allow. I did away as much as I could with the slammed ride-height and super-stiff springs. Anyway, more camber on the rear looked kind of wrong so I flipped the camber values front to rear and it's much better, feels more "natural". I've noticed, with the bigger camber figures, when the tyres do saturate they seem to take much longer to come back "on" and the cars require much more precisie "driving". In the past, with an essentially standard AE86, if I set a drift up a little early the car could sit (very birefly) sideways before actually entering the corner, in true Initial D style. There's no way this NSX would be so forgiving the way it's set up. Would you think that's accurate to real life Tony ? Quote Link to comment Share on other sites More sharing options...
Tony Posted March 29, 2009 Report Share Posted March 29, 2009 No..... It's a good model for sure, predictable like tomorrows weather but not absolute fact. Chassis dynamics is a vast arena even if we deny it's sisters, like suspension dynamics, aerodynamics's, mechanical and kinematics's, at best we hope to offer the final tuning solution's to those who have developed the car before us. When you are setting the Geometry parameters in the game you are in essence becoming your own customer? The plus side of this is you can experience some level of consequence Quote Link to comment Share on other sites More sharing options...
CIH Posted March 31, 2009 Author Report Share Posted March 31, 2009 current "project" is a 600bhp R32 GTR Skyline. Found an even 2.5ish camber front and rear is good but it never really settled down untill I added some front and rear downforce. Rear always seemed to be breaking away but I suppose big power will do that.... Quote Link to comment Share on other sites More sharing options...
Tony Posted March 31, 2009 Report Share Posted March 31, 2009 current "project" is a 600bhp R32 GTR Skyline. Found an even 2.5ish camber front and rear is good but it never really settled down untill I added some front and rear downforce. Rear always seemed to be breaking away but I suppose big power will do that.... Are you running rear toe? Quote Link to comment Share on other sites More sharing options...
CIH Posted March 31, 2009 Author Report Share Posted March 31, 2009 It doesn't allow a zero toe angle so +0.1. Problem with Forza is when "racing suspension" is added it defaults to -0.5 camber front+rear, no toe and 6.0 castor for every car. Works well with a Mitsubishi GTO (especially it's Ddge Stealth sister, with a little toe in) but ruins a Porsche GT3. Quote Link to comment Share on other sites More sharing options...
Tony Posted March 31, 2009 Report Share Posted March 31, 2009 It doesn't allow a zero toe angle so +0.1. Problem with Forza is when "racing suspension" is added it defaults to -0.5 camber front+rear, no toe and 6.0 castor for every car. Works well with a Mitsubishi GTO (especially it's Ddge Stealth sister, with a little toe in) but ruins a Porsche GT3. Frustrating tuning then Quote Link to comment Share on other sites More sharing options...
CIH Posted April 1, 2009 Author Report Share Posted April 1, 2009 Nah, I'm not putting too much weight behind any of this. Just a little fun untill I can play with a car for real. Quote Link to comment Share on other sites More sharing options...
CIH Posted April 3, 2009 Author Report Share Posted April 3, 2009 Hey Tony what's your thoughts on a car in the 200SX/S12 vein running more camber front than rear ? I seen a few people on different sites recommend approx -1 rear and -1.5 front. Seems to me it would make the front too "pointy", and the rear not so "planted" ? That's in the fast-road/ track-but-not-drifty contect. Quote Link to comment Share on other sites More sharing options...
Tony Posted April 3, 2009 Report Share Posted April 3, 2009 Fast road 1.5 camber f+r, +8' front toe +30' rear loads of castor if avalible..... fr/ track -2d f camber -1.5 r -20' front toe +50 rear, loads of castor. Quote Link to comment Share on other sites More sharing options...
CIH Posted April 3, 2009 Author Report Share Posted April 3, 2009 but that front/rear camber spread goes against anything I've seen (mostly OEM ofcourse) ? Quote Link to comment Share on other sites More sharing options...
Tony Posted April 3, 2009 Report Share Posted April 3, 2009 That's because both examples invite progressive oversteer, oem is all understeer. Quote Link to comment Share on other sites More sharing options...
CIH Posted April 3, 2009 Author Report Share Posted April 3, 2009 I presume the extra front camber is because of less dynamic gains ? And the lower rear camber, as you say, for progressive oversteer ? I'd think more rear camber could "raise the limit" but make breakaway (tyre saturation) more agressive too ? Quote Link to comment Share on other sites More sharing options...
Tony Posted April 3, 2009 Report Share Posted April 3, 2009 Full blown track could have -4.5 f camber -60' toe, -3.5 r camber +60 toe, the tuning tool here would be how much r toe to use. Quote Link to comment Share on other sites More sharing options...
CIH Posted April 3, 2009 Author Report Share Posted April 3, 2009 hmmn, I'll have to try that in Forza. So far I've stayed within -3.0 Quote Link to comment Share on other sites More sharing options...
Tony Posted April 3, 2009 Report Share Posted April 3, 2009 hmmn, I'll have to try that in Forza. So far I've stayed within -3.0 Because your thinking domestic...... look outside of the box. Quote Link to comment Share on other sites More sharing options...
CIH Posted April 4, 2009 Author Report Share Posted April 4, 2009 Had a bash at full spec geos in Forza with a "full race" S14 Silvia and an R32 GTR. Tell you what I was surprised how much better they both behaved with the large Toe-in angles front and rear. Both semed to be lacking rear grip, though I think Forza exagerates throttle oversteer. Back in the real world it was intereting getting a look at that Evo10 I spoke to you about. Thankyou again for digging out the specs. Just gave me that extra little bit of confidence. Whole set-up is surprisingly similar to the Evo9. Quote Link to comment Share on other sites More sharing options...
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