[This message has been edited by Zac88GT (edited 11-25-2011).]

(Edit: Zac88GT used the numbers in the table of coordinates above to input them into Lotus Suspension Analyzer V.5 and generated numerous graphs depicting the change in such things as toe, camber, caster, roll centers, anti-dive and anti-squat etc as the suspension moves into varying degrees of jounce, rebound and roll angles. These graphs were deleted due to several errors found in the data. They will be reposted in a later post once the source of the errors has been found and corrected.)

Thanks again Zac for crunching and graphing the front and rear suspension data. And thanks for your interest ricreatr!

Zac has sent me the data tables for the graphs and I have my work cut out interpreting and double checking everything since not everything is easy to interpret. For example, not all the units of measure are obvious (degrees? mm's?), nor am I certain about the conventions of the scales (what do positive vs negative numbers mean in terms of direction). I found it surprising for example that both the front and rear exhibit toe-out under jounce (assuming negative values in the graphs are toe-out). I expected the rear to toe-in as I'd shown in an earlier drawing. So it's time for some off-line studying...

Anyways, the point of this post is to share my thoughts on where this build thread should go from here. As much as I am super-interested (like ricreatr) to see what the Fiero community comes up with to tweak the stock suspension, I'm just not sure that this build thread is the right place for that discussion. I would like to keep this thread focussed on what I plan to do to to my little car. Afterall, my primary goal in documenting the stock suspension was to ensure I could prove to my provincial registry of motor vehicles that my planned modifcations wouldn't adversely affect the handling of my car. (The car will need to go through an engineering assessment and certification process by the province's PEng before the car will be allowed to roam the streets).

So rather than get side-tracked with discussions on how to improve the front and rear suspensions in here, I'd like to redirect those discussions to the Technical Discussion & Questions section of the site. In retrospect, I should have started a separate thread under TD&Q a long time ago when I started delving into the stock geometry. As it stands now, there's a superb discussion in TD&Q called Redesign a Fiero Suspension for Better Geometry here: www.fiero.nl/forum/Forum2/HTML/117227.html That thread has focussed on the rear geometry so far, and probably should be kept that way to keep the thread from being too difficult to follow. So at the risk of reposting stuff that's already in here, perhaps I should kick-off a new thread dedicated to the front suspension.

[This message has been edited by Bloozberry (edited 12-08-2011).]

Anyone following this thread should take note that while reviewing the suspension data used to create Zac's curves above, I've found a few important errors in the table of coordinates I posted earlier, specifically the location of the upper and lower ball joint X-Axis coordinates, which had a 4.7 degree impact on the kingpin angle. (Edit: I have now corrected the tables for the front and rear suspension coordinates above, so they now contain correct data).

Also, not quite as significantly, I've asked Zac to review the rolling tire diameters he input into the program since they were around 15 mm taller than I measured empirically with actual loaded tires.

Lastly, I've pointed out in the "Redesign" thread that we need to sort out why there is a discrepancy between my value and the program's calculated rear anti-squat at ride height.

If you see the curves posted by Zac disappear for a short while, it's because we are reconciling the differences between what the Lotus Suspension Program he is using has put out, and my direct observations through the drawings. The curves will be back along with a post indicating they are the latest, corrected ones. Thanks for your patience.

[This message has been edited by Bloozberry (edited 12-08-2011).]