Suspension Analyzer

[NEMustang]

Has anyone used Performance Trends Suspension Analyzer or other suspension analyzer tools? If so, can someone post the numbers from a S197 platform? I have some data, but am looking for some accurate numbers. I will be measuring my car to the best of my ability with a tram gauge and some other measuring tools. However, I wondered if anyone has certified numbers from Ford or other suspension company.

 

[NEMustang]

Here's my first cut at measuring and entering into Peformance Trends Suspension Analyzer. I am going to remeasure as I think a couple of the numbers are off...First I note that the caster is a little excessive.

Also, my car is lowered two inches with Ground Control Coil-Overs and has 440 lbs springs. Note that lowering your car results in a lower roll center...not a positive for handling.

Anyone have any numbers that contradict these?

 

[DusterRT]

Have you joined corner carvers yet? There are a number of suspension gurus there..I'd bet you'd have much better luck with them. That does look like a lot of caster though, I think I'm at about 7 degrees (also on GC coilovers but I don't know how much I am lowered exactly..probably between and inch to an inch and a half). But yes, it's preferable to keep your A-arms parallel to the ground or with the outboard (ball joint) side lower than inboard to keep the roll center higher.

 

[NEMustang]

Yes, I am on Corner-carvers and posted there also. I did get some numbers and am comparing.

I know that my Caster is about 7 so I know my numbers must be slightly off...It's hard to accurately measure the Strut top mount offset from the spindle center line. I'm sure that the software must calculate the Caster from the length of the strut, strut top offset from spindle center and strut bottom offset from spindle center...I must be off on one of these.

You'll note that my ball joints are 1/4 to 1/2 inch higher than the lower control arm mount points, causing a lower roll center. This is obviously caused by lowering the car about 2" in ride height. The real solution here is either a k-member with different arm mount points and/or a 2" drop spindle.

 

[Mr. Q]

hello, i'm a little lost, but wouldn't something like steeda's x5 balljoint fix it?

 

[NEMustang]

hello, i'm a little lost, but wouldn't something like steeda's x5 balljoint fix it?

Yes, the X5 balljoint is a common fix. It is a better made part than the standard Ford balljoint (from what I understand). Also, a weak point in the suspension is the spindle. Here is a video with Bruce Griggs explaining the situation. The spindle is acceptable for the street, but not for racing:
http://www.youtube.com/watch?v=9hPRD5tY-ss

While Griggs has a spindle, it was designed for thier SLA. I think they may have engineered a strut mount.

The best spindle is made by Cortex Precision Racing (former Griggs guys and current Griggs Dealers). This is a two inch drop, radial mount spindle engineering for racing:
http://www.cortexracing.com/store/radial-drop-spindle/

The K-member is the final weak spot. It is heavy and flimsy compared to the Griggs front cradle (k-member, radiator support, etc all in one):
http://www.griggsracing.com/product_info.php?cPath=4332_4309_4320_4328_2000_3020&products_id=229

All of these are expensive options...therefore, your X5 ball joint is the least expensive for helping to correct the front roll center height.

 

[Mr. Q]

yeah, they look pretty expensive,

$3k for radial drop spindles (for the pair), and $1300 for the tubular front cradle.
as far as the spindles go, it seems like from what griggs shows in the video, that under hard loads turning and braking, it'll eventually give out (too much coding?). could this be what's causing a lot of the shuddering at high speed braking?

for the k-member replacement, a lot of guys are using the steeda radiator support with sway bar. where else are the weak links? i see with the griggs application, you have to use their steering rack...which is more gobs of money, haha.

lastly, (sorry if i ask too many questions), why upgrade the spindle? will i/u/him/her be able to push our cars to that point on the road track? is this something we (we, who are weekend racers, not pro) should be saving up money for in the near future?

i'm looking to race in hpde eventually, and i have my suspension setup in mind, coilsx4, 2-chamber dampers, rad support, k-member, watts, adj. uca/lca, relocate lca, heavy duty uca mount, alumin ds, stoptech bbk, and maybe strut tower bars. i'm poor, so everything i can find, i'm looking used, ebay, etc. should i start another penny bucket for spindles? haha, thanks in advance bro.

-e

 

[NEMustang]

Mr. Q,

You are absolutely correct on the first thing we should do to correct the front geometery of a lowered s197...replace the front BJ with an Steeda X5 BJ. It is the least expensive and most practical fix.

However, I have had the pleasure of going around Sear Point (Infineon) with John Griggs, talked extensively with Bruce Griggs, have had extensive conversations with Filip Trojanek (Cortex Racing) and have determined that many of these mods will make the S197 a true track king. We always ask the simple question...how fast do you want to spend?

I hope that we have more discussions on this forum other than "I tried those lowering springs and my car was slammed and they worked awesome...blah..blah...". I'm not a suspension engineering. However, it's great to understand what works and why...

I am running this car as a DD and at least 10 track days per year. It went from bone stock GT/CS car to having Ground Control/Konis/Eibach 440F/200R with Toyo RA1s for 6+ seconds/lap over stock...next weekend, I picked up another 2.5 seconds...no change, just experience with the track and setup.

For spring...I have GT500 Brembos with DTC60 front and DTC70 rears. I am considering X5s, Watts for rear and more...again, I can go as fast a I want to spend.

 

[Mr. Q]

nemustang,

10 track days a year and using the car as my dd is exactly what i have planned with my car. i agree about really wanting to know what works, how it works, and why. it's awesome to have that kind of information and be able to actively use it in real time to try and perfect how far we can push ourselves as drivers.
i look forward to more conversations technically related to suspension in the future as well.

-e