Flaw in F5 front suspension. - Page 2

RACERAL · #21 (**permalink**) 05-12-2003, 07:30 PM

Klayfish.. I'll bet you have 17's.. if so, throw those puppies away... and get some 15... my car was kinda twitchy.. not a ffr thing.. a low profile tire thing.. I have driven regular cars that had the twitchy feeling.. 15's are the way to go....

Excaliber · #22 (**permalink**) 05-12-2003, 09:17 PM

Nah,,keep the 17's and dial in more toe in for stability. I'd take 17's for the track anyday!

Ernie

petek · #23 (**permalink**) 05-12-2003, 09:46 PM

Steve,
is the car tracking the gooves of the road (for the lack of a better term) or is it wandering? How much steering input are you having to put into the car to keep it going straight?

I'd go with what Ernie suggests, put some toe in there and see if it doesn't help.

mr bruce · #24 (**permalink**) 05-13-2003, 03:55 AM

Another possible contributor to the twichyness, may be the "jacking effect" that is pressent because of the obtuse possition of the ball joints. I'm sorry if "it works fine" but there are folks having problems(one guy has steering stabilizers like on a 4-wheel drive on his).I'm not trying to bust anyones b*lls, but only looking to help get things rite.

John Hannaford · #25 (**permalink**) 05-13-2003, 04:28 PM

Steering stabilizers!? No kidding?

Mr. B., if you really want to make things right, I think the best thing you could do for these poor sods is to suggest they haul their rides to someone who knows what he is doing for a proper setup. Preferably someone who has actually succeeded at least once. Without whips and chains or ridiculous alignment settings.

There is sufficient proof out on the parking lots and tracks every weekend that this can be done. Since it is being done, that would seem to be pretty conclusive proof that it can be done. Instead of "imagineering", perhaps a little brotherly push toward some real help would be in order. We are all in this to get our friends out on the track, right? We wouldn't let some other factor keep us from helping a fellow racer, would we? We don't care what name came on that beautiful, fast car, do we? We're not under the impression that we're the only qualified one looking at these issues, are we?

Good. I knew that racers had more common sense than that. Now let's get on to helping these guys instead chasing internet brownie points.

If you're one of the unfortunates that has adopted this silly stuff, then do yourself a favor and get to North Cobras, or DV, or the NorCal group or somebody that you can trust to help you. They can, they will, and it's worth the effort. There is just too much fun to be had out there to let this nonsense keep you down.

I'll be thinking of you on the Andretti Straight on Thursday. Well maybe not then, but in the pits, for sure. Good luck, amigos.

Gatorac · #26 (**permalink**) 05-13-2003, 04:45 PM

Here's a picture that may help you to explain how the "upper ball joint boss is in front of the lower". Feel free to edit the photo with notes, lines and such to help explain.

Bart Carter · #27 (**permalink**) 05-14-2003, 12:35 PM

OK, I'm looking at the picture. Looks like the upper ball joint is BEHIND the lower, not in front as intially stated.

How can the upper ball joint be in front of the lower and still provide positive caster. By definition, it can't. So the upper ball joint HAS TO BE BEHIND THE LOWER. Unless you put the upper A arms on the wrong side of the car!

flipper35 · #28 (**permalink**) 05-14-2003, 02:45 PM

Steve, aggressive, square shouldered tread with the different front/rear track will follow the 'truck grooves' and other road irregularities enough to get you pulled over on suspicion of DUI (true story, no kidding). I would do what the others said and check the toe and make sure its in a bit.

Excaliber · #29 (**permalink**) 05-14-2003, 03:41 PM

Hmmmm,,,,,sure looks like the top ball is behind the lower ball....

Ernie

Satanpez · #30 (**permalink**) 05-22-2003, 09:04 PM

Klayfish, hear back from your guy?

-steve in nj-

Menace · #31 (**permalink**) 05-22-2003, 10:10 PM

Here is how crappy a FFR really handles (Sarcastic)(For bill 32)
http://www.norcal-cobras.com/videos/...ss-4-20-03.WMV

ps so it doesnt get lost in a cyber translation this video is one of the best handling fastest FFRs around Yes its been modified.
My car and none of the FFR guysI know have severe handling issue"s I personly moved my rack a little and installed a bumpster kit and have no issues

mr bruce · #32 (**permalink**) 05-23-2003, 03:43 AM

Just think how much faster that car will be with the suspension fixed.No really. Go back and read, also look in the all F5 forums.(other channel)some guys are actually putting 4-wheel drive steering stabilizers on to try to get rid of the twitchyness.The car in the video is HIGHLY modified from stockF5.(autocross forum,other channel)

Bart Carter · #33 (**permalink**) 05-24-2003, 09:57 AM

Quote:

Originally posted by mr bruce Just think how much faster that car will be with the suspension fixed.No really. Go back and read, also look in the all F5 forums.(other channel)some guys are actually putting 4-wheel drive steering stabilizers on to try to get rid of the twitchyness.The car in the video is HIGHLY modified from stockF5.(autocross forum,other channel)

Your accusations have no valid basis. The "twitchyness" in the car of a few (?) persons out of over 3000 is not due to suspension design. It is more likely due to alignment, choice of tires or wheel offset. Although you can deviate from the original specs on the car, you still have to know what the consequences will be if you do. If you don't understand the consequences, you need to seek the help of a professional that does. There are many who have done that. Not a big deal.

The car in the video ran well before suspension modifications, but of course runs faster now. One of the beauties of FFR's is that you can really modify them to be exactly what you want. An autocross champion is one choice.

It is a strong point with FFR's that there is such a large amount of information available on the car. You have some very professional shops that are glad to help home builders, even if they are not paid for it. You also have the best one-make forum anywhere, bar none, available. This is where neophytes go with their concerns and get help. You have never seen a post from a knowedgeable builder complain about "twitchyness" and suggesting 4-wheel drive steering stabilizers.

There are no positives gained by you continuing to offer such poor conclusions.

Gatorac · #34 (**permalink**) 05-24-2003, 11:34 AM

I'm really trying to understand your concerns. I'm building my 2nd FFR. I've been on the "other channels" for 4 years. I can't ever remember anyone ever having issues like you describe other than folks using the factory power steering without a control valve.

I did a search on "twitchyness" and came up with these 2 threads.

FFCobra thread
FFCobra thread

I did a search for "stabilizer" to see if anyone asked about a 4 wheel drive steering stabilizer and none of these threads had anything to do with what you are talking about.

Perhaps you could post a link to the many threads and posts about this issue so we could all see it with our own eyes.

Excaliber · #35 (**permalink**) 05-24-2003, 11:56 AM

Hey, how does that control valve for the P.S. work anyway?

Ernie

weendoggy · #36 (**permalink**) 05-24-2003, 12:52 PM

I'm going to put my .02 in. I have an FFR, no problems with any steering issues from day one. I have SN95 spindles with stock p/s rack (love it), stock rack bushings, bump steer tie rod ends, 4¼° caster, 2¼° camber and 1/16" total toe. Also running IRS with 2¼° camber and 1/16" total toe. Koni adjustable shocks on all corners and 450# front and 550# rear springs. Sway bars front and rear.

Before having the sway bars, I noticed a little push in the corners. I'd take that over being lose anyday. Once the bars were on, the car was much better in the corners. Push subsided and I could feel the cars reaction better. When the Koni's went on, a whole different thing happened. It became one fun car to drive!

I have never experienced the "bump steer" issues others claim to have. I don't even run the quad shocks. I spent the better part of last year getting my suspension to my liking. That doesn't mean it was no good, it just needed some "tweaking" for me. I don't know where someone thinks the upper joint is in front of the lower and the posted picture proves this point. We should remember we are dealing with a short wheel based car with a narrow track as well. That in itself will give you a ride if you're not careful.

In a perfect suspension setup, all the axis would rotate and pivot on the same plane but I don't think we want to spend that kind of time and effort just to get that when the car will perform just fine. The one thing that will help steering issues on these is to try your best to keep the pivot range of the tie rod the same as the lower control arm. This will keep the wheel from turning in or out during cornering or hitting those little bumps.

I suggest those who are having problems, tackle one item at a time. Once you start to "shotgun" the problem, you'll never know exactly what the problem was or what it took to solve it.

Klayfish,
I suggest you run a little more caster and camber. Maybe 3-4° caster and at least 1½° camber with 1/8" toe.

Excaliber · #37 (**permalink**) 05-24-2003, 02:14 PM

3 or 4 castor will be to much without power steering, will be hard to turn at 4 or higher for sure.

Ernie

weendoggy · #38 (**permalink**) 05-24-2003, 02:37 PM

With the rack Klayfish is using, 3-4° caster shouldn't be a problem. He has more turning to get the job done.

bwana50 · #39 (**permalink**) 05-25-2003, 08:00 AM

I think Mr Bruce is talking more about the FFR adapter bracket itself, right? Solely based on that, he's right: pass a rod through the upper ball joint hole, and it passes forward of the lower ball joint hole. The spinde also angles the bracket forward, as viewed from above (see GatorAC's picture).

However, that's moot once the car is properly aligned: a line drawn through the upper and lower ball joints to the ground falls forward of a line drawn vertically to the ground through the spindle - that's positive caster. The relative angles of the ball joint studs are irrelevent (up to the limit of their travel) because they can pivot in any direction.

IMO, the reason for the angle on the upper ball joint is the original Mustang geometry: strut. The upper pivot in that case is the top of the strut tower. Let's assume that both an FFR and a Mustang use 3 degrees positive caster. Viewed from the side, the FFR upper pivot (ball joint) at ~10" above the lower ball joint is indeed farther forward than the Mustang upper pivot (strut tower) at ~24" above the lower ball joint - but the caster angle is identical, and in both cases the line to the ground falls forward of the axle centerline to the ground. So, Ford had to move the spindle-to-strut attachment point as far forward as possible to keep that angle to the top of the strut.

Clear as mud, right?

mr bruce · #40 (**permalink**) 05-25-2003, 08:10 AM

Bwanna, now you see what I mean. Now take a look on the autocross forum. The thread is about the Atwater event. Dave B is lowering the upper balljoint adapter. Effectively turning the spindle into a Mustang 11 height spindle(?)Then ,when you roll the top of the spindle back to get you desired caster, the steering arm is on an angle relative to the ground.Ideally ,you would want the steering arm(where the tie rod end bolts on) level with the ground ,No?