Mustang performance handbook 2

[brsvo]

I got a copy from my library and started reading. I found things I would never have thought of. The part about drilling a new hole in the rear end lower control arm bracket got me thinking. Does this make a big difference?
I read somewhere else that using Global West lower control arms you shouldn't run a panhard bar only a watts link? I am redoing my suspension this off season and want a panhard or watts link. The panhard is cheaper and supposedly gives a better roll center than the watts link?
One other thing I read in here is to mill 1/4 inch off the back of the rack to gain some Ackerman steering. This too I have never heard of.
All kinds of ideas I am up for more if you have any.
Well back to reading, Bruce

[Raven855]

The Mustang performance handbook is some interesting reading. You really need to look at the entire package to evaluate what you are doing. In many cases M&Ms grip package is a better way to go. Jack has put together some well thought out stuff.

In the case of the rack bushings, many of the bushings available are thinner on the back and do the same thing as milling the rack. You could still mill the rack base for more ackermann if you like, but ackermann and a foxbody are a strange beast. If you want some interesting reading on fox body ackermann go on over to corner carvers. Ask your questions here though and we probably can help you out. It is not for the faint of heart over there.

What are you thinking of doing Bruce?

[brsvo]

My front end is stock 166K except for the H&R sports and a modded swaybar link. I want to go through the front end (new bushings and ball joints for the stock arms) and re do the rear.
I have tubular arms in the back . I installed spherical bearings in the frame end of lower arms but the poly is shot in the bottom. The uppers have poly in the top with rubber in the axel housing. I would like to get a panhard bar and redo my poly that's shot. Plus the new hole in the rear end bracket. Also I will do a bumpsteer check as my car hunts over bumps.
I used to go on CCer's but I can't find my way on any more. I know they got sick of repeating themselves a long time ago. I wanted to be a member but they never replied to my membership requests.

[Bob Holmes]

Poly sucks, and shouldn't be used with stock arms and a panhard at all. The triangulated four link that the Mustang uses requires the deflection in order to not have excessive "stiction." Adding poly and a panhard (which creates a five link that will bind) makes matters worse. However, if you go to a torque arm, everything works together. The three-link requires the panhard for side to side location of the axle. As an aside, we've found that poly is a constant replacement wear item on the racing cars. We don't run it on the street.

Stock front a-arms do not have replaceable ball joints. I know that at various times, members have set up for a run of machining stock arms for a ball joint replacement, you'll need to check around. I ended up changing to late Cobra a-arms, but I think it needs some tuning for bump.

[brsvo]

If I were to get spherical uppers with rubber in the axel can I run the spherical frame and poly in the axel of the lower with a panhard bar? I still have the springs on control arms and need the arms upright. I don't want to go torque arm for ground clearance and spring location and then frame re enforcement required to go with them.

[svono50]

I would think that spherical ends on the chassis side should eliminate most of the bind, but not sure if it 100% eliminates it up top. Now, I say that with chassis/axle polys lower and poly axle side/roto-joint (i.e.- spherical) chassis side uppers in mine. So far I have not found any snap oversteer due to bind in my combination combined with the watts link, handling is pretty darn neutral on the road and auto-x courses. I would have to think that spherical units on both ends would be best on the upper arms with some form of lateral locating device.

Bob, interesting on your experience with the poly units on the racing cars, but you are likely putting them under a lot more stress than street cars. I modified all my poly bushings to give a good path for the grease zerks I added on all of them. I hit them 2x per year with Marine grade grease and they have lasted 20 years/50,000 miles so far with no discernible wear.

[Laredo]

Do NOT use poly or spherical arms with the stock arm set-up and a panhard. There is a significant arc in the arms that are not all congruent with each other (which is why the joints have to flex) as the suspension travels. If you make these joints solid (or stiffer) and then throw in another non-consistent arc with the addition of a solid jointed panhard, it’ll bind. A Watts link is different, it eliminates the arc motion that you get with the suspension travel of a panhard.

If you’re going to install a panhard, leave the stock “soft”control arms, or…go with the torque arm.

I am personally not crazy about the poly joints for street use. Too much harshness and road noise.

[Bob Holmes]

The first thing you should do is put full sub-frame connectors on the car. The very necessary stiffness added to the car makes everything work better, and may eliminate the likelihood of unibody cracks that show up under the rear seat.

[brsvo]

Just to clarify my car has had Kenny brown sub-frame connectors with the seat braces for about 10 years. It also has a Flaming River steering shaft. The rear control arms as stated above and I removed the quad shocks.
I talked with Jim Fays at Fays2 watts link and he told me he is working on a 3 link rear for our cars. I also found out he is in WI and will deliver to my door his product. Watts link would eliminate the arc problem. A lot more involved than a pan hard bar though.

http://fays2.net/fays2_watts_link_17_.html

[SVOC]

Like everyone else has said poly is bad!

But on another note, let"s talk "Quadra Bind" yes get rid of the quadra shocks, AND if your going to go with a pan hard bar, do one upper spherical and ditch the other upper arm for better articulation.

I have found the rod ends on the MM pan hard bar just plain wear out too quickly.

So if your going to go full tilt, then go torque arm (Griggs) and a Watts link.

BTW you don't have to get crazy exotic to get fantastic handling results, I have a SPEC series package that develops 1.3g in the corners.


(damp track)


http://youtu.be/SzhBTL4r0yo

[brsvo]

What is a SPEC series package? I am not going full tilt, just trying to improve on stock while rebuilding the suspension. Mostly street use so torque arm ground clearance is not acceptable in my mind. Are you are saying run just one upper arm?

[SVOC]

LMAO, this SPEC package is so low tech compaired to what every one here is talking about, main part of it is the FRPP "C" spring, the rest of it is mixing and matching factory Ford parts.

And it uses a DOT tire, Dunlop Drezza II

[Bob Holmes]

Ahhhh, the poor man's three link. If you are going to use the single stock upper link, I would suggest that you reinforce the attachments on the unibody. There are a number of "battle box" solutions sold on drag racing vendor sites.

IF I recall (which is pretty iffeee for me) the book you are reading discusses the poor man's three link.

[brsvo]

Has anyone done the lower control arm mount hole relocation?

[J. Caraco]

If you mean the "anti-squat" brackets, yes. I made them and had em' welded up/on the car years ago. Does plant the rear end nicely, did lose some ground clearance. I have different LC arms can't remember which ones now. Either MM or Global West. One was too noisy with the spherical bearing at the chassis end. I have the heavy duty uppers, Steeda with rubber bushings. No quad shocks.

[Laredo]

...AND if your going to go with a pan hard bar, do one upper spherical and ditch the other upper arm for better articulation.



Ahhhh, the poor man's three link. If you are going to use the single stock upper link, I would suggest that you reinforce the attachments on the unibody. There are a number of "battle box" solutions sold on drag racing vendor sites....

Hmmm...had not hear of this. Might have to look into.

[brsvo]

J.Caraco you speak of did loose some ground clearance. Do your lower arms have adjustable spring perch's? My car is low enough now but I ordered the KB anti squat brackets today and am thinking of these http://www.steeda.com/steeda-mustang-adjustable-lower-control-arms-555-4414/ with the watt's link from above.

[Raven855]

The ground clearance he lost was from the antisquat brackets. The brackets extend the attachment point on the rearend down quite a bit towards the ground. There are several bracket modifications in the book and the road racing one really lower the attachment point. I imagine that if he has gone the route of watts and torque arm that he has coilovers.

[J. Caraco]

LCA's do not have adj. spring perches. I still have factory springs in back. HAL strut/shock frt/rear. Front have coil over spring's, I think 250 lbs, No name CC plates.

[MikeFleming]

Front have coil over spring's, I think 250 lbs, No name CC plates. That sounds awfully light for front CO spring rates.

[J. Caraco]

I know I had 10" 350 and replaced as I felt they were to much. I have new 12" 275 in my basement. I think the 12" to long as the lower perch won't clear the wheel/tire (245/40-17 on 8" wide SN 95 style wheel). Can't check it now as car still at the shop waiting for the engine rebuilt to be complete. 18 weeks and still counting. It's killing me!!! and now it's SNOWING!!!!!!!!!!!!!!!!!!!!! May 10" 275??

[brsvo]

The other mod in the book is to elongate the holes in the front struts 1/4 inch to move the strut closer to the spindle. (and tire) Improving scrub radius. Is this a good mod on our Koni's? With 245/40 17's I wonder about clearance. If they don't clear I guess I can always tighten them in the stock location.

[MikeFleming]

That will increase negative camber while reducing tyre to strut body clearance.

[Raven855]

If you are looking for a little additional space between the tire and the strut, the 8" Coilovers place the spring perch above the tires so there is no rubbing on the spring. It gave me an additional 1/2-3/4" of clearance.

[brsvo]

I am not going the coil over route. So I don't really need this mod? With caster camber plates can't you get enough negative camber without this?

[brsvo]

I am installing the anti squat brackets and already am lowered enough. I am thinking of getting adjustable length arms or adjustable spring perches on my lowers to compensate. If I get the adjustable length I figure to make them longer and keep the same ride height. Will this keep the anti squat working or is the pinion angle change part of the anti squat equation? I maybe off with this as making the arm longer still won't keep the spring up will it?

[Raven855]

I am not familiar with the KB brackets. How much do they lower the attachment point? You may want to readjust the pinion angle but I have some confusion on what you finially did with the top arms. Since you are not doing coilovers, and you want to keep the ride height, adjustable spring perches is the way to go. You could play with different thickness spring pads but the adjustable perches are a better solution.

To better answer your question think of the triangulation that is done with the lower attachment point, the body attachment point and the mean angle formed at the top attachment point when viewed from the side. Don't forget to imagine the pinion relationship and spring perch on the lower arm also. Anything you do will affect the pinion angle and the ride height. Springs, attachment points, adjust length upper and lower arms, a torque arm, or spring perches will all make the suspension work differently. Some mods more and some less. But remember the big lessons like the fox body is a limp weak wet noodle and the rear suspension design is atrocious from a good handling point of view. Don't overthink what you can accomplish with the stock suspension. You can only make small improvements with the stock designs. Put your brackets on, put on a k member 4 point brace and go have have fun with it. If you want to play with the ride height in back put on some lower arms with the adjustable spring perches. Might get a set that will work with a future suspension and beef up the body attachment points but save your money at that point.

[Jack Hidley]

The pinion angle has nothing to do with the amount of antisquat or has any affect on traction whatsoever. Having the relationship between the pinion angle and driveline angle set incorrectly, will result in driveline vibration and reduce the efficiency of the driveline. The pinion angle by itself is completely meaningless.

The angle of the RLCA in the side view is one of the factors that determines the amount of antisquat. By RLCA, we mean the link which is a line drawn between the center of the front RLCA pivot bolt and the center of the rear RLCA pivot bolt. The shape of the RLCA has nothing to do with anything. Only the angle of the line mentioned affects the dynamics of the suspension. In general I would set the combination of ride height and RLCA position in the AS brackets, so that this line is level. Don't adjust things so this line is uphill when looking forward. This will result in roll oversteer, which makes it easy to spin the car. This would be ok for a drag race setup, but not normal street driving.

[Under Pressure]

Thanks that's good information I'll keep in my book. Rick

[brsvo]

OK Jack now I'm confused. It seams the line of the RLCA is already uphill and using the anti squat brackets will make it more uphill. (side view) I thought this was going to move the instant center further back and improve squat and dive while giving more traction for corner exit. Thanks for answering my question about the pinion angle as this too will change with the AS brackets.

[Raven855]

The pinion angle has nothing to do with the amount of antisquat or has any affect on traction whatsoever.
Bruce, I hope I didn't give you the impression that the pinion angle would affect antisquat. There had been talk of adjustable upper and lower arms, spring perches, different shocks and different suspension types and I was simply trying to make you aware of something else to consider.


Having the relationship between the pinion angle and driveline angle set incorrectly, will result in driveline vibration and reduce the efficiency of the driveline.
This is why I brought this up and kept it in a separate paragraph and not even mention antisquat or lower control arm angle there. Unfortunately I also restated it in the second paragraph.

It can be challenging trying to visualize all of the angles that are formed with the suspension and attachment points. Sorry to add to the confusion.


In general I would set the combination of ride height and RLCA position in the AS brackets, so that this line is level. Don't adjust things so this line is uphill when looking forward.

OK Jack now I'm confused. It seams the line of the RLCA is already uphill and using the anti squat brackets will make it more uphill. (side view) I thought this was going to move the instant center further back and improve squat and dive while giving more traction for corner exit.
Jack's explanation is 180 degrees out from what Mathis shows in the book and his answer does create some confusion. I hope he will answer it for you, but I find his answer more confusing than mine.

[brsvo]

Changing the control arm pickup point will change the pinion angle unless the upper arms are shortened or the lowers lengthened. I knew from the book that the control arm angle change was to move instant center. I have heard drag racers talk of changing pinion angles but didn't know why. Maybe the same reasons just a different way of looking at or describing things.