cortex watts link

[Rabee]

As said earlier, I think it is a matter of driver confidence that created the name for the watts links, may be it will get better lap times due to pushing the car harder? May be, may be not. No data to dissect. I will be buying one though

 

[Pentalab]

I wouldn't exactly categorize those observations as handling deficiencies as long as they don't 'overshoot', bobble around, or otherwise bring on directional stability or tire grip issues that would be.


Brakes I'll give you, at least as far as performance driving is concerned. But the lack of camber adjustment is more a tuning limitation than a handling deficiency. The factory preferred camber of -0.75° is the deficiency. There's a difference.


Have you ever driven a stock-suspended Fox/SN95 or a RWD GM Intermediate in anger? The differences are hard to miss.


That's just sloppy assembly, with some cars coming off the production line closer to symmetrical or otherwise better off than others. My car had and still has no rear axle centering issues, and the front cambers were less than 0.1° different . . . at a little over -1.7°.



The height at the midpoint of the bar. I measured to the bolt centers of the axle and chassis side pivots with the car weight fully on the ground and divided by two to get just under 11-7/8". That's pretty close to the as-loaded axle center height (half of ~27" tall tires minus tire compression under load. That 11-7/8" will drop another 3/16" or so (stock springs) when the guy measuring all that stuff crawls out from under the car and gets in the driver seat.

For the PHB to be well above axle height only exists under droop to the point that the rear tires would not be carrying much load or carrying none at all because it is up on a 2-post lift. Only the PHB brace is well up there all of the time with the car fully resting on its tires . . .


When you did all that stuff but the last, you altered the rear suspension roll steer geometry, making it better for your launch more by accident than by your own intent. The last item added rear roll stiffness, which mostly works to offset driveshaft torque unweighting the RR and planting the LR a little harder. As a secondary effect, it reduces roll by a small amount, which ultimately reduces the amount the rear axle steers.

Theoretically, rear squat with a PHB and LCAs that are skewed in plan view will produce a finite amount of axle steer, but this effect is so tiny as to be below the level of human perception and lost in the "noise" from OE LCA bushing distortions.


Norm

Factory spec for camber is -1 deg to -1.5 deg. Nothing is stated that they both have to be the same either. IE: local ford dealer tells me that as long as either wheel is withing those specs..it's .."within spec". If you see -1.7 on both fronts..it's out of spec. You will also eat your front tires..esp with a staggered steup, where you can't rotate front to back. I installed the steeda front adjustable struts....and set em both to -1 deg. That's a good compromise between tire wear and handling..esp for my staggered 255-40-18 front and 285-40-18 rears. (nitto-555). (9" front rims..and 10" wide rear rims).

At the last 3 x stang car shows I went to..plus checking out stangs at local monthly meetings...I have yet to find one that has the axle centered. It's blatantly obvious with wider tires. And this is on 05-14 GT cars, Roush cars, and 07-14 GT-500 cars. The axle is always .5" to .75" towards the driver's side.

As per oem stock suspension..it's junk, plane and simple. Front end nose diving and back end lifting when u stand on the brakes is fubar. No wonder the front brakes get beat up so much. I saw a recent auto cross video..whereby the last 200' the cars are floored..then a row of cones across the end. You stand on the brakes at the end of the run. You shoulda seen the HUGE gap between the top of the rear tire and wheel well. I couldn't believe it..and replayed it several times. ( stock 2012 GT car). The bone stock suspension doesn't work on the street....so why even mess with it on any track?

I lowered mine 1" front + back. When the LT's went in... I used new steeda eng mounts..which allow for a 0-.25-.5-.75" eng drop. I dropped the eng and tranny .25". This was more to allow some wiggle room between my steeda front STB and my air intake tube. ( roush blower).

Jimbo

 

[jmauld]

I'm running just over -2 degrees of front camber, and notice no abnormal tire wear. If my camber plates would let me adjust it to -2.5, I would.

Can you guys give your thoughts on where the rear roll center should be set, to improve handling?

 

[Pentalab]

Actually, the S197's PHB tends to load the driver side tire more than the passenger side tire because the PHB's axle-side attachment is on the driver side.



As noted in my preceding post, the rear sta-bar uses the engine torque reaction to re-plant the RR tire that gets unloaded under acceleration.


Norm

Huh? If you look at JDM's 2 x pix... ( 1st pix).. you can clearly see that the pass side front is barely off the ground, but the drivers side front is a mile off the ground. The eng is lifting on the drivers side, torquing the entire body towards the pass side. All the weight is being transferred to the pass rear. (RR). You don't want that effect when drag racing....and you sure as heck don't want that effect when road racing. IE: go around a right / left hand sweeper...and stomp on the gas when you get to the apex of the turn.... the last thing you want is to transfer weight to the RR. This is when the eaton tru trac really shines.... it will transfer TQ to the wheel with the least traction, usually the outside...so you can power out of the corner.

IMO, it doesn't help matter's any...when the oem PHB causes the axle to be off towards the driver's side by .5" to .75" inch to begin with. You naysayer's out there with the oem PHB setup are in for a rude awakening when you switch to a WL-watts link. For folks who are contemplating the WL-griggs-cortex watts link setup, I'd suggest changing the rear differential + any rear gear..... all at the same time. Going from the oem PHB /oem differential / oem 3.31 /3.55 rear gear.....to a watts link + tru-trac + 3.73 is a night and day difference.

Jimbo

 

[SoundGuyDave]

Quote:
Originally Posted by Norm Peterson

Actually, the S197's PHB tends to load the driver side tire more than the passenger side tire because the PHB's axle-side attachment is on the driver side.



As noted in my preceding post, the rear sta-bar uses the engine torque reaction to re-plant the RR tire that gets unloaded under acceleration.


Norm

Huh? If you look at JDM's 2 x pix... ( 1st pix).. you can clearly see that the pass side front is barely off the ground, but the drivers side front is a mile off the ground. The eng is lifting on the drivers side, torquing the entire body towards the pass side. All the weight is being transferred to the pass rear. (RR). You don't want that effect when drag racing....and you sure as heck don't want that effect when road racing. IE: go around a right / left hand sweeper...and stomp on the gas when you get to the apex of the turn.... the last thing you want is to transfer weight to the RR. This is when the eaton tru trac really shines.... it will transfer TQ to the wheel with the least traction, usually the outside...so you can power out of the corner.

Reread what Norm posted, Jimbo. He never said that on a drag launch the LR tire was loaded. What he DID say was that "... the S197's PHB tends to load the driver side tire more than the passenger side tire because the PHB's axle-side attachment is on the driver side." Think that statement through. The PHB is what is being discussed, and if you think in terms of force vectors, you have one end pushing into the axle (at the driver's side) and one end pushing into the frame (at the passenger side). The axle side can't go up, so the force tends to be directed into the tire, thus the "loading" part of his statement. Realize, though, that the forces he's talking about are relatively insignificant, and not a good soap-box to climb onto to preach the miracle of the Watts Link.

IMO, it doesn't help matter's any...when the oem PHB causes the axle to be off towards the driver's side by .5" to .75" inch to begin with.

So? If anything, that would be a thrust-angle alignment issue. Also, realize that the body is NOT necessarily square on the chassis. Does it look ugly? Yes. Is it functional? Yes. Would centering the axle within the confines of the sheetmetal be more aesthetically pleasing? Yes. Could that screw up a perfectly good 0* thrust-angle? Yes. It's been FAR too long since I had any stock componentry under the rear of my car for me to remember how the alignment angles and "axle offset" played together, but I can certify that with an adjustable upper, adjustable lowers, and an adjustable PHB, my pinion angle is perfect (no driveline vibrations with an aluminum shaft at speeds under 130mph) my axle is perfectly centered under the chassis, AND has a 0.05* thrust angle. I gave up on the last little bit after barking my knuckles one too many times on the edge of the alignment rack. There's a lot more suspension geometry going on than I think you realize.

You naysayer's out there with the oem PHB setup are in for a rude awakening when you switch to a WL-watts link.

Or a proper rod-ended adjustable PHB. Absent the roll center relocation, it does the same thing, +/- 0.100". At a fraction of the cost. Remember that there's more than one way to skin a cat.

For folks who are contemplating the WL-griggs-cortex watts link setup, I'd suggest changing the rear differential + any rear gear..... all at the same time. Going from the oem PHB /oem differential / oem 3.31 /3.55 rear gear.....to a watts link + tru-trac + 3.73 is a night and day difference.

I can't argue with that. You're going from OEM high-mileage-life, low NVH, softly bushed hardware that is designed for the 50th percentile user, and replacing it all with tight-tolerance high-performance equipment that offers a MUCH higher torque multiplication to the axle. All you need for that is $1000 for the Watts kit, $500-800 for the differential, $200 for the ring and pinion set, $100 for the master installation kit (seals, bearings, shims, etc.), another $75 in fluids and RTV, and around $1500 in labor.

 

[Whiskey11]

Factory spec for camber is -1 deg to -1.5 deg. Nothing is stated that they both have to be the same either. IE: local ford dealer tells me that as long as either wheel is withing those specs..it's .."within spec". If you see -1.7 on both fronts..it's out of spec. You will also eat your front tires..esp with a staggered steup, where you can't rotate front to back. I installed the steeda front adjustable struts....and set em both to -1 deg. That's a good compromise between tire wear and handling..esp for my staggered 255-40-18 front and 285-40-18 rears. (nitto-555). (9" front rims..and 10" wide rear rims).

Jimbo

There is a lot more to tire wear on these cars than camber angle in and of itself. I've seen cars with -0.5º of camber eat the inside shoulders of tires faster than cars with -3.0º of camber. Toe angle is HUGE as is scrub radius. Combine a toe value with large scrub radii and tire life suffers even quicker.

I daily drove a set of 200 treadwear, 245/45/18 Dunlop Direzza Z1 Sport Star Specs (mouthful...) at -1.7º of camber for 12k miles and the inside shoulders looked pristine when I flipped them on the rims. The outside shoulder took a beating because -1.7º of camber on a softly sprung vehicle is nowhere near enough camber for autocross duty. At the time I had ZERO toe. I also drove my car for 500 miles during Nationals with -3.0º camber, -0.10º toe out and +7.0º Caster and the insides definitely look better than the outsides. Hell, they still have the nubbies on the shoulder blocks. I also daily drove that setup with -1.5º camber and zero toe and never had any issue with tire wear.

The biggest killer of tires is toe settings. Large toe angles (in or out) will wear tires out insanely quick, way way way way way way waaaaay faster than high camber settings. In order to really see camber wear on the S197 over a long period of time you'll have to drive essentially straight at -3.0º or more camber and constantly be engaging the ABS (which will cause the tires to skid along the inside of the tire). Staggering tires will certainly shorten life because you can't rotate tires.

 

[Norm Peterson]

In the 1/4 mile your 60' time lowering on Average of half a tenth or .05 is alot!

I'm not questioning the competition value of 0.050 better 60' times and certainly not the driver's experience. I am familiar with the approximate 2:1 relation between improvements in 60' time and ET.

What I am interested in is identifying specifically the effect(s) made that happen, and isolate it/them from anything else that might have been going on. Swapping to a Watts link is the 'what'; I'm looking for the 'how' and the 'why'.

Your example has about a 3% time improvement, which as a crude first-cut approximation means a 6% improvement in acceleration over that time. Of course it's significant. Those percentages only increase as the 60' times themselves decrease.


If you're wondering why somebody oriented to corner-carving is interested in this level of drag racing detail, consider that autocross is also a standing-start competition. The difference is sort of like having 10 - 20 feet between pre-stage and stage instead of only a few inches (and the pre-stage light must remain lit until you get the green, not that you'd want to give away any acceleration distance before the start light).


Norm

 

[Gray Ghost GT]

Factory spec for camber is -1 deg to -1.5 deg. Nothing is stated that they both have to be the same either. IE: local ford dealer tells me that as long as either wheel is withing those specs..it's .."within spec". If you see -1.7 on both fronts..it's out of spec.

Road surfaces are built with a crown to help rain run off, which is why the Ford dealership said its "out of spec" if you have the same camber specs on the left and right side to keep the car driving straight with a high point being on the left side of the road. However, having the same negative camber specs on the left and right is ideal for the road courses. I've run -1.5 on both the left and right on my daily driver that goes to the road courses with no issues because toe angle is another factor and I have 275/40-18s at all four corners allowing me to rotate the tires to minimize excessive wear over time.

 

[dontlifttoshift]

Ultimate test would have been to install the watts link on the car at the track same day, same conditions, same driver, etc..

There was the answer to the rest of my question. Thank you.

 

[Sky Render]

You know, I'm starting to consider that weld-in adjustable Steeda bar that's been mentioned by myself and others in this thread several times. The rod-ends eliminate deflection, and the adjustability allows change in roll-center height. The only disadvantages I can think of are increased NVH (which shouldn't be much based on my previous experiences with rod-end PHBs), requiring professional installation (I don't weld), and the fact that the cutting/welding required means the car cannot be returned to stock.

Anyone have any opinions on this piece?

 

[Pentalab]

I can't argue with that. You're going from OEM high-mileage-life, low NVH, softly bushed hardware that is designed for the 50th percentile user, and replacing it all with tight-tolerance high-performance equipment that offers a MUCH higher torque multiplication to the axle. All you need for that is $1000 for the Watts kit, $500-800 for the differential, $200 for the ring and pinion set, $100 for the master installation kit (seals, bearings, shims, etc.), another $75 in fluids and RTV, and around $1500 in labor.

My problem with mustangs is....they are not built right to begin with..hence why we have to mod the crap out of them! Installing a 3.73 gear vs a 3.31 /3.55 on the ford assembly line would have cost em... nothing. An adjustable PHB vs oem junk woulda cost em a few $ more. If ford was on the ball, they coulda offered a watts link as an option.

The small difference in price between the failure prone, semi useless oem traction lok differential vs an eaton tru-trac is well worth it. $200 more for a differential..that actually works..and is maintenance free.

The oem 2 piece DS is another abortion. Check out what your local dealer wants for a replacement...aprx $1200+. I installed a DSS-DS.... one piece DS. It has a CV joint at axle end, 3.5" diam main shaft, 900 hp rated. With the CV joint, pinion angle is not critical at all. Zero vibration at 150 mph on the dyno in 4th gear @ 6 krpm...with a 3.31 rear gear. Why ford is using a 2 piece steel clunker....with cxr bearing is beyond me.

Baffles me why Ford doesn't either (A) build em right to begin with..or (B) offer some of this stuff as an option. I see that ford offers the Torsen as an option on the 13-14 GT-500's....and folks buy it. Why Ford used a long gone obsolete M-122 blower from 07-12 on the GT-500 is another one. The TVS-2300 blower was used by Roush back in 08. Ford finally figures it out in the 13-14 GT-500's...along with a CF DS. The De-gas bottle is still way too small in the 07-14 cars.

Fast forward to the 2015 mustang. Now has IRS. Since it's now a world wide platform car...and knowing that Europeans etc won't buy a solid axle car with fubar PHB setup, they switched to the real deal.

OK, back to the main issue. Take a good look at the JDM pix #1..with oem phb. LF is a mile off the ground vs the RF. Pix #2 has em both the same distance above the ground. What happened ?

Jimbo

 

[Norm Peterson]

Factory spec for camber is -1 deg to -1.5 deg. Nothing is stated that they both have to be the same either. IE: local ford dealer tells me that as long as either wheel is withing those specs..it's .."within spec".

Actually, the preferred camber is -0.75° with the acceptable range being from 0.0° up to -1.5°.

Yes, I knew my cambers were out of spec. I also know enough about my driving to realize that that was a far better place for me to be starting out with in this car even for pure street driving than if I'd brought it in for Ford-approved camber correction back to -0.75°. The proof is in the pudding - I'm getting nearly dead-even wear other than a tiny bit of OUTSIDE shoulder wear from a couple of autocrosses and track days. One of my other cars is sitting with front cambers out toward -2.3° and they aren't getting all chewed up on the inside shoulders either. You'll have to take my word for this unless I get motivated enough to post pictures of a Mazda in a Mustang thread.

If you see -1.7 on both fronts..it's out of spec. You will also eat your front tires

I've got 12,000 - 15,000 miles on these tires, 240 treadwear Goodyear Asymmetrics, and they've been rotated a couple of times. They are only about 45% worn, and there is less than 1/32" difference in tread depth between inside and outside shoulder regions. The two rear tires are in the same condition. I went out a few minute ago to thake these pictures and make the necessary measurements especially for this post. Care to re-think your concern?

Actually, the cambers after I installed my Konis ended up closer to -1.8°, but who's counting hundredths here anyway.

As per oem stock suspension..it's junk, plane and simple. Front end nose diving and back end lifting when u stand on the brakes is fubar. No wonder the front brakes get beat up so much. I saw a recent auto cross video..whereby the last 200' the cars are floored..then a row of cones across the end. You stand on the brakes at the end of the run. You shoulda seen the HUGE gap between the top of the rear tire and wheel well. I couldn't believe it..and replayed it several times. ( stock 2012 GT car). The bone stock suspension doesn't work on the street....so why even mess with it on any track?

You're letting the wrong things bother you and you are jumping to the wrong conclusions. Believe me, I know all about nose dive and tail rise. This picture was taken at what they called "Speed-Stop-Squared", I'm still on the OE springs, and I'm holding the brakes just out of ABS. From inside the car it really is not as big a deal as you seem to think from only seeing it from the outside. Nowhere near "fubar". You're welcome to ride shotgun and I'll nail the brakes and demonstrate the lack of drama for you. Anytime.

Norm

 

[Pentalab]

I just thought of something. I don't believe you can use jack stands on the axles, IF a Fays2 or steeda Watts link is used. Zero issues if a WL watts link is used.
That could be a deal breaker in some cases.

Jimbo

 

[Sam Strano]

I just thought of something. I don't believe you can use jack stands on the axles, IF a Fays2 or steeda Watts link is used. Zero issues if a WL watts link is used.
That could be a deal breaker in some cases.

Jimbo

That is not true.

 

[Conekiller]

You can use jack stands just fine there with a fays2 installed, done it a few times.

 

[Sam Strano]

I think it's pretty silly to opt to run a Watts link then get one that is mounted in single shear (and there have been issues with that), and/or with bushings at the 4 ends of the two arms. Each of those bushings has some deflection, the more the car is pushed the more they flex and deflect. Yes the basic geometry is improved, but you've also added in two more bushings to deflect vs. stock.

 

[Norm Peterson]

Huh? If you look at JDM's 2 x pix... ( 1st pix).. you can clearly see that the pass side front is barely off the ground, but the drivers side front is a mile off the ground. The eng is lifting on the drivers side, torquing the entire body towards the pass side. All the weight is being transferred to the pass rear. (RR).

Like I said before (I think), that's only half of the story, usually the "little half" unless you're wheelstanding.

You don't want that effect when drag racing

You abso-damn-lutely do. Driveshaft torque unloads the right rear and transfers that much load onto the left rear. Ever wonder why cars with "one-legger" diffs almost always spin the right rear" It's this.

There is no better solution than to use engine torque reaction to lift some of that transferred load off the left rear and put it back on the right rear where it belongs. In fact, there isn't reasonably (or racing-legally) any other way to make that happen.

When you put a huge rear antiroll bar back there, it attracts a large amount of the engine torque reaction back there. That is where the forces go. But due to its large stiffness, you don't see the same amount of roll. Since you can't see the stiffness, there may appear to be a disconnect between how the body moves and where the loads keeping it from rolling even more are ending up.

....and you sure as heck don't want that effect when road racing. IE: go around a right / left hand sweeper...and stomp on the gas when you get to the apex of the turn....

Aside from the fact that stomping on the gas at the apex suggests agricultural (re?)familiarity in your immediate future, there isn't much you can do about this except with some sort of limited slip or torque sensing differential. Or a locker (like NASCAR) or a spool (I think the Porsche 917s in Can-Am) - if and only if you're willing to learn a whole other way to drive the corners and tune the handling. Right turns and lefts respond a little differently, and this asymmetry is there because the driveshaft can only rotate in one direction as long as you're driving in a forward gear (over-simplified, but see driveshaft effects, above, and add that to the lateral load transfer effects of cornering).

the last thing you want is to transfer weight to the RR. This is when the eaton tru trac really shines.... it will transfer TQ to the wheel with the least traction, usually the outside...so you can power out of the corner.

????

IMO, it doesn't help matter's any...when the oem PHB causes the axle to be off towards the driver's side by .5" to .75" inch to begin with.

That cannot possibly be proved geometrically, and I tend to doubt that there is enough bushing compression being released or added to make that much happen either. I suppose that I could toss 300 lbs of barbell plates in my '08's trunk and measure it for myself, but that probably won't be happening today.

Nobody is saying that the Watts link isn't any good here. If there are any naysayers, it's those trying to describe the PHB as "complete junk" without having the tools to give it a proper evaluation.


Norm

 

[sheizasosay]

This is hilarious!

 

[Pentalab]

You're letting the wrong things bother you and you are jumping to the wrong conclusions. Believe me, I know all about nose dive and tail rise. This picture was taken at what they called "Speed-Stop-Squared", I'm still on the OE springs, and I'm holding the brakes just out of ABS. From inside the car it really is not as big a deal as you seem to think from only seeing it from the outside. Nowhere near "fubar". You're welcome to ride shotgun and I'll nail the brakes and demonstrate the lack of drama for you. Anytime.

Norm

No wonder your front brakes are getting a work out ! That back end rise is unacceptable imo, you can stuff a log in there. You have oem springs and stock ride height...that's why. I can just see myself flying down the hwy, then having to slam on the brakes and swerving hard to the left/right...or same deal on an on/off ramp, twisty bit etc. We get a lot of deer etc on our roads.

The LAST thing I want or need is the back end going sky high..while flying around corners. So yeah, the oem springs ARE fubar. Throw in some rain, or going down hill..and now you have a real mess on your hands.

Mine is lowered 1" front + back with the Roush street/race suspension kit,..springs/shocks /F+R sway bars etc, etc. (I use the middle holes on the BMR LCA relocate brackets). Slam on the brakes...and front end doesn't nose dive any more. Back end doesn't lift either. It essentially brakes flat. If I sit on top of either front wheel well, it doesn't deflect. It's stiff. Front + rear stb's, rear BMR tunnel brace, a pair of welded in steeda triangular sub frame connector's..and a BMR A arm brace.... + a pair of steeda front sway bar mount braces complete the stiffening. ( it already came with the Ford K arm brace)

Of course with the car lowered 1", the oem LCA's are at the wrong angle. With the oem PHB in there, the axle was shifted 3/4" to the driver's side. End result was... the oem LCA's were trashed, they are being bent over 3/4" towards the driver's side. Fix for that was BMR UCA + uca mount, BMR lca's and BMR lca relocate brackets...+ the BMR adjustable PHB + brace. Problems solved. No more back end wobbling about at the top end of 2nd gear. I got my traction back..and then some.

BMR adjustable PHB + brace were later replaced with the WL watts link + eaton tru-trac. The difference between bone stock when car 1st purchased....and after all the above myriad of mods is literally like night and day. The oem suspension is dangerous imo.

Re: tru-trac. brain fade on my part. TQ gets transferred to the wheel with the MOST traction. The oem diff belongs in the nearest dumpster...along with the oem suspension+ DS.

Jimbo

 

[NoTicket]

No wonder your front brakes are getting a work out ! That back end rise is unacceptable imo, you can stuff a log in there. You have oem springs and stock ride height...that's why. I can just see myself flying down the hwy, then having to slam on the brakes and swerving hard to the left/right...or same deal on an on/off ramp, twisty bit etc. We get a lot of deer etc on our roads.

The LAST thing I want or need is the back end going sky high..while flying around corners. So yeah, the oem springs ARE fubar. Throw in some rain, or going down hill..and now you have a real mess on your hands.

Mine is lowered 1" front + back with the Roush street/race suspension kit,..springs/shocks /F+R sway bars etc, etc. (I use the middle holes on the BMR LCA relocate brackets). Slam on the brakes...and front end doesn't nose dive any more. Back end doesn't lift either. It essentially brakes flat. If I sit on top of either front wheel well, it doesn't deflect. It's stiff. Front + rear stb's, rear BMR tunnel brace, a pair of welded in steeda triangular sub frame connector's..and a BMR A arm brace.... + a pair of steeda front sway bar mount braces complete the stiffening. ( it already came with the Ford K arm brace)

Of course with the car lowered 1", the oem LCA's are at the wrong angle. With the oem PHB in there, the axle was shifted 3/4" to the driver's side. End result was... the oem LCA's were trashed, they are being bent over 3/4" towards the driver's side. Fix for that was BMR UCA + uca mount, BMR lca's and BMR lca relocate brackets...+ the BMR adjustable PHB + brace. Problems solved. No more back end wobbling about at the top end of 2nd gear. I got my traction back..and then some.

BMR adjustable PHB + brace were later replaced with the WL watts link + eaton tru-trac. The difference between bone stock when car 1st purchased....and after all the above myriad of mods is literally like night and day. The oem suspension is dangerous imo.

Re: tru-trac. brain fade on my part. TQ gets transferred to the wheel with the MOST traction. The oem diff belongs in the nearest dumpster...along with the oem suspension+ DS.

Jimbo

I assure you that you would not have to be concerned about braking on any highway conditions with the stock suspension. I am on stock suspension and routinely brake from 120-30mph in a very short distance when on certain tracks and while there is obviously brake dive and rear lift, it does not feel like much at all in the moment.

Regardless of whether your rear end lifts, the Roush springs are not stiff enough to resist very much of the weight transfer under heavy breaking. I would be willing to put down money that you actually have less contact patch in the rear under heavy braking than Norm does in his car. The difference being that the rear end lifts, using suspension travel in Norms car. In your car you likely have some Anti-Squat/Lift geometry that is resulting in your chassis staying flatter to the ground while it is actually pulling the rear tires up under braking rather than using suspension travel.