Watts Link and Shock/Strut Upgrade Question

[cobrarob]

Soft is good..

https://imgur.com/a/sZIEy

That’s grip! Is that with the “tiny” swaybar or none at all?

https://imgur.com/a/6WpSS

 

[blacksheep-1]

Not positive, I think it's the 18mm bar

 

[cobrarob]

Gotcha. DWW Motorsports that works on my car talked me into swapping the Watts out for the Panhard bar, I did it for 19’ but I put it back in for this year. Guess it’s all personal preference.

 

[Coz]

Soft is good..

Is that soft that good only on slicks? Would weight transfer that great overpower a 200TW tire?

Also, with respect to rear sway bars, I thought the stiffer the bar, the more likely it was to lift the inside tire. Or do I have it all wrong?

 

[blacksheep-1]

Is that soft that good only on slicks? Would weight transfer that great overpower a 200TW tire?

Also, with respect to rear sway bars, I thought the stiffer the bar, the more likely it was to lift the inside tire. Or do I have it all wrong?

yeah, those are slicks, but they were Hoosier DOT tires, as I recall A7s..but it was a while back, the lower pic was on Pirellis, 2 totally different compounds. the uppers were maybe 305s, as were the bottoms tires, but totally different sidewall, compound composition. The smaller the tire. the more you need to get it planted..to a point, but not overload it, the top car is definitely loading the right rear, but the car is also accelerating forward, which is what you need.

Here's tonight's homework...

How Sway Bars Work and Why You Should Care

If you’re reading this, chances are you appreciate the thrill of turning a fast corner as much as you enjoy laying down a big patch of rubber. There really is more to life than living it a qu…

speed.academy

 

[Coz]

Here's tonight's homework

Who knew you could be so mean... ;-)
But I will accept the assignment.

 

[blacksheep-1]

Who knew you could be so mean... ;-)
But I will accept the assignment.

the car they use is a Subaru, so it will prolly mean an engine change after the 5 minute video.

 

[Coz]

Ok, I completed my homework assignment and this quote seems to confirm my suspicions:

"...but too stiff a setup can actually reduce the freedom with which each corner of the suspension acts independently, meaning you can start to lift the inside tire in the slower and more severe corners if you run too aggressive a sway bar setup."

If that is indeed correct, wouldn't the Phoenix Mustangs pictured be an example of too stiff of a rear sway bar?

Or are you saying that given the slicks used that even stiffer bars would have introduced oversteer to an extent the weight would not have been transferred to the extent it did to allow the tire to plant itself as it did?

 

[blacksheep-1]

Ok, I completed my homework assignment and this quote seems to confirm my suspicions:

"...but too stiff a setup can actually reduce the freedom with which each corner of the suspension acts independently, meaning you can start to lift the inside tire in the slower and more severe corners if you run too aggressive a sway bar setup."

If that is indeed correct, wouldn't the Phoenix Mustangs pictured be an example of too stiff of a rear sway bar?

Or are you saying that given the slicks used that even stiffer bars would have introduced oversteer to an extent the weight would not have been transferred to the extent it did to allow the tire to plant itself as it did?

The top pic is a bit misleading as the inside rear tire is actually firmly planted, , the bottom , the car is on the curb, so I doubt any inside tire is planted, however, it does point out that a soft suspension will more closely follow track irregularities, (including curbs) than one that is stiffer. Keep in mind the video was referring to an import type car, where lifting an inside rear tire (front wheel drive) is not uncommon. Mustangs really don't have that issue on the rear, but they clearly will pull the front inside, a lot of this also has to do with ride height, and just how much the suspension can actually travel. I think your last paragraph nails it. Generally a stiffer bar will "loosen" that end of the car a flexible bar will "tighten" that end of the car unless..unless..the suspension is overwhelmed at some point that the tires no longer adhere to the track (stick...stick..stick..OMG unstuck!!).
One of the things I see guys do is if the car is, say tight (understeer) they will take methods to "stick" the front end of the car..when maybe, they should unstick the rear of the car,people think that you always have to work with the end of the car that is unstuck.. Not always, sometimes you can bind a chassis up so tight it's a complete pig (you see this on oval track cars) which leads to the old adage "slow cars always handle".

 

[Coz]

@blacksheep-1 , thanks for the thorough explanation!

 

[blacksheep-1]

@blacksheep-1 , thanks for the thorough explanation!

Keep this in mind as well, a lot of guys are running the cars down against the bump stops, this all started in the 60s when some of the Shelby GT350s actually used a strap around the diff at each end to limit the axle travel, once it got to a certain point, it had to physically lift the other side of the car off the track. For the most part, now days, you can't do that within the rules, so they run the car against the bump stops to limit movement and force suspension compliance.

 

[blacksheep-1]

For those that didn't click on the link, I'm going to copy/paste AJ's comments here...

"About watt's links. We were told they were the holy grail. but here is our history and thoughts.

In the GA/IMSA CTSC, you had to use the Ford Racing rear lower arms with poly bushings and a panhard rod, we made the car work pretty good there. We bailed on CTSC and started looking at PWC for 2015. In the middle of the switch we rebuilt a car with the PWC stuff, and wing and splitter, spherical rear arms, took it to Laguna for the SCCA runoffs as a back up car, had to use it, and it worked pretty well even with our base "GS" setup.

"For PWC we were told you had to have the Watts link to be competitive. So we purchased a car that was for sale that had been strong in GTS, looked at the watts link, did some reading, went testing and ran it back to back with our car at a track that we had never run our car on. Out of the box our car was faster. Our car only got better during the day, while the car with the watts link didn't show much potential after some tinkering. Went home found the diff cover was leaking and bolts had already loosened up and decided along with lack of speed it wasn't worth the aggravation. By the end of the season we were the highest finishing Mustang at 10 of 17 races, and in 5 of the races we were not, we finished directly behind the highest.

Now in both PWC and IMSA, you were limited to stock pickup points, PWC allowed the watts link, but no moving of pickup points. For something that is unlimited, you might find something, but that is going to be a lot of work and money. If you like to tinker, go ahead. In what we do with the rule sets we race to you have to keep the basic suspension layout and its kind of cool making the S197 fly as fast as we did while still sharing most pieces and design with the street car.

Is our setup for everyone one? No. Its pretty costly, and requires all the pieces of the puzzle to be put in place to make it work to its best potential. However I would feel fine selling it, setting it up, and saying go learn to drive it and don't over think as long as all those pieces were installed. I feel what is most frustrating is having someone bring their car in complaining of leaks, squeaks, and not handling right, all because they put *insert part here* on thinking just IT would magically change the car. But a lot people just buy random parts thinking it will solve all problems without proper setup or interaction with other parts. I feel so confident in what we use because it was fine tuned against the stop watch and took the checkered flag ahead of competition.

On messing with the rear end of the S197. If it could have been improved so easily, why did the car last until 2014, and why did it take so long to bring out an IRS car? Think about that."

omitted++++another person's comment++++

back to AJ..
"No rules on suspension sounds like it will be a very expensive path.

1. No experience with the SLA. Never allowed to use it.
2. The cambered rear axle. Another magic 2 seconds a lap... This was going to be the end all-be all. Again we were told it was worth so much in back to back testing. When we first used it, it wasn't. More like a couple hundredths of a second slower. But it showed promise as we were sent the wrong hubs a week before the next race, and couldn't get the proper degree hubs in time. After we got it properly setup with the correct camber, I'd say on certain tracks its probably worth a half of a second on a car that works well already. On cars that don't work well it may fix some things or it may screw things up further.

The real benefit was running fixed calipers on the rear. Much better and consistent brake pedal."