Question about items in the performance package

[Whiskey11]

In the Mustang world, the brace you describe is called the Strut Tower Brace. A K-member brace triangulates the K-member, the cradle which holds the engine and mounts the Lower Control Arms. This brace keeps the LCAs from moving inward during high-load situations, stabilizing the front suspension and the front alignment.

I can only speak to the effect on a Fox. A Strut Tower Brace is a night-and-day difference on that floppy old structure. It's so dramatic it's always one of the first things I do when I get a new Fox. I've done the K-member brace a couple of times, and have skipped it more often. It's subtle, but you can (on the Fox) feel a little difference in front grip and stability. The more solid the structure, the less the body moves in reaction to impacts, and the more the suspension complies. Sure is easier to dial in a suspension if the body is not whipping around like al dente linguine.

I can't imagine the S550 will be even faintly related to the Fox, flexibility-wise, but the K-member brace can't hurt on track days.

All that said, if Ford has come up with a new name for a strut tower brace, I'll stand corrected. But those are the terms the industry has been using for 25 or more years.

When what you are talking about first showed up on the S197 chassis in 2007 (due to the GT500 power level) it was called an A-Arm brace, not a K-brace.

I guess my assumption was they were articulating the reasons why some variations don't have a triangulated Strut Tower Brace and calling it a "K brace" since they don't call it a K-Member Brace. A conventional 2 point brace does a grand total of fuck all for increasing chassis rigidity on the S197 as it ties the strut towers together and forces them to move in the same direction. The only time it really "works" is during braking events. The S197 had a false firewall so a proper 3 point brace (the two towers together and then the firewall) would not have worked. I'm not sure why they wouldn't just call it an A-Arm brace like it actually is.

I see now that all of the recent S550 display models we've seen have the triangulated strut towers so you must be correct.

As for your Fox chassis, a lasagna noodle has more rigidity when boiled for 10 minutes than the Fox Coupe has from the factory. Anything you do to add stiffness is going to make a huge impact. The S197 chassis does not benefit nearly as much from the same bracing. The 2 point STB on the S197 doesn't do anything for rigidity as I said above. It doesn't on older Mustangs either. The benefit only comes when you tie the strut towers into something that doesn't move in the direction the strut towers move. The firewall is the most common.

Sponsored

 

[Old 5 Oh]

As for your Fox chassis, a lasagna noodle has more rigidity when boiled for 10 minutes than the Fox Coupe has from the factory. Anything you do to add stiffness is going to make a huge impact. The S197 chassis does not benefit nearly as much from the same bracing. The 2 point STB on the S197 doesn't do anything for rigidity as I said above. It doesn't on older Mustangs either. The benefit only comes when you tie the strut towers into something that doesn't move in the direction the strut towers move. The firewall is the most common.

Thanks for the S197 update. I agree, a two-point STB improves looks more than any performance benefit. Triangulation is the name of the game. I have always preferred the Maximum Motorsports STB for the Fox, which ties into the firewall pinch-weld rather than screwing to sheet metal. It's the engineer in me.

 

[Old 5 Oh]

My 1980 Fairmont had one, a flattened tube bolted between the rear control arm mounts. Removed it to fit headers and t-sump oil pan. It closed the "K"

Yeah, not the best. Kinda like the lame subframe connectors Ford used to bolt on. The K-braces I have used are four-point, heavily gusseted, and tie not only to the LCAs but to the subframe. A little more bullet-proof. Max Motorsports.

 

[Tim Hilliard]

Yeah, not the best. Kinda like the lame subframe connectors Ford used to bolt on. The K-braces I have used are four-point, heavily gusseted, and tie not only to the LCAs but to the subframe. A little more bullet-proof. Max Motorsports.

I was actually looking for the eco on it's side to compare to the gt pp on it's side.

Just wondering if the k-brace on the GT PP is on the ECO. This brace is actually shaped like a K sort of and faces forward to the under tray. Cant find a Eco to compare it too.

 

[908ssp]

I think it's more insulting to post blatantly wrong information.

Correct. It is wrong it should be called out as wrong. I see people repeat incorrect crap all the time and when asked where they heard that they either make stuff up or heard it on the internet from someone else that was wrong.

If there is enough brake to lock up the front wheels then there is enough brake to achieve threshold braking. The car will not stop shorter than threshold braking. I don't care what you're running for brakes. In actual fact the big rotors have more momentum than the small brakes and have to slow down so it could be argued that bigger brake rotors leads to longer not shorter braking distances. But luckily that isn't an issue since the all Ford brakes achieve threshold braking large or small at least once.

 

[DivineStrike]

Do you get driving advice from the back of a cereal box!?

You stop much faster just before the point your ABS engages (called threshold braking). ABS is much slower for stopping compared to this; You even stop quicker without ABS (depending on vehicle, this is usually the case), just locking the wheels up, but you lose the ability to steer.

Don't worry Joe, I take no offense to him, I'll play. My point is in reference to the individual bringing up ABS and that a larger rotor won't have decreased stopping distance vs the smaller rotor with ABS. My point applies to threshold braking as well. Larger rotors will get you to that point faster. Therefor shorter stopping distances than a smaller rotor. Although it will be a small difference.

Btw ABS also prevents your tires from heating up too much from skidding. Also, preventing blowouts. Locking up the wheels is in no way shape or form ideal for stopping. Might be faster to stop from slower speeds but other risks are involved.

Correct. It is wrong it should be called out as wrong. I see people repeat incorrect crap all the time and when asked where they heard that they either make stuff up or heard it on the internet from someone else that was wrong.

Which is exactly what you are doing.

If there is enough brake to lock up the front wheels then there is enough brake to achieve threshold braking. The car will not stop shorter than threshold braking. I don't care what you're running for brakes. In actual fact the big rotors have more momentum than the small brakes and have to slow down so it could be argued that bigger brake rotors leads to longer not shorter braking distances. But luckily that isn't an issue since the all Ford brakes achieve threshold braking large or small at least once.

Just because a smaller rotor can lock up the brakes doesn't mean it will have the same stopping distance as a larger rotor. The larger rotor will slow down the wheel faster than it takes the smaller rotor to do the same task. The faster you get to the same point means a shorter stopping distance. The argument of weight is valid, but just depends on what the weight of the vehicle, on where the point of diminishing returns happen. It is more of an argument with lightweight cars.

Sorry to say but in regards to stopping distances and larger rotors you are the one that is wrong. However after a little further research, non OEM big brakes on cars with ABS might not stop as well because the ABS system might get "confused' so to speak and try to back of the pressure early. This might effect threshold braking as well if the ABS is getting confused. So my comment in reference to ABS might not be true in all situations, just depends on whether the ABS system can handle the larger brakes.

Which also might explain Fords tuning of the ABS system when going with PP

 

[Whiskey11]

Just because a smaller rotor can lock up the brakes doesn't mean it will have the same stopping distance as a larger rotor. The larger rotor will slow down the wheel faster than it takes the smaller rotor to do the same task. The faster you get to the same point means a shorter stopping distance. The argument of weight is valid, but just depends on what the weight of the vehicle, on where the point of diminishing returns happen. It is more of an argument with lightweight cars.

Sorry to say but in regards to stopping distances and larger rotors you are the one that is wrong. However after a little further research, non OEM big brakes on cars with ABS might not stop as well because the ABS system might get "confused' so to speak and try to back of the pressure early. This might effect threshold braking as well if the ABS is getting confused. So my comment in reference to ABS might not be true in all situations, just depends on whether the ABS system can handle the larger brakes.

Which also might explain Fords tuning of the ABS system when going with PP

No it's definitely 100% true all the time. Larger rotors, all else being equal do not stop the car any shorter than smaller rotors provided ABS can still be engaged. The limiting factor here is not brake torque, is not how quickly the brakes can lock up (which the difference would be measured in miliseconds or less) but on available grip that the front tires produce. The only reason a Brembo GT or Trackpack GT or a Boss 302 slows down any better than a base GT is because they come with wider, stickier summer tires (which are still junk). It has absolutely nothing to do with the brake rotor diameter. The only thing rotor diameter will do is increase brake torque upon initial pad contact (which changes the feel, not the stopping capability) and increase the thermal capacity of the system. The 12.4" GT rotors will more than lock up a set of 315 Hoosier A6's, the grippiest tire I know of to exist that has been tested on the S197 chassis (Avon slicks would be stickier) so you gain nothing but thermal capability and a little more initial bite. That initial bite means nothing in braking distance tests, literally nothing.

For the record this is 908ssp's car:

 

[DivineStrike]

You are missing the fact that larger brakes will lock up those tires faster (the slicks you mentioned) than the smaller brakes. The faster you get to optimal braking the less stopping distance you have, and i've already seen his car. Although it was a different article(Edit: never mind it was the same article, just didn't see how much power he was making when I first looked at it). Having a lot of mods on your car doesn't make you an expert, no matter how impressive the project. He has a very nice car. That's not to say he doesn't race or anything like that, I would assume that he has. However you both are flawed in the way you are thinking about braking systems. There is more friction (and better leverage) in a larger brake system, more friction (same is true for leverage) means faster slowing of the wheel. (The same reason pad size increases with larger brake systems, because the larger rotor can't do it by itself, let alone the thermal benefits) Which gets you to the point where the tires are stopping your car. And time is time, if it does it faster it does it better. Trust me I know all too well you can't stop any faster than your tires let you.

Everything you guys are saying is correct, just not that larger brakes don't stop your car faster than a smaller brake system given all other variables are constant. I will gladly post up the articles I found after we started this little argument if you'd like. None of which btw were my original basis in this argument.

 

[Swoope]

tires are almost always the limiting factor. on the street stock brake size does not matter.. if the abs can engage, the tires control stopping distance..

brembos on the street are a poser / image thing. if you are getting fade on the street a pad change would fix it. and dont drive like an asshole on the street..

this place is starting to remind me of every oil thread i have ever read..

beers

 

[Swoope]

No it's definitely 100% true all the time. Larger rotors, all else being equal do not stop the car any shorter than smaller rotors provided ABS can still be engaged. The limiting factor here is not brake torque, is not how quickly the brakes can lock up (which the difference would be measured in miliseconds or less) but on available grip that the front tires produce. The only reason a Brembo GT or Trackpack GT or a Boss 302 slows down any better than a base GT is because they come with wider, stickier summer tires (which are still junk). It has absolutely nothing to do with the brake rotor diameter. The only thing rotor diameter will do is increase brake torque upon initial pad contact (which changes the feel, not the stopping capability) and increase the thermal capacity of the system. The 12.4" GT rotors will more than lock up a set of 315 Hoosier A6's, the grippiest tire I know of to exist that has been tested on the S197 chassis (Avon slicks would be stickier) so you gain nothing but thermal capability and a little more initial bite. That initial bite means nothing in braking distance tests, literally nothing.

For the record this is 908ssp's car:

wow,

thanks for that. really the op question has been pretty much answered, maybe take the braking / my friend has a car that has been in a magazine stuff to pm. or better yet, start a braking thread in the proper section.

beers

 

[DivineStrike]

wow,

thanks for that. really the op question has been pretty much answered, maybe take the braking / my friend has a car that has been in a magazine stuff to pm. or better yet, start a braking thread in the proper section.

beers

Lol don't know if you noticed this or not but we are in the braking section

 

[Swoope]

Lol don't know if you noticed this or not but we are in the braking section

well how about that!!!! at least i was correct about where it should go and being a dick..

did this get merged and i missed it?

still right about the tires, and arguing about brakes is like arguing about oil. why? if you guys want to fight about the finest points of braking maybe start a thread about it.. but the tit for tat is tiresome, and really little is learned. ends up looking like two different white papers with different views.

beers

 

[DivineStrike]

I never said anything different about how tires effect stopping distance, they are the absolute limiting factor in how soon you stop. it doesn't matter what else you improve, you will always be limited by what a tire can handle. And no not merged, just moved. and arguing brakes is a little different than oil lol.

 

[Whiskey11]

You are missing the fact that larger brakes will lock up those tires faster (the slicks you mentioned) than the smaller brakes. The faster you get to optimal braking the less stopping distance you have, and i've already seen his car. Although it was a different article(Edit: never mind it was the same article, just didn't see how much power he was making when I first looked at it). Having a lot of mods on your car doesn't make you an expert, no matter how impressive the project. He has a very nice car. That's not to say he doesn't race or anything like that, I would assume that he has. However you both are flawed in the way you are thinking about braking systems. There is more friction (and better leverage) in a larger brake system, more friction (same is true for leverage) means faster slowing of the wheel. (The same reason pad size increases with larger brake systems, because the larger rotor can't do it by itself, let alone the thermal benefits) Which gets you to the point where the tires are stopping your car. And time is time, if it does it faster it does it better. Trust me I know all too well you can't stop any faster than your tires let you.

Everything you guys are saying is correct, just not that larger brakes don't stop your car faster than a smaller brake system given all other variables are constant. I will gladly post up the articles I found after we started this little argument if you'd like. None of which btw were my original basis in this argument.

I haven't missed your point at all. In conventional stop tests (60-0) what you are saying does not come into play in the slightest. Why does 60-0 matter? Because that is more than what most people will be doing with the braking system. I can just as easily lock up my stock tires by pressing firmly on the brake pedal with stock pads, lines and fluids on my 09 GT and hit ABS. Hell, I did it in the Crown Victorias at 70 MPH, repeatedly, on a road course. It isn't difficult nor does it require a lot of pressure on the pedal. At no point does the higher brake torque come into play during those speeds.

At higher speeds it will if the stock braking system cannot handle the heat generated by the brakes. I bet if we had Hawk HP+ in stock calipers and HP+ in Brembo calipers on the same Mustang and tested them back to back the difference would be pretty negligible even at higher speeds.

Every single test I've seen comparing "big brakes" to "stock brakes" has compared stock brake pads to aftermarket pads in the bigger brake kit. "Shorter stopping distance!" but the speeds they were pushing overtaxed the stock pads to the point where the test isn't a true comparison of rotor diameter but of brake compound.

Considering how much work 908ssp has done to his car, considering the knowledge he has and has provided on numerous forums, I KNOW he knows his stuff and his car is more than just a bunch of crap bolted together. I've seen the tech he brings to discussions and it is solid. He ranks right up there with Norm Petersen for tech delivery and the "knows his shit" scale.

 

[DivineStrike]

Yea ok clearly you just don't get it. But here is just one article talking about brakes. Withstanding heat is not the only benefit of larger brakes. It doesn't matter that you can lock them up with with oem brakes. It matters how fast everything happens and how your car is set up. Anyhow, I won't post every article up because just a quick search will yield many articles talking about the benefit of larger brakes. But here is the best one I've seen and goes into great detail about braking.

And yes it does come into play in the slightest, if it didn't it wouldn't have any effect with higher speeds.

I have already mentioned at higher speeds that advantage of bigger brakes is amplified but they still have an advantage at slower speeds. There is also more to maximum braking grip of a tire than the compound themselves. Many variables come into play when maximizing maximum stopping distances of tires. Suspension, tire, pressure, brake bias. All these things change how well an identical set of tires on any given car perform when braking.

http://www.mgf.ultimatemg.com/group2/brakes/big_brakes/Big_Brakes.htm

in the last section of the article.

"
So why bother with bigger brakes?

1. More leverage means you can apply brakes harder faster: this can mean that the reaction time to maximum retardation is more rapid - and it probably makes it feel as though you are slowing faster. In fact, this can mean shorter braking distances if the brakes are applied quickly enough - and is usually more noticeable under those circumstances where the rate of brake application is at its most significant - i.e. from high speeds.
2. Better heat dissipation - there is more material for the heat to be soaked up into, and a greater area for that heat to be transferred into the surrounding air."

Please do further research on this matter on your own before you just start spouting unmeasured tests of your own based on the ability to engage abs or wheelskid.



IT doesn't matter how much it effects stopping distances at slower speeds, an advantage is an advantage no matter how small it is.

and I have no doubt 908ssp is very skilled and has a lot of knowledge, but it doesn't mean everything he says is right. I most certainly am not always right but I'm not about to let a bunch of misinformation keep spewing onto the forums. There is plenty I still have yet to learn and I couldn't dream of being as talented as that man is when it comes to fabricating and everything he did to that car. Just doesn't mean that everything he says is gospel and should be taken as fact without doing your own research. We have lots of people in my career field with all kinds of knowledge and experience, and ya know what? They get it wrong too sometimes.

Sponsored