The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

New guy needs help.Suspension questions

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

I purchased a 2013 GT/CS and the previous owner has installed H&R super sport springs.
It's bottoming out a lot and rides horribly and the rear is very bouncy.

I'm looking at the Maximum Motorsport Road and Track pack with their K member.
Do you think it will be a good daily driver setup with occasional track use? If not I'm open to suggestions. My budget for suspenison is about $3500.

Thanks
 
2,198
1,065
Bay Area
Ugmmm, 1st off... what do you want out of your car? Just throwing money at a car is not very smart. Give us some info and then some seasoned vets can point you in the right direction. And then if you look at te vendors here you can also reach out to them once you decide how and where you want to go. Oh and welcome to TMO.
 
Ugmmm, 1st off... what do you want out of your car? Just throwing money at a car is not very smart. Give us some info and then some seasoned vets can point you in the right direction. And then if you look at te vendors here you can also reach out to them once you decide how and where you want to go. Oh and welcome to TMO.

I would like for the car to ride more comfortably and feel more planted than it does now. My end goal is a comfortable daily that has sharp turn and isn't upset in the rear by every bump in the road. Which is the opposite of how it is currently.

I plan on doing some track days in the future starting with autocross. The stance of the car is not important to me at all. Handling,ride quality and durability are the most important things to me. Maximum morotsport R&T kit and the Vorshlag Bilstein kit are the two main ones I have been looking at.

Thanks for the advice and if I can provide more info to help y'all answer my questions please ask.
 
1,289
1,113
Exp. Type
HPDE
Exp. Level
5-10 Years
Philly Metro Area
The heim joints in the panhard bar, and LCAs in that package may transmit more NVH than you want.

I think the K-member is overkill for you at this point.

If you're still running with stock struts/shocks, that may be your main problem since the aftermarket springs will almost always overpower the stock dampers.

If the rear being upset by every bump is when driving straight ahead, it is probably your rear dampers. If your complaint is that the rear skips sideways when hitting bumps in curves, then the panhard bar may help. A Watts Link may help even more.

To save money, I would suggest installing just the Koni struts & shocks and a panhard bar with urethane bushings.

If the H&R springs make you ride too low, then while you're doing the dampers you can switch to either the Ford "P" springs, the Steeda Sport springs, or the Roush Lowering Springs.

Spend the money you save on better brake pads and brake ducts.
 
Last edited:
2,198
1,065
Bay Area
Id recommend you start with Boss 302 shock/ struts, Ford P springs, CC plates, a pan-hard bar and maybe LCAs. It's not very expensive and might get you where you want to be. You might even find the stuff FS here in the classifieds. Oh read the post above mine. And 99% of the guys on TMO sell solid stuff. Ive bought pallets of parts from members here.

Next question is; Whats your autocross / track experience level?
 
6,361
8,184
Actually, you really don't need anything except to find out why the car is bottoming, which I suspect is because you need to cut or replace the bump stops on the rear end.
I always recommend one of the Ford Racing track packs for that car ,they make 2, one is a bit more harsh and has adjustable shocks, but in any case, buy all your stuff from 1 vendor, that way it should be all compatible.
As stated right now is the time to decide where you wan to be a year from now, and start planning accordingly, seat time is always the biggest factor.
BTW the K member..as well as coil over shocks are overkill in my opinion, especially for righty now.
 
Agree the rear jounce bumpers need to be cut especially if the rear "sproings" back after a bump that causes the rear end to sit down. Cut off the convolutions one at a time to test it. Cut it with a sharp utility knife or even a hacksaw. The front's should be done as well but they are a little harder to access without removing the struts. Reduce their height to about 1/2 of stock. It should have been done when the spring were installed. But H/R springs don't have that much drop... sooo

Or don't cut the bumpers at all and replace the springs with the stock springs.

Get better shocks and struts! Better damping will help all the way around even with stock springs. Not coil-overs but maybe with some adjustment. Tokico D-Specs work pretty well and adjust both directions with a single knob. Koni Sports are good, too. Konis adjust rebound (extension) only. Bilsteins don't adjust but are a good choice.
 

Grant 302

basic and well known psychic
I think CC plates and shocks/struts are all you need to get. And trimming the rear bump stops should be done with any lowered car.

Stock dampers can't control even a modest increase in spring rate. That's the main thing to fix.

Even though your budget allows for some very good suspension upgrades, I think you should save it until you figure out how far down the rabbit hole you want to go first.

Another inexpensive option would be finding a set of stock springs near you for cheap or free.
 
I purchased a 2013 GT/CS and the previous owner has installed H&R super sport springs.
It's bottoming out a lot and rides horribly and the rear is very bouncy.

I'm looking at the Maximum Motorsport Road and Track pack with their K member.
Do you think it will be a good daily driver setup with occasional track use? If not I'm open to suggestions. My budget for suspenison is about $3500.

Thanks

Hi and welcome,

I have everything in that MM Road and Track kit, but opted for MMs Bilstein Struts instead of the Konis and use Vorshlag Camber plates instead (mostly for the billet upper spring perch). I also have MMs complete K-member and bracing with rad support.

Is it daily driveable? Yes.
Will your passengers like it? Not everyone, and especially not over rough road.
Is the NVH too much? "N" and "V" - almost no different than my old poly setup. "H" on severe bumps, my passengers don't like it much.
Does it handle? HECK YAH! especially with the right tires.

But here's the important question - What do I use my car for?

90% competitive use - Regional Time Attack, Autoslalom and Instruction
10% road use - Cause my wife and kids love a good Sunday drive

Coz is correct that your setup's issue with the H&R is most likely the shocks/struts either being stock or worn. The H&R lower the car slightly less than the aggressive 2" drop of the MM Road and Track springs, and MM recommends aftermarket shocks/struts when installing theirs, along with their shortened bumpstops.

On that ride height, the front and rear control arm geometry is off (roll-center etc.), so the K-member, bumpsteer kit and adjustable RCAs will fix that. Without it, you'll feel strange roll while on sustained, sweeping turns (on track), despite the higher spring rate and upgraded shocks. This won't be noticeable on a daily drive (IMO).

In the end, it is your project and from my experience, doing it all at once would've been ideal. I did the k-member and U/LCAs last, hence knowing the difference with just shocks/struts and springs in my explanation above.

However, I will go back to the fact that my car is 90% competitive use. If that isn't the case for yourself, Coz's suggestion on saving the money for "not as aggressive" springs, track pads, brake cooling is primary. I'd add, High-temp brake fluid, really good tires and track time to that.

I basically did all the above on the 7th year of my ownership, and racked up a whole lot of track time before the major modification.
 

Apex Wheels

Race Proven, Street Approved
Supporting Vendor
670
1,061
Exp. Type
Time Attack
Exp. Level
5-10 Years
Bay Area, CA
As others have suggested, I would avoid the K member right now and put that money elsewhere. Not that it's a bad unit, because it's not, but it is simply unnecessary for the kind of driving you say you'll be doing. Here's my recommendation, based on the $3500 budget

Bilstein dampers with springs of your choice and Vorshlag camber plates- $1400
Adjustable front sway bar from Eibach or Ford Performance- $300
Rear LCA with relo brackets- $400

At this point we're just over $2000 and have the main upgrades completed. I would spend the rest on brakes for the front if you don't have the Brembo's already, and then whatever is leftover into a wheel/tire fund :)

I much prefer the Bilstein dampers over the oft mentioned Ford Performance or Koni's due to their construction and durability. Bilsteins are a monotube in shortened housings so they will last longer than a comparable twin-tube (FP, Koni, etc) damper would and they have more bump travel. Sure, you don't get the adjustability, but I've personally never found those other dampers to have much of a difference when being adjusted.

As a rule of thumb, the more metal and less poly you have in the suspension, the better it will handle but the worse it will be to live with day to day. I would not recommend anything full spherical for suspension, but the poly/spherical combo units from BMR are great for a dual-purpose car.
 
Thanks everyone for the info. From what I can tell is that most people prefer the Bilstein's over the Koni's so I'll probably go with the Bilstein's because of what I've read here and in other threads.

Red5oh thank you for the input on the MM kit,that was the main one I have been looking at. Do you think it would be a better kit for the road if it had a different set of springs that didn't lower the car so much? or do you think that it would compromise the handling too much?
 
Thanks everyone for the info. From what I can tell is that most people prefer the Bilstein's over the Koni's so I'll probably go with the Bilstein's because of what I've read here and in other threads.

Red5oh thank you for the input on the MM kit,that was the main one I have been looking at. Do you think it would be a better kit for the road if it had a different set of springs that didn't lower the car so much? or do you think that it would compromise the handling too much?

For what it's worth, I feel that comes down to preference. I had the Steeda Boss Springs initially which only lowered the front by about .9 inches and the rear by 1.1? I felt it was a perfect height with stiff enough springs to enjoy it on the track and the street. As I became more competent on the track, I began leaning towards lower / stiffer setup (now on coil overs).

That being said, I would feel something like a stock "track pack" or even stock Boss springs would be too soft. These cars are heavy and tend to float! As others have said, Bilstein is the way to go for a dual purpose car (you will definitely feel more bumps in the road with these as well)!

Enjoy the car!
 
Thanks everyone for the info. From what I can tell is that most people prefer the Bilstein's over the Koni's so I'll probably go with the Bilstein's because of what I've read here and in other threads.

Red5oh thank you for the input on the MM kit,that was the main one I have been looking at. Do you think it would be a better kit for the road if it had a different set of springs that didn't lower the car so much? or do you think that it would compromise the handling too much?

Actually the MM K-member is great for the road. It's more the spherical bushings in the rear control arms and panhard, that transmit the rough road harshness. The MM k-member is built for those springs or a good quality coilover setup, as it's main goal is handling for competition use, but sturdy for road use as well. Which is why it isn't much lighter than stock, but the gusseting and tubing, add a great deal of stiffness over stock (not to be confused with harshness) through geometry and material choice. This translates into better steering feel.

Here's why. Firstly, MM recommends the use of the stock front control arms rather than a poly or spherical bushing unit. This is to not upset the electronic steering rack. Secondly, since the springs lower the car by 2" and many competition coilover setups do the same or lower, they have 2 settings from which to mount said control arm to, both of which are higher than the stock points. You'll notice that it comes with their MM bumpsteer kit, because along with that modified mounting point the kit also makes sure the steering arm is parallel to control arm (like stock). Combined, they correct front roll-center (back to stock), often forgotten by those who lower aggressively. Not correcting this makes the front sloppy on aggressive "competition situation" turns. So you get all the complete benefits of proper lowering:lower center of gravity, better braking and weight transfer.

As you can see it's a system. Substituting one needs careful thought, otherwise you'll either not get the benefit for the $ you spent or make it worse when you want to push it.

I will reiterate though, that it is more for competitive use. On the daily road, the thoughtfulness you paid MM for won't be noticed on your daily commute. Sure, the stiffer springs will be noticed on twisty roads, but you can get that with springs with a 1"-1.75" lowering, good shocks with camber plates, on the stock k-member, poly-bushing control arms and panhard. In fact, you can have a lot of fun, with this setup and some wide wheels and sticky tires (Ehem..Cory and Apex ;) )
 
334
352
OP, one more vote for the Bilsteins. I have a 2011 gt and swapped oem dampers with 45K miles on them for Bilsteins. It was a game changer in terms of getting rid of the multiple suspension cycles over bumps, settling the rear axle on bumpy corners and roads, and just generally far more controlled handling. Huge improvement. The stock dampers were bad when new and they're worse with age.

I paired the Bilsteins with P springs and Vorshlag camber plates as part of Vorshlag's "street pro" setup. It's a great 'tweener setup for a daily driven car that sees some track time. In terms of the handling problems you are having I think the Bilsteins were responsible for most of the improvement.

You may already know this but the nice thing about Bilsteins is that they are quite stiff on low speed shock movements but then they blow off a bit on high speed movements. So they tend to ride "stiff" and you feel the road a lot but they aren't super harsh on impacts like potholes and expansion joints.

You don't mention how many miles on your car but on any older car I would also check all the simple stuff, UCA and LCA bushings, sway bar links, PHB, front control arms, etc.
 

TymeSlayer

Tramps like us, Baby we were born to run...
3,787
2,740
Exp. Type
HPDE
Exp. Level
3-5 Years
Brighton, Colorado
Agree with Coz - The Koni Yellow Sports have worked well for me both on and off track (HPDE). If I ever start running competitively and get a big raise at work, I'll move to a coil over system.
 

TMO Supporting Vendors

Top