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Discussion Starter #1
Hey all,

I am looking to re-do the entire suspension on my '92 in terms of dampers and springs. Currently I have KYB shocks all around and unknown springs. I have no idea how old they are as they were on the car when I bought it 6 years ago. All I know is the car handles like s***! I am looking to enter the AutoX and road racing scene, but I also like to drive the car a lot, so would need a setup that appeals to both.

I really don't know where to start. I would like to get Coil Overs for the front and leave the rear to the traditional damper/spring setup. I would still like to drag race the car 1-2 times a year and have heard that rear coil overs are a no-no for this. I am not familiar with coil over rates either. I have heard Maximum Motorsports has a great coil over kit. I'm also a big fan of what UPR does, but I feel like their stuff is more oriented towards drag racing, so I am not sure how their stuff would hold up to road racing. I'm unfamiliar with good quality shocks to pair with the coil overs though.

Some help would be appreciated!

Thanks!
Ryan
 

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Go to FAQs & Tech Tips
Read it. ALL of it.
Come back and ask questions.

I have Bilsteins on my car with the MM coil over kit on the front / conventional rear set-up with Panhard bar and a long list of other bits.
There are other makers of good quality road-race oriented hardware out there. They just aren't as good at explaining it.
 

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Depending on your budget, LMR has a spring package matched with KYB shocks for $375. Front springs a bear to replace but rears are cake. Panhard bar is a must, some frame stiffeners, shock tower braces, foxes flex. Are you talking road course track days or actual racing, watch what mods you do for different racing classes. https://youtu.be/ldrDFD59NQU
 

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Depending on your budget, LMR has a spring package matched with KYB shocks for $375. Front springs a bear to replace but rears are cake. Panhard bar is a must, some frame stiffeners, shock tower braces, foxes flex. Are you talking road course track days or actual racing, watch what mods you do for different racing classes. https://youtu.be/ldrDFD59NQU
It's not a bad place to start. The KYB shocks are going to disappoint. Maybe not day one, but they will eventually. The MM website goes into the flex issues. The first mod they recommend is frame connectors and a STB. The Panhard can't compensate for worn bushings in the rear end. It won't be as effective with good STOCK ones. If you need bushings, get good control arms. I'll say it again: Go read MM's FAQ's. Then go over the install instructions. It's all in there.
 

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OP is on the right track looking for coilovers. I'm not sure a room full of computers can account for how many people have spent more than coilovers cost by the time they get done screwing around with conventional springs that didn't suit them.
 

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OP is on the right track looking for coilovers. I'm not sure a room full of computers can account for how many people have spent more than coilovers cost by the time they get done screwing around with conventional springs that didn't suit them.
^^^WERD^^^ Love my coil-overs!
 

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Casey's cheap-ass foxbody fixer (ignore things you already have):

Koni yellows front and rear (buy Koni's annual spring 25% off sale)
front coilovers (375 lb./inch springs) (buy a used kit from MM or Griggs if you can find one, used springs are ~$60/pair)
junkyard SN95 FCAs with the balljoint spacer (stupid cheap)
SN94-95 spindles (~$100)
camber/caster plates
SN95 rear axles (stupid cheap)
used SN95 brakes (preferably Cobra stuff)(I got my whole '98 Cobra setup for $500 a while back, that was probably a very good deal, not sure what they go for these days)
MM SN95 FCAs on a Foxbody bumpsteer kit
MM 43TA7 rear springs (used ~$80/pair)
height-adjustable RLCAs (varies, anything but Granatelli)
torque box reinforcement kit (might as well while doing RLCAs)
1 rod-ended/spherical-bearinged UCA ($155 from TRZ, yes, they will sell you just one of each)
Panhard bar
various fox front and rear swaybars of different sizes from junkyards (stupid cheap)
18*9s (+36mm offset) (~$500 for cheap, round wheels that hold air. Not expected to be used for HPDE)
with 4 barely used 285/650-18 Continental GT-R slicks (~$500 shipped)
Bushings
 

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Discussion Starter #8
So after some research, I found out that the springs on my car are branded Mustang Unlimited - P/N MU5300A-01. Fronts are 660 lbs/in and rears are 260 lbs/in. After checking the MM website, the front equates to a coil spring rate of 183 lbs/in., which appears to be really soft.

I have read the MM FAQs and its all really good information, but there are 2 things which wasnt really answered:
- why would i buy coilovers over a good set of traditional shocks/springs? For what i want to do with my car, does it make sense to go with coilovers, or should i bite the price bullet and get them?
- what spring rate for the coil springs and what type of strut is right for me and my application?

What i would like my plan to be is to get new shocks/springs/coilovers to get me on the auto-x and test days on the circuit track. right now i have 9" rims up front with 255s. Whenever i hit a pothole or take a corner really hard, my tires hit the fenders. The front fenders are rolled, and this inteference only exists during those two events. A stiffer spring should help mitigate this and get me on the track. from there, i will slowly build the rest of my chassis stiffeners.

I should note that I already have the cobra big brake upgrade on the front of my car from LMR.com and I have UPR adjustable rear LCAs and UCAs.
 

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I started out with the Cobra brake package and Eibach Sportlines with KYB shocks. This is part of the combination that I described as riding like a dump truck.

The MM site explains about the difference between wheel rate and spring rate. It also explains about the inherent bind caused by the strut and the spring not operating in the same vector. The coil over eliminates the bind, so you can put in a softer spring and keep the wheel rate the same. THIS gives you a better ride for a given level of handling. The only reason to NOT go with coil overs is budget or rules.

Aurdraco's post gives you the details you need. Koni or Bilstein for the struts and shocks. He's got you at 375# for the springs. I went softer with 300#. As I live where the roads are arguably the worst in the country, and I am more "cruiser" than open tracker.

Do the chassis stiffeners FIRST. Coil-overs will put a LOT more load on your strut towers. You are no longer supporting the weight of the front end in the K-member where the conventional springs locate.
 

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I recommend the 375 rate with the Koni Yellow single adjustables because that is the max rate recommended by MM. This would be for people looking to maximize the Koni's abilities. For more of a daily driver, the 300# front rate is a great compromise. For mostly daily driving, I'd even go down to 250#. To compare, I used to have 1000# conventionals up front. Car rode like absolute horse ####. Even with the 425 coil-overs it was WORLDS better.

I had 425s on a few years ago and I blew a strut. No idea if too much spring rate caused it, or running out of travel, etc., but I decided to lower the spring rate for that reason and because I was picking up the front inside tire big time when auto-x'ing (I had the softer MM torque arm springs at the time, I bumped those up at the same time. No more tire lift.). Helped balance out my f/r wheel rate ratio as well. I still probably need 100# more rate in the rear to really dial the car, if I am recalling what Jack advised last year (that reminds me, I need to hurry up and get that taken care of while it is winter).

Re: strut tower braces being necessary for coil-overs, I don't buy that. There is a huge thread on Corner Carvers about strut tower braces and the consensus seems to be that no one can agree whether or not they actually do anything. I've had coil-overs on mine for at least 6 or so years now, with some seriously grippy auto-x'ing. Car hasn't fallen apart (yet). Why add weight up front and high when there seems to be no consensus that they are needed? Plenty of fast CP (and now probably CAM) cars out there without them.
 

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Re: strut tower braces being necessary for coil-overs, I don't buy that. There is a huge thread on Corner Carvers about strut tower braces and the consensus seems to be that no one can agree whether or not they actually do anything. I've had coil-overs on mine for at least 6 or so years now, with some seriously grippy auto-x'ing. Car hasn't fallen apart (yet). Why add weight up front and high when there seems to be no consensus that they are needed? Plenty of fast CP (and now probably CAM) cars out there without them.
I have to agree that there isn't much real data to support the use of them. No stories of front ends falling apart or deforming. But there has to be something to them. From the 1st '65 Shelby to the production hot rod Mustangs (Boss, GT500, GT350) they have all used strut braces. In going to coil-overs on a Fox, you DO transfer a big chunk of suspension loads from the pockets in the K member (and frame rail) to the top of the towers.
 

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If you are considering autocross, C/Os may put you in an undesirable class. If that isn't a concern, then yes front C/Os are a huge advantage to both handling and ride quality. The fact is, running a higher rate C/O spring rides and handles better than a lighter rate conventional. As for dampers, while I respect Casey's SA Koni recommendation, my experience with them has been less than steller. As a result, I run Bilsteins. No "dark art" getting the correct settings and near perfect response with the spring rates recommended by MM. Besides, fewer things to set/test leaves more time for having fun.
 

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Discussion Starter #13
If you are considering autocross, C/Os may put you in an undesirable class. If that isn't a concern, then yes front C/Os are a huge advantage to both handling and ride quality. The fact is, running a higher rate C/O spring rides and handles better than a lighter rate conventional. As for dampers, while I respect Casey's SA Koni recommendation, my experience with them has been less than steller. As a result, I run Bilsteins. No "dark art" getting the correct settings and near perfect response with the spring rates recommended by MM. Besides, fewer things to set/test leaves more time for having fun.

I am not looking to compete in AutoCross; I'm looking to go out there and have fun. The car is driven on the streets a lot more. Once I get a good suspension on the car, I would like to AutoCross once a month, or along those lines.




This is all good input. What say you for the rear setup?
 

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Yeah, the Konis are just because they are the only dampener I am familiar with. From what I can tell, there is no competitive advantage that separates Koni Yellow SAs from Bilsteins, it's all about preference. I like the idea of being able to make a change the day of the event to account for changing conditions, different tires, etc. However, that being said, I did spend previous years with the fronts too soft.

Now, Koni Orange DAs, those allow more front spring rate so there should be some advantage there. Then you get into more serious shocks, like ASTs, Motons, etc. That's where things get REALLY interesting (and $$$$).
 

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This is all good input. What say you for the rear setup?
The pat answer is always MM weight jacker LCA's and torque arm. IMHO this is overkill for a "street" car.

I have run the rear with MM LCA's, Panhard bar, Bilsteins and stock SN95 uppers. I explained my set-up to MM and they gave me springs for the rear. They match up really well. Overall balance is decent.
I am collecting parts for a PM3L so I can reduce my rear spring rate a bit and reduce the tendency for oversteer. There is a new lump going under the hood that is going to provide plenty of it. >:)
 

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If you want a mostly street and sometimes track car you will have to try and find a happy medium. Stiffer suspension will make better for track but pretty bumpy on the street.
 

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I am collecting parts for a PM3L so I can reduce my rear spring rate a bit and reduce the tendency for oversteer.
You have that backwards. When you remove 1 or both of the UCAs, you need to increase the rear spring rate to offset the loss of rear bind. For a PM3L, the torque arm spring rates should be used (matched to the front springs and weight of the vehicle, of course).
 

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You have that backwards. When you remove 1 or both of the UCAs, you need to increase the rear spring rate to offset the loss of rear bind. For a PM3L, the torque arm spring rates should be used (matched to the front springs and weight of the vehicle, of course).
I knew that. I just wrote it backwards. I already have a set of the "lighter" TA springs. I hope they are compatible with my 300# fronts.
 

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Discussion Starter #19
Found this MM FAQ page to be useful: Damper Selection for Coil-over Springs

It looks like the suspension setup for Road Racing / AutoX and Dragstrip are on opposite sides of the spectrum.

If I was looking to perform in both AutoX and the drag strip, is there a recommendation for suspension? Otherwise, it is primarily street driven. I live in a mountainous region; I like to haul ass down the curvy roads here.

Once again, I never have competed in Drag racing; I only do it to accrue new personal bests. I look to do the same with AutoCrossing.
 

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Found this MM FAQ page to be useful: Damper Selection for Coil-over Springs

It looks like the suspension setup for Road Racing / AutoX and Dragstrip are on opposite sides of the spectrum.

If I was looking to perform in both AutoX and the drag strip, is there a recommendation for suspension? Otherwise, it is primarily street driven. I live in a mountainous region; I like to haul ass down the curvy roads here.

Once again, I never have competed in Drag racing; I only do it to accrue new personal bests. I look to do the same with AutoCrossing.
I grew up outside of Pittsburgh and know the roads of which you speak!! NIETHER the autocross nor drag set-ups are optimal for "spirited cruising". That being said, you will be much closer with the Autocross-oriented parts under the car.
I have put mine together focused on what I want for the car: Handling on par with 2012-2014 Mustangs. Brakes that can scare your passengers. Enough power to make the handling and brakes necessary. Comfortable enough to take long trips with my wife and not regret it. No regard for being competitive in any class racing.
If all you're after at Autocross and drag events is setting a baseline and improving the driver, you can do that with ANY set-up. If you DO get hooked into either discipline, and start changing parts, just be ready to accept the down side of going so far in one direction that the street manners are compromised.
 
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