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post #1 of 49 Old 01-04-2016, 11:30 AM Thread Starter
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Fox Suspension Overhaul

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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post #2 of 49 Old 01-04-2016, 06:07 PM
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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.


'88 LX hatch. Mild 331. Full MM suspension minus the Torque Arm, Cobra Brakes. Not as slow as it used to be.
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post #3 of 49 Old 01-07-2016, 09:50 PM
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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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post #4 of 49 Old 01-07-2016, 10:07 PM
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Originally Posted by MB88LX View Post
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.

'88 LX hatch. Mild 331. Full MM suspension minus the Torque Arm, Cobra Brakes. Not as slow as it used to be.
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post #5 of 49 Old 01-07-2016, 10:08 PM
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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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post #6 of 49 Old 01-08-2016, 09:28 PM
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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!

'88 LX hatch. Mild 331. Full MM suspension minus the Torque Arm, Cobra Brakes. Not as slow as it used to be.
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post #7 of 49 Old 01-09-2016, 12:11 PM
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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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post #8 of 49 Old 01-09-2016, 07:28 PM Thread Starter
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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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post #9 of 49 Old 01-09-2016, 09:38 PM
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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.

'88 LX hatch. Mild 331. Full MM suspension minus the Torque Arm, Cobra Brakes. Not as slow as it used to be.
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post #10 of 49 Old 01-10-2016, 12:53 AM
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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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post #11 of 49 Old 01-10-2016, 01:02 PM
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Originally Posted by aurdraco View Post
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.

'88 LX hatch. Mild 331. Full MM suspension minus the Torque Arm, Cobra Brakes. Not as slow as it used to be.
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post #12 of 49 Old 01-10-2016, 09:08 PM
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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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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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post #14 of 49 Old 01-11-2016, 08:55 PM
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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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post #15 of 49 Old 01-11-2016, 09:07 PM
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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.

'88 LX hatch. Mild 331. Full MM suspension minus the Torque Arm, Cobra Brakes. Not as slow as it used to be.
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post #16 of 49 Old 01-11-2016, 10:03 PM
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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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post #17 of 49 Old 01-12-2016, 12:48 PM
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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.

'88 LX hatch. Mild 331. Full MM suspension minus the Torque Arm, Cobra Brakes. Not as slow as it used to be.
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post #19 of 49 Old 02-08-2016, 11:58 AM Thread Starter
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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.

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post #20 of 49 Old 02-10-2016, 12:08 PM
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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.

'88 LX hatch. Mild 331. Full MM suspension minus the Torque Arm, Cobra Brakes. Not as slow as it used to be.
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post #21 of 49 Old 02-10-2016, 12:34 PM
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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.
^^^ This. Where is the line to be drawn has always been my problem. In my case, from experience in both the drags and A/X, the line tends to be elusive. This is because I add parts incrementally, so any small change is easily adjusted to from a ride quality standpoint. Then suddenly, and seemingly without warning, it changes.

My current setup is 300# C/Os and Bilsteins up front, and lightest MM T/A conventionals with Bilsteins out back. This has proven to be both acceptable on the street and adequate at the A/X/HPDEs I run.

With that said, I'm about to go up to a 325# spring in front and convert to rear C/Os with a 225# spring. This may prove to be a mistake regarding ride quality, especially if the handling is not greatly improved.
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^^^ This. Where is the line to be drawn has always been my problem. In my case, from experience in both the drags and A/X, the line tends to be elusive. This is because I add parts incrementally, so any small change is easily adjusted to from a ride quality standpoint. Then suddenly, and seemingly without warning, it changes.

My current setup is 300# C/Os and Bilsteins up front, and lightest MM T/A conventionals with Bilsteins out back. This has proven to be both acceptable on the street and adequate at the A/X/HPDEs I run.

With that said, I'm about to go up to a 325# spring in front and convert to rear C/Os with a 225# spring. This may prove to be a mistake regarding ride quality, especially if the handling is not greatly improved.
Why coilovers in the rear?

I think I am going to do 350-lb coil overs up front and conventional Springs out back with the aspirations to have a torque arm setup in the rear.

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post #23 of 49 Old 02-10-2016, 01:32 PM
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Why coilovers in the rear?
One of the things I've been experimenting with is rear spring rate. General rules are fine and I've followed them. But, I've learned that there is a lot to this from both a ride quality and performance perspective. IMO conventional spring rates are too large between options and often times not available just for the rear. And given the increments and how cheap C/O springs are, I've decided I need more precision.

Initial C/O buy in is pricey but spring changes once in are very cheap especially on the used market.
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post #24 of 49 Old 02-11-2016, 10:16 PM Thread Starter
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^^^ This. Where is the line to be drawn has always been my problem. In my case, from experience in both the drags and A/X, the line tends to be elusive. This is because I add parts incrementally, so any small change is easily adjusted to from a ride quality standpoint. Then suddenly, and seemingly without warning, it changes.

My current setup is 300# C/Os and Bilsteins up front, and lightest MM T/A conventionals with Bilsteins out back. This has proven to be both acceptable on the street and adequate at the A/X/HPDEs I run.

With that said, I'm about to go up to a 325# spring in front and convert to rear C/Os with a 225# spring. This may prove to be a mistake regarding ride quality, especially if the handling is not greatly improved.

I have been looking a lot at the bilstein dampers. I think I would like to explore the setup you have - around 300 in-lb springs in the front with coilovers and rear conventional springs. Doesn't seem like MM offers such a package though...

I have been looking a lot at coilovers in the rear, too, but from MM info, it sounds like coilovers in the rear would be very detrimental to drag racing.

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post #25 of 49 Old 02-12-2016, 03:58 AM
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350lbs/in front coilovers are not going to work well on most Mustangs with the available conventionally located springs that we have for the rear. In most cases, you would need to use a coilover spring in the rear also.

For most Mustangs that are drag raced, you don't want to use a coilover spring in the rear. The minimum coilover spring rate in the rear that can be used is about 175lbs/in. This results in a wheel rate that is higher than optimal for drag racing. It is possible to install a softer coilover spring in the rear, to get the wheel rate down to an optimal value, but then the spring will coilbind when the car drives over a large bump. Parts will break as a result. There just isn't enough vertical space to package a 125lbs/in coilover spring, with an adequate free length, in the stock location.

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post #26 of 49 Old 02-12-2016, 08:40 AM Thread Starter
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350lbs/in front coilovers are not going to work well on most Mustangs with the available conventionally located springs that we have for the rear. In most cases, you would need to use a coilover spring in the rear also.

For most Mustangs that are drag raced, you don't want to use a coilover spring in the rear. The minimum coilover spring rate in the rear that can be used is about 175lbs/in. This results in a wheel rate that is higher than optimal for drag racing. It is possible to install a softer coilover spring in the rear, to get the wheel rate down to an optimal value, but then the spring will coilbind when the car drives over a large bump. Parts will break as a result. There just isn't enough vertical space to package a 125lbs/in coilover spring, with an adequate free length, in the stock location.
Thank you for your input. Would you happen to have a recommendation?

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post #27 of 49 Old 02-12-2016, 09:29 AM
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I've been holding the front at 300# while messing with conventional rears. With the stock uppers in place, they add spring rate as they articulate, So getting the "right" rate is difficult with this configuration. Thus, I relied on advertised rates, and did the math to come up with the rear spring package for the suspension I was using at the time. I started with stock, added the PHB removed uppers and added a rod-ended PM3L, and then went TA.

In all cases but the first (retaining the stock rear uppers), my rate selections are and were on the light side compared to the front. But since I have an adjustable rear bar, I simply added more bar in an effort to find that compromise between street ride and A/X performance. To some degree this has worked (favors ride quality). But as noted above, my next iteration will be a whole new setup and spring rates which I hope provides better performance at not much if any ride quality sacrifice.

As for trying to do an acceptable drag race, A/X suspension plus street ride quality - that is a very tall order based upon my experience.
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post #28 of 49 Old 02-12-2016, 09:51 AM Thread Starter
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I've been holding the front at 300# while messing with conventional rears. With the stock uppers in place, they add spring rate as they articulate, So getting the "right" rate is difficult with this configuration. Thus, I relied on advertised rates, and did the math to come up with the rear spring package for the suspension I was using at the time. I started with stock, added the PHB removed uppers and added a rod-ended PM3L, and then went TA.

In all cases but the first (retaining the stock rear uppers), my rate selections are and were on the light side compared to the front. But since I have an adjustable rear bar, I simply added more bar in an effort to find that compromise between street ride and A/X performance. To some degree this has worked (favors ride quality). But as noted above, my next iteration will be a whole new setup and spring rates which I hope provides better performance at not much if any ride quality sacrifice.

As for trying to do an acceptable drag race, A/X suspension plus street ride quality - that is a very tall order based upon my experience.

By "stock uppers," I assume you mean Rear Upper Control Arms? If so, I should mention that I have UPR adjustable upper and lower rear control arms.

It sounds like even though your original setup (300-lb coil overs up front with conventional springs in rear) was not rigid enough for your personal use, they were still adequate for both street and strip and with the conventional springs in the rear, the setup will still be good on the strip. Is that all safe to say?

The other setup I have been researching is Bilstein dampers with #300 coilovers in the front and MM Road & Track springs in the rear. At the same time, I plan to get the MM XL subframe connectors, too. I'm looking at this setup as building my own version of the MM road and track package. From what you are saying and from what I'm reading on MM FAQs, this would give a good all-around setup and would still be greatly improved over my current setup.

I am kind of torn between the Bilstein non-adjustable dampers and the Koni SA dampers. The adjust-ability seems nice to have if I want to take long trip in the fox I can soften the dampers and If i go to the track on the weekend I can stiffen it. But on the other hand, I think I would rather focus on my driving ability rather than the rate of the damper. What are your thoughts on this?

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post #29 of 49 Old 02-12-2016, 02:39 PM
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RTW0223, You are building my car.
300# MM C/O's on the front, currently MM (Non adjustable) Extreme LCA's in back with STOCK UCA's and their PHB and Road&Track springs. Full-length SFC's and strut tower brace. I went with the Bilsteins for simplicity. I am one of those guys that will take as much time as needed to get the car right, then just drive it. I don't really need many more knobs to play with. (A steering wheel and 3 pedals is enough!)

I have a set of their TA springs and an adjustable upper to do PM3L. I just dropped a new engine in the car, so I want to get it out a few times with the existing suspension under it. I am used to the way it reacts. Once I know how it responds with lots more power, I will make the suspension changes.

'88 LX hatch. Mild 331. Full MM suspension minus the Torque Arm, Cobra Brakes. Not as slow as it used to be.
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post #30 of 49 Old 02-12-2016, 03:10 PM
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RT,

For a spring rate recommendation, you'd need to go to the link below and follow the directions very carefully at the bottom of the page.

Damper Selection for Coil-over Springs

Warning: If all of the questions are not answered, we won't respond to the inquiry.

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post #31 of 49 Old 02-12-2016, 09:21 PM
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By "stock uppers," I assume you mean Rear Upper Control Arms? If so, I should mention that I have UPR adjustable upper and lower rear control arms.
Stock, rubber bushed, stamped channel arms. These are designed to twist and grow as the suspension articulates. But during the process, the bushings and arms can only twist so far; when they can't, the result is bind. When bind occurs it essentially creates a rigid suspension and all traction is lost typically causing unexpected snap over-steer. When you replace the uppers with arms that will not allow the growth and twist of the stock arms, you create more bind than with the stock stuff = not good for handling.

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It sounds like even though your original setup (300-lb coil overs up front with conventional springs in rear) was not rigid enough for your personal use, they were still adequate for both street and strip and with the conventional springs in the rear, the setup will still be good on the strip. Is that all safe to say?
Rigid is not what you want for handling; you want compliance so the suspension can react to the road conditions and driver input without skipping over stuff. In drag racing you want weight transfer to the rear for traction for a very brief few seconds. Not at all interested in how the weight moves from side to side and front to rear in a AX car in 60 seconds, or a OT car for 20 minutes. When we move either car to the street, ride comfort is generally compromised to some extent. The question is, what are we willing to tolerate?

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The other setup I have been researching is Bilstein dampers with #300 coilovers in the front and MM Road & Track springs in the rear. At the same time, I plan to get the MM XL subframe connectors, too. I'm looking at this setup as building my own version of the MM road and track package. From what you are saying and from what I'm reading on MM FAQs, this would give a good all-around setup and would still be greatly improved over my current setup.
I'm most familiar with my own iterations. The worst was using the stock upper arms and some performance springs. The extra wheel rate added by the uppers nearly made the car not enjoyable to drive; buckboard like. And frankly, the handling sucked. The most improvement in ride quality and handling came with the addition of the PM3L. Cheap and effective; transformed the car. But it has some down-sides. Lots of gear noise transferred to the cabin. And you need to watch the upper chassis side mount. There has been damage reported from guys running lots of HP/TQ and sticky tires. I was fortunate to not suffer any damage during the three season I ran my PM3L.

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I am kind of torn between the Bilstein non-adjustable dampers and the Koni SA dampers. The adjust-ability seems nice to have if I want to take long trip in the fox I can soften the dampers and If i go to the track on the weekend I can stiffen it. But on the other hand, I think I would rather focus on my driving ability rather than the rate of the damper. What are your thoughts on this?
I put some Koni SAs on my spouse' s 01 Prelude. Also converted to adjustable COs. While the concept of adjustability is attractive,
once we got the dampers set for AX duty, we left them alone. This is because on that car, the lower shock settings caused the car to hit the bump-stops way too often; very uncomfortable. And ride height was not nearly as low as the Mustang. Frankly, the SAs leave a lot off the table. Not nearly as impressed with the Koni SAs as I am with the HD Bilsteins.
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post #32 of 49 Old 02-13-2016, 06:55 PM
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I'm most familiar with my own iterations. The worst was using the stock upper arms and some performance springs. The extra wheel rate added by the uppers nearly made the car not enjoyable to drive; buckboard like. And frankly, the handling sucked.

Not nearly as impressed with the Koni SAs as I am with the HD Bilsteins.
Our experiences are juuust about identical, except that I went with the Bilsteins right out of the gate. I have the parts for the PM3L sitting in the barn right now. As soon as I get the engine swap done, I'll be putting that in. I am running a mild 331 and street tires. I also welded the crap out of the mounts. and torque boxes.
I'm looking forward to spring in the worst way...

'88 LX hatch. Mild 331. Full MM suspension minus the Torque Arm, Cobra Brakes. Not as slow as it used to be.
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post #33 of 49 Old 02-13-2016, 08:49 PM
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Our experiences are juuust about identical, except that I went with the Bilsteins right out of the gate.
I did too. The Konis were on my wife's Prelude. That experience convinced me to either go with the Bils, or move up to Penskes, Ohlins, JRI, etc. No reason to go intermediate.
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post #34 of 49 Old 02-14-2016, 08:38 PM
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It sounds like even though your original setup (300-lb coil overs up front with conventional springs in rear) was not rigid enough for your personal use, they were still adequate for both street and strip and with the conventional springs in the rear, the setup will still be good on the strip. Is that all safe to say?
Rigid is not what you want for handling; you want compliance so the suspension can react to the road conditions and driver input without skipping over stuff.
Based on the context of his comments, I don't think RTW0223 meant "rigid", I think he meant firm. You're electing to go firmer on your front spring rates because you decided 300#/in wasn't firm enough.

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Not at all interested in how the weight moves from side to side and front to rear in a AX car in 60 seconds, or a OT car for 20 minutes.
You lost me there.

'89 GT convertible, N/A 357W, MM front susp w/425# coil-overs and Koni D/As, MM TA/PB rear setup (Koni Yellows, 390-430# springs), Stoptech 332mm / 12" Baers, MM 6 point rollbar, Maier 1.5" flared fenders & quarters, 18x9.5" front/18x10.5" rear Enkei RPF-1s (street), 18x10" CCW C-10s (track), etc...
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post #35 of 49 Old 02-14-2016, 10:07 PM
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qtracer,

With a rear wheel drive car, you want 100% weight transfer to the rear tires in a drag racing situation. That will give the car the most possible traction at the tires (rear in this case) that determine how quickly it can accelerate.

In the case of a front wheel drive car, you want zero longitudinal weight transfer, for the same reason. This gives the front tires the most possible grip for acceleration.

In an AutoX or road race situation, you do still care about weight transfer. When you minimize lateral weight transfer, the four tires which determine how much cornering grip is available, end up with more total grip. For any given pair, or more, of tires, they have to most total grip when they share the load equally. This means that the cg needs to be as low as possible, and/or the track needs to be as wide as possible.

You also care about the front/rear distribution of lateral weight transfer as that is almost the sole thing that determines the handling balance of the car.

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