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Discussion Starter #1 (Edited)
I am looking at the MM T/A springs, and have a question about which shock I should use with them?

The car is not a daily driver, and will see a few auto-x events. I am not really worried about comfort in it. Let us say it's 95% want good handling, and 5% comfort. I am not worried about NHV either. I really want to keep a conventional spring just because that is what I am familure with. I have looked at the MM2 Race series combo for the car. I have looked at the chart and the stock location suggestions is H&R Super Race. Would I be able to use one of the MM T/A springs in the rear, and not be over or under dampened in the rear? Here is the T/A kit that I have.


Here is the setup on the car/going on it.
Steeda K member
T/A kit
Undecided on damper combo
Undecided on spring combo
 

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FWIW I'm running Koni Yellows on mine with no trouble.
 

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I think the 390-430's were the old torque arm spring rates before they did an update to what they have now on their site.

If it were me, i'd run the heaviest rear TA spring you can.....it needs alot as the roll resistance is minimal at best with that design, basically just whatever type of control arm you're running.

I would imagine a conventional front spring would need to be in the 1000-1200 range to be balanced, and you'd need a high end Bilstein(MM), or at minimimum a Koni single, with a DA being a better choice.
 

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Discussion Starter #5
I think the 390-430's were the old torque arm spring rates before they did an update to what they have now on their site.

If it were me, i'd run the heaviest rear TA spring you can.....it needs alot as the roll resistance is minimal at best with that design, basically just whatever type of control arm you're running.

I would imagine a conventional front spring would need to be in the 1000-1200 range to be balanced, and you'd need a high end Bilstein(MM), or at minimimum a Koni single, with a DA being a better choice.
I remember you telling me that. That is why I focused on the MM2 race series and the H&R super race up front and one of the T/A rear. I guess I am second guessing myself where I have time to collect funds.
 

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Pick your front spring rate, then pick the appropriate rear spring to match.
 

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If this car is used for AutoX with only 5% concern given to street use, I would skip the TA springs and go straight to these:

MM Weld-In Rear Spring Adapters, 2-1/2 [MMCA-1] : Maximum Motorsports, the Latemodel Mustang Performance Suspension Leader!

The installation instructions are here:

http://www.maximummotorsports.com/content/install/pdf/rear_susp/MMCA-1r2.pdf

These are spring adapters that weld onto the center of the stock upper rear spring perch. They allow you to use a 2.5" diameter coilover spring in the rear. This will give you a huge range of spring choices to work with. The only downside is that since you would be using a linear rate spring with them, the spring will come loose at full droop. This will occur when the car is jacked up for instance or when going through a driveway at a 45 degree angle. Since the spring perch has a several inch long pilot tube in the middle of it, the spring has virtually zero chance of ever falling out.

The rear spring rate you use will be a function of the car weight, tire size and compound. A heavier car with larger, stickier tires, will need the highest spring rate to control the chassis lean angles. Start with that information.

The only reason to use a conventionally mounted spring in the front is due to cost. A coilover will give you better ride quality and handling due to less friction in the suspension, less overall weight, and the ability to adjust ride height and corner weights. The only time we recommend the front Super Race spring is when there are class rules that don't allow coilovers. Customers who switch over from SR front springs to coilovers always comment on how the ride and grip improved, even though the body roll/brake dive didn't become worse.

The front coilover spring rate is a function of the items mentioned for the rear spring rate, plus the rear spring rate itself.

If you install coilovers in the front, the only required added cost is that of the coilover kit. The spring price is about the same. If I remember correctly, the Steeda k-member allows use of the stock FCAs, so there is no required added cost there. However, in the future you have the option of losing about 14lbs of unsprung mass and/or extending the wheelbase for better weight distribution.

Once the front and rear spring rates are chosen, then the struts and shocks are picked which have adequate damping for the spring rates and car mass.

BTW, your TA link has an extra http\\ that is keeping it from working.
 

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Pick your front spring rate, then pick the appropriate rear spring to match.
Jack,

One of your techs told me a while back on a torque arm car the rule of thumb for a starting point is a 100lb difference front to rear with a stock front and rear bar.

So with your front and rear coil overs a 425lb/325lb combo would be a good place to start for a road race car. I was thinking more like 250lb rears.

Given the expense of suitable struts and shocks and the relatively small range they dampen in, is this a reasonable rule of thumb? Close is fine, but if it could be +- 100lbs or so it seems you'd want to figure out the spring rate pretty well before choosing the valving.

Any words of wisdom?;)
 

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Jack,

I also run the old TA-1 springs in back. OEM rear LCAs with urethane bushings, Evolution Tri-link, MM adjustable anti-sway bar, and MM panhard. Car is autox and track only. Rear shocks are 7 yr. old Bilstein HD, and wanting to upgrade. Should I go with the MM Sports or Race 2 valved shocks? Front setup is Race 2 struts with 1500 lb. conventional springs and Steeda 1 3/8" anti-sway, with MM CC plates. 315 R compounds all the way around. Great front grip, and the car is pretty neutral in quick transitions, but lacks forward "bite". Is a little better with a full gas tank.
Car is '00 GT, running in E-Street prepared.

Thanks.
 

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my vote coilovers front and rear, better ride quality,less weight, better suspension setup, more handling, more options, adjustable..its a win win
 

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Chris,

When I first read your post last night, I was quite confused. Your combination of parts should result in quite a bit of steady state understeer. You have a lot of front roll stiffness and shock damping and much less in the rear. Then I reread it and noticed that you had stock RLCAs with polyurethane bushings.

That is doing two things. It is adding about 55lbs/in of wheel rate in roll. It is adding significant friction to the rear suspension, particularly during roll. For the axle to roll, the RLCAs have to change angle with the centerline of the chassis when looked at in plan view. This requires the sides of the polyurethane bushings to compress. This is adding the roll stiffness and adding friction. The increased friction is hurting the forward grip of the rear tires. It keeps the tires from following the ground.

I would lose the one piece polyurethane bushings in the RLCAs. This could be done by installing an RLCA with either spherical bearings at both ends or a spherical bearing at one end and a properly designed three piece polyurethane bushing at the other end. When you do this, the amount of roll stiffness in the rear suspension will drop 55lbs/in or so. This will require a spring rate increase on the RLCA of about 125lbs/in. Removing the polyurethane bushings will remove friction and the increased spring rate will both require increased damping in the shock to balance things back out.

For the rear shocks, I would use an MM sport valved to match the spring rate. This would be 525lbs/in mounted on the RLCA or 225lbs/in if a coilover.

If you run the 525lbs/in spring on the RLCA, the easiest way to do this is to install an upper spring perch adapter:

MM Weld-In Rear Spring Adapters, 2-1/2 [MMCA-1] : Maximum Motorsports, the Latemodel Mustang Performance Suspension Leader!

and use an RLCA with an adjustable spring perch height.

Overall I think this will improve the forward grip of the rear tires as the rear suspension will behave more linearly due to the reduced friction. I would also consider raising the rear ride height some to increase the antisquat percentage.
 

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Discussion Starter #17
Thanks for the help everyone. I hope I didn't annoy to bad with the question lol. Fixed the T/A link as well.
 

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Thanks for the response, Jack. Very helpful insight. The reason for the conventional springs and OEM LCA's is the street prepared ruleset for SCCA. You can change bushing material (non-metallic), but can't use aftermarket LCA's. Makes it difficult to get a well-balanced setup. The super stiff front setup allows for very lttle camber gain, and with the 315's, and the 275's I run for track days, the car turns very well. I will definitely look into the weld in rear spring perches and changing the rear bushings back to rubber.
My Tri-link is currently adjusted with the max amount of anti-squat (over 100%). I'm assuming that I should leave that alone?
Thanks again.
 

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I just bought the MM Sport shocks to pair up with the MM torque arm springs (415-515 rate). When going this route, you will need to purchase the shock eye bushings since the sport dampers are designed for a C/O setup. For me personally, I like the fact that they are non-adjustable, support a high spring rate, and will work with either standard or C/O spring setups.
 
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