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Old 08-01-2014, 07:29 PM
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Mustang Alli Mustang Alli is offline
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Location: SF East Bay
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Default Coilovers for ALL Full Prep Cars?

Hello everyone, I have been thinking about this for a while now and want to get your feedback on it. What do you think about allowing front coil-overs on all Full Preparation cars?

Most of the newer cars allowed in the class have them stock and it is a mostly straight forward conversion for the older cars. So you ask, why would I want to go coil-overs? There are several advantages to this that can help the older cars narrow the gap in suspension design.
1 - Reduced control arm bushing bind\friction.The spring mounted on a control arm applies considerable force to the inner bushing, it actually increases the resistance of the control arm to move. Moving the spring to the damper reduces this resistance and allows for more precise tuning of the front suspension.
2 - The control arm bushings can be moved fore and aft, inboard and outboard to allow for some geometry adjustment.
3 - The coil-over should be a slight weight savings over an adjustable control arm mounted spring setup.
- There are others but these are the big ones that I see.
* There may also be tire clearance issues that may preclude the conversion.

Now I do not see this as a "rules creep" but more of a "competition adjustment" as the newer suspension designs incorporate coil-overs. If given the budget to build a new car my '87 Mustang would not be near the top of the list to choose from. With the newer cars having wider track's and longer wheelbases to start with plus many other improvements, my car is at a disadvantage to them. So would I put them on my car, yes but there are a lot of other things I need to do to my car first. Brake pads, new window net, Hans device, 11 year newer tires (no I don't drive on them), seat time, fiberglass hood, lexan windows, are all higher priority right now.
Allison Palitz
#82 '87 Mustang
San Fran Region
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Old 08-01-2014, 09:41 PM
jimwheeler jimwheeler is offline
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Join Date: Oct 2004
Location: Kansas City
Posts: 5,275

I assume they have them available for the GenIII cambirds although I'm not sure. It would certainly make things simpler, although I doubt that I would make the change. Building a new car, however, it would probably be the way to go. Pretty simple on the SM.
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Old 08-02-2014, 06:29 PM
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As a fellow foxbody racer, I would love to see this happen
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Old 08-03-2014, 11:01 AM
fastandyracing fastandyracing is offline
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Join Date: Aug 2008
Location: Apopka FL
Posts: 546

Hey all of you (us, I have an 83 hatch) fox body racers out there, don't forget that a four eyed, fox, hatch won the national championship just year before last.

Now Andy McD had to break, and it took an amazing last straight pass (but that old fox body had to be in position to make that amazing pass), but Ed Hosni won the national championship without cheater carbs, with bad aerodynamics, with basically a 78 Fairmont chassis, against all of the newer later, higher tech cars.

Do we really need more technology?? and expense??? What are the chances we will out trick ourselves and update our cars into being even slower (less fast?). Or do we need to just get what we have working correctly, and just plain be better drivers. I know I am constantly trying to achieve improvements in both those areas.

Don't give up on the old fox body cars, Ed has proved they are still a viable platform!

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Old 08-04-2014, 11:29 AM
kim mcdonald kim mcdonald is offline
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Location: grand island, ne
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Coilovers are available for 3rd gen cambirds and I think that would be a great change. No more weight jacks, easier spring changes and overall more adjustability.
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Old 08-04-2014, 11:51 AM
jimwheeler jimwheeler is offline
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Location: Kansas City
Posts: 5,275

I'm sure the ASAC would consider and discuss, if someone wants to send in a letter. Don't know what the result would be of member response. Might be worth a WDYT.
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Old 08-04-2014, 04:15 PM
andy mcdermid andy mcdermid is offline
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Join Date: Jul 2006
Posts: 271

If building a new car, coilover springs would save a ton of time and expense.
Also would help the older cars in the field without a large $$$ output.
Just my 2 cents

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Old 08-05-2014, 03:01 AM
MarkMuddiman MarkMuddiman is offline
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Join Date: Dec 2004
Location: Belleville, MI
Posts: 175

Cost is not major - about $300 per axle for adapter kits. Those running high-dollar shocks and struts probably already have threaded tubes.
Not really a major performance improvement, as there aren't any issues with finding spring rates/lengths for current setups.
Loads on the control arms will disappear - a benefit on paper but I've never heard of anyone failing control arms. Bushing friction reduction is real, but not a major improvement. My front bushings have been on the car since '98 and they're still good.
Ease of adjustment is a decent convenience compared to dropping the front suspension to adjust the perches.

But, I would probably not put coil-overs on the front of my Fox.
I've increased caster and camber by pushing the strut mount rearward and inboard to the limit of the strut body clearance to the tower. I'd have to back off caster and probably lose camber at the top mounts. Clearance between the coil-over spring and the top of the existing spring perch may be a serious restriction on camber and steering angle.

On the rear, there may be fatigue issues with the shock towers. The towers may need to be reinforced (or at least "repaired" heavily) to take the added spring forces.

I'd support coil-overs since the expense is not huge and it's not really a "must-have" in my mind.
Mark Muddiman
AS #71
Detroit Region
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Old 08-22-2014, 08:14 AM
aszilagyi aszilagyi is offline
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Join Date: Aug 2009
Location: Northville Mi.
Posts: 116

I like the idea of a coil on the strut in the front.
That is how a McPherson strut should be (IMHO).

Positive attributes:

It would (long term) lower the cost of spring tuning.
As 2.5” springs cost less.

Easer to change.

Are of better quality (do not loose rate with age).

Would ease the work required to set ride height. (When adjusters are installed correctly) .

Would make it easy for NASA guys to cross-over.

Spring Rate change increments are more favorable. As the motion ratio improves.

Down side:

CG will go up.
If your current springs are optimal. There will be no measurable performance gain.

Have to consider the stress level at the strut tower (load levels will increase).

There will be a lot of unnecessary / unused metal. On the K-member and A-arms. Where the original springs were. Seems a bit waste full, But would open the door for the next rule change, tubular K-member and A-arms.

If the rule changed, I would make the change
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Old 08-24-2014, 03:02 AM
Talladega Talladega is offline
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Join Date: Nov 2004
Location: Pa
Posts: 342
Default Coil overs,

Only way to allow them is with Tube ft sub frames , in what I see is early fords and 3rd gens, but do we really want to go there?

do them in rear end would change mounts upper and lower, to another tube frame
to mount them right and get leverage ratio right ,

seems more of a plus for 05 up cars,
but than would a tube style lower a arm on a fox or 3rd gen help with
a stock strut
on the lower a arm it would make it more adj, maybe not as strong , but lighter with dif ball joint ,
I would like to use stock strut /sub frame with tube lower arm ,on 3 rd gen/fox but , it changes RC and IC

reminds me of the ball joint rule in 1998 when Eric did what was allowed
to take advantage of it, than ball joint rule was re wrote , not to
alter role center,dive,track, with mount and as we have today use stock replacement, not a 1/4,3/8/1/2 inch longer,shorter to fine tune
role center, IC and than use SSBB setup,

so did I loose everyone on that?
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