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Topic: Front coil-over install (Read 7788 times) previous topic - next topic

Front coil-over install

I finally got the front half of my 5-lug swap done today and drove it around. The whole process went quite smoothly, except for a missing spindle-caliper bracket bolt.

"New" parts:

  • '03-'04 Cobra LCAs
  • Koni Double Adjustable coil-overs (275 lb/in - 12")
  • Maximum Motorsports Caster / Camber Plates
  • '94-95 SN95 Spindles
  • SN95 Outer Tie Rod Ends
  • '99-'04 V6/GT Calipers
  • '99 Cobra Wheels (17x8 - 30mm offset)
  • spoogeho Ecsta ASX 225/45/17

A '03-'04 Cobra rack and solid steering shaft had already been installed beforehand.

I only drove it a short distance to test out the brakes, but the difference was very noticeable. I did two ~55-5 braking stints and was amazed at the amount of feedback that was apparent. The old setup (stock with spoogeho A/S 795s 205/70/14 ) would lock up the RF with a quickness; especially in the wet. It was downright dangerous and the cause of an offroad excursion several months ago. Disassembly of the old calipers didn't offer any answers to why it was so.
I didn't really notice the 140% increase in wheel rate. Maybe I will after the newness wears off, but the ride appears to be just as smooth as before. No added NVH.

The '99-'04 V6/GT calipers are cast aluminum with two 44.5mm pistons. This results in a 10% piston area. That, when superimposed with the 11" rotor, makes for a system with is biased ~20% more towards the front. An aftermarket proportioning valve is a good idea. If you are going to upgrade to SN95 spindles, but aren't going to use the Cobra setup; I would highly recommend the '99-'04 V6/GT calipers, they're lighter and stiffer than the single piston steel '94-'98 calipers. The only downside is they're a bit more expensive.

I found that '94-'95 spindles increased track width from 58 3/8" to 59 7/32" (w/'99 Cobra wheels). This ends up to be an actual increase of .9" when the difference in wheel offsets is accounted for. The stock wheels are 14x5.5" with 1.12" (28.45mm) offset. The wheel/tire combo lines up almost exactly with the outer fender. If you drop a plumb bob from the fender, it just clears the tire.

The OEM strut is 23.6875" (all decimals are just a manifestation of their fractional equivalent) when measured from the bottom mounting hole to the end of the threaded portion of the shaft.
The Koni strut is 22.125" long

Given this information, I believed it was possible to run the Koni struts and only lower the car ~1". I forgot about the C/C plates up top. :hick: They raised the strut relative to the top of the strut tower.
The OEM strut mount positions the strut 1.5925" above the sheetmetal.
The MM C/C plates moves the strut to 2.25" above the tower.

Thus, the distance from the top of the strut tower sheetmetal to the lower spindle mounting bolt for the two are:

OEM: 22.095"
Koni: 19.875"

A difference of 2.22" :punchballs:

The OEM strut has 6.875" of travel, versus the Koni's 6.125". This means, at full compression (negating the fact that the bumpstop cannot compress to 0") the previous measure is:

OEM: 15.22"
Koni: 13.75"

A difference of 1.47"  If you try and average out the two differences in length to calculate ride height, you will end up running 1.845" lower to achieve the correct proportions of bump/droop travel.

Clear as mud? Kewl. ;) Basically, it means you must lower the car at least 1.845" to run Fox Mustang Koni D/A struts. I don't have exact measurements for SN95 Koni struts, but by my best guess; they don't turn out much better.

I don't want to lower my car that much, so I am going to cheat on droop travel (unless it ends up causing poor driving characteristics) and by raising it some. The only possible solution might be Koni's SA strut inserts. Depending on the insert length, you could cut the original strut higher than intended and use a spacer at the bottom to get a bit more length out of the setup.

The 2nd half of the project will be completed (hopefully) in two weeks.
7.5" w/'99-'04 axles, Eaton TrueTrac, 3.08 gears from Motives Gears, and all new bearings.

[SIZE="3"]---------------Pictures---------------[/SIZE]

[SIZE="1"]
My friend Scott helping get this party started right[/SIZE]


[SIZE="1"]Old'n'Busted[/SIZE]


[SIZE="1"]Ye ole strut[/SIZE]


[SIZE="1"]BRAKE FAILURE IMMINENT[/SIZE]


[SIZE="1"]Old LCA Bushing[/SIZE]


[SIZE="1"]New LCA Bushing[/SIZE]


[SIZE="1"]
'03-'04 Cobra LCA[/SIZE]

[SIZE="1"]

Koni/OEM Comparison[/SIZE]


[SIZE="1"]Closeup[/SIZE]






[SIZE="1"]Remember kids - Safety First![/SIZE]


[SIZE="1"]Clearancing the spindles for the 99+ calipers[/SIZE]


[SIZE="1"]Brake bracket that needs to be modified to work the the 99+ hoses[/SIZE]


[SIZE="1"]Not much clearance between the hose and chassis[/SIZE]


[SIZE="1"]
$17 bolt - I thought it would cook me breakfast for that price[/SIZE]


[SIZE="1"]The New Hawtness[/SIZE]


[SIZE="1"]New setup with unadjusted tie-rods[/SIZE]


[SIZE="1"]Side Profile[/SIZE]


[SIZE="1"]
Finished product. Poor T-bird needs paint and bodywork something fierce :(
You can see the hood/header panel/fender misalignment caused by my agricultural excursion[/SIZE]


Both cars. Both needing much TLC.

Front coil-over install

Reply #1 –
OK, You said that you used a SN95 steering rack?

And by this:
If you are going to upgrade to SN95 spindles, but aren't going to use the Cobra setup; I would highly recommend the '99-'04 V6/GT spindles, they're lighter and stiffer than the single piston steel '94-'98 calipers. The only downside is they're a bit more expensive.

Do you mean spindle or caliper?

By the way, very nice.

Front coil-over install

Reply #2 –
Yeah, I meant calipers.

Front coil-over install

Reply #3 –
Engineer + Tbird = Results!
One 88

Front coil-over install

Reply #4 –
Nice progress Jeremy.  Just curious, why the 03-04 a-arms were chosen...?

My 88 TC was the first car I worked on (somewhat still is...on going project!) back when I bought it at 17 yrs old so I did things kinda of mixed up and without research.  :hick:  This is why I ended up years later with a 13" cobra brakes and then just recently fox mustang a-arms to finally fix my front track (it was about 1" to wide on each side with the 95 R's - 17x9, 24mm - that were perfect with my stock brakes)...

Anyway, just kind of curious if you know if there is a track width difference between your brakes (new) and the 13" cobras like I have.  Always wondering if there is a better setup especially because I still don't know if I'm going to be able to dial in the optimal amount of negative camber...
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

Front coil-over install

Reply #5 –
Quote from: booksix;180060
Just curious, why the 03-04 a-arms were chosen...?
The '03-'04 arms are the same length as '87-'88 LCAs, but have stiffer bushings and an improved stamping that allows for greater steering angle.
They cost $189. New bushings and new ball joints cost ~$179. So, it was a no brainer for me to buy the Cobra arms.
Quote
Anyway, just kind of curious if you know if there is a track width difference between your brakes (new) and the 13" cobras like I have.
The track width is determined by the spindle. If you have '96+ spindles, you'll increase your track width 5mm per side. (Some say 5mm, some say 8mm). If you have '94-'95 spindles, your track width will be the same as mine, excepting allowances for different wheel offsets.

Front coil-over install

Reply #6 –
That's strange.  I have "94" spindles.  But I got them from a junkyard back in WI.  Wonder if they screwed up and sold me what was actually a later model piece...  So the 94-95 spindles supposedly keep a similar track?  My question then is:  is the track width increase gained with 96+ spindles gained between the strut mount point and the wheel mount surface?  The reason I ask is because my spindles pushed my 17x9 R's from sitting perfect (stock brakes) to sitting WAY outside the fender (WAY for me is about 1").  So, to correct this, I used 89 mustang arms, but this pulled everything in and I'm not sure my MM plates will have enough adjustment to correct it, even in the negative position (because the whole strut moved so much).  :beatyoass:

oh man, I'm gonna be so pissed if all I needed was the 'correct' 94-95 spindles...  I could have spent my time putting those poly bushings in my stock arms (NOT spent the money on stang arms) AND wouldn't have to take drastic measures to get negative camber (if that is the case - assuming you have 'normal' or stock like adjust-ability on top)... 

Does this make sense?  hit me back so I know if I should be pissed!!  :mad:
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

Front coil-over install

Reply #7 –
PS:  what did you have to clearance on those spindles?  I didn't have to do anything...  I seem to remember this was a difference between the 94-95 and 96+ spindles...  i bet I have 96+
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

Front coil-over install

Reply #8 –
Quote from: booksix;180102
PS:  what did you have to clearance on those spindles?  I didn't have to do anything...  I seem to remember this was a difference between the 94-95 and 96+ spindles...  i bet I have 96+


You only have to clearance the 94-95 spindles when you use the dual piston PBR calipers that are found on the 99-04 mustangs

Front coil-over install

Reply #9 –
JermeyB, did you just have to replace the outer tie rods?  I'm not sure, some say you have to, and others say you don't.  Also, where did you get the LCA's?

Front coil-over install

Reply #10 –
I didn't do anything with my tie-rods...  perhaps he did because of the cobra rack..?
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

Front coil-over install

Reply #11 –
Quote from: booksix;180101
That's strange.  I have "94" spindles.  But I got them from a junkyard back in WI.  Wonder if they screwed up and sold me what was actually a later model piece...  So the 94-95 spindles supposedly keep a similar track? 
94-95 spindles have a curved steering arm. 96+ spindles have a straight arm. You can see the curved arm in two of the pictures. 94-95 spindles will add ~.9" of track width to wheels with 28.45mm offset. More/less offset will increase/decrease the change in track width.
Quote from: Sduneman3;180107
JermeyB, did you just have to replace the outer tie rods?  I'm not sure, some say you have to, and others say you don't.  Also, where did you get the LCA's?
I converted to metric tie rod ends (TREs) when I installed the SN95 rack (because the rack came with inners already installed). I had to use Taurus outers with the stock spindles, because the SN95 outers didn't have enough inward adjustment. I changed to SN95 TREs with the SN95 spindles because the Taurus TREs weren't long enough.

Fox cars use SAE threaded tie rods. SN95/Taurus cars use metric threaded tie rods. You cannot mix and match Fox/SN95 tie rods.

It sounds like booksix used his Fox tie rods. I am curious how much engagement there is between the inner/outer.

Front coil-over install

Reply #12 –
Ok, so do SN95 steering racks bolt right in?  or are there some modifications that need to be done?

Front coil-over install

Reply #13 –
They bolt in, but the input shaft is different. You can buy a shaft from Maximum Motorsports that allows the Fox column and SN95 rack input shaft to mate.
Also, as I said earlier, you need to change the TREs too.
Taurus for stock spindles
SN95 for SN95 spindles

MMST-13 $220.

Front coil-over install

Reply #14 –
Ok, so they must have a bigger backspace.  At first I thought the offset difference was because your wheels are 17x8 and my are 17x9 but then I thought about it and realized it's just a different wheel...  Ok, well, guess I need different wheels if I want to get a more stock strut setup...

anyone wanna buy 5 17x9 Cobra R's  :D
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats