Blunder
New Reader
6/12/22 4:39 p.m.
I'm looking for some advice about lowered foxbodys. I have a 93 that I have put steeda sport springs on. They have rates of 650lbs in the front and 200/250 lbs in the rear. The car rides like donkey butt currently with stock shocks. I was interested in the koni str.t setup or the yellow single adjustables. The car is just a street car but would definitely like it to handle well. I don't need a super cushy ride but don't want anything extremely harsh. Any advice would be appreciated.
I love the yellows to the point of obsession. I have not experienced the str.t shocks, but if they behave like the fsd of old, they're a little soft for high spring rate setups.
j_tso
HalfDork
6/12/22 6:15 p.m.
Fox body rear shocks fit 1st gen RX-7s and I have a pair of STR.T in the back of mine.
They're supposed to be OEM replacement so I figured dampers for a heavier car would be stiffer in mine, but I find them too soft.
Maybe they would damp the ride better with a stiffer spring, however with yellows you can go softer or harder.
Yellows or yellow sports were the hot ticket for Mustangs with lowering springs without making the leap to coil overs. The Common thread on the Bilsteins were that they were too harsh in the foxbodies.
gumby
Dork
6/12/22 6:38 p.m.
I run str.t's on my fox chassis Tbird with 800lb front coils and 250lb rears. I also have a torque arm out back, so less inherent bind. If I was chasing peak performance, the rear springs are likely too soft.
I am really happy with the str.t dampers in a 99.8% street car that may go to an autoX or drag strip on rare occasion.
Dusterbd13-michael said:
I love the yellows to the point of obsession. I have not experienced the str.t shocks, but if they behave like the fsd of old, they're a little soft for high spring rate setups.
Str.t shocks are basically stock replacements. Valving (in the applications I know) are similar to a yellow on full soft. Best for stock springs. They're made in Vietnam but have the same lifetime warranty as the Dutch shocks.
FSD has been renamed as "Active", I think.
I would recommend yellows for this application. You need more rebound damping than you have.
Blunder
New Reader
6/12/22 8:42 p.m.
I appreciate all the replies. Sounds like the yellow single adjustable konis are the way to go. This foxbody is a forever car for me. Does koni still offer a lifetime warranty?
In reply to Blunder :
Yes and you will want Yellows with those springs.
Blunder
New Reader
6/12/22 9:47 p.m.
I heard that the koni str.t are similar to the yellow konis on the softest setting. If the the str.t konis are too weak to use with the steeda springs does that mean it will be bad for the yellow konis if I use them on the softest setting?
Blunder
New Reader
6/12/22 9:49 p.m.
In reply to AnthonyGS (Forum Supporter) :
Do you know much about the steeda sport springs? Are they a decent handling spring? I bought them because they popped up for sale near me at a good price and because they didn't lower the car excessively but I honestly don't know much about them.
In reply to Blunder :
Yes they are a quality part. I was a Fox Mustang guy for decades. Mustangs like Miata's has quite a few quality vendors. Steeda won a lot of SCCA events on thise springs back in the day. You will want the adjustability of the yellows I feel. The rear suspension is the weak end of the platform. Steeda even made a really cool 5 link rear at one time. Maximum Motorsports is a great place to shop suspension options too. Their lowering springs will be very similar to the Steeda ones. Ford Motorsport later made their own version too copying the spring rates.
Fox springs tend to be stiff 600-750 # per inch fronts with fixed or variable rate rears, 250-325#. These cars are heavy in the front so bad springs will sag a lot over time. The really bad thing is the stock suspension design allows the rear axle a lot of side to side motion. This requires smooth driving inputs to allow the rear to take a set. Snap movements result in a vicious bind and snap oversteer.
Javelin did a lot of autocross and other invents in a Fox Cobra. He probably has good input as well.
Blunder
New Reader
6/15/22 6:56 p.m.
I ordered the yellow konis and they arrived today. The directions weren't very clear. I assume all the stock bushings and dust cover go onto the konis but I'm unsure where to put the large ribbed plastic washer that came with the konis. Does anyone happen to know?
I had Koni STR.T shocks on my Miata with Flyin' Miata springs and I was not happy with how quickly they wore out. I finally replaced them a few weeks ago with KYB AGX. Although I had the Konis on the car way past when they should have been replaced, I was surprised how corroded they got:
Javelin
MegaDork
6/15/22 10:04 p.m.
I just saw this. I used to autocross and track day my SN95 Cobra heavily, but nothing about that car translates. I had true front coilovers, tubular control arms with no spring pockets, offset rack and bumpsteer kit, caster/camber plates, and a lot of reinforcements.
That said I think you're on the right track with Yellow Konis to pair with your springs. I'll echo that the orange STR.T's are worthless. Do you have a strut bar? K-member brace? Frame connectors?
Blunder
New Reader
6/15/22 10:09 p.m.
In reply to AnthonyGS (Forum Supporter) :
Thanks a lot. That is where I thought they went but it is nice to have confirmation.
Blunder
New Reader
6/15/22 10:13 p.m.
In reply to Javelin :
The car is a street car and will most likely not see any kind of racing. The car has steeda sport springs, koni yellows sa thanks to this forums input, poly front control arm bushings, and some south side rear lower control arms from the early 2000s. I was looking recently at adding full length weld in subframe connectors. I'm not very knowledgeable about suspension set up so any advice about how to get a nice handling street car is appreciated.
Javelin
MegaDork
6/15/22 11:44 p.m.
In reply to Blunder :
Fox chassis are notoriously floppy, meaning that the actual sheet metal tub flexes under load. Adding reinforcements like subframe connectors and a strut brace will make it handle better and ride worse.
Honestly I'd lose the poly bushings for OE rubber, check the rear quad shocks to make sure they are working, and look at your wheel/tire choice and alignment specs. Remember that this suspension was designed for 14" wheels with 70 series tires, even putting 17's on makes it ride pretty rough. My SN95 beat my kidneys out of me.
Bigger hollow sway bars helped a lot. Eibach and Steeda both had good street options.
You did get bump stops with those I hope. How much lower is the car from stock? Did you call Koni and check with them on length? If you crash the valve into the bottom of the strut housing you trash the units. This is why it is very important to install the stops in the struts on lowered cars. I did this on one of my 944s. It was only lowered 1 1/2 inches on Progressive rate springs
Bump stops look like this.
Blunder
New Reader
6/17/22 12:01 a.m.
In reply to dean1484 :
The steeda springs lower the car about 1.25 inches I believe. The rear konis came with bumpstops. I have the 94-95 mustang rear konis on the car since they are supposed to work better with lowered foxs. The front konis didn't come with any kind of bump stop. I just switched all the bushings and dust covers over from my old front suspension. Do I need bump stops for the front too? Should the fronts have come with them?
Maximum Motorsports
This is not a canoe. I have no affiliation.
MM has a treasure trove of instructions and data on their website and really know how to set up Fox Mustangs. They are good folks and usually answer the phone if you need immediate help.
Here are their Koni bump stop for stock strut mounts. If you have after market camber plates, then you probably need specific bump stops for those plates.
The struts don't come with them usually. Need??? No but hit a good bump and bottom the strut out and it can damage the strut.
I would call Koni and speak with someone there about if they recommend them for your specific setup. I personally put them on every car that is lowered with shorter springs.
Lee Grimes at Koni is who you want to speak to. He was on the GRM forum and also was on the GRM YouTube channel in a live stream at least once. He is an all around great guy!!!
Blunder
New Reader
6/17/22 8:31 a.m.
In reply to dean1484 :
So the rears definitely came with bump stops just like you pictured. Same color and everything. Once I thought about it the stock fronts did have bump stops that I moved over to the konis. I'll check if the fronts need some kind of aftermarket stops. Thanks for all the good info. I DONT want to ruin the konis.
Blunder
New Reader
6/17/22 8:36 a.m.
In reply to tester (Forum Supporter) :
I will go ahead and pick those up for the fronts. I don't want to mess anything up and take chances The rears came with stops. Thanks for the reply.