Springs....

I believe you would notice no difference with the mach 1 springs they sat like pick - up trucks and were heavier than fox cars anyway it would problably sit higher

Why not just get a Ford spring that you know would work and only lower it a bit?

just buy a 5300 B or C kit from Ford they are dirt cheap and will lower it about an inch

I have the Machs in my vert and like 'em alright.

They dropped the car a little bit (over very springs) but are not too harsh like C's can be (relatively speaking).

Bullit and/or Mach 1 springs are becoming a popular upgrade for foxes. They are known to drop the car about 3/4 of an inch while maintaining ride comfort and providing good performance. At that kind of drop you shouldn't need CC plates. Do a search. Plenty of info out there on this. Here's an example of Mach 1 springs from a member on a different site. Do NOT go with the B springs, way too soft for the drop, and the C springs are a little too harsh IMO. If you want a slight drop and still be happy with the ride quality, the Bullit springs are the ones to go with.

PUNISHER RACING said:

just buy a 5300 B or C kit from Ford they are dirt cheap and will lower it about an inch

Click to expand...

Wow, you're way off! IMHO, B springs are one of the worst things possible to do to a Stang! Also, they drop a Stang ~1.5+".

Mach1 springs drop a Stang ~1/2"-3/4". Bullitt springs drop a Stang ~3/4"+. There are MANY factors in the drop! Some are hatch/notch/vert, GT/LX, AOD/T5, AC, alum heads, relocated battery, etc. The first 3 I listed have a very important influence on the amount of drop for some non stock spring. Ford had a number of OEM springs for GTs (and Stangs) depending on options/style.

The Mach1 & Bullitt springs are the *only* OEM springs (and likely aftermarket) that are not too soft for the drop. I don't what you've been smoking, but both the Mach1, and Bullitt Stangs were *lower* than GT and for a OEM car, they are pretty low. The fender line is BS! The fender line is not how low the car is. You can take a sawzall to your fender and have a very high fender line. Or, get a very wide Griggs fender and some bondo, and have a very low fender line.

For at 1"+ drop, you'd want a 1000+ rate spring. That's to keep the same jounce amount/rate as stock. People with B springs (and many other lowering springs) often have their strut & shock bottom out. Most of the time, they may not even notice. It's not until they get broken struts, shocks, and strut/shock towers do they realize what a POS mod the B & C springs are.

I have a bunch of info here (needs to be updated):
http://veryuseful.com/InvisionBoard/index.php?showforum=2

If you do a search on the corral for stangPlus2Birds and springs, you'll see a LOT of "stuff". You'll see many people trying to defend their poor choice of springs and also keeping the springs. But, notice, you won't see a single person defend the other springs that has an engineering degree or any classes in mechanical engineering (heck, some high schools even have "mechanical engineering" / force-vector classes!).

If people want the lower springs for looks only and they are willing to RISK bottoming out their suspension on occasions, that's their choice! But, *I* care that people get the correct and accurate information on springs.

BTW: More pictures of my car:
http://www.veryuseful.com/mustang/tech/misc/Mustang1986_with_Mach1_springs/
http://www.veryuseful.com/mustang/tech/tmp/OTC-spring-tool/

I have an AOD, 3-core radiator, and I have wide tires (245/45/17 RE720s) with the smaller '86 fenders. So, I needed very little drop. I use the Steeda spacer to gain ~0.4" with the Mach1 springs. The 3-core radiator holds more water and that's further up front (more leverage). Add that to an AOD in a GT and the Mach1 springs would have dropped my car by over 3/4". Like I said, there are many considerations in choosing a spring!

FYI: So people don't have to hunt:
I'll also add that a drop of 1"+ screws up the CG (center of gravity) of the car (a *Stang*) as it corners. So, unless you go with very stiff race springs, don't even think of dropping the car more than ~1" if you want focus on handling.

Summary (assuming installed in the same car - a stock 93 Stang GT 5speed with AC):
GT spring: ~1,855 lbs of force to compress.
Mach1 Spring: ~1,800 lbs of force to compress. Coincidence? NO!
B Spring: Only ~1000 lbs of force to compress. That's because they are not a spring made for a Stang! They are an OEM spring that Ford offered for another vehicle!

Gee, it seems like the Mach1 & Bullitt springs were made for the Stang by real automotive engineers and not by some aftermarket company selling BS parts, doesn't it?

CC plates will increase the NVH to the car. So will a new steering shaft (MM).

If you want a better handling car, go with the Mach1 Springs. They'll lower the car ~1/2" and up the spring rate from 425 to 600. Lowering a GT more than 1" means a LOT of stuff to consider for a PROPER setup.

The 400 rate springs (4 cyl) do give a better ride. But, you MUST also raise the fender height because the GT's are heavier.

IMHO, the Prokit or "B" springs are a very poor choice! The rate is far too low for that amount of drop! You should also put in a bumpsteer kit. With ANY CC plates, IMHO, you MUST use an STB.

Also, a drop of more than 1" is a very poor choice for a STREET car that's used in for the majority of the U.S. There are a *few* places and a *few* people where a STREET car with a drop of over 1" may make some sense.

Fox V8 Stang came with 425/530 front springs. See pg 376 in the book by Al Kirschenbaum. The *Fox GT*'s (and V8's) have ~3.5" of jounce and rebound travel (pg 368).
So, lowering a car by 1.5" with the stupid "B" springs means that the springs bottom out with ~1000lbs of force - which isn't that uncommon in bad street bump. That means that the stock springs allow 75% more jounce than a GT with the stupid "B" springs:

1.5" (more travel with OEM springs)
------------------------------------- (divided by)
2" (total jounce with stupid B springs)


A bigger rim means a shorter sidewall. That means *more* harshness. The tires you pick also make a big difference! The sporty tires (Ultra performance tires) have very stiff sidewalls. That means a lot more harshness and also often noise. Although tread design has a lot to do with road noise.


With the Mach1 & Bullitt springs, it takes just about as much force to fully compress the spring as the Fox GT springs. It's hard to say exactly because the Fox springs are progressive.

See pg 376 in the book by Al Kirschenbaum. The *Fox GT*'s (and V8's) have ~3.5" of jounce and rebound travel (pg 368). A V8 should still have the 425/530 front springs.

So, that's a max of ~1,855 (3.5 * 530) pounds of force to compress a GT spring (assuming it was at 530 at stock height - which it isn't).

For a Mach1 Spring (~3 * 600) we get ~1.800 pounds of force to fully compress the spring. Coincidence? NO!

So, since we know that the Fox GT springs don't start out at a rate of 530 at stock height, we can see how the Mach1 and Bullitt springs are fine for the street! Gee, it even seems like they were made for the Stang by real automotive engineers and not by some aftermarket company selling BS parts, doesn't it?

Click to expand...

stang&2Birds said:

Wow, you're way off! IMHO, B springs are one of the worst things possible to do to a Stang! Also, they drop a Stang ~1.5+".

B Spring: Only ~1000 lbs of force to compress. That's because they are not a spring made for a Stang! They are an OEM spring that Ford offered for another vehicle!

Click to expand...

Not trying to flame you here, but on one hand you say Ford knows what they're doing with the Mach1/Bullitt springs, and on the other what you've said above contradicts with Ford's own data.

Now the 'B'&'C's have been around for a while, so I'm willing to bet the .875"F/.5"R is the average drop based on the Fox3 platform (guestimate those specs are within 1/8"(+/-) for nearly any Fox, given they have good shocks and retain factory isolators). Especially when you consider the 'B' spring has the same progressive rate as a Fox GT. With that said, I agree with you that equipping B-springs with the same rate as the stockers is going to add more stress to the shocks and struts, you just need ones that can keep up. That's why you don't keep the stock shocks/struts or KYBs for very long with a lowering spring

I also thought it was around 1.5" of lowering that the Foxes and SN95s started to have serious geometry issues (but I don't know the url to that technical website atm, so it is just hearsay ). Steeda, H&R, Suspension Technqiues etc... all make their race/compeition level springs around the 1-1/8 to 1-1/4 lowering mark. Wouldn't they have had to change their Fox/SN95 springs to 3/4"ish long ago, if all these cars were facing serious issues with anymore of a drop?

GREAT observation!

Uhm, the FRPP info is BS, plain and simple. Yes, I agree, it sucks! And, if you do a search on the corral, you see a *number* of places I outright said that FRPP has a moron in charge of the catalog!
HEAR THAT FORD & FRPP!!!

I 100% agree, that there is no reason at all that the FRPP catalog should have so many errors for so many years!

I used to be a FRPP mega leghumper. Again, a search will confirm that. But, after the B springs and their POS bumpsteer kit, I tell people to stay away from most FRPP cr*p!

Many people have put on B & C springs. Do a search.
I have a set of B springs. That's how I got into this whole BS. See the link I posted. Call FRPP and ask about the drop on a 93 Fox GT 5sp Hatch with AC, power windows, power door locks, power mirrors, etc. In other words, the vast majority 93 GTs sold.

The B springs are too way too short to be 3/4" drop. I *think* the problem is that some fool saw that the springs were ~3/4" shorter and said that the drop would be ~3/4" shorter. But, a spring that's the same rate but ~3/4" shorter than stock results in a drop of ~1.4"! The MR is very roughly ~0.5. Then, moron in charge of the catalog just lets it go for ?10/15? years. Not giving a rat's *ss about screwing people buying their products. Hmm, is that the type of "company/division" that you want to buy parts for that you depend on?

Yea, they do have some great products. It's a shame that they have a moron in charge of the catalog! I LOVE their M2300K Cobra brake kit. IMHO, it's the BEST mod in the world for a Fox Stang!.

Oh yea, after a ~1.5" drop, the Stangs do have major geometry issues. But, that's *not* what I said. After 1", the CG gets "screwy" (actually gets higher up in some cases). Again, I'm talking about an otherwise stock GT! People that run OT/CT can run lower. But, those cars are far from "stock".

As much as I hate to blow off an intelligent questions (seems like they are far a few today), I'll have to say "do a search here and on the corral". This topic comes up just about every week! There is a ton of info. Unfortunately, a lot of it is bad info. Even when people say how much their car is lowered, 90% of the time they are *wrong* (not very accurate). You need to have the fender height measurements, know the EXACT tire model and size, know the tire air pressure and wear, and so on.

If you want to know, with the correct tire size (diameter) and correct air pressure, my fenders sit at ~26-7/8". And, that's with the poly isolators that "add" about ~1/8" to the fender height. AND, that's with the springs installed correctly!. There can be ~1/4" difference depending on how the springs are installed. See my links to see that I have my springs lined up correctly in the FCAs!

I've said my piece. As I've mentioned. I'm consulting with 2 clients (one full time, the other part time) and I'm swamped. The search function is very useful. Just be careful were you get the info from and how much you trust the info.

____________
Joe
'86 Stang GT with M2300K Cobra brake kit, ABS, subframes, eaton rear-end, MM CC plates, STB, tok 5 way adj struts/shocks, mach1 springs, BBK isolators, poly swaybar isolators & link bushings, FRPP Fox FCAs (firmer bushings & lifetime ball joint), RE720 245/45/17 tires, D78 rims, bla, bla, bla.