Rear ride height adjustment..if any? Sitting too low and pissed off.

I have a 1990 GT that I have had 3 sets of springs on now. I bought the vehicle as a roller and it had the stock GT springs with those turn in spring booster knuckles. Anyway they went in the garbage, and I installed Eibach Prokit front for 1 - 1.5 drop and sportline for 1.5-2" drop because the added weight of the big block I WAS PLANNING on putting in would have made it lower. Anyway I did a 306 instead and needless to say found out that the sportline springs only look good and are usless for any weight transfer. So I replaced them with 4 cylinder springs. They are soft and have great weight transfer but the car still sits lower in the rear with 4 cyl sprigs than the front with the Eibach Prokit....weird?:shrug::shrug: Im currently running 18"s on it now and have clearenced the rear lip to keep tire from bitting over bumps but the rear is still too low. Nothing looks out of whack back there at all that I can see. I also have UPR solid lowers and MM double adjustable uppers with Lakewood 50/50's. Has anyone ever seen or heard of 4 cyl springs being this low???? I thought they were taller but softer than GT springs which is why it is a good cheap swap because the ride height stays the same but launches better. ....I know control arm adjustments are made for pinion angle so what the balls mahoney do I do about correcting ride height in the back????? Im at a loss but need to get this adressed.
 
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ride height

You running isos? If not put those in.

I've read plenty of threads where people either have had the Eibach sag or just be too low.

I'd go with Steeda springs, they will give you the least amount of drop and should be stiff enough for what you need.
 
I'm at a loss of what you're doing to your suspension and why. What are you trying to accomplish? Right now, what you have is a mess. It's great if you want to rattle off what add-ons you have.

That setup doesn't make sense for handling.
That setup doesn't make sense for the quarter mile.
That setup doesn't make sense for a lowered looks only car.

So, first, decide what your goal is for the suspension. Sorry, regardless of the spew that some people give, you can not "have it all". The stock Stang or the stock Stang GT suspensions are the best overall compromises there are (giving costs). So, other than those choices, you must decide why you want to modify your suspension.

Quickly:
For handling: Never ever go below 1". Go with at least 600lbs springs. Get CC plates and a bumpsteer kit.

For Quarter Mile: 4 Cyl springs. You want the height and the easy weight transfer.

For Looks: Do what you want. :) The geometry and characteristics of the ~30+ year Fox chassis get so screwed up when you drop it below 1" (which is ~2" below what it was originally designed for), it's pretty much hopeless. At least get CC plates and a bumpsteer kit. Even 600 rate springs are a joke at the drop. A spring rate of well over 1000lbs/in would be needed to keep stock jounce rates. So, go for the drop you want, and realize that the handling will be worse, and you're going to have a number of issues with real-life pot-holes, speed bumps, driveway ramps, driveways, ramps, and so on.

Last: You can get (just about :)) any rear fender height you want (at Alice's restaurant ;)) by going with adj height rear LCAs. MM sells them, and Summit also has a decent pair for ~$200.
 
I'm at a loss of what you're doing to your suspension and why. What are you trying to accomplish? Right now, what you have is a mess. It's great if you want to rattle off what add-ons you have.

That setup doesn't make sense for handling.
That setup doesn't make sense for the quarter mile.
That setup doesn't make sense for a lowered looks only car.

So, first, decide what your goal is for the suspension. Sorry, regardless of the spew that some people give, you can not "have it all". The stock Stang or the stock Stang GT suspensions are the best overall compromises there are (giving costs). So, other than those choices, you must decide why you want to modify your suspension.

Quickly:
For handling: Never ever go below 1". Go with at least 600lbs springs. Get CC plates and a bumpsteer kit.

For Quarter Mile: 4 Cyl springs. You want the height and the easy weight transfer.

For Looks: Do what you want. :) The geometry and characteristics of the ~30+ year Fox chassis get so screwed up when you drop it below 1" (which is ~2" below what it was originally designed for), it's pretty much hopeless. At least get CC plates and a bumpsteer kit. Even 600 rate springs are a joke at the drop. A spring rate of well over 1000lbs/in would be needed to keep stock jounce rates. So, go for the drop you want, and realize that the handling will be worse, and you're going to have a number of issues with real-life pot-holes, speed bumps, driveway ramps, driveways, ramps, and so on.

Last: You can get (just about :)) any rear fender height you want (at Alice's restaurant ;)) by going with adj height rear LCAs. MM sells them, and Summit also has a decent pair for ~$200.

I have Progressive rate springs not Specific rate, therefore I dont have at a SPECIFIC LB/IN rating. I was advised by a friend to use the 4 cylinder springs. I do have MM camber caster plates in the front along with theyre bumpsteer kit and Lakewood 70/30"s and I chose those because this is a street car that I want to hook up but not ride like garbage. I did want to drop the rear some but right now it is more than I want so I am trying to figure out how to correct buy getting input from some other people, what they run and what works. I know that there are different combos for differnet purposes. So next time instead of going of on a rant of things not making sense or saying at least get this or that just ask a ****ing question about what else I have on the car or what Im trying to accomplish and make a suggestion from there. Alot of this type of setup is trial and error, what works well on one car may not work well on the other and I realize that. I dont know about you but I dont have $1,000's of dollars to piss away buying all sorts of different stuff nor have the time to run tests on everything. I appreciate alot of input but you have to realize that Im not an idiot and understand how to be helpful not a blantant jerk.
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Easy there killer... There's no need for any of the profanity, or the abrasive response. S&2B has probably forgotten more about suspension than most us will ever know. You say you appreciate the input, but you're talking out of both sides of your mouth. Cool it.

-Matt
 
I want a car that will just ever so slightly tuck 18's (Well at least sit over top of them without daylight), but be able to squat and go when need be. This car is intended for 70% street cruiser and 30% at the track. It will more than likely get boosted or sprayed in the next year. I started this post because Im very suprised 4 cylinder springs on the back of a GT make it sit lower than the front with Eibach Pro Kit. Im sure a drag launch spring with an airbag will hookup best without a doubt but how do they ride? Does it sit at stock height or higher? Etc.....All I was looking for was input on what you guys have seen work on a street car and what is a waste of time. Its obvious that Ive followed some bad previous advice and already wasted some time but want to adress this without having to redo the car.
 
First, YIKES! I take it back about the POS Granatelli LCAs!
So, it looks like MM LCA only. And, they are far from cheap ~$400 -> ~$500.
Wow, don't I EVER learn -- **MM ONLY**!!
Check out: http://forums.corral.net/forums/showthread.php?t=1031620
Granitelli_LCA_2.jpg
 
but I dont have $1,000's of dollars to piss away buying all sorts of different stuff nor have the time to run tests on everything.
That's why I bother with these threads.


Im not an idiot and understand how to be helpful not a blantant jerk.
YOU are not. But, realize that ricers rule the forums! All it takes is 2 ricers, that don't know the first thing they are talking about to SWAY people and then end up with the other PEOPLE GETTING SCREWED!Ever hear or the MORONIC RICER advice to set your TPS to 0.98v? The knowledge was out there, but someone had to take on the ricers. I did that. They same is true about suspension setups. I read over and over about "How great my B springs are". The car handles likes it's on rails, it beat an 2009 on the circle track course, it beat a rocket car at the track, and RR wants to rent my cars because the ride is so great! Oh yea, and it never ever bottoms out! Yea, those people are on crack - big time!!

If you also search hard enough, you find people asking how to get rid of their POS B and C en Eibach springs because the car handles like a pig and bottoms out going over a pebble. Also, I get far too many PMs asking what to do to "fix their suspension setup". So, my post above is a mini FAQ.
 
I want a car that will just ever so slightly tuck 18's (Well at least sit over top of them without daylight), but be able to squat and go when need be. This car is intended for 70% street cruiser and 30% at the track. It will more than likely get boosted or sprayed in the next year. I started this post because Im very suprised 4 cylinder springs on the back of a GT make it sit lower than the front with Eibach Pro Kit. Im sure a drag launch spring with an airbag will hookup best without a doubt but how do they ride? Does it sit at stock height or higher? Etc.....All I was looking for was input on what you guys have seen work on a street car and what is a waste of time. Its obvious that Ive followed some bad previous advice and already wasted some time but want to adress this without having to redo the car.
Sigh, define "track". To me, track means OT/CT.

Again, if you want a suspension that's good for the quarter mile, then do NOT lower the car. And, go with softer springs.

I'll say again and again, for an overall compromise between street, handling, and quarter mile, you can not beat the GT factory setup. Any change will take away from one or more of those areas.

Your rear setup now is better for the qtr mile and for handling, but you loose comfort. If you want to lower the car a *little* to get a slightly more aggressive looks, that's fine. You can go with the Mach1 Springs (~1/2 drop). You get better handling, less comfort, and a lower look. But, at a rate of 600, they are not as good for the qtr mile. If you want to drop the car *only 1/2"*, you "could" cut the *GT* springs. I don't recommend dropping the car without upping the spring rate accordingly. Otherwise, you run the very real risk of bottoming out the suspension.car. For a drop of ~1/2" to ~3/4" you need to go up to a specfic rate spring of at least 600 lbs/in to keep the jounce amount. That's why Ford chose that spring rate for the Bullitt and Mach1.

Still, cutting the GT springs for a drop of ~1/2" is better than the all out for looks only FRPP C and B springs.

Air bags are a good idea for the qtr mile. Just realize that when used on a street car, depending on the mileage per year, they may last only 2-5 years. They are cheap and easy to replace. So, it's no big deal. But, it's one of those many things that people seem to forget to mention (similar to how a Stang with B springs has a hard time with standard driveway ramps and speed bumps). I had air bag on my T-bird. They don't effect the street ride much at all. You should NOT use rear air bags to gain rear fender height (for a street car). The air bags will wear out pretty quickly with that type of use.

If the rear-end of the car is off-center, that also effects how long the rear springs have to stretch, and the effects the fender height. If the rear-end of off-center more than ~1/4", you should fix that first.

Oh well, that basically most of the info. I'm swamped with 3 consulting contracts. Good Luck! And, be very careful of the advice and the info that you read on the forums!
 
Ride Height: I fought ride height for a while when I built my 81 coupe. I have HPM Mega Bite Jr LCA's. You can adjust the ride height with those by simply raising the mounting bolt location. I raised mine by just over 3/4". They also come with two 1/4" springs spacers for each side. So with no spacers, the car is 1/4" or 1/2" lower than with one or both spacers. The LCA's are cheaper than MM or Granitelli's with the weight jacker. You don't want to go with tubular control arms anyways. They all break. Even the HD MM's....many on here and Corral have blown the bushings out on them with 12 second cars. The HPM's are HD. I have had them on my Cobra for 8 years, and my 81 notch for the past 6 months, and I bought those used, so they are at least 4-5 years old.

For handling: You should match all your springs in all four corners. My Steeda Sport springs ride nice over small bumps, but are a killer over rough rail road tracks or pot holes. However, the handling is very, very nice.
 
I've messed with springs, spacers, control arms for years.
And i have to agree with Stang2birds.
You have to pick one theme and stick to it. You are not going to get looks, handling, straightline traction. You can get looks and handling together, but straight line has to be separate.

Sportlines are crap, so are 4cyl springs. Yes, i used the 4cyls myself, god what a death trap that was.
I got tired of messing with stuff and attempting pretty much what you are doing, i wanted it to look good, hook, and not get me killed in a bend.
In the end i landed up with my saleen springs back in, definetely with ES isolators, koni adjustables up front, qa1 12 ways out back. And my best investment for traction, 18 inch bfg drag radials.

Using the adjustable shocks and struts with the lowering springs, allows the car to handle, and then be adjusted for a bit more traction for the track. Are you going to pull the wheels off the ground? No, but for a street car, it makes for a decent ride, pleasurable handling and good safety.
Mixing, matching and cutting springs on a street car rarely turns out good.
IMO, put your entire set of eibach pro (not sportline) springs back in, and ES isolators, and get yourself some good adjustable shocks and struts. Trust me, your driving will be much more fun.
 
Have you thought of going with a coilover setup? You can choose your spring rate and adjust your height. It sounds like it might be the best solution in your situation. I understand that you don't have a lot of money but MMR on the corral forum is offering a discount of some sort for the rear coilover kit. I am not sure how good they are but the concept is pretty much the same for any company that makes kits. I have yet to install my front conversion but just by looking at the kit it seems pretty nice.
Kevin
 
Sigh, define "track". To me, track means OT/CT.

Again, if you want a suspension that's good for the quarter mile, then do NOT lower the car. And, go with softer springs.

I'll say again and again, for an overall compromise between street, handling, and quarter mile, you can not beat the GT factory setup. Any change will take away from one or more of those areas.

Your rear setup now is better for the qtr mile and for handling, but you loose comfort. If you want to lower the car a *little* to get a slightly more aggressive looks, that's fine. You can go with the Mach1 Springs (~1/2 drop). You get better handling, less comfort, and a lower look. But, at a rate of 600, they are not as good for the qtr mile. If you want to drop the car *only 1/2"*, you "could" cut the *GT* springs. I don't recommend dropping the car without upping the spring rate accordingly. Otherwise, you run the very real risk of bottoming out the suspension.car. For a drop of ~1/2" to ~3/4" you need to go up to a specfic rate spring of at least 600 lbs/in to keep the jounce amount. That's why Ford chose that spring rate for the Bullitt and Mach1.

Still, cutting the GT springs for a drop of ~1/2" is better than the all out for looks only FRPP C and B springs.

Air bags are a good idea for the qtr mile. Just realize that when used on a street car, depending on the mileage per year, they may last only 2-5 years. They are cheap and easy to replace. So, it's no big deal. But, it's one of those many things that people seem to forget to mention (similar to how a Stang with B springs has a hard time with standard driveway ramps and speed bumps). I had air bag on my T-bird. They don't effect the street ride much at all. You should NOT use rear air bags to gain rear fender height (for a street car). The air bags will wear out pretty quickly with that type of use.

If the rear-end of the car is off-center, that also effects how long the rear springs have to stretch, and the effects the fender height. If the rear-end of off-center more than ~1/4", you should fix that first.

Oh well, that basically most of the info. I'm swamped with 3 consulting contracts. Good Luck! And, be very careful of the advice and the info that you read on the forums!

THANK YOU THAT IS ALL VERY HELPFUL...THATS ALMOST EXACTLY THE INPUT I WAS LOOKING FOR. I just got back from the beach so I have to read through all this.