front suspension questions 87 t

greeneyegi

Well-Known Member
Joined
Feb 21, 2010
i put on hotchkis uppers and the new qa1 lowers that work with coil overs or standard springs. i've got hotchkis lowering springs and double adjustable shocks now.
it has the 94 impala drop spindles also.
i have a set of qa1 coil overs to install.
i want to make sure the geometry will work with this setup, with the frankenstein setup i want to be sure it should still work.
 
i put on hotchkis uppers and the new qa1 lowers that work with coil overs or standard springs. i've got hotchkis lowering springs and double adjustable shocks now.
it has the 94 impala drop spindles also.
i have a set of qa1 coil overs to install.
i want to make sure the geometry will work with this setup, with the frankenstein setup i want to be sure it should still work.
ttt
 
Most of what you want to know can be found by searching, but this presents an opportunity for some summation for future searchers:

Your plan is straight out of 1992. If you want good results, you can abandon it right now. I get what you're doing because I did it, and worked OK sort of, but I still ended up junking most of it.

The problem with the G-Body front geometry is the spindle height and the kingpin inclination. You can fix the height with aftermarket ball joints with a taller stud. You can use a taller upper ball joint with no negative impacts. Adding a taller lower balljoint requires a bumpsteer correction kit for the steering arms. The kingpin problem is overcome either with a different spindle available from SpeedTech, or dialing in a ton of caster in the alignment (I'm running over NINE degrees of positive caster). Getting enough caster to overcome the kingpin inclination requires a set of control arms that offset the ball joint pads, otherwise the amount of shims you'd need in the UCA mounts would put the arm somewhere in the middle of the headers.

Replacing the arms without adding spindle height doesn't really help much.

The B-Body spindle is taller and has a better kingpin inclination, but the tie rod attachment is not in the right place to work with the G-Body's shorter control arms and creates a very serious bumpsteer issue that is not easily correctable.

Also, drop spindles are for looks, not performance.

Then there's the heat problems with our application. The control arms available now are all basically interchangeable. They all work great... on a Monte Carlo. Our headers/downpipe will melt delrin bushings right out of all of them. The only solution is the UMI Race arm with the steel rod-end pivots.

Then there's the sway bar problem. Since RideTech stopped selling their monsterbar, there really isn't a bolt-on solution with enough rate for us, which sends you down the road of either uncomfortably high spring rates, a fabbed setup using a torsion bar, or both.

All that said, for the next person that finds this thread: It is cheaper and simpler to pick a vendor and buy their entire system. I've learned from bitter personal experience that trying to save money by cobbling it together doesn't actually save money, because you'll go through three or four iterations before it's right, and it may never be right.

Sorry if this isn't the affirmation you were seeking, but I do wish you good luck. The combination you have will work OK, but it'll only just be OK.
 
Most of what you want to know can be found by searching, but this presents an opportunity for some summation for future searchers:

Your plan is straight out of 1992. If you want good results, you can abandon it right now. I get what you're doing because I did it, and worked OK sort of, but I still ended up junking most of it.

The problem with the G-Body front geometry is the spindle height and the kingpin inclination. You can fix the height with aftermarket ball joints with a taller stud. You can use a taller upper ball joint with no negative impacts. Adding a taller lower balljoint requires a bumpsteer correction kit for the steering arms. The kingpin problem is overcome either with a different spindle available from SpeedTech, or dialing in a ton of caster in the alignment (I'm running over NINE degrees of positive caster). Getting enough caster to overcome the kingpin inclination requires a set of control arms that offset the ball joint pads, otherwise the amount of shims you'd need in the UCA mounts would put the arm somewhere in the middle of the headers.

Replacing the arms without adding spindle height doesn't really help much.

The B-Body spindle is taller and has a better kingpin inclination, but the tie rod attachment is not in the right place to work with the G-Body's shorter control arms and creates a very serious bumpsteer issue that is not easily correctable.

Also, drop spindles are for looks, not performance.

Then there's the heat problems with our application. The control arms available now are all basically interchangeable. They all work great... on a Monte Carlo. Our headers/downpipe will melt delrin bushings right out of all of them. The only solution is the UMI Race arm with the steel rod-end pivots.

Then there's the sway bar problem. Since RideTech stopped selling their monsterbar, there really isn't a bolt-on solution with enough rate for us, which sends you down the road of either uncomfortably high spring rates, a fabbed setup using a torsion bar, or both.

All that said, for the next person that finds this thread: It is cheaper and simpler to pick a vendor and buy their entire system. I've learned from bitter personal experience that trying to save money by cobbling it together doesn't actually save money, because you'll go through three or four iterations before it's right, and it may never be right.

Sorry if this isn't the affirmation you were seeking, but I do wish you good luck. The combination you have will work OK, but it'll only just be OK.
there are so many threads i was completely overwhelmed with info.
i really appreciate the explanation
i will be purchasing all new one vendor setup.
i figured it was a frankenstein setup als thought i was spinning my wheels
thanks for the reply
 
i put on hotchkis uppers and the new qa1 lowers that work with coil overs or standard springs. i've got hotchkis lowering springs and double adjustable shocks now.
it has the 94 impala drop spindles also.
i have a set of qa1 coil overs to install.
i want to make sure the geometry will work with this setup, with the frankenstein setup i want to be sure it should still work.
What are you trying to do exactly?
 
Drag setup? Or turns only or a little bit of

Drag setup? Or turns only or a little bit of both?
I do hit the tracks a few times a year to get kicked out and really want my 60" times to lower and also car shows in summertime. But I want to put 4 people in it to cruise also. So Basically a bit of both, I do have Trans brake so launching is a bit easier. I run 18" wheels with Nitto Dr's so not expecting anything under 1.6 in reality.
Car is a bit heavy @ 3850 with me in it.
 
I do hit the tracks a few times a year to get kicked out and really want my 60" times to lower and also car shows in summertime. But I want to put 4 people in it to cruise also. So Basically a bit of both, I do have Trans brake so launching is a bit easier. I run 18" wheels with Nitto Dr's so not expecting anything under 1.6 in reality.
Car is a bit heavy @ 3850 with me in it.
1.6 with good good driving habits is not a hard task.
What is your combo?
You can pm me if you like
 
1.6 with good good driving habits is not a hard task.
What is your combo?
You can pm me if you like
My car was in the Car Craft magazine back in 1994-97. One of the editors owned it, I ended up with it 11 years later
It was in the shootout with a 5.0 mustang article and the first type of Baer brakes episode and a paint article too.
It has some stuff i want to keep like the 4-wheel disc brakes from the article I want to stay with, but I want the best I can get, is it ridetech or umi or qa1 any suggestions i havent mentioned ?
Im goig to remove my setup sale and purchase a new setup. I want coil over not air bag only because of the air tank.
You mentioned UMI and i checked them out, looks nice but is it the best , is there better?
I want drag/street setup . setup is in sig, lmk if im missing somethig
thanks happy friday!!
 
Last edited:
My car was in the Car Craft magazine back in 1994-97. One of the editors owned it, I ended up with it 11 years later
It was in the shootout with a 5.0 mustang article and the first type of Baer brakes episode and a paint article too.
It has some stuff i want to keep like the 4-wheel disc brakes from the article I want to stay with, but I want the best I can get, is it ridetech or umi or qa1 any suggestions i havent mentioned ?
Im goig to remove my setup sale and purchase a new setup. I want coil over not air bag only because of the air tank.
You mentioned UMI and i checked them out, looks nice but is it the best , is there better?
I want drag/street setup . setup is in sig, lmk if im missing somethig
thanks happy friday!!
I in the rear i have hr bar, hr adjustable uppers with longer lower trailing arms and Eaton true track center, Moser axles, chrome-moly yolk, Dennys drive shaft and stage 3 trans brake .
I really want to launch more then cruising.
Looking to see what works best with the HR stuff. I like that part
 
Last edited:
My car was in the Car Craft magazine back in 1994-97. One of the editors owned it, I ended up with it 11 years later
It was in the shootout with a 5.0 mustang article and the first type of Baer brakes episode and a paint article too.
It has some stuff i want to keep like the 4-wheel disc brakes from the article I want to stay with, but I want the best I can get, is it ridetech or umi or qa1 any suggestions i havent mentioned ?
Im goig to remove my setup sale and purchase a new setup. I want coil over not air bag only because of the air tank.
You mentioned UMI and i checked them out, looks nice but is it the best , is there better?
I want drag/street setup . setup is in sig, lmk if im missing somethig
thanks happy friday!!

Do you have any idea if the Bear brake setup will work with stock spindles?
I went with UMI for my coil spring set up.
UMI moves the lower ball joint location forward so you get more caster, plus it centers the wheel in the center of the wheel well opening to provide clearance for larger tires.
I believe RideTech offers the same benefits plus the coilover specific A-arms should weigh a bit less.
1” taller upper ball joints will help the camber curve for better cornering (per: Turbo6inKY).

Clearance on UMI with 285/35-18’s on the front.
3B7E1C8C-D663-4F57-92B3-5CC4887072E8.jpeg


I’m not sure why this one’s sideways.
E5D6024F-5280-4247-9AE2-EB5EA5B1EE93.jpeg
 
Do you have any idea if the Bear brake setup will work with stock spindles?
I went with UMI for my coil spring set up.
UMI moves the lower ball joint location forward so you get more caster, plus it centers the wheel in the center of the wheel well opening to provide clearance for larger tires.
I believe RideTech offers the same benefits plus the coilover specific A-arms should weigh a bit less.
1” taller upper ball joints will help the camber curve for better cornering (per: Turbo6inKY).

Clearance on UMI with 285/35-18’s on the front.
View attachment 392477

I’m not sure why this one’s sideways.
View attachment 392476
Yes I believe the spindle is stock replacement with a 2 "drop is all.
 
I have the full Ridetech setup on my car I like it. It does move the wheel like the UMI. I don't have any doubt that I could fit 275 or maybe even 285 tires on the front if I had the right wheels. I have CPP spindles that use C5/C6 brake mounting. Just as a FYI if you start comparing packages i had to dig to find spring rates and shock specs on my Ridetech setup.

Looking at the paperwork for my Ridetech coil over setup they use 8" long 700# rate springs for the front and 12" long 150# rate springs for the rear

I think you can't go wrong with UMI, QA1, Ridetech or Speedtech.
 
Also on the rear I went with all Ridetech R-Joints (UMI calls them Roto-Joints, basically a streetable heim-joint) instead of poly bushings and I can't believe the difference in articulation vs how it was with the old hotchkis poly bushings I had.
 
Yes I believe the spindle is stock replacement with a 2 "drop is all.
That's the worst thing you could do if you want it to leave really hard.
It effects the instant center in the wrong way depending on the weight if the car and its distribution.
 
Also on the rear I went with all Ridetech R-Joints (UMI calls them Roto-Joints, basically a streetable heim-joint) instead of poly bushings and I can't believe the difference in articulation vs how it was with the old hotchkis poly bushings I had.
the bushings in the trailing arms?
 
Yes I believe the spindle is stock replacement with a 2 "drop is all.
That's the worst thing you could do if you want it to leave really hard.
It effects the instant center in the wrong way depending on the weight if the car and its distribution.
And sh9ck8
My car was in the Car Craft magazine back in 1994-97. One of the editors owned it, I ended up with it 11 years later
It was in the shootout with a 5.0 mustang article and the first type of Baer brakes episode and a paint article too.
It has some stuff i want to keep like the 4-wheel disc brakes from the article I want to stay with, but I want the best I can get, is it ridetech or umi or qa1 any suggestions i havent mentioned ?
Im goig to remove my setup sale and purchase a new setup. I want coil over not air bag only because of the air tank.
You mentioned UMI and i checked them out, looks nice but is it the best , is there better?
I want drag/street setup . setup is in sig, lmk if im missing somethig
thanks happy friday!!
You need to scale the car
See where the weight is
Get a coil over double adjustable set up based on weight distribution and tire setup.
Then the car will hook in a car wash like my cars do😉
 
the bushings in the trailing arms?
Yes. Both UMI and Ridetech make versions

This is Ridetechs sale piece about it.

I am sure there are flaws with his demonstration but my experience is close to what he does there.
 
That's the worst thing you could do if you want it to leave really hard.
It effects the instant center in the wrong way depending on the weight if the car and its distribution.
And sh9ck8
Yes Im getting rid of this one, just rrying to decide on best option
You need to scale the car
See where the weight is
Get a coil over double adjustable set up based on weight distribution and tire setup.
Then the car will hook in a car wash like my cars do😉
Thats what I want!! I heard about a suspention shop prtty close I can weigh and get tuned.
 
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