More suspension questions...

J

jsta6

John 15:17
Joined
Nov 12, 2001
sorry so long...

I have been checking out the suspension converstations since April, but I still can't seen to figure some things out regarding sway bars, bushings and front end set.

My 87 GN has the original suspension. And it is real bad. Mushy and bouncy.

I am on a tight budget, so I decided to only upgrade the bushings, springs, shocks and sway bars.

For shocks, I found the Bilsteins at www.hotchkis.net for $55 ea.

For srings, I found the hotchkis 1" drop kit at www.summitracing.com for $250.

My confusion now lies with the sway bars and bushings.

For sway bars: I found the global west front (1 1/8" or 29mm) for $210 and rear (1" or 25mm) for $190. And the hotckis front (1 1/4" or 31.75mm) and rear (1" or 25mm) set for $329.

My quesion with the sway bar is I read that the mid 80's f-body has a 36mm sway bar that bolts right on to our cars. Is this true and what year/model is this exactly? If the factory front sway bar is 32mm, that is the same size as the hotchkis. Does size matter? Is bigger better or worse? What about the rear?

Now for the bushings:
I found the energy suspension hyperflex Complete Polyurethane "bushing" set for $159.
The PST polygraphite complete "front-end" set for $219 for regular and $359 for super.
The global west del-a-lum - front upper "bushing" kit $117 - front lower "bushing" kit $129.

What is the difference between the energy suspension and global west "bushing" kits and the PST "front-end" kit? What is the difference between polygraphite and polyurethane?

www.globalwest.net
www.p-s-t.com
www.energysuspension.com

Many thanks-
 
What do ya wanna do with the car?
Drag race? Road race? Regular driving?

--For starters...whatever you do..don't buy the Del-A-Lum kit unless you are AJ Foyt or something... You won't want that if you drive the car daily...

--Also, you don't need to buy new sway bars unless maybe you were road racing... The F-body sway bar is from the late 80's Irocs and Trans Ams... It is hollow... LIGHTER

--I *believe* that polygraphite is polyurethane with graphite in it to help prevent squeaking and binding.

--If everything is mushy and bouncy you might want to think about replacing your body bushings too. I don't have a GN, but I've heard the ride is better.

--If you're into drag racing...You don't wanna mess with the front sway bar...(you might even want to disconnect the end links or remove it entirely) The F-body piece would lighten things up if you want a sway bar

--Stiffening up the rear sway bar will help the car launch and I have heard it also improves the overall handling... (the ATR piece)
 
Get a set of the Bilstein's. These can be purchased from Autozone for $54.95@.
For springs, you can maintain the original ride height and eliminate the "mushy" ride and excessive body roll with Moog replacemnet springs for under $70/pair.
The main problem with these cars is the fact that even the heavy duty F41 package which the turbo cars came with, had very soft spring rates of 420lbs/in. The standard G body springs were 345lb/in to give you a modest comparison.
The sway bars are already as large as any G body came with. I believe they were 31mm. A nice, inexpensive upgrade would be the 36mm hollow F body sway bar which would also save you about 10lbs of frontal weight.
On my own car, I am using Moog 5660 front springs which a rate of 639lb/in rating. If you want to go one further, you could use Moog 5662's or 5664's which are 706lb/in and 760lb/in respectively. If you want some excellent info, go to the tech area at www.montecarloss.com for some great suspension info. For a good chart of all the spring options, go to http://www.show-n-go.com/gfiles/g_spring.html
 
Most pick pull junkyards I've been to have a couple F-body's with hollow sway bars for less than $20 complete that will bolt on with minimal mods.

For a street car, firmer front springs like 600lb moogs a stock or hollow f-body bar and a big rear bar like the one from ATR along with the bilsteins will give pretty good handling and kill a lot of the cars natural tendacy to understeer, especially when you bolt big tires like 275 BFGDR's out back.

Rebuilding the front suspension with new polygraphite bushings will make the car ride like new, also.
 
Just curious, these front springs or whatever is going to be used, what will actually drop the whole car level about an inch or so, to get a lowered sleek look with a closer ride to the ground with out affecting anything on the vehicle??

thanks

jojo
 
DOH!

The car is my daily driver. 22 miles to work round trip. I have not been to the track yet (I just bought it in april and it needed a trainsmission), but I do "race" her on the street when I can. I prolly will go to the track a couple of times a year.

My tires now are 245-60-15 on stock rims, but I am moving to 245-50-15.

The hotchkis will lower it 1" front and back.
 
Re: DOH!

Originally posted by jsta6
The car is my daily driver. 22 miles to work round trip. I have not been to the track yet (I just bought it in april and it needed a trainsmission), but I do "race" her on the street when I can. I prolly will go to the track a couple of times a year.

My tires now are 245-60-15 on stock rims, but I am moving to 245-50-15.

The hotchkis will lower it 1" front and back.
Click to expand...

Is the model #hss1902? and are these supposed to be pretty good quality, do they go front and rear and replace rear springs also? and will they look pretty bad ass an inch lower? please let me know. And im assuming it will stop the sway some along with the bilstein shocks all around.

thanks

jojo
 
Another quick question on suspension, how are those Hotchkis front and rear sway bars compared to the stock ones on the vehicles now. If i replaced shocks with some bilsteins, and replaced the sway bars with Hotchkis sway bars 329.00 and the springs front and rear with the lowering affect about one inch or so, how with my car handle?? Please id like to know from the pros.

thanks

jojo
 
jsta6,
Just a couple things to consider, your front tires might rub a bit if you drop the car before you go to the 245/50's, I've got 235/60's on mine that just barely fit.

Also have you checked your body bushings? that will make a difference in both ride and how well your front tires clear when lowered.

The polygraphite bushings do squeak. I've never ridden in a car with regular polyurethane to compare to but I have the PST kit in my car. After a year it started to squeak a little on warm days regreasing helped (but its a pain in the ass). In the winter it they squeak ALOT.

I personally would trim moog springs instead of going with hotckiss or eibach, considerably cheaper. I have f-body lowering springs in mine that i got for $100 that dropped it ~1.5" and were 700 in-lbs.

With the springs, and polygraphite bushigns up front and for body bushigns, and 1LE's in the rear my car rides real stiff, but feels solid going through turns, its no longer mushy and floaty. I drive the car every day to.

If I had to do it over again I'd probably put rubber 1LE bushings in the front, if I didn't want to pay for del-a-lum's. Those sites mentioned above have lots of good info about the different springs.

Hope that helps,
Tom

86 GN basically stock.....12.99@106
 
Originally posted by jsta6
sorry so long...

I have been checking out the suspension converstations since April, but I still can't seen to figure some things out regarding sway bars, bushings and front end set.

My 87 GN has the original suspension. And it is real bad. Mushy and bouncy.

I am on a tight budget, so I decided to only upgrade the bushings, springs, shocks and sway bars.

For shocks, I found the Bilsteins at www.hotchkis.net for $55 ea.

For srings, I found the hotchkis 1" drop kit at www.summitracing.com for $250.

My confusion now lies with the sway bars and bushings.

For sway bars: I found the global west front (1 1/8" or 29mm) for $210 and rear (1" or 25mm) for $190. And the hotckis front (1 1/4" or 31.75mm) and rear (1" or 25mm) set for $329.

My quesion with the sway bar is I read that the mid 80's f-body has a 36mm sway bar that bolts right on to our cars. Is this true and what year/model is this exactly? If the factory front sway bar is 32mm, that is the same size as the hotchkis. Does size matter? Is bigger better or worse? What about the rear?

Now for the bushings:
I found the energy suspension hyperflex Complete Polyurethane "bushing" set for $159.
The PST polygraphite complete "front-end" set for $219 for regular and $359 for super.
The global west del-a-lum - front upper "bushing" kit $117 - front lower "bushing" kit $129.

What is the difference between the energy suspension and global west "bushing" kits and the PST "front-end" kit? What is the difference between polygraphite and polyurethane?

www.globalwest.net
www.p-s-t.com
www.energysuspension.com

Many thanks-
Click to expand...


jsta6,

IMO, you said your car is really mushy & bouncy, and that's easy to diagnose. The bouncy is coming from worn-out shocks.

IMO, you should just replace your shocks before you do anything else. Replacing your current units even w/ some fresh generic units would make the car not bouncy and probably less mushy. Don't underestimate the benefits of a fresh set of shocks, esp. some performance shocks like bilsteins.

As for the mushy, that could from eitiher your current shocks,
springs, suspension bushings, or some combination of the three.
But, start w/ the shocks. Do this one step at a time.

As for your springs, be advised that stiffer, lowering springs will transmit more "shock" to your car's chassis & body. If your car is missing body bushings or isn't braced, then you car will develop more squeaks & rattles because of this. If you find this tolerable, then you're good to go. If this would slowly & eventually drive you nuts, then you should probably get a fresh body bushing set and get all of the g-body chassis braces. The braces can be had from salvage yards for minimal $$$.

Replacing your swaybars isn't necessary for the purpose of making your car less mushy, though, again, you don't define what you mean by mushy. If you just want to make the car corner more flatly, well, stiffer springs will probably make the car corner flatly enough for you.

To answer some Q's, the size of a swaybar matters, along w/ some of it's other features, like the lenght of it's "arms". As for size, my suspension books' theory is that the size of the swaybar to the fourth power = stiffness, so that a 33mm bar is much stiffer than a 32mm bar, all else being equal.

There is also swaybar thickness; the bar's thickness is supposed to also determine how stiff it is. I beleive that it does, but I don't know of any formula that can quantify the stiffness that is caused by thickness.

Swaybars, of course, make the car corner more flatly by adding more (body) roll resistance- resistance to leaning. They also increase weight transfer, whiich is why they affect steering balance. Swaybars are usually used to tune a car's steering characteristics, those being the difference between if a car oversteers (the car's rear end slides out during cornering), understeers (you're cornering & turning the steering wheel, but the car won't turn enough; the car turns in a wider arc than you want it to).

IMO, leave the swaybars as-is for now.

As for the bushings- first, you'll have to understand that rubber bushings function by deforming under loads. Picture a rubber bushing- it's cylindrical, and has inner & outer mounting sleeves. In the front A-arms (control arms), they twist about their inner mounting sleeve. In the rear of the car (trailing arms), they twist about their inner mounting sleeve AND about the length of their inner mounting sleeve. My description of how the trailing arm bushing works is pretty ambiguous. Sorry about that :eek: But anyhow, polyurethane doesn't twist, because it isn't a twistable rubber, it's basically a hard plastic that slides about it's inner mounting sleeve. That means that w/ out lubrication, it'll squeak, and in the winter when it's cold outside, it may shrink, in which case it may squeak even if lubricated.

Polygraphite, I guess, is polyurethane impregnated w/ graphite.
The sales propoganda that I've read says that the graphite impregnation results in a self-lubricating bushing. I'm really unsure about that. I confess that I don't know, but I am skeptical.

Global West del-a-lum bushings look killer! They're 3-piece bushings, w/ grease fittings, and have interior surfaces in which grease is supposed to be able to circulate. The inner sleeve supposedly rotates freely, which allows fluid suspension movement. I think that's what I read. These seem like the best to me. However, they're really expensive!!!


summary:
*install the Bilsteins, see how that feels.
*if the car is still too bouncy, replace the springs w/ some stiffer units.
*if you go w/ lowering/stiffening springs & don't want too many more squeaks & rattles, you'll probably want a fresh body bushing set & all the body & frame bracing.
*probalby leave your swaybars alone for now; changing swaybars might change the car's steering characteristics in a way that you won't like
*if car is still mushy on the highway & in it's steering feel, you'll probably want a fresh rubber bushing set
 
whew...

Too much information...
;)
:eek:

Thanks everyone for their reply.
brcrabbe, BuickTom, GNVAIR, RandyCustomShop, thanks big time.

My buddy has an 85 442 that handles amazingly. He flies around corners and there is no body roll. On and off ramps on highways are serious fun. That is what I am looking for. Belive it or not, all he did was cut the front springs for a 1 1/2" drop, and add the energy suspension Hyperflex system.

Between you guys and the folks over at www.gnttype.org I think I have made up my mind.

Bilstein shocks - $55ea
Hotchkis 1" drop coils - $250 set
PST front end kit - $219 set
Energy suspension body bushings $107 set
Sway bar will be "wait and see"...

I don't think the 245/50's will rub. I have room now with 245/60's and the 245/50's will be about 1" lower. I should make it fine.

I sent Hotchkis an email asking them what their coil rating was and one to PST asking if they made body bushings for our cars.

Thanks-

BTW, I did go to some of those sites you suggested. They were pretty cool. Here is one of them:
http://www.darklair.com/monte/howto/howto.suspension.html
 
JoJo

JoJo:

The part number is 1902. Take a look at my web site for the part numbers and vendor web sites. The set is for all four coils.

I don't think that the $329 is worth it for the sway bars. I would take that $329 and buy new front end and body bushings.

I have had a lot more people tell me to do the bushings then the sway bars.

Also check out the suspension thread at www.gnttyp.org:
http://www.gnttype.org/discus/messages/8/8.html?1010202723
 
Re: whew...

Originally posted by jsta6
Too much information... ;)
Click to expand...

It can get complicated real quick with so many things involved. I will try to help without confusing anyone any further.

I would have to agree that the swaybar upgrades should be your last thing. For a mostly daily driven car, the stock swaybars work great. If you go to upgrade them anyway, I have heard many say don't go bigger on the front. Stick with the stocker or remove the front. The back one going bigger helps more for racing & serious handling, but the stocker works fine.

As for Polyurethane vs Polygraphite, they are basically the same except for the addition of fine pieces of graphite. It is hard to tell the difference unless you are looking at a cut edge, the graphite will sparkle. The graphite HELPS, but does NOT make it greasless. Either type will start to bind & squeak after about one year without greasing. Most types are put together without grease and have no way to get grease to them without dis-assy.

That is why we took the best polygraphite bushing and made a replacement bushing that has a grease fitting built into them. No binding or squeaking, firm but not harsh, great on street & full race mode. We only have them available for the rear right now. If anyone has left-over stockers from the front that they do not want, please E-mail me. That is another area we would like to make a better bushing for.

Definitely do the shocks first. Bad shocks not only feel crappy, but it makes it very unsafe to drive, especially at high speeds (not that you would do that :) )

To get inches from millimeters, take mm x .03937
25.4 mm x .03937 = 1"
36 mm x .03937 = 1.417 or just over 1-3/8"

My only suggestion for you would be to box at least the lower control arms. They help more thannn the uppers being boxed in because they are longer and they are being compressed on take-off. Up & lower are both important, but if $$ is tight... You might as well do that while you have the bushing out, it's very easy at that point. You will have to do all the work over again to do it later. We made boxing kits also to make that easier for those that don't have access to steel plate/cutting equipment. Makes welding them in place a snap.

Hope that helped out.
PS- our website is in a transition period, so E-mail me if you need any info or pictures. Thanks.

Oh yeah, stay away from poly BODY bushings on a street car, everyone I talk to says they make the car ride very rough. Evidently, the body is one area you can't stiffen up that much without getting a negative effect. Just get good rubber replacement ones for the body.
 
Alright, this is my take on all this. Most is from experience, the rest is from alot of trusted people. I had a stock 87 MCSS. Now, before you discredit what I say, just read :)

First thing I did was brace it will all the braces I could find. Go here for a list on my site:
http://www.geocities.com/jfon101231/brace.html

Then I needed brakes and my suspension had 147k, so I went buck wild. First off, my car is a daily driver, which means that it needs to handle well, but I still want to haul ass straight ahead. This car is also driven in the cold and snow. OK, enough of that.

I went w/ B-body spindles, TRW 5658 springs, Delalums in the lower control arm, and custom upper arms w/ Nylon bushings. I kept my stock shocks and sway bar (and sway bar bushings), although I just go all that for X-mas, yet to be installed :)

With this setup, the car is unbelievable. I picked it up after the alignment and drove 30 miles back to school with a smile on my face. I can go through corners at speeds I never though possible. This is with stock size 15" rims and 1/4 tread remaining GT Qualifiers. The tires simply can't handle this abuse, and thats without the shocks or sway bar bushings. At the same time, I also rebuilt my entire front suspension. This made it drive like a new car, and the rest made it better :)

Now, here is my thoughts.
Do not change the stock sway bar. Get some poly bushings and you will be happy. If you want, go to a 36mm hollow bar from the F-bombs. Do not pay Hotchkis or someone else $200 bucks for nothing. You can get the same thing for $40 or so.
Get Bilstein front shocks. $110 for the pair, lifetime guarantee, at your local Autozone.
Upgrade front springs. I went w/ the 5658 (I got TRW, but Moog is the same thing) at Advance auto for $45 !!! They are 580lbs, and the car still rides smooth. I wish I had went w/ 5660 or even 5662's (higher spring rates). The major difference came from the b-body spindle/upper arm and the delalums in the LCA. However, the kit w/ the spindles and upper aarm is $690. So thats not really in your budget. But, with that you get better tire wear and 12" brakes. Those spindles and arms keep the tire flatter on the road. Oh, as a side note, the b-body spindles and 5658 lowered the car a little over an inch. there is pics on my site.
I would check out your body bushings to see their condition. If they are bad go w/ the poly body kit
I would also pull your rear control arms and add some 1LE rubber to them also. If you need the part # email me. I agree that delalums are expensive, but they work. If you want a substitute, get 1LE rubber. Its harder than stock, but won't bind or squeak like poly.

HTH
Jeff
www.geocities.com/jfon101231/12_brakes.html
PS. I don't check here often, so if you have a question email me
Jfon10@aol.com
 
I agree with Jeff. The Moog springs are the best bargain going. Period! Stick with the 5660's or 5662's rather than going for the Hotchkiss or Eibachs. You will save a ton and can use the extra money for a good set of shocks.
As for the bushings, if you plan to drive the car everyday in wet weather, etc, then stick with stock or 1LE style. I dont care what anyone says, Poly, Nylon, Polygraphite bind. If someone says they dont, then they are lying to you. If you want to see for yourself. Do this. Jack up the car and remove the rear coils. Have a friend help move the rear axle with the stock rubber bushings. You can see how much travel you have. Now install Polys in the rear axle and the bolt it all together without the coil springs. Repeat the first exercise. You will see that you can barely move it. That force is limiting the travel when going into a curve. Try taking an highway ramp at speed and you will most likely lose it. Poly is fine for a drag only car, but has no place on the street.
The only other bushing I could recommend are the Del A Lums. These are pricey, but are also the best. They only make these for the front suspension.
 
body braces

brcrabbe, can you tell me about the body braces from the junk yard?
Thanks-
 
hmph...

argh.

Getting closer. Still seems cloudy...

This is what we have so far:

SHOCKS: bilstein - $55 ea.

SWAY BAR: don't bother

COILS: call moog (800-365-6664) and get the part number for 1" drop; MAY be 5660 ($44) front pair and cc651 ($40) rear pair.

BODY BUSHINGS: GM replacment?

FRONT END BUSHINGS:
"rubber" is stock
polyurethene squeak a lot and bind
polygraphite squeak a little and bind
del-a-lum are expensive and their website mentions nothing of a "all inclusive" kit
1LE are still a mystery to me...just found it it was an option package on the camaro...what fits on our cars? does GM have a front end package? jfon10 do you have part numbers?
anyone know about moog rubber?

am I missing anything?
 
Re: body braces

Originally posted by jsta6
brcrabbe, can you tell me about the body braces from the junk yard?
Thanks-
Click to expand...


This is a much-discussed topic. It seems there are a few oem g-body braces, and a few that people home-make. This page sums it all up:
http://www.geocities.com/jfon101231/brace.html

Here is a list of the braces and what cars they can be found on. Neither the list of braces nor the cars they can be found on are definately complete, so don't take this as an absolute, but a reference. This list is based mostly on the above web page.
1. front framerail-to-framerail brace
can be found on- Pontiac Gran Prix
2. engine crossmember-to-framerails bracing
can be found on- Monte Carlo & Cutlass
*together, 1 & 2 are the "front end triangulating" braces
*to use 1 & 2 together may have to use some washers to space apart their bolt holes. If you get both braces, this should be self-explanatory.
3. radiator x-bracing
can be found on- cutlasses, some regals
4. radiator wall-to-firewall braces
dunno
5. front fender braces
can be found on- Gran Prix
6. body backseat bracing
can be found on- Gran Prix, BUT!... the general opinion is that this thing is hard to remove from the donor car and/or it's easier to just make your own. There are many discussions on how to make your own.
7. trunk/rear fender brace
can be found on- Gran Prix
 
Looks like you got the all the info you can handle. I have 2 things to add. PST also makes a factory replacement (rubber bushings)front end kit for $149. This is what I will be putting on my car. I have checked; you can't go to the local parts store (Autozone) and put a kit togther for that price.

Second thing is that I have a set of rear seat braces that I made. You could have them for $25 plus shipping.
 
The 1LE rear bushings are for the lower control arms only. I just bought a set of 4 from the locak Chevy dealer and they were like $10@
Just specify a 1992 Z28 with the 1 LE and they will know what you are talking about.
 
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