87 GT- 3800sc+, to improve the handling, I put a 1" sway bar at the front, moved the old one to the back,new KYB shocks, eibach springs, new ball joints, camber kit, alignment, all this has done for me is give me the feel of eau de cadillac. I've had cars that handle well at high speeds and this ain't one of them. I was looking for a firm sports car ride but didn't get it. WHY
Thanks

High speed stability is the problem or all around crap?

Air gets trapped up front at high speed and makes it pretty squirrelly

You didn't mention bushings

Replace all of them with poly and get some aluminum cradle bushings

You should get poly bushings everywhere and an 88 cradle, they're solid-mounted with aluminum unlike the 84-87 cars. You might also want to look into an anti-bumpsteer kit and better shocks/struts, KYB is good but only average, KONI is #1. You might not need the anti-bumpsteer kit if you go with the '88 cradle, cause I think you can use the '88 rear suspension and brakes. My '88 GT has stock'ish shocks/struts/springs but it has poly bushings all around and its like 10x better than stock, it handles like a true sports car.

Also, why'd you need camber kits for your lowering? IIRC Fieros have a slotted bracket for camber adjustment so you can vary it widely, adapting easily for lowering. My MR2 pisses me off because Toyota was retarded and didn't use slotted brackets, I need a camber kit on all 4 corners of that car because of that .

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The problem is at high speed- but that's where I wanted the improved handling. I have actually vented the front hood a bit ( two little vents) , new bushings all around, rubber at front , poly at back. How does having new cradle bushings really help. I have a poly at the top rear. This car can really disapoint.

What speeds and what is the problem exactly? It just doesn't feel planted/stable? Is it understeering? You could've lowered the car 1.8" in the front and 1" in the rear, giving it a better rake for higher speeds. That would help, along with the hood vents you put in. Konis would help too since you can adjust them to ultra stiff. BTW putting those camber kits on is idiotic, your mechanic told you wrong (most ricer cars need camber kits when they're lowered, so mechanics ALWAYS say you need a camber kit) you should take them off and see if the car can be aligned without them.

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Most of the heavy lifting is in the rear where the engine is.Did you install new coils in the rear or struts?

There are a lot of unanswered questions to this. What kind of tire pressure are you running? What's the tire profile? What kind of tires? Did you change the wheel offset with aftermarket rims? Do you have poly on the sway bar(s)? Is your steering rack and associated linkages tight? Any of those and much more can adversely affect handling.

I have KYB struts/shocks, poly cradle mounts, poly bushings all around, w. front and rear Addco sway bars (matched set). Handling and stability are superb. If your Fiero is unstable, it can be caused by your rear tires being out of alignment. If the camber is more than 1* out it can create an unstable feel. Fieros need EXPERT wheel alignments and lowering you car can present alignment challenges.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Did you retain the air damn ?? this makes a difference at speed..much more so on the 84 to 87

Is the front lower than the rear ??
check the driver side inner tie rod for looseness,,compare to passenger side
a draging rear brake on one side makes for a squirelly ride ,,I had this problem ,,thought the FRONT ball joint was going to fallout..The car was moving sideways when te brake would ""grab"" scarey!!

[This message has been edited by uhlanstan (edited 06-17-2009).]

yes, I did not see any mention of the 2 most important things:
the rear struts & rear a-arm bushings
even with the stiffer eibach spings - the struts need replacing. especially if they are original.

and, another aspect is - the rear will ALWAYS feel diffferent from other cars. ALWAYS.

How about a *good* description of what the car actually does that you don't like? "Eau de Cadillac" doesn't tell us anything.

Just how high are you talking about when you say "high speed"? It does make a difference...

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My Web page | The Turbo Super Duty Build.
You know that little voice that says it can't be done? I duct-taped its mouth shut and pushed it down a flight of stairs. (Leader of the Insurgency)

When they aligned it, Did you get a print-out of what they set it to? If so can you post the results?
The Fiero has 4-wheel independant suspension. If the front or the rear is off it can cause some issues.
What size wheels/tires do you have?

It is preferred to do the same work to both front and rear. (Bushing type, shock/strut type, etc.)
The cradle bushings are a very noticeable change as well.

Just to clear up a few things..............

Tinton - The 88 cradle is solid mounted to the spaceframe, but not with aluminum, as there are no 'cradle' bushings, just steel to steel front and rear. The 88 rear suspension eleiminates the need for a bumpsteer kit, and the 88 rear suspension and brakes must be used with an 88 rear cradle. As a point of interest, bumpsteer isn't near the issue on pre-88 cars that some people try to make it, especially if the car is lowered and has a rear sway bar.

Slink - If you purchased the Fiero Store front sway bar, do yourself a favor and get rid of the front bar on the rear and replace it with the Fiero Store rear bar. If you got the front bar from another vendor, get with them and get the proper bar for the rear.
Also, my Cadillac STS handles superbly at high speeds, speeds higher than most Fieros will ever see.

Taijiguy asks some very pertinent questions, and Dennis makes an excellent point concerning alignment. Always insist that the alignment shop go for as close to a ZERO thrust angle as possible, and not try to compensate for road crown. And Pyrthian hits it on the head with his post.

Hope you get it figured out, my 86 SE with the complete Fiero Store handling kit #2 w/ KYB's, full GA brake upgrade, and stock lace wheels (205 F / 215 R) is absolutely glued to the road at any speed.

Joe

Get the KYB struts for the back, that will firm up the ride to what you're looking for, I think.

The 1" bar in the front with a front bar in the back is not that far off. Not ideal, but not that far off. The only real way to find out if it's balanced is to get it on the track or skidpad and see how it handles. Take it to an autocross and see if it "pushes" or if it's trying to break the back end loose at the limits. Autocross tracks are great places to test suspension changes for very little money and no chance of getting a ticket.

As others have said, if you didn't get a printout of your suspension settings, you should have.

If at speed the car feels like the front end is "floating" or wandering, your are most likely gettine air packed in the front of the car and under the car. You'd be amazed how much lowering it an inch will help and it doesn't make it terrible to live with. Venting the hodd will help A LOT. On the race car it made the difference from being unstable over 120 to being able to run 140+ and having the car glued down.

John Stricker

My car was spooky by 75 mph, but I have an '84, and it does not have the aero nose like the pace cars and the later GTs did, so there is an awful lot of front end lift. And the GT nose still isn't great unless you extend the leading edge down a couple of inches closer to the ground. There are some nice looking ways of doing this, that are readily available. Rather than buying a better nose, I'm creating my own aluminum nose that drops straight down. Kind of like the Hot Rod Magazine Camaro they built for Bonneville. It's the white '78-'81 with red graphics. That nose might look like a blunt slab, but it works exceedingly well, and is very close to ideal for function. In my case, I'm expecting to exceed 110 mph at the dragstrip.

1-Thanks for the input- it's driving me nuts. Speed above 120kpm (Canada)the car is definitely NOT planted (that's the feel I was looking for) With new Eibachs and new kyb's all around how do I lower the car?Tire pressure is 32lb, Profile I'll get later ,steering and linkage have been checked and are okay plus the new ball joints every where.The front bar is addco 1", the rear 7/8 from the front with addco links and poly bushings,The camber is flat -I phoned the guy who did all the work and he said he has the lattest machine to do alignment and it has to be right on,rear spoiler is in place ,haven't done rear A arm bushings or cradle bushings. I complained to the installer about the ride and he said I should of got the red Eibach springs- wish I had of known- thanks

If you used the eibach lowering springs, you've already lowered it a little over an inch. You can go some more if you want to cut a coil, but they you're going to get into ground clearance issues and it's a PITA to put on a 4 post lift.

If it were me, I'd be looking at a front air dam to keep more air out from under the car and venting the hood more radically. 120kph is not that fast, though, and you shouldn't be wandering or floating at that speed so that leads me back to a mis-alignment problem. I'd get the alignment re-checked. Fieros are very, very finicky about bad alignments, especially in the back end. Double check your tie rod ends and make sure they're tight as well, that can really wreck your feeling of precision when driving.

John Stricker

quote Originally posted by slink: 1-Thanks for the input- it's driving me nuts. Speed above 120kpm (Canada)the car is definitely NOT planted (that's the feel I was looking for) With new Eibachs and new kyb's all around how do I lower the car?Tire pressure is 32lb, Profile I'll get later ,steering and linkage have been checked and are okay plus the new ball joints every where.The front bar is addco 1", the rear 7/8 from the front with addco links and poly bushings,The camber is flat -I phoned the guy who did all the work and he said he has the lattest machine to do alignment and it has to be right on,rear spoiler is in place ,haven't done rear A arm bushings or cradle bushings. I complained to the installer about the ride and he said I should of got the red Eibach springs- wish I had of known- thanks

your car is now lowered with Eibach springs, could the shop have done the alignment to the stock factory settings ?. What have you not done, eg. rear A arm or aluminum cradle bushings ? If you haven't done either of those or if your drivetrain has rubber mounts, they all compound. rear sway bar ?

Half measures avail nothing.

quote Originally posted by slink: The camber is flat -I phoned the guy who did all the work and he said he has the lattest machine to do alignment and it has to be right on. Haven't done rear A arm bushings or cradle bushings. I complained to the installer about the ride and he said I should of got the red Eibach springs.

The camber should not be flat, look at the spec. The REAR TOE setting is CRITICAL on a Fiero.

You NEED to do the rear A arm bushings and cradle bushings before it will ever be 'tight'.

This has nothing to do with the wrong Eibach springs being used and almost everything to do with worn bushings and/or alignment errors in the rear. New machines are great but incorrect settings are incorrect settings.

[This message has been edited by carbon (edited 06-17-2009).]

I did complete stock front and rear suspension build with kyb's, poly all around, ball joints, etc. stock springs. Car felt unstable even at 60mph. Then I replaced the cradle bushings with poly and had it realigned - made a tremendous difference. Therefore I would recommend that your next step would be the cradle - poly, or solid or a 88 version. Also as others have mentioned it is hard to get some shops to align the car properly.

I will caution you. I had a car aligned correctly I might add but they used the wrong specs, make sure they use 84-87 specs which are much different than 88 specs.

Thanks again for the suggestions

Cradle and control arm bushings will make a HUGE difference, I highly recommend solid bushings in the cradle and poly bushings in the control arms they arent very expensive either!

I sent you an e-mail.

quote Originally posted by jgrotzin: I will caution you. I had a car aligned correctly I might add but they used the wrong specs, make sure they use 84-87 specs which are much different than 88 specs.

BTW, there was a TSB on the alignment for the pre '88 cars. They changed the rear toe. Originally it was .15°, +/- .1° and was changed to 0° +/- .1° in TSB 87-3-10.

Here are the factory specs:

Caster 5° +/- 2° (any good shop should be able to get closer to 5° than that)
Camber Front +.5° +/- .75°
Camber Rear -1° +/- .5° (not really adjustable anyway)
Toe In Front +.1° +/- .15°
Toe In Rear +.1° +- .15°

Rear toe is critical to making the car stable. Loose rear tie rods or bushings will really make the car wander on the road. Make sure your bushing, ball joints, and tie rod ends are all up to snuff.

John Stricker

(BTW, the alignment information is from my Mitchell OnDemand so if it varies from what the shop manual calls out, take it up with Mitchell )

quote Originally posted by jstricker: BTW, there was a TSB on the alignment for the pre '88 cars. They changed the rear toe. Originally it was .15°, +/- .1° and was changed to 0° +/- .1° in TSB 87-3-10. Here are the factory specs: Caster 5° +/- 2° (any good shop should be able to get closer to 5° than that) Camber Front +.5° +/- .75° Camber Rear -1° +/- .5° (not really adjustable anyway) Toe In Front +.1° +/- .15° Toe In Rear +.1° +- .15° Rear toe is critical to making the car stable. Loose rear tie rods or bushings will really make the car wander on the road. Make sure your bushing, ball joints, and tie rod ends are all up to snuff. John Stricker (BTW, the alignment information is from my Mitchell OnDemand so if it varies from what the shop manual calls out, take it up with Mitchell )

The factory tolerance for caster is wide because the factory caster adjustment method is to swap the spacers between the sleeve in the crossmember and the upper control arm bushings. This effectively gives only two possible settings for caster.
If you're willing to pay by the hour, a capable shop may be willing to remove the factory spacers and adjust caster via washers and/or alignment shims, but this is highly irregular and you'll probably have to go to a specialty performance/racing alignment shop to have that done.

Not sure why you're saying the rear camber's not really adjustable...

For an autocross alignment, set FRONT toe to -0.15 degrees (toe out). That's not what the OP wants for high speed stability, of course. Never use toe out in the rear.

quote Originally posted by jstricker: Only if the existing bushings are worn out. If the rubber is new and tight, you won't see a huge difference. I do advocate solid mounting the cradle, though. It never should have been rubber mounted to begin with. John Stricker

He's right, GM did a crappy design and I'll say it too. I don't understand why GM had to wait 4 years to correct something that could of been done in 1985. You notice that the import car companies have a problem, they correct the issue for the next model year, not 5 years later. That's why people get fed-up with domestics and there "slow attitude" correction.

GM should of never used rubber to mount the cradle. That is a stupid idea, period. Plus the bump steer problem was something GM should of seen with there tests that they did in 83-84 before they released it to the public. If they can have the brain to make / build a car that was ahead of its time, the engineering dept. responsible for designing the suspension geomertry and handling, that team sucked.

Take that cradle and install poly or aluminum bushings. That's the best improvment you can do. If you have the money, change every bushing in front and the rear. Install 4 new ball joints and 2 rear ball joints. Then all struts, and inner and outer tie rods. Good tires too. The rack bushing can have a looseness feel when checking the inner tie-rods in front. Grab the inner tie rod and move side to side and up and down for slack. Rodney sell and new rack bushing on his site for 21$.

The biggest mistake I did years ago was not realising that the rear end was rusted out. On my 86GT, the strut rails were rotted out with did a big effect on handling and all the new parts was a waste of time and money. If the rear frame is rotted, forget about all new parts. I see in your location profile that your from Canada. I am too. And many Canadian cars were driven in the winter and after 20+ years many are rotted out. Mine was and I learnt the hard way. After 3000$ of new parts and labour and it still wasn't right. I decided, that's it.

If your frame is rotted, forget it. It can be repaired but its a big job, plus rust will always come back.
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fierogt28

88 GT, loaded, 5-speed

[This message has been edited by fierogt28 (edited 06-17-2009).]

Thanks for your reply- it's nice to see somebody tell the truth about GM. My car was never winter driven
so it's pretty rust free My kid has a $3500. civic with a $500. engine and a set of springs- handles and drives like a little race car. It just ticked me off paying for new sway bar front, install old one rear, new shocks and struts, new springs, new ball joints, camber kit and it handles a way worse than before
kind of like throwing your money down the drain

If it handles worse than before you got everything than they F'ed up your alignment

Will,

Unless something is tweaked you can normally get closer than +/- 2° on the caster using the stock spacers. If you can't, then look for something bent and it's probably one of the lower A arm mounts. BTDT.

I was under the impression the OP wanted to make his car stable and firm at high speed. Toe out in the front, while suitable for autocross, is not suitable for the street for the most part and definitely not going to make it more stable at high speeds.

Absolutely agree, NO toe out in the rear. Ever.

Thrust angle as close to 0° as possible. Make them work at it until they get it right.

I typo'd the "not really adjustable". I was going to put that line under the Front Caster line to note that normally the rear caster is not adjustable (nor does it need to be). I was typing this off my Mitchell sheet and that was supposed to be inserted along with the words "rear caster", so thanks for catching that. Of course the rear camber is adjustable and much easier than the front.

When I was playing with the pickup points for my rear tie rod inboard mount locations, though, I did play with moving the top of the strut forward and back to see how it affected the bump steer and it had some, shall we say, odd results. If you think about it, I'm sure you can imagine what it was doing.


FWIW, I have my race car specs set as follows:

Caster, 3°. That's as little as I can get and helps turn in greatly but you have to stay on top of it at speed
Camber Front, -1° I've used more negative camber, but can't see any benefit and do see more tire wear
Camber Rear, -2° That's all I can get with the top strut mounts in the stock location on the driver's side so the passenger side is set the same.
Toe in Front, 1/8"
Toe in Rear, 1/16"
Thrust angle, 0°

With my pickup points for my rear tie rods, I get almost no bump steer until the last inch of rear strut travel and it is all toe in. When we go open road racing instead of autocrossing, I do add 1/16" to the rear toe (for 1/8" total) and 1/16" (for a total of 3/16") to the front toe to help at speeds over 125-130 for long stretches of straights. It helps keep it from being too twitchy.

John Stricker

quote Originally posted by Will: The factory tolerance for caster is wide because the factory caster adjustment method is to swap the spacers between the sleeve in the crossmember and the upper control arm bushings. This effectively gives only two possible settings for caster. If you're willing to pay by the hour, a capable shop may be willing to remove the factory spacers and adjust caster via washers and/or alignment shims, but this is highly irregular and you'll probably have to go to a specialty performance/racing alignment shop to have that done. Not sure why you're saying the rear camber's not really adjustable... For an autocross alignment, set FRONT toe to -0.15 degrees (toe out). That's not what the OP wants for high speed stability, of course. Never use toe out in the rear.

quote Originally posted by fierogt28: He's right, GM did a crappy design and I'll say it too. I don't understand why GM had to wait 4 years to correct something that could of been done in 1985. You notice that the import car companies have a problem, they correct the issue for the next model year, not 5 years later. That's why people get fed-up with domestics and there "slow attitude" correction. GM should of never used rubber to mount the cradle. That is a stupid idea, period. Plus the bump steer problem was something GM should of seen with there tests that they did in 83-84 before they released it to the public. If they can have the brain to make / build a car that was ahead of its time, the engineering dept. responsible for designing the suspension geomertry and handling, that team sucked. Take that cradle and install poly or aluminum bushings. That's the best improvment you can do. If you have the money, change every bushing in front and the rear. Install 4 new ball joints and 2 rear ball joints. Then all struts, and inner and outer tie rods. Good tires too. The rack bushing can have a looseness feel when checking the inner tie-rods in front. Grab the inner tie rod and move side to side and up and down for slack. Rodney sell and new rack bushing on his site for 21$. The biggest mistake I did years ago was not realising that the rear end was rusted out. On my 86GT, the strut rails were rotted out with did a big effect on handling and all the new parts was a waste of time and money. If the rear frame is rotted, forget about all new parts. I see in your location profile that your from Canada. I am too. And many Canadian cars were driven in the winter and after 20+ years many are rotted out. Mine was and I learnt the hard way. After 3000$ of new parts and labour and it still wasn't right. I decided, that's it. If your frame is rotted, forget it. It can be repaired but its a big job, plus rust will always come back.

A garage tinkerer or racing guy can out engineer even a team of PHD engineers from GM on a already built car. The problem with higher education is that they dont just "try something" but have to research it, run simulation models, have meetings about it, and write extensive whitepapers on it's possible changes and advantages. Every second of engineer time costs a crapload of money. 3 days of a garage tinkering guy costs nothing.

This is why the best modifications and engineering corrections to cars comes out of garages and race tracks. and never out of the engineers at the factory.

Also when several thousand tinkerers have had 20+ years to go over the car completely we certainly have more knowledge about the car than the guys who actually designed it. The Fiero community knows every single engineering defect of the cars, and we have designed solutions available. The guys at the factory could have never EVER been able to do what we did and actually build a car to sell. they put what they learned into the next one. It's why the current cars have a engine/tranny/drivetrain cradle system like our cars. remove 4-6 bolts and the whole thing comes out. Fiero engineering lives in every GM, they learned it was a good idea and spread it far and wide.

Just remember, They build cars to make them a LOT of profit, not to make the best car. you will never see the perfect car out of any car company, it's just not profitable.

Finally, The fiero was a cheap commuter car. it was NEVER designed as a sports car, therefore it was never engineered with sportscar in mind or it would have came with something better than the crappy chevette calipers, decent sized rotors, and all the parts that were for the corvette line, Far better A arms would have really helped the suspension.

[This message has been edited by timgray (edited 06-18-2009).]

The Fiero was originally conceived to have the '88 suspension from the very beginning of production... if that had happened, it would have grown into a sportscar.

Lots of good tips here. On my 87GT that handles great ( after adding poly bushings), I tried to take things to the next level by adding an Addco rear sway bar. The oversteer was terrible until I added the Accco front swap bar. You've got to use these in matching pairs and some tips here on this forum confirmed this. On my other Fiero I just added the Fiero Store ( Herb Adams design) rear sway bar and it complemented the stock front bar well.
Getting back to your problem I'd have to go with the suggestion that you have an alignment problem. Fieros are very finicky about alignments. A guy in my club spent over $300 to have his aligned properly as it took the garage hours to get the right adjustments. With a lowered Fiero the alignment task is undoubtedly more pronounced so I would have it checked by an expert in the field. As John said, Fieros with the 4 wheel independent suspension are very sensitive to slight out of spec alignments.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

while I genericly agree with the above sway bar statements - I'd avoid using them as "rules of thumb"
there are way to many variables to make blanket statements - which includes driver preference.
tire size, brake bias, sway bar material, sway bar arm lengths, sway bar end link design, mounts

you put big fat steamrollers on the rear, you may want to stiffen up the sway bar
if you have more rear brake bias, you may want to loosen the rear sway bar up some
the end links & the mounts change how quickly the bar becomes "active"
the arm length changes how "active" the bar will be

Just an update I thought I would try adding some wieght (to the front and back of the car) to see
if that would help nada, next I'm going to remove the rear Fiero Bar and leave the new front 1" addco bar to see if that helps. Still trying to get info on the alignment ? thanks again for all the info.