69 GTO Rebuilt Suspension - RIDES way TOO HARD. HELP!
 

I have searched threads for suspension the last 3 days and my head is spinning. I am looking for help to improve the suspension of my 69 GTO Auto w/out A/C. I have totally upgraded/ Improved everything, but I think I went over board. The car handles great, & rides pretty nice on the highway, but around town it rides way too hard. Very harsh to the point I need to make some changes.... but where to begin? I'd like it to handle, but want a softer ride. (not sloppy like it was 35 years ago) but not like an empty 1 ton truck like it is now.
I have replaced the front end & bushings with a PST Polygrahite Super Kit - New ball joints, idler arm, Upper & lower control arms, end links & swaybar bushings. Monster Front & rear sway bars are from HO Racing - 1 3/8". TRW coil springs up front (supposedly stock replacements) Cargo Coils in rear. Shocks consist of Monroe Sensatracs all the way around. I had KYB's at first - but took them out. That improved the ride a little. Tires are BF GOODRICH Radial TA's Front = 235/60/R14. Rear = 245/60/R14 on Enkie aluminum rims. I also upgraded steering box to an 86 Monte carlo SS box.
Great improvements, but the front end hits so hard it will knock your fillings loose. Before I replace the bushings back to RUBBER I wanted some opinions on what I should change. Note, If I try to make the front end bounce up & down by pushing on bumper, the front end is very hard to move. (not springy)
Any suggestions would be great. Thanks guys

???????
 

Unless bushings are too tight,[doubtful] shock valving and spring rate should be the determining factors, not bushings. Sway bars probably tightened up the car, as well. Any car that handles will sacrifice ride, that's the trade-off. Take a ride in an early 'Vette or Trans Am.

as above, check those control arm bolts - loosen them all up, put the car's weight on teh wheels, then tighten tehm to spec.
be sure the poly bushings are properly lubed with correct nasty poly grease.
the monster swaybars do impact ride somewhat; on any non-equal left/right-side bumps, they come into play.
you can use spring-loaded end links, which will take some hit off the swaybars, if needed.

SpeedshopMike - Thanks, I'll try loosening the control arm bolts and applying proper lube. I assume it goes in where the bolt goes thru the bushing. I'll re-tighten with the weight of the car on the ground. (I did not install them, so perhaps whoever did, performed the job with the car in the air)
I had just thought that harshness was a characterisitc of the poly bushings all this time.

no. it must go in between the polyurethane part and the sleeves. it does not do anything between bolt and inner sleeve since the inner sleeve does not move. you must disassemble the bushings.

i recommend to remove temporarly the connection between front sway bar and lower control arms, fix the sway bar and do a CAREFUL test drive to check if it's the too thick sway bar. that's what i suspect.

i have poly bushings and KYB shocks and stock sway bar and it feels already quite firm.

Have not heard good things about Eaton - I'll leave it at that. As far as removing the Poly bushings to grease them - If they are comming out -I'M REPLACING THEM WITH RUBBER.
I removed front sway bar tonite and the front end seems to move more freely. I'd love to take it for a spin, but my radiator is out for repair. (which is why I started taking things apart) I wonder if I can run it without a swaybar in front at all.... Unless i have the stock 1 uptop my garage somewhere....
Pittsburgh64, let me know how the spring loaded end links work. I'm curious.

also look at your rear suspension those cargo springs don't welp any, remember that the rear suspension gives you most of your ride quality

Wow, suprised to hear you're not happy with ride quality. :confused:
I have the complete HO suspension pkg too, front and rear including HO springs and the monster bars. My '70 GTO feels great around town, on the freeway, or at the track and it handles like a T/A on the twisty turns, I've yet to explore the limits of cornering G's fully but can take those 45 mph offramps at 65-70 mph no problem.

Different about your setup and mine is that i am running bilstein shocks and I'm also running custom made boxed and gusseted lower control arms on the rear with adjustable control uppers on the back too.

Silver Judge, Believe me, it's great on the highway, It handles great - I love the off ramp speed thing too, But to feel every little seam or bump in the road around town is annoying. [Forget RR tracks!] I'd love to just tone it down a bit, instead of going to the other extreme (rubber bushings). I'd rather change shocks & springs instead of a complete tear down. What springs do you recommend? Need suggestions or part numbers to go by - [No A/C] I'd prefer not to replace them 5 or 6 times to get the right ones though. I've heard good things about Blistein & Edlebrock IAS shocks...
Whats the advantage of adjustible rear control arms? i don't take my car to the track, so hard launches are not a major factor. Don't get me wrong, I get on it now & again, but I don't race it.

here's a minor thing to check. how much air pressure is in the tires. my car ran a bit harsh, lowered the pressure just a bit and it rides much smoother now. only a couple lbs made a difference.

64, glad they worked.

glider is correct regarding the bushing lube.

moog's cargo coils usually ride quite well; they're very progressive in most apps.
poly bushings generally dont hurt much in this case; long as the control arms are not binding they're ok.

my 68 convertible has a manufacturer who shall remian nameless' full control arm setup front and rear using delrin bushings and solids; i'm using edelbrock shocks; the car rides very pleasantly, to say the least - but you do feel the tiny stuff, though it's not bothersome.

I'm guess I could swap springs with new MOOG Springs, Edlebrock IAS, and put the stock swaybars on with the addco adjustable endlinks....
If I use MOOG springs that are 1 inch lower, Will it make it ride harder or handle better or both? I want to be able to get it to handle without being so harsh up front.... So many spring choices though. I hate to be at the mercy of the guy at the parts counter. I'd rather know what I'm asking for with a part number. I found this list:

http://www.classiccarsprings.com/springrates.html

Boggles my mind on the choices though... Any help narrowing this down would be greatly appreciated.

Also found this statment which seems to make sense and identify part of my problem:
"Just replacing the old rubber sway bar bushings with urethane is equal to increasing the bar size, but when doing both the bar size upgrade and going with urethane bushings you may have reached the overkill zone. And unless you want to feel the mint mark on a dime, keep the rest of the suspension bushings rubber."

Front springs for A-bodies are 3.630" inside diameter. '68-up has one square end and one tangential end ('67-back has both tangential ends, FYI). If you extract all those, you can sort for the characteristics you want.

Somebody mentioned air pressure in tires possibly being an issue, that reminds me...What kind of tires are you running ? Excuse what may be obvious but if you've got 45 series 17 inch tires, that'll obviously contribute to ride quality (or lack thereof) Just reminding all of some of the issues that affect ride quality. Again, my setup on my 70 GTO is similar, I run 50-series 16 inch tires on mine and sometimes I gotta remind myself I'm not in a cadillac it feels so cushy. Don't give up on the HO suspension! Consider talking to Ken Crocie about it too.

Tires are BF GOODRICH Radial TA's Front = 235/60/R14. Rear = 245/60/R14 with 30 psi all around. Silver Judge - yours rides cushy??? Wow, perhaps I need to go with bigger rims as well. Mine is far from cushy.
I have a set of Rally II's 15 x 7 but no tires mounted to try them out. I 'd hate to give up the HO Suspension... i'll have to pick Kens brain.
Thanks Shadowjack as well for narrowing down the A-body springs.

I need to sit down and write a book on installing poly bushings! And suspension tuning! First , take the upper control arm bushing washers and turn them backwards-cup side out. they are grabbing the entire bushing when installed normally. #2 put a spacer(nut,washer,etc) between the front sway bar bracket and the frame to obtane a zero preload condition.#3 bounce the car ,see if it moves freely.#4 if not ,try backing off the lower control arm bolt pre load and bounce test again.If ok double nut the bolt to prevent it from wandering away.#5 If all the above fails,there is too much iterference fit between the poly bushing and it's inner steel sleave and the sleave must be sanded andf/or turned down for a smooth easy turningg fit.It helps to sand or scuff the ID of the poly bushing to help retain the grease. This is the method we used @ H-O when installing Poly.

what sense does it make, to install first a stiffer sway bar and then connect it to the control arms with softening springs???

Just one observation. I thought it was taboo to run the same size anti-sway bar all around. He said that he has 1 3/8" all around. Personal opinion but 1 1/4" front and 1" rear shoud be about ideal for a normal driven "A" body. My 66 with that combo is just shy of being too stiff, what I think saved the ride quality was going with all rubber bushings. Springs are TRW with Monroe Gas shocks.

Ken, Great info, THANKS. I will follow your detailed instructions before purchasing springs and shocks & hopefully have success. (fingers crossed)
Pit64 I'll try those endlinks too, for $20 it can't hurt.

I have heard the same thing before as well, many, many times but it depends on the application, vehicle, F/R weight distribution, 4-corner weight distribution, etc.
Ken Crocie and his HO suspension equipped GTO has blown doors off of corvettes and all sorts of pretty bad ass vehicles in all around performance contests including the high speed slalom, published in countless magazines, etc. No, Ken doesn't give me any commission.