I am usually long winded so I actually posted my dilemna on my website at:

http://zumaz.com/chevelle_plans.html

If you have a quick minute to dig through it I would appreciate any advice. There are plenty of pictures to look at so please visit my link!

Thanks,

Zuma

I used global west stock BB springs and they shot the front of my car so far into the air it was sorry. I love their tubular arms though.
I tried cutting the springs, but they got too hot and eventually sagged.
I said enough of this, went with a QA1 coil over and have never regretted it since.
I also bought global west lowering rear springs and tossed them for stock springs, they were too soft and offered no benefit track or street.
I also have a pretty darn heavy car, with my very light race wheels on, I weighed in at the track at 3998lbs and have weighed in at 4020 with my street tires and a 1/4 tank at the track.
I would recommend anything global west sells including those tie rod end sleeves, their special bushings, tubular arms (upper and lower front), except the springs they sell.
I also was not thrilled with their lower rear "boxed" control arms. They shove the sway bar in an awkward place.
They work great though.

Matt

Thanks for that info, MadMarv.

Unfortunately, I already have purchased the full Hotchkis springs setup and KYB shocks. I decided to just keep this combo for now till I have 4 grand to buy all new wheels/tires, tubular arms, a disc brake setup, and all the miscellaneous pieces. I'm just going to do all that in one shot when the time comes.

I'm another GW customer that is VERY happy with their products and the overall performance of the combo in the handling department, but I am a bit unhappy with the stance. I wish I had purchased the coilovers to allow a bit of adjustability. I'm sure there are IC and roll center issues that come into play which played into their spring selections and ride height choices but the fact remains the final results aren't totally pleasing to me; also, given the varying weights and distributions on different cars (bench, buckets, A/C, stereos in the trunk, etc) they can only provide an "average" spring that works for "most" applications and gets 90% of the cars within their desired ride height range.

GW has a very valid reason NOT to go too low in the front-- basically, because of the negative camber gain on suspension compression with the tall spindle setup, if you go too low you will have a lot of negative camber to dial out and it's very likely you'll run out of shims and won't be able to align the car properly for camber specs. This is even more true if you have a bit of frame sag-- which is very, very likely after 30+ years of time on the road.

Also, Matt, their new rear arms don't have the funky "flange" on the bottom that the old arms did to mount the sway bar; the new arms have flat inserts and bar provisions built into them to bolt the bar in the stock location.

Also, I'm unsure of the weight of a 4 door and their weight distribution compared to a 2-door, but I recently installed full GW suspension (including springs) on a friend's 66 Chevelle 2-door, and the stance on his car is similar to your third picture only a tad higher in back.

I would definately go for the coilovers in front to allow you to tweak your rake, and as long as you can properly align the car in front I would consider it an acceptable ride height.

However, I didn't design the parts, nor am I a suspension expert... a call to GW would probably be the best thing to do.

Troy

Troy, I highly doubt RC or IC was even considered when GW selected spring rate/height. I sit about 3"" lower than the GW spring height and my FRCH is still way too high. The tall spindle swap provides for neg camber in bump conditions, not static. Some of GW's stuff is cool for a street car, I wouldn't recommend their springs. The arms are a bit pricey but the Delrin bushings are a nice plus. Coil overs are a nice way to go for adjustability and spring rate selection.

Keep in mind that GW calls out specs for "all around performance", this includes just regular street driving and expecting 30K miles of tire life. Remove some of the "factory mistakes" from the equation and correct the suspension design flaws and all of the sudden GW's specs are worthless. If you are going to run all GW parts and want reliable/family wagon style handling then go with their specs. If you want to build a corner burner, throw the rear links in the garbage and get work fabbing up a Satchell link or 3-link, do some track evaluations on spring selection and set the front end up with some real alignment numbers. I like 1-1.5 degrees neg camber, 5-6 degrees positive caster and 1/16-1/8" toe-in.

This is a clipping from the Global West page (at http://www.globalwest.net/handling_charts%20abody.htm) that got my gears turning:

"Did you know Hot Rod Magazine did an article on a 65 Chevelle using Global West
suspension components. The article's premise was to see if we could make a Chevelle handle
with bolt on equipment, using no tricks. The tire size was 245/ 50/16, our street springs not
racing springs, Koni shocks, 1-1/8 inch front sway bar and no rear sway bar. The 65 Chevelle
pulled .96g's on the skid pad.
(One G is capable with spring and tire/wheel combination change)."

I wouldn't exactly call .96 g "reliable/family wagon style handling."

Regardless,
If we forget about using the Global West stuff, then what would be the most complimentary "stock" type parts to go with. The car is a daily driver but I would like a decent ride quality and a relatively flat cornering ability. I don't need to compete with Corvettes or anything, just don't want it to feel like a boat.

I'd like to see that test considering AM just put together a pupose built car just for handling-tube frame, C4 underpinings, all the bells and whissles, 18" rubber and they only pulled off .92 I beleive. Viper only pulls 1.2 so I'd really like to see a 65 with just GW bolt-ons pulling .96. I think it's more like .86, if that high.

I notice there was no tech data available on their site with regards to this claim, just his say so.

GW has found a market of folks who just want to bolt on tested parts in asn afternoon and do no research or fab themselves, this a capatistic economy, more power to them. I am simply suggesting there are far better alternatives out there if you are willing to fire up the torch and do your own work. If you want to fire up the Mastercard and be done with it then GW is probably your best bet (although DSE is starting to do A body stuff too). For alternatives check out some circle track warehouses, they have much better prices on equal quality products, you just have to the work to make them fit.
Going ther circle track route also allows you to research better rear suspension systems, ie. Satchell link, 3-link, 4-link, T/A arrangement etc..

Unfotunately man,

I'll be the first to admit I'm not such a great mechanic and I'm definitely not a fabricator. So for a guy like me it pretty much has to be bolt on stuff.

I guess I should ask this: Using bolt-on parts, from your experience, what gives the best results in suspension upgrades?

My thoughts go two ways:

First, just replace everything with polyurethane and new parts where needed, 1 1/8" sway bar in front, 1" in back, 11" disc brake kit, tires and wheels, DONE.

Second, go with the OPG arms, then same as above, DONE.

Any thoughts on this strategy? Would my first option give me "flat" cornering for regular city driving (no more than, say, 75mhp)?

For someone who has never done this before I would like to get it right the first time and not say damn, I should have went with "the other plan." Know what I mean?

Stay away from poly-anything. If you want the best bolt-on approach, GW is the way to go. There are more than a few horror stories about shipping dates, just to forewarn you. It seems buying just bushings from them is very difficult to do, you can get the same style bushings from AFCO (do a google search). I would strongly recommend using coil spring specialties and specify your own springs. They will pretty much build you exactly what you want and you don't have to deal with "springs settling" (not normal). A good quality spring does have to "take a set" once installed. AFCO springs are pretty good as well but not custom built, you have to trim your own height. 1 1/8 front bar is really un-necessary if you tune the front suspension properly. The sway bar should not "be" the suspension (a 1 1/8 bar is being the suspension), it should be used only as tool to fine tune the suspension. Unfortunately there is no precise answer to what you want, things like spring rate are going to be trial and error until you find the right compromise of NVH and handling. I am running about 600 lbs right now and am stepping up to 900 lbs when I go through it again this winter. I will gladly give up NVH for better handling. The rear rate should around 175-200 lbs for a street car with the incorrectly designed factory converging links. Going to a spherical bearing or Delrin (not preferred) in the rear links will help. Using poly in any of the moving parts of the suspension will cause additional bind-not good.

Thanks for the info, Dennis.

I appreciate all the info so far. Could you elaborate on the "incorrectly designed factory converging links." I love to read about such technicalities.

The factory converging links are good for one thing, keeping the rear differential positioned under the car in a somewhat centered position. The problem comes in when the suspension attempts to move either up or down and those links do not move smoothly and independently. In a perfect world(3-link with watts-I don‘t care for IRS), one wheel can move up/down and stay centered in the wheel house without affecting the other wheel (or minimally). Due to the way the converging links were laid out originally it is not possible for one wheel to move smoothly through it's arc. The simple fact that arms are all angled toward the CL (center line) of the vehicle prohibits smooth up down movement as the arms are trying to move in 2 directions at once. This bind situation is what keeps the rear differential centered. Other factors in designing a rear suspension are RRCH (rear roll center height) which on a factory converging link is about 25" if I remember correctly from earlier computations, way too high. A stock late model Camaro, by contrast is around 9". Anti-squat is another factor, this is what keeps the vehicle level as you accelerate out of a corner (or off the line for you straight line guys). Ideally, and in most properly designed suspensions AS is around 100%. Never below 70ish and not usually above 200%, the trade off to high AS is increased chance of brake hop and usually shorter SVSA (we’ll get there). The AS on the stock set up is an estimated 50% at best. SVSA (side view swing arm) is the imaginary line drawn between where the links actually attach to the differential and where they would meet if the links were long enough. Years of testing by people with far more experienced than me has revealed a SVSA distance of not less than 42” to prevent axle hop (Herb Adams). When the effective SVSA becomes too short (usually as a result of tying to increase AS) axle hop becomes more and more prevalent. Axle hop is very bad, that is a condition where under braking the rear end tends to hop off the pavement , the harder you brake, the worse it gets. Probably not a condition you would want on any car especially not something you drive on the street. I have 4-5 books on designing suspension systems, all of which are 100+ pages each, it would take days to summarize all the data and still not get into advantage/disadvantage of each system. The simplest and most basic of the books is “Chassis Engineering” by Herb Adams. I think anyone even considering suspension modification should read this book and at least try to have a basic understanding of what is actually happening when the suspension is working. Having this understanding will make it much easier to determine what is not working and how to fix it.

Hope this helps a little, don’t feel overwhelmed. It wasn’t very long ago I would read similar threads and sit back and scratch my head. Go to corner-carvers.com. I don’t recommend trying to log in and post (they are pretty mean and especially like belittling the new guys), but there are some of the brightest minds in road racing over there. Use the search button in the suspension section for more information then you could ever consume. Most of the posts are Mustang related, but the theory is still the same.

Dennis is 100% correct, although I will disagree with his "incorrectly designed" comment-- the factory C4L (converging 4 link) setup was probably chosen because it was easy to produce (stamped arms, a few bushings and bolts), it did a reasonably good job especially considering tires at the time were very limited in capabilities, and it had to fit in the space required without cutting into the passenger compartment. Is it a perfect setup? Heck no. As he said, as the suspension moves further away from center it encounters more and more bind, and the roll center is far from ideal. It was likely the best design they could do given packaging and space constraints. It isn't "incorrectly" designed so much as "not ideally designed" at least from a performance and handling standpoint. It did do the job adequately for nearly everyone out there, and heck, GM used the design well into the late 80's on G and A bodies. Remember, these cars were not meant to be corner carvers and with flimsy stamped arms and rubber bushings a lot of the inherent binding issues are absorbed and "muted" as it were by bushing and arm flex. However, if you try to stiffen things up by adding say boxed arms and poly bushings everywhere you will DEFINATELY feel the binding; it will feel as if the rear of the car is riding on a washboard. Been there, done that, wasted my money, DO NOT buy 4 boxed arms with all poly bushings. You will regret it!

However, I have found the GW/Edelbrock arm combo with their spherical bearings to be a DRAMATIC improvement in smoothness and handling predictability over all stock stuff. Is it ideal? Definately not as the inherent C4L geometry problems are still there but the spherical bearings help out quite a bit and the setup works much better and more predictably than stock, and IMO it is more than adequate for 95% of everyone out there. There aren't many of us who like to sling A-bodies into hard turns, but unfortunately if you do (like me and Dennis) the factory rear suspension will become the achilles heel of the entire car.

I'm still trying to work out a way to stuff IRS into my car without losing lots of trunk space and the backseat. You can make a solid rear axle car handle extremely well with a well designed setup (3 link w/Watts or less ideally a panhard, etc) but I still consider that to be a partial solution as you'll still experience tire cupping from hard driving as you can't build any negative camber into the system; however unless you totally thrash the car on an open track day this is another problem you will probably never see.

Until I find a solution that makes me happy on all fronts, I'll stick with my geometry-deprived but predictable GW/Edelbrock rear end. It still works pretty darn well (enough to get me into trouble) and will hold me over until I find my ideal solution. I'm waiting to see yours, Dennis. smile.gif

Troy

Your right Troy, it isn't incorrectly designed-just typical bean counter philosophy. I hate seeing cars that have so much potential held back to save a buck. The public would gladly spend another 500 bucks for the car if handled that much better.
I too like the Edlebrock arms with the "johnny joint" style ends-much better option than the Delrin lined GW arms.

Troy,

What exactly are you running out back? GW lowers and Edelbrock uppers?

Dennis, thanks again for that info. I am checking out that website and I'm going to Borders to buy that book.

One last question I'm sure many people have:

You mentioned not to use Poly (urethane) anything. What the hell is this stuff good for anyway then?

Nothing-well maybe body mounts if you didn't want to make some aluminum one's.

Poly bushings are pretty good if they only have to rotate-- i.e. the front control arms and sway bar bracket bushings. They aren't much good if they have to torsionally flex-- i.e. in the rear control arms. They also make great motor mounts.

Poly is a good material for body mounts however. I'm using poly body mounts. Very noticeable increase in felt "stiffness" of the car without a ton of added NVH.

And dizzy, yes I'm running Global West TBC-4 lowers with Edelbrock uppers and rubber bushings on top the rear end. Both the GW lower arms and Edelbrock upper arms have spherical bearings at the frame end which really help out with the smoothness of the rear suspension's movement. It's still not perfect, but you can work the suspension by hand fairly easily if you jack it up and leave the springs off; something which is VERY difficult to do with either all rubber bushings, or worse yet 4 aftermarket boxed arms with full poly bushings.

Troy

Awesome, thanks for the info. Global West lowers and Edelbrock uppers are on the list now!

I'll add my GW combo and experience to the pot smile.gif

Front suspension:
I went with GW tubular upper control arms for the front suspension with delrin bushings. Also had GW install delrin bushings on my lower control arms. B-body spindles were used, 1LE rotors, '70-'76 Camaro calipers, '68 Corvette 1 1/4" bore MC, 1 1/4" sway bar. Initially, I installed stock height GW springs. Stance was too high, and I ordered Hotchkis 1" lower springs for all four corners. I think the stance is great. I was able to get the alignment close to what GW recommends. Tire wear has not been an issue.

Rear Suspension:
BMR upper and lower control arms with poly bushings. I'm going with the Edelbrock spherical uppers soon as the poly crap isn't working out. Bad move. I'll stick with the lowers until funds permit. NO rear sway bar. I may order the Hotchkis sway bar front/rear set in the future.

As it is right now (see signature picture), I think the car handles great. Tires/wheel are 215/50/15 front 255/60/15 rear with Weld Draglites. With 17" wheels and lower profile tires it'll handle even better. I'm not out to win autocross races, so the setup works for me. There is very little body roll in corners. My achilles' heal are the wheels/tires at the moment. I'm happy how it turned out.

Alan

Your car looks kick-ass!

I'm glad to read your specs as they are almost exactly what I will end up doing: GW front arms, big brakes, all Hotckis springs (I already had bought them at all four corners), Edlebrock and GW in the back, tires and wheels, then I'll see what kind of sway bars it needs.

Question for you Alan:

Is bump steer an issue for you with your taller spindles? Did you get the Edelbrock tie rods?

Thanks for the compliment dizzyzuma!

Question for you Alan:

Is bump steer an issue for you with your taller spindles? Did you get the Edelbrock tie rods?
I've had this suspension setup on all kinds of wacky roads from crappy freeway surfaces to windy roads with road patches. I've slug the car into curves and hit bumps in the road. Car tracks beautiful. I've taken my hands off the wheel while going straight on a rough patched up road - car stays it's course. I haven't experiences any bumpsteer. My '94 Impala SS had worse steering effects over rough roads than my Chevelle. Much worse. I used Moog tie-rods, centerlink, idler arm. I'm very happy with this setup. Real smooth. Is it perfect for all out racing? NO. I'll tell ya what though, since I put this suspension system on, I seek out the windy roads to give the car a workout smile.gif . What I like the most is I used many GM parts or aftermarket equivalent. They only thing I couldn't get in the middle of nowhere is a turned down balljoint that is required for the tall spindles. Well, that and the tubular upper a-arm. I wanted reliability, durability, and easy of finding replacement parts.

Side note: I used Bilstein shocks at all four corners. They are what Hotchkis sold on they're website (I bought through a cheaper source). I see Hotchkis doesn't sell the Bilstein shocks anymore though.

dizzyzuma, I have an Excel spreadsheet listing just about every part # and price of the suspension and steering components I installed. I could e-mail it to you if you wanted it.

That was a long winded, dang :eek:

I ditto Alan's experience on the bump steer. It is most definately there (all you have to do is jack the front of the car up and it's quite apparent) but during "normal" driving conditions and normal ranges of suspension travel I have never had a bump steer issue with the car darting this way and that way over bumps. It is a non-issue IMO during the normal operating range of the suspension, but it is definately there at the extremes of droop. However, how often do you have one side of the suspension droop all the way down to the bump stop?

Troy

Yes, please, Mr. Alan.

Please send the spreadsheet to:

zuma@zumaz.com

Thank you VERY much and thanks for all the input guys!

dizzy,

YGM!

Alan

Hey dennis, I would like a copy of your speadsheet as well, if you could email it to
Chevyman@comcast.net
that would be great I am looking at doing suspesion on mine sometine and am interested to know what everyone else has and how it works!!!!
thanks,
Kevin

oops, I mean Alan, can you email it to me!!!

hahahaha

alan,
if you are so inclined would you be willing to part with another copy of your speadsheet?

alan,
if you are so inclined would you be willing to part with another copy of your speadsheet?

I've send the spreadsheet to those who inquired about it smile.gif . If anybody else would like it, just post or shoot me an e-mail. It's inclusive of my whole project (rear-end, brakes, suspension, ect.).

See Ya,

Alan