fatbillybob

Is it just me or is the C5 the biggest POS to try and align? I'm from a coilover world and poly bushings and these transverse leafs and rubber bushings are the worst! Unfortunately I have to use them for my class.

First I'll say I do my own alignments for years. My materials are race scales, a bucket of water, aquarium hose, flooring tile, ride height gage, rulers, tape measure, angle iron, L squares, digital level, various hand tools. My usual MO is to set ride height, scale the car, then align thrust, camber, rear then front toe and caster.

What I have found is that even with a C5Z with less than 10K miles on the chassis you can't get reproducible results because every time you measure things change! I guess that is because of the bushings being so sloppy that theres a few mm of change right there. Then the suspension has an amazing amount of stichion that can take miles to settle out.

Typical coilover tricks do not work to get stichion out of these suspensions. Greased slip plates do not work on C5Z even if I stand in the trunk and jump up and down to settle the suspension. Rolling the car back and forth say +/-10 ft. several times like on a scale platform does not work to get full settling of the suspension! I just can't believe it. What seems to be best is driving the car around the block. However, if I let the car sit a few days and drive the car a few miles the suspension is fully settled. There is no way guys can put these cars on 4 jackstands and settle the suspension. Why is this so important? Well you have to have a fully settled suspension to do the next steps which are scale the car, then align thrust, camber, rear then front toe and caster. And the worst part about these next steps are that without an alignment rack you really have to lift the car up and down to reach the adjusters easily and that means you just screwed the ride height settling which screws everything else.

Well what's my point? Well maybe after spending half a day in the hot sun just trying to adjust rideheight am just blowing off steam. But if any of you guys have any suggestions on an easier way to remove the stichion let me know.

I guess that also means for you guys who are sending your cars to alignment shops your settings are probably not what they are on the alignment machine because the suspension and rubber bushing have just an amazing amount of play that precludes reproducible results.

So what does this mean? Well I think because of these problems my initial measurements after multiple drivings around I am seeing rideheights of +/- less than 0.25", camber +/- less than 1/2 a degree, toe +/- 1/16". I think this is huge variation when we are trying for 1/4" rakes, camber in the 1.5 degree range, and toe in the 1/16" range.

These cars need coilovers and poly or solid bushings. Working with this car is like a fat girl in a too tight dress. The dress looks like it fits but sometimes she busts a seam.

davidfarmer

I've never had any problems, but having access to a drive-on lift certainly makes things go much faster. The leaf springs have just enough torsion during suspension play, that things do tend to bind up if you have to jack up a lot.

Anyway, even working on the floor, I have just learned to trust myself. You measure before you start, and you learn how much to adjust to get the end results. Once I get everything dialed in, I do actual test drives as I'm setting toe. Toe can do the most damage to street tires (if you have too much), so thats' where I often spend a lot of time. Getting camber close goes really fast with practice.

Ideally though, just like at an alignment shop, you never jack the car up. I use a friends shop (except for emergencies), and never lift the wheels. In that case, simply rolling back and forth settles everything nicely.

And when in doubt, max out all of the concentrics and set the toe......it will STICK whether it's "right" or not

**money is money, but for $1500 you can get a cheap 4-post lift. That is the ticket for alignments. Maybe talk a wealth friend into buying one...........

fatbillybob

I only have a twin post lift and scale ramps to roll back and forth. I think one of the big areas of stichion is the bolt height adjuster pad on the rough internal of the A arm on the front. When that binds it prevents the spring from moving freely and screws your rideheight and every other measure down the line. In all these years why not a smooth surface on the A-arm and a rolling ball so the thing can move? And that rear is living in a mush of rubber.

Have you ever aligned your car drove it around then check it more than once? Everything moves...or should I say there is huge play in the stock vette suspension that is not in a coil over suspension. I wonder if we racers would get better tire wear and save money if we had a controlable suspension? I wonder if SCCA allowed us in T1 to use poly bushings if our tire wear profile would change and we could get more miles out of our tires which is our biggest single expense.

I think the guys who post up alignment specs that look good at the shop yet are having car handling problems that sound like alignment may be suffering from this slop in the system.

drivinhard

here's my midnight wrench hack philosophy

I think ride height is over-rated. Set your cross, and go. I'm near perfect cross and I still have the stock non adjustable end links (bolts are surprisingly close in adjustment to).

I agree with you on the front adjusting pads and arm contact points, have thought similar (and plan to change the front pads)

camber with the stock rubber bushings? I may do a double check at the end just to see what I got, but I just pull it out as far as I can at all 4's. It's close side to side, -2.8/-2.7 front, -1.7 rear. After all this and that and checking front event to event, the toe seems to stay pretty close, so no problems there.

Have Pfadt's new poly kit but haven't tried it yet. I will be putting it on the spare set of control arms I have and saving the stockers in case I don't like it. Don't mind the stockers, biggest problems is pulling the arms off the bushings though.

Best thing I have done so far is dump the old style rear T1 bar for the newer adjustable, and running it at the softest setting, lubing the bushings good, and shimming the brackets to keep the bar from binding. The difference of all that was huge.

Hoping Farmer can do a "seminar" and learn me some day

SIK02SS

something tells me you have a trick up your sleeve on this one for our race in a couple weeks Carl

fatbillybob

Yes...based on my last sunday performance my trick will be to stay on the same lap as you guys.

mountainbiker2

After any adjustment, you have to drive the car around the block. I always do that and get repeatable numbers every time.

Steve A.

trackboss

If you are required to run the facyory front leaf pads then you will have to get creative, but delrin pads will help a bunch. I polished the pad area on my front lower control arms and it seemed to help the car settle. Grease can be used, but it will attract dirt and in order for it to be effective the area will need to be cleaned and re-greased every event. More so if you go off track.

sperkins

Yeah me too. I'll offer up my drive on lift to have the suspension seminar. With my lift and your scales, I think we could gather quite a few folks to make it worthwhile for David - I'll even throw in the hotel room. I'll just need a few days to clean up the shop.

froggy47

I set it and drive it, then next day (or same if there is time) I check everything, do minor adj, drive, repeat. Eventually it's spot on, but to do it perfect in one session is tough.

drivinhard

didn't know you could get a basement in south GA

exracer28

Are you jacking the car up? I use slip plates and have not had a problem but I do not jack up the car. Roll back and forth but I was always taught not to jack the car during alignment.

fatbillybob

Yes see paragraph 3. Slip plates are for when you jack up a car or lower it from a lift which I do all the time with CO suspensions. Rolling back and forth should work fine but not on my C5Z! I'm going to build a scaling platform because these suspension stick so much. TRACKBOSS is so right about the front perches. I do have the delrin things and they still suck. After 50 years of corvette development this is what GM comes up with...amazing! Anyway...I've calmed down since yesterday and have finished most of my swearing at this car.

0C5stein

Here's the deal, the front height adjuster sticks to the lower control arm and basically deflects durring suspension travel rather than sliding. If you need to jack the car up off of the ground, then you are screwed. Polishing the arms and grease has worked the best for me for the cars that can't switch over to Coilovers. Of course cleaning and re-greasing prior to each alignment will become part of your procedure. (You don't need to drop the control arm, Just get your big pry bar out and pry the spring away from the control arm, shoot brake clean in there to clean out the grease and dirt, squirt some grease in there and remove your pry bar. Rear doesn't seem to bind up so I deduced that it was the height adjusters that was sticking on the front suspension. Before I got my drive on alignment rack, i built 4 platforms (Aluminum boxes 16"x16"x16") that were perfect for my scales, used two pieces of 1/8" sheet aluminum greased on top of each for slip plates. I'd raise the car, set it on the platforms and reach up with my pry bar and release the bind on the front springs on each side, then I could do my alignment without jacking the car up again because I could hit all of the adjusting bolts while laying on a creeper.

Rake and ride height are 'mouse nuts small' in the grand scheeme of things, so get an equal cross weight and level side to side with your weight in the car and don't sweat a small variance in rake. What happens over time is that you'r cornerweight/ride height adjustments will become very small, so then you just confirm and duplicate ride height prior to Caster, camber, toe adjustment.

I'll disagree with David on simply maxing out camber and just setting toe, I've just seen too much variation on the C5s side to side as the Cradles don't always get bolted to the cars absolutly on center and we have seen up to 1/2 degree difference side to side on camber and caster.

My shop, MSI, aligns over 250 Corvettes each year and we set up alot of race cars (Corvettes, Vipers, Porsches, BMWs, Lotus' (or is that Loti) NASCAR, NASA, SCCA...) as well. Most C5s and C6s align pretty easily, but some seem to bind up more than others. Sound like yours binds up like mine used to. The grease and polishing seemed to do the trick for me and I realized that camber and then toe were the most important items to be critical, so if your running out of time, make sure the camber and then toe are set.

C5s like alot of caster for road racing, but if you run more than 7.75 degrees and don't add additional PS cooling, your going to kill your PS rack and pump (it took me two to finally realize that was what was killing em). C6 Z51 and Z06s can take up to 8.5 degrees caster without problem. If you can get the front caster up, you don't need to run as much static negative camber, yielding better tire wear and beter braking performance.
RE: your sequence, I'd suggest, Corner weight & ride height, Rear Camber, Rear Toe, Front Caster & Toe (kinda need to do them at the same time) and then front toe.

Re: toe preference - front toe out helps the car turn down crisper, but makes the car "darty" under hard braking. I like zero toe to In 0.05 on each corner.

I hope this helps.

exracer28

I use a scale/setup platen with greased slip plates in front of each scale. Disconnect sway bar links, drive the car onto the platen and stop just before the scales. I add weight in drivers seat, zero scales and then roll car onto scales. Roll forward for adjustment, bounce it a bit and roll back onto scales. Very repeatable and once you find/mark level scale location it does not take long to check adjust as needed. I am open to better ideas.

This is what i designed my platen from and I hade it higher to better acess alignment points without having to jack car.

varkwso

I am all for that also.

trackboss

How do you adjust camber/caster without lifting the car even with an alignment rack? I can only assume that is done on stock type cars with only eccentrics for adjustment? I have locked out my lower arms and adjust with the upper arms. The only way to get to them is to lift the car, remove wheels, etc. which unloads the suspension. I can't see it being any different whether its done on a rack or on the ground.

Z06_BluByU

I've already read that using Brake Cleaner on the stock laminated transverse leaf springs is a VERY bad idea as it causes the springs to DE-LAMINATE. I think the mention this in the owners manual and in teh service manuals to only use a mild soap and water solution to clean the springs..

Zenak

thats why im on coilovers, front and rear sways, chanigng out the bushings to polys with zerks, bigger and more solid blal joints, and tie rod ends all poly no rubber. After wasting money on laser alignments for a race shop near me and seeing that it was all gone by the end of 1 day i realized moeny was better spent to be ahead of the curve. these thigns are not built as race cars but high performance street vehicles. the OEM parts are godo for their intended usage. Weekend spirted high way driving. ON teh track the OE parts fail quick and are POS IMHO.

0C5stein

I only have half a dozen customers with c5s and c6s that have the camber plates that fix the lower control arms and need to shim the top. I hate em!!! Especially for those still using the stock leaf springs for exactly the reason you state. You cant adjust the upper control arm without jacking the car up. I think that the camber plates are a PITA and have seen so few adjustment change with the stock eccentrics (when properly torqued) in normal track driving and street driving that I steer clear of them. Heck on the cars that run the plates and have shocks that are too short, you've got to take the wheels off in order to reshim the upper control arm. That is unless you let us relocate you coolant and washer tank and cut a few access holes in your inner fender well, then you can just reach down from the top and use a pry bar to take the pressure off of the shims as you change them one at a time. Of course I've only found one customer that found that solution acceptable. Now his car is as easy to adjust as a C4.