Cal Club Autocross Forums

This is a little maddening!

I'm trying to level the car side to side with the rear a 1/4" higher then the front. After making the adjustment to the ride height on the driver front side to match the right side ... and adjusting the sway bar for zero pre-load ... and making sure the shocks were at their race pressure and tire pressures up ... and driving around to settle the new settings ... I find that both front sides have gone up?

I'm as low as I can go on the Right Front (backing off a half turn to that the adjusting screw doesn't bind) so all I can do is keeping going higher on the driver side. Perhaps this is why Brian had the Left Front so much lower then the right side of the car?

I checked the centering on the front spring ... at most it's a couple of millimeters off set ... I didn't think that warranted the work necessary to perfectly center it. Perhaps that IS what I need to do?

Of course when I raised the Left Front ... the Rear Right went down ... losing my 1/4" rake to the Right Front.

The Left Rear is 1/4" above the Left Front, but if I make and adjustment to the right front, that's going to change so that I no longer have my desired rake ...

I'm trying to get the ride height set and evened out BEFORE I corner balance next week. Perhaps I can only do so much now, and then hope I can compensate in the right directions when it's on the scales.

The LF is 5 mm, about a 1/5th of an inch higher then the RF, when it seems that the driver side, if anything, should be higher then then the passenger side. We need to have the rear higher then the front to try to combat understeer.

The rear height isn't super critical right now because we gain 1/4" when we put the 710's in back ... but I was hoping for a bit more then a 1/4" total rake

You are doing this without scales and want to worry about it not being level. It WONT be level after you corner weight it, so don't get in a twist about it when you are guessing.

Right ... but the Vette forums seems to indicate that one should be able to achieve level ... so I thought that would be a good place to start when I do the balancing.

Steve Towers wrote:Dead plumb would be great, but it's not deal breaker. Even if the turnbuckle is off by 5 degrees the error would be relatively small. You'd just be measuring the long side of the triangle instead of the side adjacent. I'd guess that by eyeball the off angle wouldn't be more than 2-3 degrees. If you wish to be accurate within thousandths, then yes, accurate right angles are necessary. Even then the subjective feel of the turn buckle, combined the the subjective feel of what you use to measure with, can be inaccurate when thousandths are involved. Shouldn't be an issue if your ok with +/- 1/32 inch (.031).

That's good enough.

Mako Koiwai wrote:Right ... but the Vette forums seems to indicate that one should be able to achieve level ... so I thought that would be a good place to start when I do the balancing.

You believe everything you read on the forums?

A car with rubber in the suspension bushings will be slightly different every time you try to measure it. Just get it in the ballpark for now... don't worry about it untl you're on the scales.

It's a sad fact that if you can measure to 1/32", you'll find the chassis won't cooperate. Every time you drive around the block and recheck, numbers will be a little different. Best you can do is measure a few times and settle for a good average. Another reason I'm not big on shop alignments...when was the last time they asked you to drive around the block so they could re-check their numbers? Oh, but they've got lasers good to thousandths...

Just remember that whenever you adjust the height on one corner of the car it's going to change every other corner in a somewhat predictable manor. When you raise the RF you know that you're also going to raise the LF and RR, and lower the LR. It takes some practice and forethought to get to the point where you can level the car quickly. If you really wanted to you could actually calculate exactly how changing one corner effects the rest, but that would end up being a fairly complicated relationship between track width, wheelbase, center of gravity location, spring rates, and motion ratios. Not sure if anyone has actually tried it.

I aligned Andrew's Miata in two rounds last night, the 2nd round just to correct a minor steering wheel issue. I've done a LOT of Miata and Suby alignments. The alignment place he took it to last week said they could only do oem "alignments," not alignments to customer spec, Hunter rack and all. Andrew wanted zero toe in front, they gave him 1/8" in, he wanted 1/8 in back, they gave him 1/4" in. He wanted Max camber, they gave him Max on one side and minimal on the other side. I to use a laser, a mm precise survey laser that I use at work.

Yeah, every time I measure the Vette after driving it, it's different. FOUR times yesterday. Good enough reason to go ASP! The figures I ended up with are a quandary. I can't change one thing without screwing up another corner. I'll wait until I get our Team Blew scales back before proceeding. The really odd thing is that the Right Front is as low as it can go and it's still almost a 1/2" higher then the Left Front! I'm really sick of adjusting front end links ...

when was the last time they asked you to drive around the block so they could re-check their numbers?

Every time you go to Darren at Westend. I've had to drive it three times around his loop before we were happy with the steering ... at 8 in the evening ... WAY past his closing time. I've asked him to stop futzing while corner balancing ... but he wouldn't let me leave until he was satisfied. You would think you're paying by the hour, but you aren't. I learned a LOT from him ...

Bob Plante wrote:If you don't own a setup plate, and if your garage floor is decent (no potholes) is it ok to take the ride height measurements frame to floor? Just the ride height, not all the other setup adjustments.

I usually use a tape measure, case on the floor & extend the tape up to the frame. Good to about 1/32 with a decent tape.

Anyone? Expert? Garage floor good enough?

:ibrightdea:

Bob Plante wrote: Anyone? Expert? Garage floor good enough?

:ibrightdea:

depends on the garage. Is your garage floor flat?

Marshall Grice wrote:

Bob Plante wrote: Anyone? Expert? Garage floor good enough?

:ibrightdea:

depends on the garage. Is your garage floor flat?

There is no such thing as a flat garage floor, they all have a slope for water drainage, how much depends on the the codes at the time the house or garage was built.

There is no such thing as a flat garage floor, they all have a slope for water drainage,

Flat vs slope are different things. A wall can be flat. Think in terms of wavy or high/low spots.

Steve Towers wrote:

There is no such thing as a flat garage floor, they all have a slope for water drainage,

Flat vs slope are different things. A wall can be flat. Think in terms of wavy or high/low spots.

I would call that a crappy job. As in the Cement Contractor didn't use the proper equipment / expert labour. High -low spots prevent water drainage.

I have poured a few driveways and garage floors.

Tom Denham wrote:

Marshall Grice wrote:

Bob Plante wrote: Anyone? Expert? Garage floor good enough?

:ibrightdea:

depends on the garage. Is your garage floor flat?

There is no such thing as a flat garage floor, they all have a slope for water drainage, how much depends on the the codes at the time the house or garage was built.

Tch. I have a flat (horizontal) garage floor. But only because I specified it that way building the house. Didn't seem to be a problem out here in the desert, code-wise. Whether you need a horizontal or just "flat" floor depends on what kind of work you want to do. If you use bubble gauges or digital camber gauges like the Watkins, you need a horizontal floor. At least left to right. Front to back is less important. Traditional way of getting that is stacking vinyl flooring tiles to raise the low tire. How far? A length of cheap clear plastic hose mostly filled with water will tell you. Or a long straight edge with a good quality carpentry level.

Tom Denham wrote:
There is no such thing as a flat garage floor, they all have a slope for water drainage, how much depends on the the codes at the time the house or garage was built.

The Berry's have a level and (kind of)flat garage spot under the lift, specifically for doing cornerweight and alignments.

I know most have a slope, and I know to do camber you need left/right level,

but

back to the question

for RIDE HEIGHT

is a measure to the (sloping and decently smoothed concrete) garage floor correct? I think it is.

If you stack tiles to remove the slope & l/r inconsistency then I think your ride height is off by the amount of those little stacks.

You are setting chassis to bottom of tire, yes? Tire should not be on top of a stack of tiles, yes?

Learning.

Bill Martin wrote:

Tch. I have a flat (horizontal) garage floor. But only because I specified it that way building the house. Didn't seem to be a problem out here in the desert, code-wise. Whether you need a horizontal or just "flat" floor depends on what kind of work you want to do. If you use bubble gauges or digital camber gauges like the Watkins, you need a horizontal floor. At least left to right. Front to back is less important. Traditional way of getting that is stacking vinyl flooring tiles to raise the low tire. How far? A length of cheap clear plastic hose mostly filled with water will tell you. Or a long straight edge with a good quality carpentry level.

Some thing you were aware enough about,to ask for. But MOST floors are never (Horizontal/flat )(for those that want to play word games).

I'll leave you to your discussion

I blame Brian.

Nope. I've got it on good authority that Dubya is behind this. Another GOP plot.

Bob Plante wrote:I know most have a slope, and I know to do camber you need left/right level,

but

back to the question

for RIDE HEIGHT

is a measure to the (sloping and decently smoothed concrete) garage floor correct? I think it is.

If you stack tiles to remove the slope & l/r inconsistency then I think your ride height is off by the amount of those little stacks.

You are setting chassis to bottom of tire, yes? Tire should not be on top of a stack of tiles, yes?

Learning.

You're correct. For ride height it isn't necessary to level the car. And if in doubt about any effect of the garage slope, you could always measure twice, once pointed in and once pointed out. If they're different, use the average.

Mako Koiwai wrote:I aligned Andrew's Miata in two rounds last night, the 2nd round just to correct a minor steering wheel issue. I've done a LOT of Miata and Suby alignments. The alignment place he took it to last week said they could only do oem "alignments," not alignments to customer spec, Hunter rack and all. Andrew wanted zero toe in front, they gave him 1/8" in, he wanted 1/8 in back, they gave him 1/4" in. He wanted Max camber, they gave him Max on one side and minimal on the other side. I to use a laser, a mm precise survey laser that I use at work.

Name that shop so everyone can avoid going there. Toe-in in the front?

Something to consider: F1, CART [RIP] and IRL cars go through set-up adjustments at every different track where they have little control over the surface they get to use. Pretty good in the F1 pit garages and the modern IRL/CART{RIP] circuits. But at Long Beach, teams are setting up shop floor tiles on crappy asphalt and putting ramps and scales down.

Bill Martin wrote:

Bob Plante wrote:I know most have a slope, and I know to do camber you need left/right level,

but

back to the question

for RIDE HEIGHT

is a measure to the (sloping and decently smoothed concrete) garage floor correct? I think it is.

If you stack tiles to remove the slope & l/r inconsistency then I think your ride height is off by the amount of those little stacks.

You are setting chassis to bottom of tire, yes? Tire should not be on top of a stack of tiles, yes?

Learning.

You're correct. For ride height it isn't necessary to level the car. And if in doubt about any effect of the garage slope, you could always measure twice, once pointed in and once pointed out. If they're different, use the average.

Thank you Bill.

That place in Pasadena is our beloved Island Tires ... where they do GREAT tire mounting on the cheap. You never have to remind them to line up the Dots with the tire stem. I guess they just don't do great alignment work?

I put a BIG front bar in Andrew's SK2 Miata ... he seems very happy with it ... and can't wait to challenge in SK2 on Sunday.