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Question - Improved Camber Curve

Shocks, Springs, Brakes, Frame, Body Work, etc

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Rick!
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Re: Question - Improved Camber Curve

Post by Rick! »

Are we still talking about Harry's 57 Chebby or did someone take a left turn into the weeds?
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Re: Question - Improved Camber Curve

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Oops! How the (bleep) did we end up way over here? :? :lol:
Felix, qui potuit rerum cognscere causas.

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Re: Question - Improved Camber Curve

Post by David Redszus »

Rick! wrote: Tue Nov 24, 2020 1:10 pm Are we still talking about Harry's 57 Chebby or did someone take a left turn into the weeds?
Perhaps a better understanding of suspensions might keep us out of the weeds and on the race track.
Some roads and tracks turn both left and right.
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Re: Question - Improved Camber Curve

Post by dannobee »

Speaking of left turns, when we put the data logger on our stock car, at 200mph it would decelerate at over 1G by just closing the throttle, no brakes applied.
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Re: Question - Improved Camber Curve

Post by David Redszus »

dannobee wrote: Tue Nov 24, 2020 6:19 pm Speaking of left turns, when we put the data logger on our stock car, at 200mph it would decelerate at over 1G by just closing the throttle, no brakes applied.
That is a very interesting car you have.
To decelerate from 200 to 189 mph at 1.002G would require a mere .5 sec.

Could you guess at the weight and frontal area?
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Re: Question - Improved Camber Curve

Post by dannobee »

The weight was known, 3400 lb stock car. Couldn't tell you the drag area or frontal area; it wasn't my side of the shop. Half a second sounds about right though. First rule of superspeedway driving, NEVER LIFT. To slow down, gently and slightly lift off the gas pedal. It's one of the reasons for spectacular multi-car crashes that are so common.
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Re: Question - Improved Camber Curve

Post by enigma57 »

Rick! wrote: Tue Nov 24, 2020 1:10 pm Are we still talking about Harry's 57 Chebby or did someone take a left turn into the weeds?
:D Y'all go right on with the discussion, Rick! Love it! I'm learning a lot sitting in here and may be able to apply some of it to my '57 Chevy.

Mods to suspension, steering and brakes will be old school stuff in order to retain the character of the car. Much as you would expect to see under a mid-'50s transporter or NASCAR racer. Mainly because I like the way those cars drive. And this will be on a shoestring budget. Only concessions to modernity in the chassis will be radial tires, and ceramic brake linings suited to the car's purpose (road car with occasional towing duties).

I will be doing some minor mods to the lower control arms to accept later year lower ball joints in order to fit '59 - '64 spindles and larger drum brakes. Might be able to shift position of lower ball joints forward a bit to gain a couple degrees more positive caster whilst doing this.

Might use upper ball joints having longer studs to induce negative camber gain in turns. Still thinking about that. When doing mods to mount later year lower ball joints...... If I made them so as to raise position of lower ball joint, wouldn't that have same effect as longer upper ball joint stud or taller spindle? Or am I thinking about this all wrong?

Also...... Have heard that there are tall tie rod ends available for Camaros and this helps reduce bump steer when running taller spindles on those cars. If this is helpful inthat regard and I can work out a way to adapt the Camaro tie rod ends on my car...... Is this worth looking into?

Thanks,

Harry
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Re: Question - Improved Camber Curve

Post by David Redszus »

enigma57 wrote: Fri Nov 27, 2020 8:04 am
Rick! wrote: Tue Nov 24, 2020 1:10 pm Are we still talking about Harry's 57 Chebby or did someone take a left turn into the weeds?
:D Y'all go right on with the discussion, Rick! Love it! I'm learning a lot sitting in here and may be able to apply some of it to my '57 Chevy.

Mods to suspension, steering and brakes will be old school stuff in order to retain the character of the car. Much as you would expect to see under a mid-'50s transporter or NASCAR racer. Mainly because I like the way those cars drive. And this will be on a shoestring budget. Only concessions to modernity in the chassis will be radial tires, and ceramic brake linings suited to the car's purpose (road car with occasional towing duties).

I will be doing some minor mods to the lower control arms to accept later year lower ball joints in order to fit '59 - '64 spindles and larger drum brakes. Might be able to shift position of lower ball joints forward a bit to gain a couple degrees more positive caster whilst doing this.

Might use upper ball joints having longer studs to induce negative camber gain in turns. Still thinking about that. When doing mods to mount later year lower ball joints...... If I made them so as to raise position of lower ball joint, wouldn't that have same effect as longer upper ball joint stud or taller spindle? Or am I thinking about this all wrong?

Also...... Have heard that there are tall tie rod ends available for Camaros and this helps reduce bump steer when running taller spindles on those cars. If this is helpful inthat regard and I can work out a way to adapt the Camaro tie rod ends on my car...... Is this worth looking into?

Thanks,

Harry
Hi Harry,
Considering that stock suspensions were often designed to accommodate several passengers and a trunk full of
luggage, it is no wonder they are far from optimum for even low level performance applications.

My suggestion is to do a little homework regarding your suspension and your intended purpose.
You might consider a very useful suspension software program: Suspension Analyzer, found at:
PerformanceTrends.com

Ask for Kevin.
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Re: Question - Improved Camber Curve

Post by Kenova »

enigma57 wrote: Fri Nov 27, 2020 8:04 am Might be able to shift position of lower ball joints forward a bit to gain a couple degrees more positive caster whilst doing this.

Might use upper ball joints having longer studs to induce negative camber gain in turns. Still thinking about that. When doing mods to mount later year lower ball joints...... If I made them so as to raise position of lower ball joint, wouldn't that have same effect as longer upper ball joint stud or taller spindle? Or am I thinking about this all wrong?

Also...... Have heard that there are tall tie rod ends available for Camaros and this helps reduce bump steer when running taller spindles on those cars. If this is helpful in that regard and I can work out a way to adapt the Camaro tie rod ends on my car...... Is this worth looking into?

Thanks,

Harry
Moving the lower ball joint forward and/or the top one rearward is a good way to gain caster. It is commonly done with Vegas and Monzas when stepping up to S10 ball joints.

Moving the lower ball joint higher or using a longer stud will increase your camber gain but will also affect your bump steer. Might make it better, might make it worse. You really don't know unless you measure for bump steer.

The early Camaros had bump steer designed into them. I suspect some engineer just got lazy or they just didn't give a damn. The bump steer kits or longer tie rod studs address the problem with both stock and tall spindles. Interestingly increasing caster on the early F and X body suspension actually improves the bump steer.

Take a look through Howe Racing's catalog. You may find something of use in it.

Ken
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Retaining it is the hard part.
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Re: Question - Improved Camber Curve

Post by enigma57 »

:D Thanks, David and Ken. Appreciate your input and will do.

Best regards,

Harry
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Re: Question - Improved Camber Curve

Post by dannobee »

The factory engineers have different design criteria than those on the high performance side, either at the factory or race teams.

The factory guys want to appeal to the greatest number of average drivers. That means good parking lot behavior, decent handling at freeway speeds, lots of driver feedback to let them know that they're approaching the limits of adhesion. That usually leaves a suspension setup with lots of tire squeal, lots of body roll, and very predictable (pushing/understeering) characteristics when driven hard. And results in lower warranty costs as lots of grip tends to break suspension and drivetrain parts.

Most of us, on the other hand, want the car to stick like glue until the moment all 4 tires lose traction and it flies off the track, give us just enough feedback, stable as a rock at 150mph, hook like a top fueler on launch, and don't give a rats ass about turning into a parking spot at the Piggly Wiggly or the handicapped spot at Costco.

The factory high performance engineers can do a respectable job when given the opportunity. Look what Herb Adams did with the Pontiac Trans Am or what Tadge Juechter (and Zora Arkus-Duntov before him) did with the Corvette.
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Re: Question - Improved Camber Curve

Post by Rick! »

Harry, if you want to do some reading, I have an extra Gillespie book you can borrow. It's written in plain english so it's very easy to understand all the concepts regarding vehicle dynamics.
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Re: Question - Improved Camber Curve

Post by enigma57 »

Thanks, Dan that makes perfect sense!

Thanks for your offer, Rick! Much appreciated. I would feel better if I could get the Title and ISBN number from you and pick up a copy of my own, though.

I figure it will take me the better part of 3 more years to have the Chevy back on the road. At my age, its one day at a time and I never take tomorrow for granted. Wouldn't want to worry about returning your book if I should check out before I can get the car running and sorted out.

Best regards,

Harry
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Re: Question - Improved Camber Curve

Post by Rick! »

Fundamentals of Vehicle Dynamics - Thomas D. Gillespie
1-56091-199-9
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Re: Question - Improved Camber Curve

Post by enigma57 »

:D Thanks, Rick! Really appreciate the info. I'll find a copy and study it. I have much to learn.

Best regards,

Harry
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