Spring rates and body roll ?? - Page 4 - Alfa Romeo Bulletin Board & Forums
 9Likes
Reply
 
LinkBack Thread Tools Display Modes
post #46 of 50 (permalink) Old 01-12-2016, 10:14 PM
Registered User
 
Join Date: May 2003
Posts: 1,952
while we are on the topic of spindles, any know where i can find the rare 69-70 105 stepnose update spindle with the closer caliper mounts?
davbert is offline  
Sponsored Links
Advertisement
 
post #47 of 50 (permalink) Old 01-13-2016, 01:53 PM
Registered User
 
Join Date: Aug 2003
Location: Ozark, MO.
Posts: 712
Quote:
Originally Posted by Alleggerita View Post
Not.

A drop spindle just moves the stub axle and all things equal the camber curve remains identical to the standard spindle. It just changes the whereabouts of the camber curve where you find yourself. The curve does not change.

If you increase the length/height of the spindle as you are purporting to do this no longer is a drop spindle, even if you were to call it that, but rather a completely re-engineered spindle which then will certainly change the camber curve as well as other variables ...

While your statement is correct based on your definition of "drop spindle" that clearly is not what Richard's post was about. A spindle elongated between the spindle and lower ball joint resulting in an upright with a longer overall height , as he described, has the effect he describes.

Additionally for a given ride height which is what we are really getting at here, even a "drop spindle" upright modified in no other way than to move the pin, results in dramatically different camber geometry in addition to the discussed role center effects, again at a given ride height. When you just lower a car with spring you screw up a lot more than just the roll cener. Then when you correct by leveling the lower a-arm out/take its upward tilt away it tucks in less quickly leading to less positive/more negative camber change in bump. Similarly when you correct by increasing the angle of the upper a-arm you cause it to tuck in more quickly increasing negative camber gain/ decreasing positive camber gain.

While all this is more than just moving the spindle, it really does have exactly the same effect as use of knuckle risers and ball joint spacers and all sorts of other common mods that also change the pivot to pivot height of the upright. And the pivot to pivot height is just as important as the spindle placement within it's range.
Curtis is offline  
post #48 of 50 (permalink) Old 06-04-2019, 10:50 PM
Registered User
Platinum Subscriber
 
vespam5's Avatar
 
Join Date: Feb 2005
Location: Los Angeles
Posts: 1,316
Guys, this thread has been a really interesting read. We have been working on a customer GTA at my shop for the past few weeks. This car was set up as a wide body car by Mozeglio in period. It runs a Autodelta sliding block/knuckle risers/13x9 wheels/etc. When rolling the car around my shop I can help but notice the insane amount of scrub which has me wondering if Autodelta intentionally ran the front end of these cars soft in order to induce the "inner wheel in the air syndrome" and therefore momentarily fixing the scrub radius issue (while in action)....am I crazy?

Follow me on Instagram: dorian_alfa
My website:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

69 Giulia 1300TI
69 Giulia TI racer
65 GT Sprint
83 GTV6
vespam5 is offline  
Sponsored Links
Advertisement
 
post #49 of 50 (permalink) Old 06-04-2019, 11:32 PM
Registered User
 
Veep's Avatar
 
Join Date: Mar 2005
Location: Overasselt, The Netherlands
Posts: 1,070
how is the alignment set up? with wide tyres on 9 inch some scrub may be there, gets worse if there is too much toe in or toe out. more so when engine is out.
Veep is offline  
post #50 of 50 (permalink) Old Yesterday, 08:21 AM
Registered User
 
Join Date: May 2003
Posts: 1,952
Quote:
Originally Posted by vespam5 View Post
Guys, this thread has been a really interesting read. We have been working on a customer GTA at my shop for the past few weeks. This car was set up as a wide body car by Mozeglio in period. It runs a Autodelta sliding block/knuckle risers/13x9 wheels/etc. When rolling the car around my shop I can help but notice the insane amount of scrub which has me wondering if Autodelta intentionally ran the front end of these cars soft in order to induce the "inner wheel in the air syndrome" and therefore momentarily fixing the scrub radius issue (while in action)....am I crazy?
insane scrub because of the insane scrub radius in the geometry :-) they actually ran the fronts harder to the overly soft rear with sliding block for more rear end traction. thats why they have comical looking "leg up" stance trod around corners... not because of a soft front but a stiffer front in relation to the rear. having inner up in the air will not fix the scrub radius though.

i saw an interview translated in english a few years ago on a famed autodelta test and race driver (forgot his name) when ask about the odd wheel lifting cornering, he said every time they set up the car with 4 wheels on the ground they were slower despite try multiple set ups. so they eventually just ran that car that way based on the stop watch which was 3 wheeling.

of course with today's stickier tires and massive front neg camber settings compare to the past, nearly all the current vintage 105 racers have 4 wheels on the ground.
davbert is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Alfa Romeo Bulletin Board & Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome