 Corner Balancing a Twisted Tub ..., Adventures in Weight-Distribution Land ... |
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| SirAndy |
  Apr 22 2006, 02:00 AM
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#1
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Resident German  Group: Admin Posts: 41,623 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California  |
so, McMark and i spent all day today trying to corner balance my tweaked and twisted tub.
i started out with all 4 corners the same ride-height. but the car felt awful. twitchy like hell and the left front always wanted to slide on me. so, we got a bunch of scales and went to investigate. almost 3/4 tank of gas and my fat ass in the drivers seat ... the end result is still not perfect, but *much* better than before. interestingly enough, now that the corners are balanced, the tub looks all crooked. (IMG:style_emoticons/default/wacko.gif) i guess it makes sense, it's either: - twisted tub, same ride height on all 4 corners, corner weights waaaay off or - twisted tub, corners balanced, tub looks bend. we'll see how it holds up at the AX this AM, but it felt *much* better on the ride home from napa ... thank you Mr. McMark! (IMG:style_emoticons/default/smilie_pokal.gif) here's a printout from the high-tech software we used to track the data ... Attached thumbnail(s) 
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| SirAndy |
Apr 22 2006, 02:12 AM
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#2
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Resident German Group: Admin Posts: 41,623 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
oh, and btw. looks like my car comes in at around 2000lbs without me but 3/4 tank of gas ...
not too shabby for the gallons of bondo the PO threw at it ... (IMG:style_emoticons/default/wink.gif) Andy |
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| McMark |
Apr 22 2006, 02:53 AM
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#3
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914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
Yeah, a nice set of scales from SMART is on my short list.
I had a good time and learned a lot. Tomorrow morning we'll see if it was worth it. (IMG:style_emoticons/default/driving.gif) |
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| r_towle |
Apr 22 2006, 09:01 AM
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#4
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Custom Member Group: Members Posts: 24,573 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States 
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Ill have to say..
The graphics on that software is amazing. The details and the ability to see all the data on one portable screen is perfect... And I love the fact that the battery never runs out... Nice job. Would you mind showing us how you used scales...without the special racing scales.... Rich |
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| rhodyguy |
Apr 22 2006, 09:31 AM
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#5
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Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,072 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
did you alter the corner balancing after the alignment? where did you make the biggest move? the adj perches, up front, or a combo?
k |
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| Flat VW |
Apr 22 2006, 09:50 AM
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#6
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Illegal Soapbox Derby Racecar Group: Members Posts: 1,692 Joined: 13-November 04 From: Phoenix, AZ Member No.: 3,105 |
My bookie runs that same software.
John (IMG:style_emoticons/default/laugh.gif) QUOTE(r_towle @ Apr 22 2006, 08:01 AM)  The graphics on that software is amazing. The details and the ability to see all the data on one portable screen is perfect... And I love the fact that the battery never runs out... Rich |
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| McMark |
Apr 22 2006, 11:38 AM
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#7
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914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
QUOTE(r_towle @ Apr 22 2006, 08:01 AM) Would you mind showing us how you used scales...without the special racing scales....  Ghetto corner balance. It actually worked pretty well. Scales went up to 360+ lbs even though they were only rated for 300 lbs. $6 per scale on sale. (IMG:style_emoticons/default/wink.gif) QUOTE(rhodyguy @ Apr 22 2006, 08:31 AM) did you alter the corner balancing after the alignment? where did you make the biggest move? the adj perches, up front, or a combo? The car was aligned when we started, now it's a little out of alignment. That the price you pay for night-before adjustments. The image Andy posted shows how obviously tweaked the chassis was. The left rear was above 600 lbs constantly, the front right was below 500 lbs most of the time and the front left/right rear were pretty stable and balanced at around 550 lbs. The left rear suspension pickup is probably tweaked downwards and the front right suspension is visibly tweaked upwards. So we made a lot of progress, considering the chassis. Next step for Andy's car is the Celette Bench! (IMG:style_emoticons/default/wink.gif) |
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| SirAndy |
Apr 22 2006, 07:26 PM
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#8
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Resident German Group: Admin Posts: 41,623 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
QUOTE(McMark @ Apr 22 2006, 01:53 AM) well, what do you know? for some reason, we got it "dead on"! (IMG:style_emoticons/default/smilie_pokal.gif) weird bump-steer and random lane change is gone. it felt really nice on the freeway on the way home ... then the AX today, well, what can i say, the car handled great! crisp turn in and perfect balance. even the (more or less random) sway bar setting was dead on. just a tad of oversteer, which is gud on a guttless 1.7L. felt like i had power oversteer, helped a lot in getting the car around those tight turns ... i was only 3 secs of trekkor, which was plenty good enough for me ... (IMG:style_emoticons/default/clap56.gif) Andy |
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| SirAndy |
Apr 22 2006, 07:29 PM
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#9
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Resident German Group: Admin Posts: 41,623 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
and here's the fun part, this is *AFTER* the corner balancing, holy mother of bent tubs ...
(IMG:style_emoticons/default/av-943.gif) Andy Attached image(s)  
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| Qarl |
Apr 22 2006, 07:36 PM
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#10
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Shriveled member Group: Benefactors Posts: 5,233 Joined: 8-February 03 From: Florida Member No.: 271 Region Association: None  |
quick question...
what does one do when corner balancing to "adjust" the weight distribution? Does it involve adjusting spring height, torsion bar tension, etc.?? Just curious? |
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| SirAndy |
Apr 22 2006, 07:39 PM
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#11
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Resident German Group: Admin Posts: 41,623 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
QUOTE(Qarl @ Apr 22 2006, 06:36 PM) Does it involve adjusting spring height, torsion bar tension, etc.?? yupp, all of that ... basically, move each of the corners up/down until you get the weight numbers on each corner you want. BUT, it sounds much easier than it is, a good setup can be tricky, not to mention when the tub is bend ... (IMG:style_emoticons/default/smile.gif) Andy |
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| Qarl |
Apr 22 2006, 07:42 PM
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#12
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Shriveled member Group: Benefactors Posts: 5,233 Joined: 8-February 03 From: Florida Member No.: 271 Region Association: None |
So what was your final distribution percentage Front/Rear?
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| Andyrew |
Apr 22 2006, 07:46 PM
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#13
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Spooling.... Please wait Group: Members Posts: 13,376 Joined: 20-January 03 From: Riverbank, Ca Member No.: 172 Region Association: Northern California
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Wow andy... thats bent!
How was the difference in handling? |
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| SirAndy |
Apr 22 2006, 07:48 PM
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#14
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Resident German Group: Admin Posts: 41,623 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
QUOTE(Qarl @ Apr 22 2006, 06:42 PM) So what was your final distribution percentage Front/Rear? total weight, with me (~215lbs) and a 3/4 tanks of gas: 2210 lbs front/back ratio: 46/54 still slightly heavier in the back, but i don't want to go any lower in the front and i didn't want to put that twisted back up in the air any more ... car looks funny, but it handled great at the AX today ... (IMG:style_emoticons/default/driving.gif) Andy |
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| Van914 |
Apr 23 2006, 06:48 AM
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#15
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Van914 Group: Members Posts: 698 Joined: 5-January 03 From: Cincinnati, Ohio Member No.: 90 Region Association: Upper MidWest
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Andy,
The drivers side should be higher without you in the seat. Let's see a picture with you in the seat and compare. Having the same issues, Van914 |
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| Katmanken |
Apr 23 2006, 09:10 AM
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#16
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You haven't seen me if anybody asks... Group: Members Posts: 4,738 Joined: 14-June 03 From: USA Member No.: 819 Region Association: Upper MidWest |
I agree wth Van, getcher butt in the car and reshoot the pics.
Van, your car looked perfect from what I could see. Shiny black paint and door gaps usually show up those kinds of issues. Bet I have the same problem as you guys. Dang PO bondoed the right front wheel well and front bulkhead so I coudn't seee the ripples. (IMG:style_emoticons/default/ar15.gif) Trying to come up with a ghetto method of frame checking and fixturing using my rusty spare car as an alignment baseline. It has many fewer miles and only one rear fender crunch, but a lot more rust. If it measures good, it could be used to make alignment fixtures off of it, and supply good unbent parts to fix my suspected bent car. Move the fixture to the bent car, and use it to "align" the new parts for welding. Kinda like a ghetto Cellete. Ken |
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| rhodyguy |
Apr 23 2006, 09:23 AM
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#17
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Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,072 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
note the ds rear is high and the pass front is low. i would think the car will settle a bit with the driver's weight in the seat but more of a complete f to r side change. i'll look for my final alignment figures on the silver car after while. you two went through all of this just for an a-x? if trekor took off 2 plug wires and leveled the playing field i think you would've beat him.(IMG:style_emoticons/default/smile.gif)
k |
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| McMark |
Apr 23 2006, 10:17 AM
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#18
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914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
The car isn't going to sit level until it's straightened. Even with Andy in the seat it still looks funny. We went through the trouble because it was fun. Isn't that what these cars are about?
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| SirAndy |
Apr 23 2006, 12:37 PM
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#19
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Resident German Group: Admin Posts: 41,623 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
QUOTE(McMark @ Apr 23 2006, 09:17 AM) The car isn't going to sit level until it's straightened. Even with Andy in the seat it still looks funny. (IMG:style_emoticons/default/agree.gif) with the 250lbs springs in the back, even with me in the car it looks pretty much the same. the car doesn't move all that much when i get in the car ... and kevin is right, the car was hit in the drivers rear AND pass front, presumably at the same time ... (IMG:style_emoticons/default/sad.gif) Andy |
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| Aaron Cox |
Apr 23 2006, 12:41 PM
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#20
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Professional Lawn Dart Group: Retired Admin Posts: 24,541 Joined: 1-February 03 From: OC Member No.: 219 Region Association: Southern California |
whats it run to straighten a tub on a cellete fixture?
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