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All else being equal........ #1184780 02/23/12 02:01 PM 02/23/12 02:01 PM
Joined: Feb 2010 Posts: 18,493 Granite Bay CA Kern Dog OP Striving for excellence
Kern Dog OP Striving for excellence Joined: Feb 2010 Posts: 18,493 Granite Bay CA	What effect might be seen by moving weight lower and rearward? The Charger as it is has a tendency towards oversteer. To quickly recap the stats: '70 Charger, 440 block with aluminum heads, 727, 8 3/4 axle. 1" T bars, 1 1/8" front sway bar, MP leaf springs, 7/8" rear sway bar, KYB shocks, welded frame connectors and torque boxes. My previous understanding is that in most cases, moving weight away from the front toward the rear reduces UNdersteer. I'd planned on relocating the battery to the trunk, but at this point, I need LESS understeer like I need a 3rd leg. The frame connectors and torque boxes added about 48 lbs to the car, luckily the weight was low and in the center. The relocation of the battery can wait until I sort out the balance of the car. I'm going to run the car without the rear bar to see how it feels. One option is to use a 3/4" bar with rubber end link bushings. Please let me know what you think. Thanks, Greg.

Re: All else being equal........ [Re: Kern Dog] #1184781 02/23/12 02:11 PM 02/23/12 02:11 PM
Joined: May 2003 Posts: 96,666 On The Boat, On The Lake, Wa. ... amxautox Still Retired. Still Posting on Moparts. A Lot.
amxautox Still Retired. Still Posting on Moparts. A Lot. Joined: May 2003 Posts: 96,666 On The Boat, On The Lake, Wa. ...	Use a 3/4" rear bar. Tom "Everyone should believe in something; I believe I'll go fishing." -Henry David Thoreau Men and fish are alike. They both get into trouble when they open their mouths author unknown

Re: All else being equal........ [Re: amxautox] #1184782 02/23/12 02:23 PM 02/23/12 02:23 PM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	Quote: Use a 3/4" rear bar. "The Armies of our ancestors were lucky, in that they were not trailed by a second army of pencil pushers."

Re: All else being equal........ [Re: 1_WILD_RT] #1184783 02/23/12 02:24 PM 02/23/12 02:24 PM
Joined: Feb 2011 Posts: 4,302 Nebraska 72Swinger master
72Swinger master Joined: Feb 2011 Posts: 4,302 Nebraska	Or more back tire Mopar to the bone!!!

Re: All else being equal........ [Re: 72Swinger] #1184784 02/23/12 02:36 PM 02/23/12 02:36 PM
Joined: Feb 2010 Posts: 18,493 Granite Bay CA Kern Dog OP Striving for excellence
Kern Dog OP Striving for excellence Joined: Feb 2010 Posts: 18,493 Granite Bay CA	295 45-18 on a 10 inch rim......... I SAW your specs though.... pretty impressive! To fit a wider tire, I'd need to modify the outer wheel tubs. The design is such that they do NOT follow the quarter panel straight up. Instead, the tubs sit inboard of the quarter by 3 inches before they go vertical. This makes it impossible to push the tires flush to the wheel arch at my current ride height. 7086520-493(2).JPG (48 downloads) Last edited by Frankenduster; 02/25/12 03:56 AM.

Re: All else being equal........ [Re: 72Swinger] #1184785 02/23/12 02:36 PM 02/23/12 02:36 PM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	Quote: Or more back tire Edit, Ok there is more room but playing with the bar still is the better option... I think he's about maxed that option out...He could go with less front tire but I don't think that's really an option he wants to explore either... Besides, new tires cost more than a new bar.... Fact is I'd consider going with a 5/8" rear bar but with adjustable end link mounts so it could be tuned..... A 5/8" bar with the effective lever shortened can act stiffer than his current 7/8" bar but with long arms is could be softened to the point that the car understeers.. Last edited by 1_WILD_RT; 02/23/12 02:42 PM. "The Armies of our ancestors were lucky, in that they were not trailed by a second army of pencil pushers."

Re: All else being equal........ [Re: Kern Dog] #1184786 02/23/12 03:04 PM 02/23/12 03:04 PM
Joined: Jan 2003 Posts: 1,376 NORTHERN CA HUSTLESTUFF pro stock
HUSTLESTUFF pro stock Joined: Jan 2003 Posts: 1,376 NORTHERN CA	When I took my car to Willow Springs last year it was very neutral to me and the instructor. I didn't run a rear bar because the hardware was at the powder coat shop. Try unhooking the bar completely and see how it drives. Mike "Were in it to win it. Anything less will end up being..... A whole lot of fun doing!!" UNLAWFL RIP UN

Re: All else being equal........ [Re: Kern Dog] #1184787 02/23/12 04:25 PM 02/23/12 04:25 PM
Joined: Feb 2011 Posts: 4,302 Nebraska 72Swinger master
72Swinger master Joined: Feb 2011 Posts: 4,302 Nebraska	Quote: 295 45-18 on a 10 inch rim......... I SAW your specs though.... pretty impressive! To fit a wider tire, I'd need to have the rims re-hooped with more backspace. I have about 1 3/4" of room to the springs. I suppose that I could squeeze a 315 or 335 back there...... I keep forgetting what you have for a car lol! With Duster in your name! I agree that playing with the rear bar is probably a better option as others have said especially when a couple wrenches and a bungee cord will let you give it a good test. Mopar to the bone!!!

Re: All else being equal........ [Re: Kern Dog] #1184788 02/23/12 05:07 PM 02/23/12 05:07 PM
Joined: Jan 2003 Posts: 5,394 Pikes Peak Country T TC@HP2 master
TC@HP2 master T Joined: Jan 2003 Posts: 5,394 Pikes Peak Country	Since we don't have chevy's, it may not be so easy to just swap in another diameter rear bar. Summit has .75, .875, and 1 inch axle hung bars. Firm Feel offer .75 and .875 frame hung bars. A .75 frame hung bar does not have the same rate as a .75 axle hung bar. They have differing length lever arms and will produce different results. They also attach on the axle housing differently so they have differing motion ratios, which further impacts applied rate.

Re: All else being equal........ [Re: HUSTLESTUFF] #1184789 02/23/12 05:55 PM 02/23/12 05:55 PM
Joined: Jan 2003 Posts: 27,471 So Cal autoxcuda Too Many Posts
autoxcuda Too Many Posts Joined: Jan 2003 Posts: 27,471 So Cal	Quote: When I took my car to Willow Springs last year it was very neutral to me and the instructor. I didn't run a rear bar because the hardware was at the powder coat shop. Try unhooking the bar completely and see how it drives. Mike Experiment with what you have. Using an adjustable rear sway bar bar is very helpful in this respect. Mike, what that Bob Reed that drove you car and didn't want you to put a rear bar on it?

Re: All else being equal........ [Re: autoxcuda] #1184790 02/23/12 08:48 PM 02/23/12 08:48 PM
Joined: Jan 2007 Posts: 780 Woodinville, WA Viol8r super stock
Viol8r super stock Joined: Jan 2007 Posts: 780 Woodinville, WA	Weight low and rear will tend to free the car up. But that amount is the difference between a half a tank and full tank. I am not sure you notice the difference. You would need to make a serious effort to start moving weight around to gain some understeer. To be honest there are several things a bit off with your set-up. First off the KYB's are not a very good high speed control shock. They lack the rebound control to really help in a big car like this. Your TB's and Sway bar are under sized IMHO. I personally try to keep at least a �" bar in the rear and get the front and rear roll couple to match. This could be upwards of a 1.12 or 1.18 TB. Lastly, MP springs are different rates left and right,(always buy 2 lefts) so you are already starting out with a fairly unbalanced car before you have even hit the track. And you have not even got into camber gain and bump steer which can effect the way the car feels settling into a corner. 1968 Pro-Touring Dodge Charger *2011 Optima Ultimate Street Car Challenge Invitee http://www.popularhotrodding.com/features/1203phr_1968_dodge_charger/index.html

Re: All else being equal........ [Re: Viol8r] #1184791 02/23/12 09:19 PM 02/23/12 09:19 PM
Joined: Feb 2010 Posts: 18,493 Granite Bay CA Kern Dog OP Striving for excellence
Kern Dog OP Striving for excellence Joined: Feb 2010 Posts: 18,493 Granite Bay CA	Regarding the rear springs, I DID buy 2 of the same sides, but I'm not sure of which side. There are an equal amout of leaves on each pack. Back in 2002 when I bought the suspension parts, I bought what was commercially available. A LOT has been developed since then.

Re: All else being equal........ [Re: Kern Dog] #1184792 02/24/12 01:11 AM 02/24/12 01:11 AM
Joined: Feb 2011 Posts: 4,302 Nebraska 72Swinger master
72Swinger master Joined: Feb 2011 Posts: 4,302 Nebraska	Bigger t-bars would probably tighten her up dood. Mopar to the bone!!!

Re: All else being equal........ [Re: HUSTLESTUFF] #1184793 02/24/12 03:57 AM 02/24/12 03:57 AM
Joined: Feb 2010 Posts: 18,493 Granite Bay CA Kern Dog OP Striving for excellence
Kern Dog OP Striving for excellence Joined: Feb 2010 Posts: 18,493 Granite Bay CA	Quote: When I took my car to Willow Springs last year it was very neutral to me and the instructor. I didn't run a rear bar because the hardware was at the powder coat shop. Try unhooking the bar completely and see how it drives. Mike I removed the 7/8" rear bar and laid it on the workbench to compare its shape against a spare 3/4" bar of unknown origin. They both had the same light gold anodized finish common with Addco bars. The bigger bar had a lever length of 9 1/4" from the end link eyelet to just past the 90 degree bend. The smaller bar had a 8 1/4" lever. Correct me if my logic is flawed here, but wouldn't this mean that the smaller bar would be nearly as effective as the larger one? Example: An even SHORTER lever on the smaller bar may actually be as effective as a larger bar with a longer lever? I went ahead and drove the car without any rear sway bar. I drove on the street, but was able to make a few 90 degree turns away from any traffic. There was more body roll, but the car also felt a little less "bound up" if that makes any sense. It handled more predictably and the rear only got loose under throttle. My guess is that the currect setup leaves a lot of room for improvement, but for now it feels better to drive on the street. I have a welded and gussetted K member I'll swap in after it is painted. I'm also planning on Bilstien shocks, but I have to generate some cash to pay for them. Thanks for the suggestions!

Re: All else being equal........ [Re: Kern Dog] #1184794 02/24/12 01:01 PM 02/24/12 01:01 PM
Joined: Jan 2003 Posts: 5,394 Pikes Peak Country T TC@HP2 master
TC@HP2 master T Joined: Jan 2003 Posts: 5,394 Pikes Peak Country	Quote: I removed the 7/8" rear bar and laid it on the workbench to compare its shape against a spare 3/4" bar of unknown origin. They both had the same light gold anodized finish common with Addco bars. The bigger bar had a lever length of 9 1/4" from the end link eyelet to just past the 90 degree bend. The smaller bar had a 8 1/4" lever. Correct me if my logic is flawed here, but wouldn't this mean that the smaller bar would be nearly as effective as the larger one? Example: An even SHORTER lever on the smaller bar may actually be as effective as a larger bar with a longer lever? This logic may be correct. With that particular arrangement, there may only be a slight difference between the bars, assuming the mounting positions on the axle and connection points on the frame are similar. You can only know if you check. On my car, the difference in rate between a .75" frame hung and a 1.0" axle hung bar is only 30#, despite the large difference in diameter. Here is a link to a calculator you can use to figure out absolute bar rates: http://www.circletrack.com/car_racing_calculators/torsion_bar_rate_calculator/index.html Here is another article to understand how it all translates to the tires, this is the front bar on an oval track car, but the pricipal is the same: http://www.circletrack.com/chassistech/ctrp_1004_sway_bar_rating_techniques/viewall.html

Re: All else being equal........ [Re: TC@HP2] #1184795 02/24/12 02:26 PM 02/24/12 02:26 PM
Joined: Jan 2003 Posts: 28,068 Irving, TX feets Senior Management
feets Senior Management Joined: Jan 2003 Posts: 28,068 Irving, TX	According to that calculator the bigger bar with the longer arms is still much stiffer than the smaller bar. Try the smaller bar if you want to trade a litte cornering for the body roll control. We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon

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