Re: ROLL CENTER
[Re: BergmanAutoCraft]
#1991909
01/16/16 01:28 PM
01/16/16 01:28 PM
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Joined: Sep 2007
Posts: 14,889 up yours
Supercuda
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You'd think the aftermarket people would be able to easily provide that info, they already have all the dimensions and theoretically already did the math.
However, I suspect that with very few exceptions, most aftermarket "performance" suspensions, MII based, it's hype not performance they are selling.
I plotted out my stock suspension years ago, but that's it.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
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Re: ROLL CENTER
[Re: BergmanAutoCraft]
#1991927
01/16/16 01:43 PM
01/16/16 01:43 PM
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Joined: Sep 2007
Posts: 14,889 up yours
Supercuda
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Reverse engineering the data is not hard, unlike the recipe for KFC or your other examples. Fixing it isn't hard either, well not at the design stage, who knows how hard a retrofit would be.
I think XV probably got it right too, have you tested any of their stuff?
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
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Re: ROLL CENTER
[Re: Supercuda]
#1991933
01/16/16 01:52 PM
01/16/16 01:52 PM
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Joined: Feb 2010
Posts: 270 Mountain View, CA
68rrunner
enthusiast
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enthusiast
Joined: Feb 2010
Posts: 270
Mountain View, CA
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Reverse engineering the data is not hard, unlike the recipe for KFC or your other examples. Fixing it isn't hard either, well not at the design stage, who knows how hard a retrofit would be.
I think XV probably got it right too, have you tested any of their stuff? Some one reverse engineering a product is always a possibility, and someone could do the same with my examples, if they have the inclination or talent. But if they have the ability to reverse engineer it, then they probably could have designed it themselves. And a copy of the product through jigging would be pretty obvious. As to XV, Only their old Level 1 stuff and their current run of chassis "stiffening" products. Wasn't impressed with either.
Last edited by 68rrunner; 01/16/16 01:56 PM.
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Re: ROLL CENTER
[Re: BergmanAutoCraft]
#1991934
01/16/16 01:53 PM
01/16/16 01:53 PM
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Joined: Jan 2003
Posts: 5,388 Pikes Peak Country
TC@HP2
master
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master
Joined: Jan 2003
Posts: 5,388
Pikes Peak Country
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I've plotted my Challenger out in its current configuration and played around with varying size control arms, spindles, and other attachments to see the changes. I've got all the roll center static and dynamic points along with camber, caster, and toe curves. Somewhere I still have all the older ones I did when I was running brand C and F cars as well.
I've never bothered to do anything with aftermarket set ups because I've not considered buying them and am not concerned with how they compare. Not only that, but I'd suspect they won't readily share this info with most of us, even if asked. I'd certainly suspect they all have it since they need these data points to formulate their set ups.
While I'm sure there are a small % of drivers who want some very detailed specs of their systems and will seek to further improve them beyond what they received, I believe the vast majority only care that they have something "modern" and "better" because they don't believe that something 40 years old is superior to something made in the last decade.Currently, there are only 4 ways to suspend a car, coil, leaf, torsion, and air, and all we can do is modify the geometry imparted on those four methods.
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Re: ROLL CENTER
[Re: BergmanAutoCraft]
#1992008
01/16/16 03:22 PM
01/16/16 03:22 PM
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Joined: Sep 2007
Posts: 14,889 up yours
Supercuda
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Does DSE even make mopar specific stuff, I couldn't find a listing.
I do see a bunch of specs though.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
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Re: ROLL CENTER
[Re: BergmanAutoCraft]
#1992469
01/17/16 11:55 AM
01/17/16 11:55 AM
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Joined: Sep 2007
Posts: 14,889 up yours
Supercuda
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Point is I was hoping to see what they had for us so I could look it over and compare, but it's not applicable.
I hear NASA makes some awesomely scienced out stuff too, but it's also not applicable.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
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Re: ROLL CENTER
[Re: GoodysGotaCuda]
#1992816
01/17/16 06:17 PM
01/17/16 06:17 PM
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Joined: Jan 2003
Posts: 27,467 So Cal
autoxcuda
Too Many Posts
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Too Many Posts
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So Cal
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I've prodded for some of this information from manufactures over the years and never seem to get anywhere. I would like to see the specified improvements quantified. If nothing else it'd show me someone, somewhere was doing some kinematic analysis and not just shooting from the hip or looking at just one or two variables.
"Reduced bump-steer!"
...ok, cool. How much are we talking? 0.001"? Or 0.100"? So how bad is .100" ? Is that over 3" of rebound or jounce? 0.100" is less than 1/8".
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Re: ROLL CENTER
[Re: BergmanAutoCraft]
#1992819
01/17/16 06:23 PM
01/17/16 06:23 PM
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Joined: Jan 2011
Posts: 4,785 Utah and Alaska
astjp2
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Utah and Alaska
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1/8 of movement/turning of the spindle is a lot at the tie rod end, probably 3/8" of movement of the tire back and forth...that is more than I would like to get in my b-body
1941 Taylorcraft 1968 Charger 1994 Wrangler 1998 Wrangler 2008 Kia Rio 2017 Jetta
I didn't do 4 years and 9 months of Graduate School to be called Mister!
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Re: ROLL CENTER
[Re: BergmanAutoCraft]
#1992824
01/17/16 06:30 PM
01/17/16 06:30 PM
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Joined: Sep 2007
Posts: 14,889 up yours
Supercuda
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I think the point was that the claims of improvement are not specified and there is no way to find out short of buying, installing and testing on your own.
I also strongly suspect that there is way too much before/after claims made with the before being a wore out unrebuilt 50 year old factory installed suspension against a new aftermarket one. Well duh there will be an improvement.
Reminds me of an aftermarket cylinder head manufacturer we all know that claimed in magazine ads years ago a large HP increase over factory heads.
In the fine print you found out that the factory heads were stock 305 heads and they were tested on a 350. No [censored] the aftermarket head was an improvement on a 350, you were choking it with the 305 heads. Technically, and probably legally, a factual claim but not accurate. But at least they put it in the fine print. Same can't be said about a lot of aftermarket manufacturers.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
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Re: ROLL CENTER
[Re: astjp2]
#1992889
01/17/16 07:53 PM
01/17/16 07:53 PM
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Joined: Jan 2003
Posts: 27,467 So Cal
autoxcuda
Too Many Posts
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Too Many Posts
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Posts: 27,467
So Cal
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1/8 of movement/turning of the spindle is a lot at the tie rod end, probably 3/8" of movement of the tire back and forth...that is more than I would like to get in my b-body 1/8" of movement is a lot at 3 inches of compression? Think about what is going on a 3" of compression....low speed high G corner... The spindle will be at a high turning angle and straight line bump steer doesn't apply much. The two measuring points on my commonly used bump steer gauge are 16.5" apart. A typical tire is 26". I showed my results shown below with a guy that crew chiefs K&N Pro Series championship cars and full time designs and builds his own multi track championship cars. 1/8" of bump with the same style gauge I used at 3" is still good and he said don't mess with it. He did say 1/16" would be very good. Of course we're talking cars set up for handling. Not Drag cars. Getting .001" at jounce AND rebound at 3" is nearly impossible. That's not reality if you've ever did this or did it regularly.
Last edited by autoxcuda; 01/18/16 12:14 AM.
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Re: ROLL CENTER
[Re: Supercuda]
#1992891
01/17/16 07:56 PM
01/17/16 07:56 PM
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Joined: Nov 2004
Posts: 25,050 Texas
GoodysGotaCuda
5.7L Hemi, 6spd
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5.7L Hemi, 6spd
Joined: Nov 2004
Posts: 25,050
Texas
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I think the point was that the claims of improvement are not specified and there is no way to find out short of buying, installing and testing on your own. Correct, that is what I was going after. Thinking at all into the numbers I posted is a waste of effort, they were completely arbitrary. I'm sure there is a slim number for those that are actually interested in the details. The primary mode of marketing I see is pretty far dumbed down, something along the lines of, "We race our car. Look, it's fast! Yours can be fast too! Buy -our name- parts!" Some of these numbers you may not want your competitors all knowing, if you are a suspension component manufacturer. A fine line I'm sure. I suppose it comes back to making the case as a reputable manufacturer and showing what development goes into the car, like XV tried to do. Hotchkis tries to show theirs through their Challenger, the volume of builds they do, the number of vehicles they support, etc.
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Re: ROLL CENTER
[Re: BergmanAutoCraft]
#1992902
01/17/16 08:14 PM
01/17/16 08:14 PM
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Joined: Sep 2007
Posts: 14,889 up yours
Supercuda
About to go away
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About to go away
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Posts: 14,889
up yours
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I dunno, seems to me they could take a stock vehicle, by stock I mean rebuilt to factory stock not a worn out vehicle, test it. Then install their stuff and retest WITH the same tires and rims as the before. Bumpsteer, ackerman, skid pad, G's and maybe braking distances could easily be gotten and not give any proprietary information away, which wouldn't be proprietary long anyway, it can be reverse engineered for the price of buying one setup.
Or one could use an existing known performer, Tom's Valiant comes to mind, and use it to test the new setup in a before/after comparison. Probably a reason some don't do it.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
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Re: ROLL CENTER
[Re: autoxcuda]
#1992956
01/17/16 09:40 PM
01/17/16 09:40 PM
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Joined: Nov 2006
Posts: 1,074 Manitoba Canada
67autocross
super stock
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super stock
Joined: Nov 2006
Posts: 1,074
Manitoba Canada
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1/8 of movement/turning of the spindle is a lot at the tie rod end, probably 3/8" of movement of the tire back and forth...that is more than I would like to get in my b-body 1/8" of movement is a lot at 3 inches of compression? Think about what is going on a 3" of compression....low speed high G corner... The spindle will be at a high turning angle and straight line bump steer doesn't apply much. The two measuring points on my commonly used bump steer gauge are 16.5" apart. A typical tire is 26". I showed my results shown below with a guy that crew chiefs K&N Pro Series championship cars and full time designs and builds his own multi track championship car. 1/8" of bump with the same style gauge I used at 3" is still good and he said don't mess with it. He did say 1/16" would be very good. Of course we're talking cars set up for handling. Not Drag cars. Getting .001" at jounce AND rebound at 3" is nearly impossible. That's not reality if you've ever did this or did it regularly. How much wheel travel do you have with your set up?
A new iron curtain drawn across the 49th parallel
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