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PostPosted: December 1, 2019, 5:01 pm 
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I have started mocking up my front suspension and using Vsusp. Can anyone tell me if my setup is good. The link is not clickable must
be cut and pasted.

https://tinyurl.com/wsvue78

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PostPosted: December 1, 2019, 7:31 pm 
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Read this:
viewtopic.php?f=5&t=17856&hilit=vsusp

Great in one wheel bump at the expense of cornering/roll. Also a lot of scrub and the roll center moves a lot vertically.

Here is your setup with no changes except rolled 3 deg to show the outside tire camber loss and the chart was adjusted to show the results.

default values

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PostPosted: December 2, 2019, 7:08 pm 
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Playing with it a bit. Flat rc, loss of only 1.5 deg camber on outside wheel in 3 deg roll. Rc is a bit high but reduces need for a swaybar.

default values

I also corrected the wheel offset.

Determine the front track width based on the rear axle/irs and wheels/tires plus necessary clearance between tire side wall bulge and the frame. Track is based on the tire centerline so different offset and width from a referenced build will alter what you need. Front track should be at least as wide as the rear track width. It makes sense to build the back half (from the firewall back) first since the axle, trans, and your girth/seat design determine the rail width.If you just want to build to a specific set of plans instead of based on your components, plan to build around the plans to compensate.

After determining front track, figure out the best length, level at ride height, lca for lcap placement on the frame, then use these dims as the corner stone for altering the ucap and uca length as needed for the best geometry.

The narrower the distance between the left and right lcaps, the less the ucaps (and coilover upper mount) will stick out of the frame/bodywork.

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PostPosted: December 3, 2019, 8:28 pm 
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Thank you for your help. I not sure what I can do with the parts that I already have. I bought the wheels 7 or 8 years ago not realizing they would not work with mustang II spindles `without 1.5 in spacers. this is probably causing my high scrub numbers. Do I need to start over and try to find different wheels to space my spindles out farther and make new lower arms, or can something be done to make my parts work. My frame is a 442E.
Here is my build log. http://locostusa.com/forums/viewtopic.php?f=35&t=8929 Mark's 3800 v6 442e

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PostPosted: December 4, 2019, 6:44 pm 
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If you don’t want to use 82-03 s10 spindles, want to eliminate the front wheel spacer/5 lug adapters, and the hub bore of the wheels is at least as large as the center bore of the original rotors, just swap the stock rotors for these from speedway motors:
https://www.ebay.com/itm/Mustang-II-Dis ... 0180!US!-1

Larger brakes are an option but will be heavier and may cause lock issues with such a light car.

With a 442E, I’m guessing you will make your left and right lcaps about 18 inches apart and you’ve determined the track will be 58 inches based on the rear track? Tweaked for new control arm lengths:

default values

Tweaked further to balance bump and roll loss while trying to stay near the frame rails:default values

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PostPosted: December 5, 2019, 6:21 pm 
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What is the limiting factor driving the need for 1.5" spacers? What is the natural offset of your wheels?

Honestly, while zero scrub gets thrown around a lot, I actually think there is something to be said for a small amount of positive scrub. In large part because if you want zero scrub radius, but add any camber, your mathematically perfect zero scrub now becomes negative scrub. Negative scrub is great for FWD, but I'd rather err positive than negative on a RWD car. Which is good, because I doubt you'd have much luck finding the 63.5mm offset wheels that would be required for you to hit MV8's zero scrub geometry, and spacers that increase your wheel offset are even harder to find.

If you notice, MV's geometry follows the basic guidelines of double wishbone suspension design, that your original attempt missed. Lower control arm roughly horizontal. Upper control arm a bit shorter and angled down slightly towards the chassis. However, while VSusp is fine for rear suspension design, the fact that it only operates in 2D and does not have any ability to account for the 3D geometry of steered wheels, it is far less suitable to front suspension design than Wishbone VB...As found here: http://locostusa.com/forums/viewtopic.php?f=26&t=11985

If you play around with that, I think you'll see that once caster's effect on dynamic camber is factored in, you may not need as much camber gain and will be able to go to a little longer of instant centers than a 2D analysis would otherwise indicate. I'll have to pull out ol' Bessie, our old laptop where my old Wishbone files are, to see what type of numbers I was last looking at this stuff regularly.

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PostPosted: December 5, 2019, 8:17 pm 
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I bought my wheel years ago when I started my build, mocked up the rear end then life happened. I purchased mustang spindles and then found that the center bore would not fit my wheels. Wy wheels are 8 in. 5.5 backspace so 1.5 offset, which would be great if 73 mm bore on my wheels was the hole size and not just the groove cut in the mounting surface. I have looked into wheels for a mustang and they are all 0 offset, which is where I am at with spacers.

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PostPosted: December 5, 2019, 11:37 pm 
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What's the ID of your rims, and what's the OD of your snout?

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PostPosted: December 6, 2019, 7:27 am 
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Image

The snout is 70mm, the lip is 70mm but the hole is 62mm

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PostPosted: December 6, 2019, 6:58 pm 
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I calculated the rota grid 17x8, 114.3x5, 73mm bore offset to be 0.23" without the spacer.

I wonder where you sourced the rotors with a 70mm snout since the chevy pattern rotors are 64mm. Have you verified that you have a 4.75bc and not the typical ford 4.5bc?

For these rims to work, you need to grind with a rotary file or have them machined to remove the bore step that retains the center cap and just paint the hubs. Since the area you are modifying does not center the rim on the hub, it isn't critical except for appearance. Most machine shops probably don't want the liability.

If you don't want to modify the rims,. find the application they are supposed to fit and use those spindles.

I think Justin is probably right, but vsusp is good enough for me.

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PostPosted: December 6, 2019, 9:17 pm 
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magoins wrote:
The snout is 70mm, the lip is 70mm but the hole is 62mm
There are numerous methods that can be used to grind or machine them out.

https://grassrootsmotorsports.com/forum/grm/enlarging-wheel-center-bore/47300/page1/

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