Benja258

i'll think we all be happy if you let us know how it runs anf if you considering to market them

V.8MR

iTrader: (6)

That beautiful...

Dallas J

iTrader: (1)

I made 10 sets of these for the racers here and have been running the original prototypes on my car all summer. Right now I'm just waiting for the last bits of hardware. Fixing the roll center and bump steer has been pretty magical.

marck_c

How much $$?

Dallas J

iTrader: (1)

It's not cheap, but Im doing my best to balance price vs paying myself back which is about all I really care to do. Id have to eventually sell 30sets to fully pay myself back but I'm pricing the first batch of 10 at $1750. If I did a second set they would be $2000.

marck_c

Thanks Dallas. And the weight...?

Dallas J

iTrader: (1)

I started out about 5lbs lighter than stock but I decided to add a bit more weight back into the uprights as a trade off to make the part stronger/stiffer than stock. So the 1lb sacrifice to increase a couple bolt diameter and add material I feel was worth it considering this is a part that literally connects the wheels to the car through suspension. So in the end its 4lbs lighter than stock per side.

hispanicpanic

On my racefab arms i've corrected front roll center by 16mm. It definitely makes a huge difference but now the car is out of balance......

The rear end needs some roll center correction in order to bring the geometry back to a neutral balance.

Is the car faster like this?? I don't know.... its a big maybe... but i didn't correct the bump steer like Dallas did which i suspect to be the biggest benefit in modifying front geometry.

Dallas, love the way you correct tie rod pickup points as low as possible. Just one more thing.... In order to get a proper zero on the bump steer you're gonna have to lower the steering rack. Not sure there's a way to do it without getting a custom subframe.

LetsGetThisDone

iTrader: (1)

If you changed the lower arm outer pivot without correcting bump steer, your car is all kinds of out of whack..

Dallas J

iTrader: (1)

I actually don't think the rear needs any roll correction regardless, My opinion always has been the rear is too easy to gain grip in typically needs to lose it. This is made even more evident at higher speeds when rear aero is far easier to achieve than front.

Basically my approach is to go the front roll center near ground and let the rear drop to greater than that. With greater rear roll moment I *get* to use more rear bar. The combo of high front and low rear roll center means we don't dive on the outside front so the inside rear stays down allowing more rear bar before the tire lifts. All that leads to the front inside tire doing more work. Its all about getting that inside front working harder.

Bump steer was also something that took a real aha moment for me. I set the bump steer based on my models of the upright which were all just straight up but I realized caster changing the angle of the upright. So I set the spacing and position of my bumpsteer based on working for 3.5 - 7 deg of caster and stock and whiteline ball joints. There is no need to lower the steering rack IMO, its easy enough to get the position of the arcs to match up within our actual usable steering range. And also, with the roll correction with less dive, theres less steering changes to worry about.

The current steering arms will also work with the 16mm extended studs (same as the whiteline correction) when I make the billet control arms and shoot for 8 degrees of caster. But that's all TBD as I figure that part out.

RJones

iTrader: (5)

In for a set of those too

03whitegsr

iTrader: (8)

Great work man. Looks like you could play with the length on the strut mount too and could change slider angle and scrub, particularly if you add some control arm length to this system.

Dallas J

iTrader: (1)

That was also part of my reasoning for a modular design. Basically I've been thinking if someone wants something truly custom on that, I could either setup a few options or just create an open template for people. Like if you wanted to pull the strut in or push it out some distance or an angle change, then we could just accommodate.

My local SM buddy in a 240sx may get a slightly revised set of uprights where I just change the bolted on bearing to a 300zx part. Would also need to adjust bumpsteer range for him, but it would just be a side project bartering for a custom wing. With my design I can make relatively quick changes and get it setup for other strut configs.

I may try and make an ultra light weight version similar to the Girodisc brakes that are an AutoX (and maybe my car only) and not suitable to crazier open track build. For now, I'm completely satisfied with the strength of these as is now though.

TougeGod7

iTrader: (2)

sub'd