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1G DSM front k-member and tubular control arms

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Come to think of it - what's the point of having all that adjustment with the spherical bearing control arms if you're not going to have a swaybar mount? Why would anyone BUT road racers and autocrossers want to spend that much money on custom control arms to save 10 lbs and get more adjustment in the front? The only guys who want that adjustment are the guys who need a swaybar. Doesn't seem to be enough return for drag racers, not for as much as it would likely cost.
 
Chris,

I laid everything on the floor this evening and I gave some thought to the swaybar attachment. I think it's doable, but I'm gonna have to play with that over the weekend.

I am thinking that the way to do this is to make the uber jig and offer different versions. Cheap - Stock arms/sway bar/PS, Drag - lightweight arms, no sway bar/little adjustment of the arms/no PS, and the uber adjustable spendy version.

That would be some serious work and a hell of a jig :)

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The fab is looking awesome! Great weight savings too! I like the idea of a-arm options, but let’s face it the least amount of weight wins. What is the real cost adder for the tubular arms? No PS or sway bars for me.
 
I'm interested as well. I still have a power rack in the car with no pump etc. I'm still drag racing, but, will start road racing as well. I vote for stock control arm mounting points as I have a set of Don Polk's tubular control arms that bolt to the stock k member. Swaybar mounting would be nice, however I doubt I will run a front swaybar for the roadcourse. However, that could change in the future.
 
The anti dive adjuster would be similar to a stock eccentric mount. Slotted mounting hole with a locked in adjustment.
In my opinion, stock control arms would be a waste of time. By the time you mod them for caster, roll center and spherical bearings, you've got a nicely polished turd. May as well do it right the first time.
http://www.dsmtuners.com/forums/road-course-autocross/454870-1g-front-castor.html

And raising the inner mounting points isn't really possible with the stupidly large stock rear bushing.
 
The anti dive adjuster would be similar to a stock eccentric mount. Slotted mounting hole with a locked in adjustment.
In my opinion, stock control arms would be a waste of time. By the time you mod them for caster, roll center and spherical bearings, you've got a nicely polished turd. May as well do it right the first time.
http://www.dsmtuners.com/forums/road-course-autocross/454870-1g-front-castor.html

And raising the inner mounting points isn't really possible with the stupidly large stock rear bushing.

Well then. He will have to decide if he wants to cater to the handful that want to make these adjustments, and sell these k members for $1500. I can see wanting/needing the ability for these adjustments if you are actively competing in a NASA class. However, for the avid track day goer, this stuff is not only a bit over the top, but beyond necessary to go out and have fun in a good handling car. So, with that, making them with stock arm mounts, or taking the time to engineer both, will reach the most people, and enable the cost to be reduced.

Just my .02
 
Mark,

The cost is actually good rod ends, bushings, and uniballs. Here is an example:

Uniball cup, plus c-clip $30.96 each
2 Aurora Sperical Bearings Teflon-lined $60 each
4 Aurora Teflon-Lined rod ends at $43.94 each

This totals about $357.68

Now these are the prices of really good bearings. We can go with QA1 cheapos or Summit Racing generic brand and cut the cost significantly.
 
Dont use cheap rod ends, bushings, and uniballs if you plan to use the car for longer trips then 402 meters at the time these will wear out in notime I have friends that had these chepo styles on their cars and the have worn out i a coupple of miles of roadcourse some have even broke, using rudora or something of that quality is alot better and a insurance to not wreck your car

just my 2 cents

/A
 
This is great stuff, especially if there is a solution to change the roll center. One thing I will mention is please toss the factory swaybar mounts and instead make it so that the "standard" style mounts can be bolted on. When I got my RM swaybars, I had to spend an hour converting the Prothane bushing mounts that came with the front sway bar into the 1G frankenstein "hook" style mount. :barf:
 
Lowell,

Actually moving the control arm mounting points up is not a problem at all. I can just rotate the mounting tabs and it will be a done deal. Adding heim joints will allow you to make enough castor adjustments too. Has anyone done any precise design work on these, meaning do you have specific measurements by how much you want to move the mounting points of the control arms (up, down) and the ball joints. I read your thread and you moved the balljoint about 1.125" forward. Do you know, specifically what camber, castor and toe do you want to achieve. My friend Jake has his own alignment rack and we can throw the car on there and get them to be exactly as needed. I know this prolongs the project, but I want it done right :)
 
This is great stuff, especially if there is a solution to change the roll center. One thing I will mention is please toss the factory swaybar mounts and instead make it so that the "standard" style mounts can be bolted on. When I got my RM swaybars, I had to spend an hour converting the Prothane bushing mounts that came with the front sway bar into the 1G frankenstein "hook" style mount. :barf:

Hahah, I tried to forget that after I did one. A standard style bar mount will be a lot easier to implement as well.

Phil: I think the price increase would be minimal, and track day guys would be willing to pay the extra. The front end of an Evo is not that much different in layout compared to a 1G, but I think everyone can agree the Evo kicks ass in comparison. With the right geometry changes there's no reason a 1G can't be just as good.

The last Evo I drove had Whiteline roll center and bump steer kits, Perrin PSSR, Whiteline front control arm bushings, and Ohlins R&T installed and set up by Mueller. Perhaps I'm biased because I've driven some well set up Evo's, but I think that level of setup in a lighter and more aerodynamic 1G body would be very good on track.
 
Hahah, I tried to forget that after I did one. A standard style bar mount will be a lot easier to implement as well.

Phil: I think the price increase would be minimal, and track day guys would be willing to pay the extra. The front end of an Evo is not that much different in layout compared to a 1G, but I think everyone can agree the Evo kicks ass in comparison. With the right geometry changes there's no reason a 1G can't be just as good.

The last Evo I drove had Whiteline roll center and bump steer kits, Perrin PSSR, Whiteline front control arm bushings, and Ohlins R&T installed and set up by Mueller. Perhaps I'm biased because I've driven some well set up Evo's, but I think that level of setup in a lighter and more aerodynamic 1G body would be very good on track.

Ok, cool, I'm game for sure, I can use my Polk arms on one of my FWD cars. I'm a student here as you obviously have way more experience. Whatever the final outcome is, I'm interested. I've got the mustache diff support, and his front roll stop, so I like the work.
 
Now these are the prices of really good bearings. We can go with QA1 cheapos or Summit Racing generic brand and cut the cost significantly.

Can that be an option? Without changing anything else, like would they be interchangeable without any structural changes? Might be nice for the people that dont plan on turning :D
 
Can that be an option? Without changing anything else, like would they be interchangeable without any structural changes? Might be nice for the people that dont plan on turning :D

Rod ends are fairly standardized so that shouldn't be a problem in a race car. For street use, cheap rod ends tend to rattle and creak after a short time.
 
Mark,

The cost is actually good rod ends, bushings, and uniballs. Here is an example:

Uniball cup, plus c-clip $30.96 each
2 Aurora Sperical Bearings Teflon-lined $60 each
4 Aurora Teflon-Lined rod ends at $43.94 each

This totals about $357.68

Now these are the prices of really good bearings. We can go with QA1 cheapos or Summit Racing generic brand and cut the cost significantly.
At first I wanted to balk at the price increase for aftermarket arms instead of stock, so it was nice to see how the pricing was derived. There's no sense in using cheap components - do it right and do it once!
 
Here is an update:

I beefed up some of the support on the k-member and changed a few things around so I can possibly add a sway bar in a future revision. I am also finalizing the auto transmission clearances since the shape of the trans is a bit different. I will post pics of those over the weekend when they are done.

I also spend a bunch of time playing around with different control arm designs and I think this is what I have finally settled on (the red line is additional triangulation that I will add over the weekend):

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The "ball joint receiver" will be made out of metal and will have the option of accepting a stock ball joint for starters. Even with it being as beefy as it is, it should be able to save about 2-3 lbs per LCA.

Also with this shape of a LCA we can have accomodations for a sway bar also (down the road).

I also read all the threads concerning different ball joints and it seems that the consensus is a Howe Racing 22320S. They make cups for those and they can be easily welded in place. Is the taper on those the same as a stock DSM?

Moving the LCA pickup points up can also be done. About .625 on a manual and about .5 on an auto before we run into clearance issues with the Axle cup.

Right now I am sticking with stock geometry, but can anyone elaborate on how much would be the optimal amount that the LCA mounting points can be raised?

What do you guys think? I am open to any and all input/criticism.
 
I know absolutely nothing about engineering and suspension geometry and what not. But all of this looks WAY better than some other "homemade" stuff ive seen before. So please up the awesome work! And dont give up on this! Its looking absolutely awesome!
 
It looks very good and the control arm design I think is incredible. Unfortunately, I can't help you with that measurement.
 
Thank You, Guys.

I had a little free time last night and finished notching the arm and had everything tacked together. Not I'm gonna start machining the ball joint receiver and hopefully I like the way it all fits. If that's good, the arms will be done. I'll make a nice jig for them with the final dimensions and angles and then I'll be a lot closer to the end :)

Here is a picture:

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