This is the roll center, suspension pickup, and steering angle modification thread.

[codyace]

Originally Posted by SoSideways

See, if you have to get a drill bit to drill the stock taper to another taper, you might as well use a bolt there instead

Anyway, parts going to machine shop this week, so I should have everything on the car by the end of the week.

I will report back how the bolt will hold up.

Probably going to miss the event this month, which is on Saturday, so I will have to wait till next month I guess, to report back on how the grade 8 5/8 bolts will hold up for tie rod end duties.

Excited Keep us posted, you'll have paypal quicker than you know it

[racepar1]

Originally Posted by mmdb

Yeap I agree. I was a bit disappointed when I didn't receive solid answers from DW when and asked where the roll center was placed, and if any calculations were made to logically place toe, camber, etc angles. It is apparent though that they've used SP-TEC's knuckles as a template to develop their knuckles. They're not going to openly admit it, but that doesn't matter. I'm glad they did though, because I'm assuming SP-TEC in Japan put a butt load of time developing it. Also the S15 that holds the ~55 second lap time in Tskuba uses those as well. Does that mean it'll make your car unstoppable on the track? No. But I'm sure it's far from hindering.

It obviously doesn't surprise me to hear that. My deal is that I would rather just make my own. Then I know what I have and why it's there. For now my main goal in designing my suspension parts is to have as much adjustablility as I possibly can. I NEED to be able to adjust everything. I don't understand the geometry well enough at this point to be confident that what I do now is going to be satisfactory for the rest of the time I own the car.

Originally Posted by Silverbullet

It may sound easy to figure these calculations, but without the proper tools, such as a Farro arm, it is quite a task. By just old school measuring, being to what one may refer to as "close enough" points will yield not so accurate results since we are working with angles that depend on other angles. There is lots of room for error.

Additionally, the method in finding the vertical CG height will be dependent on how accurate your scale is. Here is a real world example: We did a little experiment on finding the vertical CG height on a Formula Mazda race car with two different methods.
1- the tilt test, and 2- the classic lifting of the rear method. The tilt test is known to be more accurate, and it showed since we already knew the specs of the car. It was dead on. The tilt method though however, resulted in about an inch off (keep in mind this is also a smaller car than a 240 lol). The source of the error was most likely the accuracy of the scales. The ones we used were accurate upto a 1 lb. There was only 2 lb total of weight transfered to the front scales when lifted 10 inches from the ground. 2 lb. Just for kicks, we plugged in worst case + and -, and CG resulted in a couple inch of variation. With the combination of an inaccurate roll center location used with an inaccurate CG location, the final result can be significantly off. A couple inches may not sound alot, but on a smaller scale formula car, it can be dramatic depending what your trying to do with that information.

Intelligent posts like this make me feel all warm and fuzzy inside...

[SicBastard]

Originally Posted by Silverbullet

A couple inches may not sound alot, but on a smaller scale formula car, it can be dramatic depending what your trying to do with that information.

The extra weight of the 240 plus a greater difference in the heights of the scales will both improve the accuracy.

[Silverbullet]

^ your right, but i was making a point. Something seemingly easy may like taking measurements can become quite a task when working with a large and heavy piece of metal like a whole vehicle.

[mmdb]

Just to add, driftwork is apparently selling their SP-Tec knuckles...

http://www.driftworks.com/forum/part...-uprights.html

[Xplat]

Originally Posted by mmdb

Just to add, driftwork is apparently selling their SP-Tec knuckles...

SPTec roll centre front and rear hub knuckles / uprights - Drifting forum - Driftworks

Lol. The proof is in the pudding.

[GripTerror]

lol and the same price what they're asking for theirs now. By the way initially the price was LESS... from what I remember then they bumped it up to that same price

[initial_jc]

its been a while since i checked this but have you guys seen these?

[PoorMans180SX]

Those are junk. All they do is space the ball joint up. What you need is a longer shank. Roll center depends on the location of the pivot points.

[initial_jc]

word

i want to make sure when i start my project that its perfect

[GripTerror]

The only aftermarket balljoints that are worth a damn are the moonface ones which are damn overpriced for so little adjustment.

Modified godspeed ones can be had for the same price and be more effective... as seen on nissanroadracing.com

[PoorMans180SX]

You forgot Sunline Racing. They're legit.

[SoSideways]

Update:

Parts were finally dropped off at the machine shop, and at first I was quoted 2 hours of work to get everything done when I went in a few weeks ago, but few days ago when I was there with EVERYTHING, ready to go, he quoted me "at least 4 hours of work".

Well, shop rates are $60/hr.

Then yesterday, I phone him up and tell him I needed one last thing done, and after discussing what I needed done via email, he said ok, can get it done.

Get an email from him yesterday afternoon, he said everything's done, and since it took him 7.8hrs to do the work, it's going to cost me $460 for the work.

I have no idea how it took them 7.8hrs to do all the stuff I wanted done, and I honestly hope he didn't include time spent on scratching their ass or drinking coffee or googling pr0n or whatever, because I ain't paying for them to be doing that shit.

I'm going to ask them for a break down on how long each item took to make, because I seriously can't see 7.8hrs spent to set up their machines to drill some holes and lathe some stuff down to spec.

Oh, BTW, I had to have them finish drilling out my front knuckles because the stepped drill that I bought from Harbor Freight was apparently undersized at the 3/4" size, since the 3/4" bolt won't go through it, and it was confirmed by measuring the hole, and since I don't own a drill press, I had them do it while I had other work for them to do. They also drilled the knuckles' tie rod end holes out to 5/8" for me, since I don't own any 5/8" drill bits, nor do I know anyone else that owned them, it was impossible to do that anywhere other than to again, let the machine shop tackle that job too.

On the one hand, I'm glad these guys have the "we do it 110% the right way the first time because we don't fuck around, since we're just gonna charge you the same shop rate for doing a butcher style hack job as it would as if we just did it right" attitude, but at the same time, they probably spent a shit load of time making this shit so it's accurate down to the 0.0001" tolerance.

*sigh*

Price of R&D and material 101 guys, now you know why dudes that come up with stuff sell them for more than companies that knock off the designs

[PoorMans180SX]

So, I need a reminder, what else did they do besides bore the holes in your tie rod and ball joint mounts?

[95KA-Turbo]

I think he was having some shanks made for the heim joints so he can run them as tie rod ends as well. Mine were 120 to get a pair made, so if you got multiple sets done at 460 thats not too bad.

When I was building my bilstein suspension set up I had some ebay top hats machined and the dude basically drilled a really big hole in it for me (way bigger then any drill bit I could buy) and charged me 100 bucks. Machine shops charge an outrageous amount of money because they offer services few can replicate.

I've got to get new tie rod shanks made so hopefully I can get it done for cheaper then 120 since I found out one of my friend's dad's owns a machine shop!

[ManoNegra]

The key is volume guys
set up, tooling and fixtures (if any are needed) is what takes time and skill
once set up, churning parts out isn't that difficult
and you'd be surprised, aside from the exotic metals like titanium, materials aren't that expensive
I think $460 is reasonable for the work done
should have gotten a few people interested in the parts and it would have driven your cost down

btw, 60/hr shop rate isn't unusual, ours is higher

[SoSideways]

Oh I wasn't complaining about the shop rate, I actually think it's quite reasonable.

And yes, I tried to get a few people interested in my part, but alas, it is afterall mostly the same as SPL Part's tie rod end (I'm not gonna lie about where I got the inspiration from), and once I take pics of my final results, you all will see that it looks pretty much exactly the same.

Difference is, mine is made for the longer S-chassis Tein tie rod ends, and use 5/8" bolts for up to 2" of adjustment (for now).

And I bet most of the time was spent on cutting the spacers and then milling them down to exactly 1.000", and also the cone shaped ones probably took a bit to make.

I bet at least 2 of the total 7.8hrs were spent on working on the knuckles and the DOM tubing needed for the spacers that are meant for the FLCAs, which is totally separate from the tie rod ends. Which is why I'd like a break down for how long each part took them to make, that way I can judge how long it will take for them to just do the tie rod ends alone.

As for making them in volume, I understand that's how the costs will be reduced dramatically, however, as this is a "new and untested part", I knew nobody would bite right off the bat.... well, Codyace is interested, but since he has an S14, I'd have to make sure that my part is interchangeable between the S13 and S14 first before I even start selling these.

But as I said before, this part is for a very niche and specific audience... ones that have the Tein S-chassis tie rods already, and need more adjustments than what the SPL Parts tie rod ends will give them.

[AWDtoyota]

Are you in South Florida?

What machine shop are you using? ...location

[SoSideways]

No I am not in S. FL, and the machine shop I'm using is one that has done some pretty spiffy stuff for businesses, and even some work for Lockheed Martin and Rockwell. I think they did some stuff for NASA and a branch of military too.

Anyway.

I finally picked up the parts, and good lord, the stuff looks so good I don't wanna put them on the car now lol

Everything fits, and everything works like butter.

There was a slight miscommunication between the shop owner and I, however, as I asked him to put a taper on the spacers for the tie rod ends. Instead of putting the taper on only 2 of them, he put them on all four.

At this point, I can either ask him to make me another 2 spacers and having to pay for them, or I can just go to Ace Hardware and buy a bunch of grade 8 washers (another advantage to using standard inch sizing hardware, you can pick up a lot of stuff from local hardware stores) and stack them to get to an inch, which will be the easier, cheaper, and faster way of going about this.

The only downside to the washers is that, the tolerances on them aren't as high as on the machined spacers, so they're a tiny bit loose on the bolt (I.D. isn't exactly 5/8"). I'm not sure how big of an impact that will have on the loading of the bolt and the aluminum spacers, so if someone can chime in on that, that would be awesome.

Here are a couple of pics.











High res pics taken w/ a proper camera will come soon... hopefully lol

[PoorMans180SX]

Ummmmmm $229?



BTW, almost done with a major update to the OP, should be a much more informative thread very soon.

[ka-titties]

i'm currently in the market for some subframe bushings and i wanted to get some of your guy's opinions on the powered by max bushings.

they are going on a car that will spend over 80% of its life on a track with small weekend stints on the street.

[PoorMans180SX]

Great bushings. Easy install with epoxy.

[GripTerror]

lol those look like spl arms indeed... for i bet alot cheaper of a price

Maaan mmdb when is that shop gona finish your rear knuckles!

And whats UP with PBM???? Are they going to produce these state side too... shit... its like so much hassle to get these going with driftworks>spherical bearings.

They better price competitively but looks like nothing is happening all together. I mean if they really are just copies of SPC ones its not like they have to do much research either lol...

[PoorMans180SX]

Sosideways paid $460 to have everything machined.

SPL's are bolt in for $229...


Driftworks are copies of SP-tec. Parts Shop MAX is developing their very own version. I don't know, I guess they're finally going to produce their promised racing bucket, so it looks like they follow through, even if it takes them a long time.

[GripTerror]

damn thats a ripoff why didnt he just buy spl...

pbm better show us stuff soon lol...

[SoSideways]

Good lord...

I thought I already explained why I didn't go with SPL?

SPL still uses a tapered pin to bolt up to the spindle, and will only allow for 1" of spacing.

Their turn buckles are also much longer since it was designed to be used with either stock tie rods, or the Z32 style tie rods.

Mine are designed to work with the much longer Tein S-chassis tie rods, and mine is designed to be able to be spaced to anywhere from 1" to 2" or more.

Trust me I would have went with SPL's design from the get go if I thought 1" was going to be enough correction.

I'm spacing my FLCAs at least 2" down, so I need at least 2" of tie rod end spacing as well to tune out bumpsteer.

Once I am done with prototyping my tie rod ends, and if there is a demand for them, I can go on to the next phase and get a group buy going or something, and that should bring the costs down some. And by the way, the total cost of everything done was $460, which included them setting up my spindles and locking them down to be drilled out, as well as milling down the GS spacers, and also drilling out and milling down the DOM tubing to use as spacers for the FLCAs... so that's 2.5hrs worth of work there alone, which came out to $150. So the tie rod ends came out to $310 for the single pair.

Again, like Mr. Skullworks said, the key is volume. If I have 5 people interested in this stuff, that will reduce the cost overall to machine everything, thus I can offer these same tie rod ends to you guys at a lower cost.

But mine are pretty hardcore, thus not for the feint hearted, since it requires a bunch of other mods too before you'd get to the point of needing my tie rod ends.

[GripTerror]

Ah I didn't know the details

[mmdb]

Originally Posted by GripTerror

Maaan mmdb when is that shop gona finish your rear knuckles!

yeah that's pending. Might be a while to get them installed.

Btw any reviews on the spl solid bushings? Anyone take em to the track yet? I'm curious to know how the antisquat changed as well.

[longfellow]

Originally Posted by ka-titties

i'm currently in the market for some subframe bushings and i wanted to get some of your guy's opinions on the powered by max bushings.

they are going on a car that will spend over 80% of its life on a track with small weekend stints on the street.

Energy Suspension solid poly bushings then machine/cut down the face. They're only like 45$. I've had them on my car for years and I machined the tops down a few months back. Work just as well as any solid aluminum ones.

[ka-titties]

hhrrrrrmmmmmmmm