Time Attack Build Blog

[gixxerdrew]

Thanks mate, best wishes to you with your project!

 

[twicks69]

Thanks mate, best wishes to you with your project!

Drew, How is Japan going? Are you able to give us a bit of details of what you have been up to? Any cool pictures you want to share?

It is a goal of mine to visit Japan in the future, and at least go to the Tokyo Auto Salon, let alone any other cool place to go and check out.

I hope that all is going well!

 

[RipperXX]

^ what he said!

 

[gixxerdrew]

Drew, How is Japan going? Are you able to give us a bit of details of what you have been up to? Any cool pictures you want to share?

It is a goal of mine to visit Japan in the future, and at least go to the Tokyo Auto Salon, let alone any other cool place to go and check out.

I hope that all is going well!

Hey, well everythings going pretty well! I'm learning Japanese much faster this time because of living on my own. Took me about a week to get settled into my apt with basic stuff going. Its a little tougher becuase you cant just roll up to wal mart in your SUV around here. You take what you can carry and going to the equivolent of IKEA was 5KM walking for me and 30 mins on a train each way. I usually lose about 5-10lbs in the first month here but I dropped 5 in the first week which is a good feeling. Besides that I got my CFD rendering box setup and started some work on aero package development. I'm going to Fuji Speedway with the RX7 tomorrow morning and doing data.

I'll share some pics but please dont ask any questions becuase what you see here is all I can share. Force scale deleted and base model shown to protect the innocent

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[snowborder714]

Good to hear everything is going well. I'm sure the food is so much better over there!!

If only I understood what was going on in that picture I'll have to do some more research on CFD.

small updates, thanks again to twicks for the idea on the upper control arms to put the markings. I figured out some band clamps meant for hydraulic lines to use for retaining the ball joint boot I'll get more info when they arrive

Just reading about the SPC arms again. I was wondering if you could provide any more info on the band clamps. I'm thinking about picking up a set soon. I believe I have also read about people safety wiring them on - think that'd be acceptable/just as good?

And I'm guessing it's easy to figure out where to put the notch marks once I have the arms in my hands?

Any other overall thoughts on the arms?

 

[Scott McIntyre]

When my SPC arms arrived in the mail, the boots had already slipped off and I hadn't even installed them yet...

I replaced the springs with safety wire. It has held up great.

For the adjustment "notches", I used a Dremel Engraver. First I set the camber adjustment to the two extremes and marked their positions with a pencil. Then I penciled increments of 1/8" with a ruler, and finally engraved them all. Pretty simple really.

One other thing I found with the SPC arms is that it can be difficult to properly torque the low-profile ball joint nut with the arms on the car. You can get a wrench on it, but it easily slips off because the nut is so short. And the fender prevents you from getting a proper socket & torque wrench on it.

So what I did was buy a cheap 27mm socket and cut it short. with my current ride height, this allows me to just barely get the socket & torque wrench on the nut.

(click to enlarge)

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If this does not work for you, then you could also take a grinder to a 27mm wrench and grind about 1mm off it's face so that it can get a better bite on the nut. If you have noticed, most box-end wrenches have "curved" ridge on each side. Hope this makes sense.

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[snowborder714]

Thanks Scott!

Sounds like I'll use safety wire, unless Drew posts more info on the clamps.

Any pros/cons with doing increments every 1/16" (as Tim did) vs. 1/8" as you did? There's 13 steps between -2.5* and +3.5*, if you count every .5*.

I have a regular Dremel, so I could use that. Or maybe pick up the engraver

Good idea on the socket chopping. I'll have to keep that in mind. I've had to do it before for other jobs, but sadly I don't think I own a 27mm socket. That's such an odd size.

Have you had any clearancing issues with the arms? If so, are you just dealing with it? If not, how did you prevent it and what front spring rates are you running?

 

[Scott McIntyre]

Any pros/cons with doing increments every 1/16" (as Tim did) vs. 1/8" as you did? There's 13 steps between -2.5* and +3.5*, if you count every .5*.

My hand isn't steady enough for that resolution.

Have you had any clearancing issues with the arms? If so, are you just dealing with it? If not, how did you prevent it and what front spring rates are you running?

It has already started "self-clearing" on the driver's side, but just barely. I run 900 lbs/in front springs with a fairly high ride height, so I suspect it won't be as much an issue for me. I'm just letting it do it's own thing.

 

[gixxerdrew]

The arms are fine yup. I'm just using Zip ties, FYI baja truck style

 

[gixxerdrew]

Good to hear everything is going well. I'm sure the food is so much better over there!!

If only I understood what was going on in that picture I'll have to do some more research on CFD.

CFD is basically a computer simulation of airflow over a car. To give you an example, the high complexity of F1 aero would likely not be what it is now without CFD. With CFD you dont need to build attach and then wind tunnel test your car. You can model the car, play with different configurations in the computer until they perform how you want them to or determine which of several is best. Then you proceed to mock them up on the car. In the case of my car since wind tunnel time is way outside of my budget constraints I only have CFD. Only the most high level teams have access to a wind tunnel so this is how its done to design and test aero outside of all but the highest level stuff. There are some new "low cost" wind tunnels on the east coast but they lack specific features that I think make them probably about as useful as CFD, such as an imobile floor. Basically I can learn most or all of what you can at a low cost wind tunnel without leaving the office and test any idea of think of relatively quickly.

 

[snowborder714]

Interesting stuff!!!

Have you heard of a racing team using an old PA turnpike tunnel as a wind/testing tunnel? Or what other "low cost" solutions have you heard of?

 

[greengoblin]

What upper hat/spring seat is that on you coilovers Drew?

 

[gixxerdrew]

Interesting stuff!!!

Have you heard of a racing team using an old PA turnpike tunnel as a wind/testing tunnel? Or what other "low cost" solutions have you heard of?

Data Aq I would say #1 tool. Never imagined how to use an old tunnel as a wind tunnel not sure how you would do that effectively, thats crazy

What upper hat/spring set is that on you coilovers Drew?

Custom and Hypercoils.

 

[snowborder714]

Are you using Solidworks for the CFD? If so, that looks like a very extensive program that can do A LOT.

A bit of info about the turnpike tunnel turned wind tunnel (end of last paragraph).
Laurel Hill Tunnel - Wikipedia, the free encyclopedia

Some better info, with links to a patent and some photos.
Ganassi's Area 51 | The NASCAR Insiders

 

[gixxerdrew]

oh that is cool!

 

[D_Eclipse9916]

Scott, I had the exact same problem with mine when I pulled it out. One of them was already off. I just put mine back on with the spring htey include because I havent used them, but I noticed they looked like they would just fall off again.

It was also mentioned that the SPC upper arms are being discontinued?

 

[Strm Trpr]

It was also mentioned that the SPC upper arms are being discontinued?

WTF? I just got off the phone with SPC and they are being discontinued...
Are these really that necessary, or can we achieve similar results using their adjustable balljoints in conjunction with adjustable anchor bolts?
I could've sworn I've read something on here about doing just that.

 

[logic]

Yep, same problem here with my SPC arms; one arm arrived with the clip already separated. Those little retaining clips are close to useless; I'd expect zipties to significantly outperform them.

I'm not at all surprised to hear that they might be discontinuing them; given some of the design problems, it's probably easier for them to just quietly drop the product than revisit the design of a part for cars that are 10-15 years old already.

I saw that wind tunnel in Race Car Engineering a year and a half ago; there was a good article describing how people were actually using it. Very cool stuff. Ah, here we go: Laurel Hill Tunnel | Technology | Racecar Engineering

Let's see if I can embed a google map to it:

<iframe width="425" height="350" frameborder="0" scrolling="no" marginheight="0" marginwidth="0" src="http://www.google.com/maps?ie=UTF8&amp;t=h&amp;ll=40.09613,-79.2184&amp;spn=0.002873,0.00456&amp;z=17&amp;output=embed"></iframe><br /><small><a href="http://www.google.com/maps?ie=UTF8&amp;t=h&amp;ll=40.09613,-79.2184&amp;spn=0.002873,0.00456&amp;z=17&amp;source=embed" style="color:#0000FF;text-align:left">View Larger Map</a></small>

 

[snowborder714]

Ya, I was the one that mentioned it to D_Eclipse. I had read it somewhere, so I called to verify. It is true, and as far as the guy knew, there was no plans on redoing them.

This is the item they now recommend:
Welcome to SPC Performance - Performance Suspension Tuning for Sport Compacts, Racing, Hod Rods, Muscle Cars and More!

The only difference with the arms is you get more camber adjustment, as well as the ability to adjust caster.

Thanks for the link Ed - I'll have to check that out!

 

[Scott McIntyre]

In addition to no caster adjustment (which is important performance-wise) the adjustable ball joint (#67170) is said to be physically taller than the one used in the adjustable arms (#72170). That translates to less suspension travel, and even worse control-arm-to-strut-tower clearance issues.

Interesting about the discontinuation of the arms... Glad I got mine when I did!

 

[logic]

Yeah, that was always my concern about the standalone adjustable balljoints; just looking at them, you can see how they pretty drastically reduce the amount of clearance up there.

Not that the arms are much better. Didn't ACM try convincing them to change up the design when they first released them?

I'm convinced that there's solid room for improvement over the SPC arms by someone with a little engineering creativity. Too bad there's very little market for them at this point.

 

[D_Eclipse9916]

Yeah, that was always my concern about the standalone adjustable balljoints; just looking at them, you can see how they pretty drastically reduce the amount of clearance up there.

Not that the arms are much better. Didn't ACM try convincing them to change up the design when they first released them?

I'm convinced that there's solid room for improvement over the SPC arms by someone with a little engineering creativity. Too bad there's very little market for them at this point.

No, nobody get creative, I want to sell my arms for double what they cost me, any takers? 800? . Just kidding!

Its a shame, ill be coming back to this platform in 4-5 years and im afraid to sell some of my parts cause they might not be here in that time. Im nervous to get rid of the SPC arms .

 

[snowborder714]

Then don't! A few hundred dollars isn't going to make a huge dent in purchasing a house

I have to check my funding and pick up a set of these soon!

 

[Strm Trpr]

I'm sure someone can design some tubular UCA's or even billet for that matter.
I'm a mechanical designer by profession, and I use Pro/E as my design tool.
I have a spare set of stock UCA's which I can reverse engineer as a base model.
The concepts will evolve from there.
I also even have access to a rapid prototype machine.

 

[Dallas J]

Ive been running the SPC arms for almost 3 years now and had one of those clips pop off and kill a ball joint. Now theyre all safety wired in, no chance their going anywhere.

One thing to note, it took about 45 days to get a replacement joint and cost $85, so dont F* yours up