Re: Anyone interested in Cobra adapter brackets
 

Big fat Jim?

Re: Anyone interested in Cobra adapter brackets
 

Yup. Figured I could start with him, then get a couple second opinions.

Re: Anyone interested in Cobra adapter brackets
 

Yeah he's a smart dude.

Re: Anyone interested in Cobra adapter brackets
 

I welcome all opinions! I'm also an engineer (however not a materials expert) and as I'm well acquainted with, you can manufacture anything, use just about any material, attain any tolerance, etc... but everything has a cost.

7075 will nearly triple the material costs, and more exotic alloys will be even more. I'd make and sell them for $120 for a set out of 7075 with current design.
If anyone has connections to get cheap 7075, that would be awesome!

I'm confident I can work something out with 6061-T6 but I need to run a few more simulations.

The struggle at the moment is that i'm not sure what type of temps this part will receive. I am designing this to sustain track/racing conditions. I'm sure it would be completely fine on the street with like a 4x safety factor. I'm currently running a simulation that peaks at about 400F. That cuts the yield strength by about 75%. I have measured race car temps that peak to 1200+F at the caliper, so this adapter could possibly be experiencing a lot of heat.

I think I might have a few made and get some running temp measurements at DCTC before committing to a big production run. I can make some extras for people, with the understanding that it is not yet proven.

Re: Anyone interested in Cobra adapter brackets
 

This guy Jim, he's pretty hard core. He's not just you're standard mechanical engineer, his specific area of expertise is material and welding, that's all he does. It's funny how real professional welding makes anything any of us (or even shops) do look like childs play. The rest of us can sit here and oogle over the prettiest looking manifold made by say Full Race. Where he'll take a look at it, their material choices, and their process and completely rip it apart like it's garbage.

Long story short, if Momin gets input from him I'd listen :)

Re: Anyone interested in Cobra adapter brackets
 

Ain't seen nothing till you've seen an E-Beam or projection weld! :D We do welds that hold up to about 10,000 psi here.

I look forward to hearing his input!

Re: Anyone interested in Cobra adapter brackets
 

How about I-STIR? :)


http://www.youtube.com/watch?v=ZCGQFJ5qcYM&hd=1

Re: Anyone interested in Cobra adapter brackets
 

Yes! another cool form of welding, I have a friend who works at PaR in that department (who bought the friction stir welding technology from MTS)

Re: Anyone interested in Cobra adapter brackets
 

Who is it? That's where I work, well used to work until Westinghouse bought out the nuclear side of PaR and they renamed us PaR Nuclear...

Re: Anyone interested in Cobra adapter brackets
 

Short version of what he said (he said a lot), was no aluminum. Basically through the heat cycles and temp range, it'll loose it's properties and is at risk of failure.

He mentioned aluminum calipers can work due to them being cast(explained the structure of the metal etc.. went beyond what I needed to know :P) and specific alloys being used/chosen combined with cooling techniques employed in car design etc.

Anyways, his first choice was Inconel.. But I said our budgets won't allow it :P

He then said, just choose a common SS and it'll work.


Like Halon mentioned, welding is a whole new world after being directly involved in it for about a year. Not machine welding, human welding. There is a ridiculous other world of AWS/ASME codes/practices etc that need to be strictly followed in the Nuclear world.

Re: Anyone interested in Cobra adapter brackets
 

Very interesting, thanks!

Re: Anyone interested in Cobra adapter brackets
 

My RTM ones were just carbon steel, came uncharted. I had Primo powder coat them.

Re: Anyone interested in Cobra adapter brackets
 

Corrugated lawn sign

Re: Anyone interested in Cobra adapter brackets
 

**coroplast. I'm gonna use 10 layers!

Re: Anyone interested in Cobra adapter brackets
 

Sorry.. this is getting delayed till after the race at autobahn this weekend and my newest (non-mitsu) car acquisition :D

Re: Anyone interested in Cobra adapter brackets
 

so I should have a couple sets of prototypes finished this week.

in lieu of some stupid issues with my DSM - is anyone going to be going to DCTC with their 1g anytime soon, and be interested in a set and letting me measure working temps?

Re: Anyone interested in Cobra adapter brackets
 

Not I. But I'd be interested in helping you develop some for the VR4/Cobra rotor combo. :D

Re: Anyone interested in Cobra adapter brackets
 

Finally... first prototypes.

I might as well just make these stupid things in steel... but some serious bling factor here.

https://scontent-a-ord.xx.fbcdn.net/...63009076_n.jpg

Re: Anyone interested in Cobra adapter brackets
 

Nice. What material are those?

Re: Anyone interested in Cobra adapter brackets
 

ally-yoo-minium

Re: Anyone interested in Cobra adapter brackets
 

So the bracket will be sandwiched or will some of that be threaded?

Re: Anyone interested in Cobra adapter brackets
 

That is a great idea! I could thread 2 of the holes..

Re: Anyone interested in Cobra adapter brackets
 

Lol, I'll take credit, but that isn't what meant. I'd actually rather have it sandwiched, as the aluminum threads could pull when at operating temp on a track.

Re: Anyone interested in Cobra adapter brackets
 

Good point. I think i'm going to make some in stainless steel anyway, and i'll include that feature.

I could probably do a threaded steel insert in a hole... but probably not worth the effort.

Re: Anyone interested in Cobra adapter brackets
 

Time to bring this one back. So I finally got all my brackets, rotors, hub centric rings and rebuilt my 3kGT VR4 calipers and they don't fit my +42mm RPF1's, F^%#. I love the 13" rotors, so I guess the Cobra calipers are in. Any word on these brackets?

Re: Anyone interested in Cobra adapter brackets
 

I wonder what if your setup will fit my rota's?

Re: Anyone interested in Cobra adapter brackets
 

What offset wheels are they? I would think +35 or less would fit. I'll test my rear RPF1 to see.

Re: Anyone interested in Cobra adapter brackets
 

They stand proud of the rotor surface by 1.75", I didn't realize how huge they were.

Re: Anyone interested in Cobra adapter brackets
 

Damn iPhone pics.

Re: Anyone interested in Cobra adapter brackets
 

I think he's pretty close to having them made now. Sounds like track testing on the aluminum ones went well.

Re: Anyone interested in Cobra adapter brackets
 

the aluminum adapters are rock solid. Well over 15 hours of track time and wheel to wheel racing, and enough heat to craze 13" rotors, but adapters are still flawless. Don't even have brake ducts yet (probably should do that..)

I need to make one small change to the design to make sure you don't have to modify knuckles (had to grind a ridge off mine) but I do want to have a run of them made. I wonder how many people would be interested? My kit would also come with hubcentric spacers. The rest are just nuts and bolts and the cobra stuff, easy for anyone to source and i'd provide part numbers, etc for all that. Maybe DB could stock them for me? Avoid shipping charges to MN.

Super busy prepping for another race this weekend at Gingerman in MI. They'll get further testing there, and i've got heat paint on them to really get a good feel of the range they reach.

Doing road race prep on this car has only expanded my list of DSM road race upgrade parts I really would love to see made and available to the masses.. Is there even a market for this stuff? I want to make a lightweight active toe eliminator kit, and a few other things.

Re: Anyone interested in Cobra adapter brackets
 

So, turns out you can even clear GSX 17s! (needed a 1/8" spacer, not a huge deal)

http://i.imgur.com/FOCCPUuh.jpg

Re: Anyone interested in Cobra adapter brackets
 

OEM 17's are pretty narrow, so they should fit with almost any other wheel.

Re: Anyone interested in Cobra adapter brackets
 

FYI - just followed up on a local machining lead, and I should be good to go once i get him the models.

Re: Anyone interested in Cobra adapter brackets
 

Sorry guys, we decided to do one more race so this is yet again on hold. For sure after mid october i'll be back on this :D

Re: Anyone interested in Cobra adapter brackets
 

Okay, I'm back on this. I'm actually ordering a 3d printer today so i can really refine and iterate on the design. I'm actually going to attempt to integrate brake duct mounts/adapters as well, as this is something we need on our car.

I also need to make a few clearance tweaks and ended up having to modify my knuckle to make the other ones fit. I don't want other people to have to do that.

More news soon, hopefully at least a few will be interested. i also will be printing my own rotorcentric adapters. I bought some off the shelf (ABS) ones and they actually did okay with the heat from racing at a track with really really heavy braking zones (Road America) so i'm fine enough continuing to use them. I'll print them in ABS.

Should end up being a pretty sweet and affordable kit. I have a CNC lined up for the work, as well.

I'm working on another part for the car which I've never seen before, not 100% sure it'll work out (won't know until I really get deep into the design) but it might appeal a lot to hardcore road race people. Most people probably won't give a crap though.

Re: Anyone interested in Cobra adapter brackets
 

Though I don't have a dsm any longer, I'm really glad people like you are still doing part development for the community. Keep it up!

Re: Anyone interested in Cobra adapter brackets
 

You know I'm in for a set.

Re: Anyone interested in Cobra adapter brackets
 

Steve, if you want some to try out before that happens, I can send you my extra set of prototypes. You might have to fight Goodhart for them, but I wouldnt' mind getting someone else to try them out.

Not sure who would try them out first :D

Re: Anyone interested in Cobra adapter brackets
 

I can bolt them up, but I'll be storing the car the minute the snow flies. Of course, that just might be in December.