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Darchangel
Feb 12, 2009

Tell him about the blower!


I guess you're going to have the starter extending aft instead of forward as standard? I mean, totally doable if you're building the bell housing, too.

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mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
That flywheel is for a SBC bellhousing with the starter aft of the engine, same as the 13Bs do. I may put the starter on the passenger side though.


Friend of a coworker picked this up for me since the seller didn't want to ship... small quick change differential. Some broken stuff, but nothing I wouldn't want to change out anyway for serviceability, and hell of a deal.

Some interesting stuff should be coming tomorrow.

Darchangel
Feb 12, 2009

Tell him about the blower!


Oh, right, the starter is aft of the flywheel on most rotaries. Not sure why I was thinking it was forward.

Edit: ooo, quick change.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull


Well hey, how about that.



Bolts may be too long but it all works. Not bad for half an hour over lunch.

Made a deal for a spool for the quick change... not because I want to run a spool but so I can measure and modify an LSD to fit. Found a few places that will broach splines... so I figure, say, get a Miata OS Giken Lsd, weld on it until it fits in the QC, then gave the side gears broached to standard US 31 spline.

boxen
Feb 20, 2011
Are the splines going to need heat treat after broaching, or is that not a worry?

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
Interesting question! So I figure that the diff side gears will be through hardened and probably carburized. I'm going to be dealing with a company that does this stuff and will ask. It may well entail extra steps.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
Thing that's been bothering me for a while... finally sat down and designed it.



I need to get a real RPF1 to figure out if the internal profile is right, but, basically a hub to take standard (big, used in circle track) bearings, and go to 4x100. If the mockup Enkei model I have is right, it gets me the ability to push the brake rotor 2" further outboards, which means the outer pivot points move out by 2" which means less scrub, longer control arms and other goodness.

The big thing though is that this time I actually did some research on what bearings I can easily get, and did some thinking on what machining processes are simpler. First hub I did would have taken CNC machining, last hub I did copied something else which was fine but geometry is much more optimized on this for what I'm doing.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
Oh yeah, I had more cool parts come in a while ago.



Itty bitty quick change rear end! Speedway Engineering Mini Stock for those keeping track at home. Ring gear is only a little bit bigger than Miata. Ring and pinion are trashed on this one but they almost never come up on the used market and rebuilding is cheaper than new.



One of the side bells to show how it goes together. Not doing that snout solution but the steel tubes just come out.



Riley and Scott water to oil cooler, as used in a lot of stuff. Not sure if that'll be a race car thing or a dyno thing.



Pimpy Alcon rear pivoting master cylinders and fabricated bracket to adapt them to normal pedal setups. Paid nowhere near list value for them, too pimpy not to jump on.

Things are a little bit slower due to income levels but I realized I never had pics of this stuff.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull


Jerico to 13B (with small diameter flywheel) bellhousing. Now to make patterns. Or maybe add ribs.



Actually, I prefer this one.

mekilljoydammit fucked around with this message at 01:32 on Sep 24, 2020

kastein
Aug 31, 2011

Moderator at http://www.ridgelineownersclub.com/forums/and soon to be mod of AI. MAKE AI GREAT AGAIN. Motronic for VP.
Speaking as an idiot who has broken 4 (or 5, I can't remember, they all blur together after a while) bellhousings, have you done any FEA on that design? What material do you plan to use?

E: personally I would move the ribs to go as directly as possible from the trans mounting bolts to the engine mounting bolts, and ideally thicken the flat surfaces under said bolts as much as possible. Mine always broke starting in the middle of a casting (!) Where it's thinnest squeezing between the edge of the flywheel and one of the bolt holes. I expected it to have started at an edge but on the second or third one, I caught it before it reached any edges.

Something I didn't know before all this was that aluminum has no fatigue limit and thus ANY level of cyclical loading will eventually result in a fracture, despite it having an elastic region. It's just a matter of time. Obviously, the higher the loading is and the higher the number of cycles gets, the more likely it is to fracture.

kastein fucked around with this message at 02:23 on Sep 24, 2020

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
It's very much a "by gosh and by golly" sort of thing, in that I copied layout of some existing proven stuff and fiddled the wall thickness until it looks about right. At the point it's at, if I got everything right it should have all the right pickup points - nothing more detailed has been considered yet.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
Well, thickened wall thickness to 3/8" due to giving myself more leeway to cast. So, yeah, having now run FEA on it after that, I'm not worried whatsoever.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
So masked up and went to the SCCA runoffs yesterday and caught the GT-3 race which was pretty darn good.

Also found out that the frontrunners are running bridgeport 13Bs. I was really dreading that as it looked like the spec line requires a carburetor with a given venturi size (engine options are 13B streetport with no intake restriction, bridgeport with 42mm chokes, and peripheral with single 37mm venturi restrictor) but apparently the rules have been interpreted such that "venturi in the throttle body but EFI" counts. So I don't have to buy a mess of carburetor poo poo and mess with that, thank goodness.

Also talked to my friend who has the FB with the bodywork I mostly like... going to borrow his molds and do a nose from that which saves a lot of time. Fender flares are going to be broadly similar but moved up an inch or two since there's different regs on wheel opening location.

This one for the record:



Oh yeah, random walking-around-photos are uploaded now: https://imgur.com/a/dHsuPkr

Rectal Placenta
Feb 25, 2011

mekilljoydammit posted:

Well, thickened wall thickness to 3/8" due to giving myself more leeway to cast. So, yeah, having now run FEA on it after that, I'm not worried whatsoever.

Do you do your own pattern making and casting, or do you have a good connection for that stuff? I'm more familiar with die cast design, but have always thought how neat it would be to cast and machine my own parts.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull

Rectal Placenta posted:

Do you do your own pattern making and casting, or do you have a good connection for that stuff? I'm more familiar with die cast design, but have always thought how neat it would be to cast and machine my own parts.

So far I've been doing investment casting using lost-PLA from 3d printers. This bellhousing I'm trying sand casting with a pattern made out of CNC routed MDF. I built my own little foundry that should be able to do 40 pounds of aluminum in a pour - at some point I may make a bigger one but this does almost anything I can be bothered to do.

None of it's overly complicated, just it all has a high requirement for thinking about what can go wrong, if you get what I mean.

kastein
Aug 31, 2011

Moderator at http://www.ridgelineownersclub.com/forums/and soon to be mod of AI. MAKE AI GREAT AGAIN. Motronic for VP.
Just don't accidentally turn yourself into Han Solo

NitroSpazzz
Dec 9, 2006

You don't need style when you've got strength!


Home foundry for "little" 40lb pours

Looked like some good racing at RA this weekend, had timing in the background most of the time.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull

NitroSpazzz posted:

Home foundry for "little" 40lb pours

Looked like some good racing at RA this weekend, had timing in the background most of the time.

I mean, yeah? I haven't done that large but I figured it's easier to partially fill a crucible than plan around insufficient capacity. Might do a larger one at some point.

A lot of good racing - I was a fan of the GT3 race from what I saw. Waiting for the replays to go up.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull


Just a little something... fairly well optimized IDA-style manifold for 4-port 13B based off GSL-SE housings and 12A irons. Not 90 vertical though; works for EFI only but fits the chassis specifically.

Figure I'm going to print out patterns and try to cast it in the next week or so.

Darchangel
Feb 12, 2009

Tell him about the blower!


That's pretty, and yeah I could see where a carb would get upset.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
Like, I could go with a 90 degree setup... but this fits in the chassis and is a bit of a straighter shot.

And is a less-scary-thing-to-work-up-to-casting than the bellhousing.

McTinkerson
Jul 5, 2007

Dreaming of Shock Diamonds


Can you make one that will fit GSXR ITB's?

That looks excellent.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull

McTinkerson posted:

Can you make one that will fit GSXR ITB's?

That looks excellent.

I mean yeah, but I'd have to get some stuff to reverse engineer, obviously the flange is going to vary with what block it bolts to, and some figuring required on the air filter / linkage / management side..

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull


Well, what have we here...?

Design's still being roughed out but definitely has potential.

Darchangel
Feb 12, 2009

Tell him about the blower!


Ooo, adjustable cupholders!
:haw:

McTinkerson
Jul 5, 2007

Dreaming of Shock Diamonds


Darchangel posted:

Ooo, adjustable cupholders!
:haw:

If there's enough overlap, you could make tennis balls dance!

honda whisperer
Mar 29, 2009

Just clicked on this thread and your title criminally undersells what's going on in here. You're absolutely mad.

:five:

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
I mean, I'm not sure what else to call it - it's mostly rotary related but then I sometimes go on other tangents what with the ADHD.

Anyway, another couple for illustrative purposes:



The spline is approximately even with the runner and port centerline, so approximately the runner length, and ends at the "short" velocity stack. 14.43" is 365mm or so, which should be tuned for an RPM of around 8300. Addon trumpet is 75mm longer so in that configuration drops it to a tuned RPM of around 7k RPM. Realistic track RPM will be maybe 6500 to 10k RPM so nice little boost to the available torque.



And why the intake manifold is bent over; with that gentle curve added, there's plenty of room for an airbox.

Currently printing is a little fitment template to make sure I reverse engineered the servo bolt pattern correctly... this weekend I should have the functional test version (in plastic) printed, some bushings and stuff for it next week and should have a cute little video of it moving around next week.

honda whisperer
Mar 29, 2009

mekilljoydammit posted:

I mean, I'm not sure what else to call it - it's mostly rotary related but then I sometimes go on other tangents what with the ADHD.

Tube frames, engine dynos, and engineering: I love triangle

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull




3d printed test mount for servo was dimensionally accurate, so good to go... finalized some details now to start printing.

the spyder
Feb 18, 2011
So what’s the likelihood we could whip up a set for a three and four rotor... asking for a friend.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
So this version was intended to go on top of a commercial Weber IDA throttle body as a conservative design. It also has a 42mm venturi for SCCA GT3 compliance. I'm intending on starting a version with an integrated throttle body and it wouldn't be all that hard to redo it with no restrictor and, say, a larger throttle plate. And if I'm not trying to be compatible with Weber IDA stuff, I could space them to whatever (IDA is 120mm bore spacing which barely fits stuff) and the actuator is easily strong enough to move more velocity stacks.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull


The Amazing Mumford (link)! Gets roll center where I want it (below where there's any chassis members) and has very little roll center migration relative to the CG. A little extra complexity compared to a Watts but what the heck.

mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
I think today's project is going to be to start detail design of the front uprights. I'm thinking bolted upper pivot point with shims - so camber can be adjusted quickly, precisely and repeatably without moving the pivot point and affecting KPI and so on. Also need to redesign the rear of the chassis a little to fit the Mumford link and quick change but that honestly doesn't have much in the way of greater implications.

At some point I need/want to start figuring out ducting and wing mounting too. Talked to the friend who owns the molds for the bodywork I want to base off of at the runoffs and probably going to pull a tooling copy of the nose (IE really heavy because it's just for making a bodywork plug) out of his molds and redo the rest of the arches myself.

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mekilljoydammit
Jan 28, 2016

Me have motors that scream to 10,000rpm. Me have more cars than Pick and Pull
OK, decided to start a new thread more focused on the tube car... all this poo poo continues over at https://forums.somethingawful.com/showthread.php?threadid=3946880

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