Tech Spam thread - because 1/4" BSP gets 5 hand spans to the jiggawatt

[xsspeed]

yeah i kinda want to check these amps and woofers so looking for a bit more amperage but then i think need a battery as a buffer anyway so 30a might be more cost effective than the 50a if the 50 cant respond fast enough to spikes anyway

[Bling]

If it's just for testing, can't just hook it up to a car battery with the car running? Amp / sub would be more than a PSU (cheap, old one) would handle so flag that idea.

/Just install them in the Datsun already, we won't judge.

 

[ThePog]

WTF is this push in fitting type called and where can I buy an adapter like this from?

[Raizer]

20 minutes ago, ThePog said:

WTF is this push in fitting type called and where can I buy an adapter like this from?

@chris r isn't that what you got for the Merc clutch line? Think you said they were listed for some LS thing?

 

https://stealthride.co.nz/products/af362-04?_pos=2&_sid=4c4eb2e27&_ss=r
 Male thread though 

[chris r]

3 hours ago, ThePog said:

WTF is this push in fitting type called and where can I buy an adapter like this from?

 

3 hours ago, Raizer said:

@chris r isn't that what you got for the Merc clutch line? Think you said they were listed for some LS thing?

 

https://stealthride.co.nz/products/af362-04?_pos=2&_sid=4c4eb2e27&_ss=r
 Male thread though 

Yeah I got it from Greenlane speed shop. 

I do have a brass fitting (some coolant fitting is the same too) I ordered off aliexpress if you wanted to Barry something up, but for the $30 ish probably not worth the effort modifying stuff 

 

[Rookie]

On 29/06/2026 at 04:16, ThePog said:

Do you think I am fuckin made of money?

I am ashamed to admit how much time I used on trying to make this work, and it still not working, I have resigned myself to buying the box that Clint posted or alternatively trying this

https://forbes-automotive.com/products/speedpulser?variant=52720568238422

 

[Rookie]

On 01/07/2026 at 10:29, RUNAMUCK said:

I couldn't find the 4 link design thread, so I'll post up here instead.

Thinking about the back end of one of the cars I own. The guy who started building it four linked the rear. But when he sold it to the guy I got it off, he kept the 9" link bars, and coil overs .

Since whichever axle I use will need to be extensively narrowed, I might as well run the mount plates which completely encircle the axle tube.

I was thinking it's no biggie to have something laser cut, or plasma cut them myself. 

I'm literally the worst drawer who ever lived. But imagine this is a plate with an axle tube hole in the centre, and a pivot bolt top and bottom for the links. 

seeing what already exists in the market, I found these for sale for way too much money.

You can see that this one has the pivot point where the arms attach forward of the axle centreline. 

Is this done to reduce the instance the arms/rod ends contacting the axle tube at the extremities of travel? Or some other rationale? (Better transmission of forward motion to the chassis, or superior ability to resist the rotational forces of the differential? You tell me????)

So back to my truely incredible technical drawings, I could do a plate like this,

(Yes, making one with a row of holes top and bottom would be a lot smarter. The hole options in the mounting plates on the chassis have already been drilled Assuming they're at uniform centres, the centre to centre measurements of the arm mounting holes would need to mirror this pre-ordained distance to maintain the top and bottom remaining parallel through range of motion. (But this drawing is just for the sake of trying to convey the guts of my query)

So far, it's all semi straightforward. 

But as for the coilover mounts on the diff, (there were coil overs on the diff the builder had in there) it seems to me like these could similarly be integrated into the same bracket too. (Mounted to the rear of the axle tube) 

More CAD quality draughtsmanship from me,

Now as this is one piece, the shock mounting ear could be sited pretty much anywhere through the 180-ish degrees on the rear side of the axle tube. Depending on the size of the bottom eye of whatever coilover was used, there could easily be a spacer (if it here narrower than the width of the ends of the link bars) or a crush tube could be employed to improve the strength. (Additionally a Brace could welded across the two plates along the bottom side to aid rigidity too.

If you're still following, my two questions are, 

Is there an ideal offset from the axle centreline to the centreline  of the link bar mounting points? (Or does this matter?)

And, is there a preferred offset from the axle centreline back to the centre of the coilover mounting point?

My time fucking about with cars has taught me that such things are never left to change by the OEM. And the blokes who design this shit are a fuckton clever-er than me.

Ta.

You're in the rabbit hole Bart, good luck.

the Mounting holes are forward of the axle tube to allow for easy adjustment from the bottom of the top bar, if it is over the axle tube you can't really get the big spanner you need for the jam nut in there.

Typical bracket widths are 16-24", with 18" being very common. I would go 18" as it dramatically improves you chance of being able to pick up a second hand housing that fits.

The coilover is an integral part of the tuning, so that also needs to be adjustable./ just buy(copy) the brackets, you wont save much by not doing it.

 

KevinWilsonSBC makes really good videos about suspension tuning.

 

To sumise my learnings on the matter:

You are always wrong, and only trial and error can save you.

Get more holes than less, like I said, you will be wrong, so make it adjustable.

Everyone will have an opinion on your setup.

 

 

/get leafs and caltracs...

 

 

[RUNAMUCK]

4 hours ago, Rookie said:

You're in the rabbit hole Bart, good luck.

the Mounting holes are forward of the axle tube to allow for easy adjustment from the bottom of the top bar, if it is over the axle tube you can't really get the big spanner you need for the jam nut in there.

Typical bracket widths are 16-24", with 18" being very common. I would go 18" as it dramatically improves you chance of being able to pick up a second hand housing that fits.

The coilover is an integral part of the tuning, so that also needs to be adjustable./ just buy(copy) the brackets, you wont save much by not doing it.

 

KevinWilsonSBC makes really good videos about suspension tuning.

 

To sumise my learnings on the matter:

You are always wrong, and only trial and error can save you.

Get more holes than less, like I said, you will be wrong, so make it adjustable.

Everyone will have an opinion on your setup.

 

 

/get leafs and caltracs...

 

 

Good video.

Thanks man.

It's a rabbithole indeed!

[ThePog]

5 hours ago, Rookie said:

I am ashamed to admit how much time I used on trying to make this work, and it still not working, I have resigned myself to buying the box that Clint posted or alternatively trying this

https://forbes-automotive.com/products/speedpulser?variant=52720568238422

 

GitHub - Forbes-Automotive/speedPulser: For pairing with Can2Cluster or OEM Hall Sensors for driving analog speedometers · GitHub https://share.google/wn01YUGon0dAnfn9r

Looks like you can build it rather than buy the unit...

[ThePog]

The board;

C3 Mini V2.1.0 - LOLIN WIFI Bluetooth LE BLE IOT Board ESP32-C3FH4 ESP32-C3 4MB FLASH MicroPython Arduino Compatible
https://a.aliexpress.com/_mNdFDAx

The motor;

DC 12V Micro 38mm BLDC Brushless Electric Motor TY3816B with Driver Board High Power 12V 4200RPM 10000HZ PWM Speed Regulation

https://a.aliexpress.com/_mOMHWhz

 

Im giving that a go for sure

[ThePog]

Fuck it, I ordered 2x sets of hardware for $50, jobs done.

[Rookie]

2 hours ago, ThePog said:

Fuck it, I ordered 2x sets of hardware for $50, jobs done.

Let me know how ya get on because I still haven't solved the issue myself.

[ThePog]

26 minutes ago, Rookie said:

Let me know how ya get on because I still haven't solved the issue myself.

Thats what the two sets are for, just in case someone needed one/or I blow shit up.

[SOHC]

I am trying to find a cople old ammeters to use the insides to fix one of thees if anyone has anything?

[h4nd]

Looks perfect, just whang a toy RC mother in there to run the needles.

Anyway, this animation of a hydraulic schematic is a beautifully clear piece of engineering communication:

 

[datlow]

On 11/07/2026 at 22:49, SOHC said:

I am trying to find a cople old ammeters to use

12V ? ill have a look

[SOHC]

11 hours ago, datlow said:

12V ? ill have a look

Thanks, Doesn't matter about voltage, they dont mind