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I's seent it firsthand Just sans stupidcharger because you're lame and played it "safe"
I was still trying to sort out parts and I'm not sure I'd actually been able to get the belts to stay on the thing at that point. Oh well. It's kinda the same just louder, faster and dumber. I'd really like to build an exhaust for it someday.
Originally Posted by boileralum
MATG has been the first weekend in August for like 25 years.
In an effort to address my soggy bottom issues I've decided to employ this little bit of vintage fried gold:
BEHOLD!
That's an original Sebring Superchargers Mazda Miata Boost controL box! By MSD of course. PN 86621. These were sold for years to the general Miata public who were looking for a way to retard timing based on boost without having to set your base timing to 4°~6° BTDC or whatever.
The theory of operation according to the tapestries woven from papyrus and the entrails of the defeated by the ancients tell us it pulls 2° of timing for each 1 PSI of boost up to 3 PSI, where it maxes out at 6° of timing retard. So in theory, if you set your base timing to 10° BTDC you'll be a 4° BTDC by the time you hit 3 PSI (10-6=4.) You get to maintain your bottom end, and the device pulls timing to keep the engine from knocking itself to death. In theory of course.
As with most of the garbage I'm playing with, I picked this thing up from some rando on the internet. I think this came from the guy in Florida who sold me the old Jackson Racing FPR with the ruptured diaphragm that sprayed fuel all over me and the car, so its totes good I'm sure.
So how do we test this thing?
Well, MSD was of no help at all, as expected. I sent several emails to their support team over a period of about 6 months. The first one got an automated reply that they would get to it as soon as possible, but lolcovid so it might be a while. The second email got completely ignored, the third email asked me for pictures of the unit, which I dutifully supplied, and then was also ignored. Undaunted by these replies, I called them directly. After being on hold for about 80 minutes I was informed that "they had no knowledge of this product" and "its not made by MSD" followed by "we no longer support that product and have no way to troubleshoot it." As these replies were in the same conversation I was somewhat confused, but undaunted, I carried on.
The installation instructions are fairly straight forward. If you dig around on the internet you CAN find instructions for one of these things, but its getting harder and harder to find. Anyway, one wire for power, one for ground, then you cut the CAS wire and run one side into the MSD unit and the other to the ECU. The nipple gets manifold referenced and away you go. My big beef with the installation is that they want you to install this thing under the hood and the power, ground and signal wires are to be tapped into at the CAS. In its original form this was supplied with more of those evil Scotchlok Vampire taps and old school butt connectors. As I find the concept of cutting up a stock wiring harness to be completely abhorrent, I chose to go another route. As you can see, its installed in the cabin behind the seat next to the ECU. It should be safer-er-ish here compared to shoving vintage electronics under the hood, and it allows me to take advantage of this beauty:
This is, I believe, the Track Dog Racing version of what is commonly known as a Boomslang Harness. I picked this up from someone's part-out and added the appropriate connections in the appropriate locations for the MSD Boost Timing Controller. Connections were made using the appropriate heat shrink butt connectors and automotive grade TXL or GXL wire (I don't remember which) and then the harness plugged inline with the ECU. The AC and Main fan triggers are jumped here as well for parallel operation (as you can see with the already completed splice) even though I don't have a second fan.
So now that its plugged in, how do we test it?
The MSD has a pair of pressure sensors inside the body. One transducer/sensor attaches to a tube to the backside of the nipple on the outside of the case, and then you run a tube to the intake manifold. The other is sealed cell of reference pressure (don't ask me how I know this, I just do) which is also attached to a tube inside the body of the device. I won't go into the why of any of that because I'm pretty sure nobody actually cares. ANYWAY, to make sure this is working, we need to verify the static engine timing, figure out a way to lock it, and then feed pressure to this Rube Goldberg device and see if the timing changes. Luckily, Mazda (kinda) gave us a way to do this. Well, partially anyway.
As this thing dates back to the Late Mesozoic period of Miata boost control development, we don't want to hook it up to the compressor and send it as this will surely destroy its internal parts. What we need is a mostly accurate, low pressure, high resolution source of compressed air. Which isn't my lungs. We'll also need a timing light for verification.
Step 1 was to warm up the car, jump TEN and GND in the diagnostic box to lock the timing advance, and set the timing to 10° BTDC. I made the balancer look like this:
I really ******* hope that's correct because this is how I've been setting base timing for years. (Not my pic, stolen from Google)
Then, I disconnected the vacuum line that runs into the cabin, capped it at the manifold, and hooked up this mess and made with the blinky-blinky
The Motive Products Power Bleeder makes an excellent source of low pressure, high resolution source signal. It applies very little pressure per stroke of the pump and the relatively huge volume of the chamber makes for an excellent buffer. It even has its own gauge.
And what's better, its actually pretty damn close to the AutoMeter Phantom Boost gauge that's in the car. (yes, I realize they read differently but I submit that its within an acceptable margin of error, the camera was at a bad angle due to the steering wheel, and I can't be bothered to give a ****.)
Lo and behold, it works! Timing was in fact retarded by an appropriate amount! It actually looked like it pulled out closer to 8° rather than the tribal knowledge of 6° that was handed down by The Elders. And what's more, it appeared to be progressive in that it didn't just werf 6° (or 8°) as soon as it saw boost as was foretold by some, but at very low boost it was only pulling a couple degrees. As it took about 10~15 pumps on the Motive to go up each additional PSI of pressure, the amount retarded was fairly observable.
My only regret is not being able to get a video to prove how it works, but I didn't feel like shoving my hand, and cell phone, into the spinning vortex of belts and things at the front of the engine.
After that I locked down the CAS, tucked all the wires away, removed the jumper from the diagnostic box, reconnected the manifold vacuum/boost line and packed things up. I need to borrow the riv-nut gun again so I can add some additional M6 mount points for the ECU, but that's another problem for another time. As soon as I get a chance to drive this thing again I'll let you all know how it goes
I wonder just how fancy of a standalone you could buy with all the money sunk into the obscure band AIDS that comprise G's Magical Museum Of Obselete and Obselescent Engine Management. Probably a nice MoTeC
I wonder just how fancy of a standalone you could buy with all the money sunk into the obscure band AIDS that comprise G's Magical Museum Of Obselete and Obselescent Engine Management. Probably a nice MoTeC
Actually, my weirdo old-school timing control lust object would be a full BIPES ACU. Not even joking.
Unfortunately, I haven't seen one for sale in years. That's the kind of thing you open a WTB thread for here on mt and also on m.net and then hope for the best.
Actually, my weirdo old-school timing control lust object would be a full BIPES ACU. Not even joking.
Unfortunately, I haven't seen one for sale in years. That's the kind of thing you open a WTB thread for here on mt and also on m.net and then hope for the best.
One thing I am noticing is that you can actually see the timing marks with the correct crossover pipe. With that fucky one that came with it, and the hard 90 attached to the dummy TB it put the crossover pipe in a place where you needed to remove it to adjust the tensioner and also see the timing marks. Funny how having the right/not cobbled together **** makes the whole thing easier.
Oh for sure! I was pleasantly surprised how much easier it is to see things down there with the correct crossover pipe. Setting the timing is super easy again.
I decided I'd waited long enough after installing the MSD box this last Sunday and took the car for a drive tonight. Putting gas in it seemed like a solid excuse. Let me just say that 10° BTDC feels waaaaaay better than 4° BTDC. Under boost it feels about the same due to the timing retard, but the bottom end feels a bit more robust when out of boost. Well, as "robust" as a BP05 can feel with all the other things I've done to the car. It picks up from a stop much, much better now. The fact that the engine didn't knock itself to pieces while huffing CA91 winter blend at 10° BTDC base with 6.5-7psi of boost from a tiny Eaton M45 and no intercooler speaks volumes. I've still got the hesitation during the transition into boost, but that's more of a lean tip-in issue due to fucky RRFPR and ECU fighting the additional fuel, but I have some more trash that might help with that issue that I'm saving for another day.
It didn't fix my ED (pretty sure the ethanol in the gas causes that), make me drop 20lbs or cause my hair grow back, but I'd definitely rate the old MSD box as "Engine didn't explode, a perfect 5/7"
I'm starting to actually kinda appreciate the effort being put in here to not make power
Thanks? I think? Remember these words before someone eventually tries to ban me for this thread
Originally Posted by 18psi
Not but seriously: you sir remind me of Joe and the thermostat being boiled in a pan in the kitchen video, which is basically the epitome of MT.net
Haha!
I don't know it I'd go that far, but high praise none the less! Thanks you very much!
I will say this: if things work out the way I'm hoping, this is going to get a lot worse before it gets better
I know that's a joke but I could legitimately use that.
Not THAT one as I'm pretty sure those axles and tires aren't rated for the weight of the car, but its got enough ground clearance that I can't use my blue Harbor Freight Racing jack without a block of wood on the pad. Its sketchy as frig, but then what isn't on this thing? I need to find a better jack solution.
I bought a trailer dolly from tractor supply to move the boom lift we rented. Wheels were the same as those. turning the dolly, putting a side load on those rimz caused them to twist. I think they are rated at 400 or 600 each but that is likely in a straight line based on how flimsy these things were.
So yep, the ones in the pic are cheesy AF. If you can find a set more stout than that then worth a shot.
Something like a 10" dirt bike/pit bike wheel and tyre combo may have sufficient load capability, but would likely not be all that cheap.
11-15-2021, 02:10 PM
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