340 upgrade

[Dan B]

Any progress to share on the car this weekend, or are you guys going to just focus on the chump car?

[BlownMGB-V8]

We did exclusively work on the racer and I've some photos to upload to that thread later, but I can also do a progress update here as there have been some new developments. First, I was able to get some high pressure wing cylinders for the bonnet lift. I called KSE and it just happened that they had done a run of 18 units to fill an order from Australia and I was able to piggy back onto that order. So I now have a set of their 1300 psi rated cylinders mounted. I was able to adjust the hydropak down to about 900 psi and now have it mounted and plumbed with 1/4" line all the way up to the bulkhead connectors at the cylinders and was waiting on more fittings to add the last 4 short lines. Then I'll be able to test it and provided that works as expected I can then run the control wires and install a switch. At the same time I ran new lines in NiCop and stainless for the air bag front suspension. Starting from the bulkhead fitting by the compressor I have 3/16 NiCop line running to a quick disconnect (for aux air and aux filling) then to the front crossmember where it transitions to some 1/8" stainless line. The 1/8" line is wound into a pair of springs which lay next to the lower control arm pivots and connect to the air bags, allowing for suspension motion while plumbing all the way with high pressure hard line. Another 1/8" line runs inside to the gage. It's now been pressurized for 3 weeks and the gage reading hasn't dropped. In fact the only variations I've seen have been both up and down and are attributed to the ambient temperature. Since bag wear has been a concern with these installations I have lined the recess in the crossmember with a thin teflon sheet bolted in place. The small line also acts as a restriction against air flow from one side to the other during cornering. Once I have the new pump plumbed in and electrically connected I will locate another switch to operate it somewhere in the dash.

Then there is the wing plumbing. Recalling that the car now has IRS, the wing control is more complex than a simple link to the differential and the motions of both sides of the suspension need to be averaged into the wing angle of attack. To do this I'm using a motion cylinder on each lower control arm and a wing cylinder on each wing support. The motion cylinders are plumbed together and then to the wing cylinders, with reservoirs to handle expansion and I have a small electric peristaltic pump to control the wing angle. I've been working on mounting everything and should get back on that tomorrow. As of now I have the motion cylinders mounted and have all the fittings on hand so it should go pretty smoothly, though I do not know how much pressure the small pump will tolerate. I'm thinking probably not much so it should be interesting to see how well it all works.

That leaves the intercooler pump and plumbing for the next job, but soon I hope to be able to get back to tuning the engine.

Here is a photo of the upper motion cylinder mounts:


Jim

[Dan B]

Word on the street is that Jim has a new development on the B.....

[BlownMGB-V8]

https://www.youtube.com/watch?v=oHTIFziaQV4&feature=youtu.be

<iframe width="420" height="315" src="https://www.youtube.com/embed/oHTIFziaQV4" frameborder="0" allowfullscreen></iframe>

[Scott Costanzo]

Very nice!

[MGBV8]

OMG it's a Transformer!

[74ls1tr6]

That is very cool!!!

[mgb260]

Wow! The Mad Scientist in his lair!

[BlownMGB-V8]

I've made a bit of progress.
Most recent has been work on the wing. Because of the IRS I had to redesign the actuating mechanism. In doing so I needed something that would combine and take the average of wheel movement and convert it to wing movement, and a mechanical linkage seemed way too cumbersome given that the wing is mounted on the trunk lid which has to open normally. So I went to hydraulics, which makes the motion conversion easier and gives on-the-fly wing angle adjustment, but adds the complication of another hydraulic system, and which is a bit tricky in terms of pressure and balance.

So anyway, the use of hydraulics meant mounts had to be built into each of the side struts and to do that the entire structure had to be dismantled. The job cascaded, as they often do, all the way down to the strut mount cushions. While apart I polished and buffed all the stainless parts, buffed the aluminum aerodynamic struts and then anodized them to a burgundy that is a close match to the car color. Not perfect but pretty darned good for an amatuer. I just got it all back together except for the top mounts for the wing cylinders and some of the plumbing. I'll try to post a photo soon. Along with the rest of the plumbing I still need to build a 2 chamber reservoir and test the balance pump which is a small peristaltic unit I'm going to try. It will shift fluid from one chamber to the other to change the wing angle. The challenge is setting a static system pressure that will give the needed system stiffness without blowing out the balance pump. Amazing how tricky these things can become.

The other big development was that I trailered the car down to the annual Megasquirt Megameet in South Carolina last month, where we took it off the trailer and I had the benefit of a couple of experts setting up the initial parameters and evaluating the system. I learned a few important things from this. First, that my coolant temp sensor is not providing a reliable signal, meaning of course that while we had the startup settings working perfectly once the engine is warmed up, it will not do so well cold, until I have that problem fixed. They felt it was a grounding issue.

Grounding the Megasquirt system turns out to not be quite as straightforward as one might think.
The goal is to isolate signal grounds from output grounds and from all the automotive noises that travel back on the return path from every other electrical component in the car. Some of these components, (such as motors, ignition, and alternator) make a LOT of noise.

So here is the basic idea, and it can be used for the sound system as well: The MS has multiple ground leads coming off the controller. It is an easy mistake to tie all of these grounds to our chassis ground point. Instead, the idea is to isolate one lead and tie that to a ground lead that goes all the way back to the battery independently of all other grounds, Then use that lead to provide a ground for all of the sensors. You see what we are doing here? We are giving the sensors an independent path all the way back to the battery post. If the battery has double posts (top and side) even better.

The rest of the MS ground leads can be tied to chassis ground along with the ground strap going to the engine and this provides the ground path for all the outputs and carries all of the noise, thereby isolating it from the inputs. It's not absolutely perfect of course, you have a tie-in at the card junction between the grounds and also at the battery, but since all current flow not generated by the MS is now bypassing the controller power leads it will help a lot. And just maybe that will resolve my noise issues on the CLT temp sensor leg.

That is something I hope to resolve next week. Then it's on to checking the MegaShift inputs and outputs. Plus plumbing of course and then more tuning. After that, plumbing the intercooler, fixing the oil leak, and then the initial A/C plumbing. Still a ways to go, but at least it'll be driveable before too much longer and should be able to make the BritishV8 meet in spring.

Jim

[Todd McCreary]

Are the output grounds for a digital signal or are most of these simply a fairly consistent output ( such as temp gauge )?

If the signal is a fairly steady DC, you should also be able to series an inductor / parallel  some caps, yes?

[BlownMGB-V8]

You can always add a filter network, even for an AC signal. Capacitance and inductance in the proper values and the right configuration will allow the desired signal to go through and the filter can be designed with a sharp frequency cutoff that excludes just about everything else. It takes a bit of math and the right sized components, in extreme cases even the creation of what is called a "tank" circuit which is nothing more than a resonant or ringing circuit made up of one inductor and one capacitor. But the goal here is to avoid the noise in the first place so that you don't have to take any sort of extreme measures, which should not be necessary anyway if the wiring is done right to start with.

Jim

[Charles]

OK, then that is the same thing I was thinking.
Jim, how about adaptive speed bump sensors that will raise the car when you approch the speed bumps.

[BlownMGB-V8]

Of course it could be done. But why? If you raise the ride height don't you also raise the spring rate and make the ride over the bump more harsh? Perhaps it would be better to just slow down a bit as the gods intended. Anyway it's probably a bit above my pay grade, doing such complicated stuff. Now if it's more a question of grinding off bits of the car on the bump, maybe the ride's already a bit lower than it should be, or the bits hang down a bit farther than they should. Is it that your bits are just too big? Maybe a large hammer could remedy that.

I do have a picture as promised, everything above and below the trunk is now complete. It's the part in the middle that still needs work

Jim

[burner1]

In the Pantera I have the distributorless ignition. It the pick up on the timing wheel I was getting interferance from the starter motor. I ended up putting a steel plate between the two which seemed to solved the issue. If it is passing near a starter/alternator wire it just might needed a shielded wire.

[BlownMGB-V8]

Got most of the noise out of the CLT sensor by changing the grounds but in the last datalog I noticed some very strange waveforms on the CLT trace. Almost digital in nature, abrupt but very uniform spikes and changes in level. May be nothing to be concerned about, or may be something I have to track down. I suppose I can look for another trace with similar changes.

Anyway, I've about finished the wing reservoir but I'm waiting for some low viscosity (wicking) loctite to treat the welds before mounting and plumbing it. It came out pretty good, with a concealed chamber in the base for the wing attitude pump.

I'm psyching myself up for the wiring checks on the MegaShift controller, which is the last step before the software revisions, and in the meantime I still have intercooler plumbing to do and a pump to mount.

Jim

[burner1]

I am sure you have covered it but your engine grounds need to be good too; otherwise everything is going to find some pretty screwy paths.

[BlownMGB-V8]

Yeah, that's all solid. I saw the signals clean up remarkably when I installed the separate instrument ground post, with a lead directly to the battery ground. But I just noticed these new blips. I'm going to watch that signal for awhile before I assume it actually is noise on the CLT sensor line though. Could have been something like a glitch in the datalog file.

Jim

[BlownMGB-V8]

I've been working on the MegaShift transmission controller installation pretty steadily since my last post and made much progress. But there is more to do. As it stands today, the paddle upshift does not yet work (appears to be a coding issue that Lance will look at), my brake sense input appears to be a signal mismatch which I can fix, the gear readout has a mismatch, possibly an incorrect ground reference or similar, I have to verify the CANbus communication between the MegaSquirt and the MegaShift, and I really should come up with a way to probe the solenoid outputs before firing the beast up. Maybe another month's worth of work.

Also, I need to make a separation tank to take the output of the intercooler condenser and plumb in those lines before I can use heavy throttle for more than a second or two. And there are a few other more minor issues.

I don't really expect to be driving the car to Townsend, shakedown is likely to take me beyond that. But I do expect to make Louisville with it, and to be driving it this summer.

Jim

[rficalora]

RE: But I do expect to make Louisville with it, and to be driving it this summer.

Bet you're excited by that Jim.  It's been a long time coming;  I'm sure you have withdrawals!!  You've done so many cool things with this upgrade; it's going to be awesome.

[BlownMGB-V8]

Thanks Rob.
Still got a crooked body, but for now I don't  care, I just want to drive it. Anyway the car always was something of a beater and may always be. For the way I drive it though that is appropriate.

Jim

[BlownMGB-V8]

Two steps forward and three steps back.
I'm down to the gear indicator, CANbus, a bit of programming and testing before I can do any driving. Plus hooking up the intercooler before I can drive it hard. But, my digital readout for the gear indicator is broken. As in, demolished during disassembly because it wasn't working right. Including the housing. And since that was made out of the old brake indicator/light/switch there's nothing for it but to find another one. I'm certain I have one here somewhere but it hasn't turned up in the usual places so a whole house search and spring cleaning is on out in the Lab (which actually needs that rather badly anyway) to see if I can locate it. Since that might easily take 2 or 3 weeks and then I'll have to build a new indicator in it, well let's just say Townsend is definitely off the table. Louisville is a maybe but that sort of depends on what turns up in the programming and testing. One possibility that looms hidden in the background is that I could have to learn C++. I hope not, but I have to recognize the possibility. Hey, could be an entirely new career direction, right? Just in time to retire. ;-)

I'll get it done someday. I just don't know when.

Jim

[Charles]

Hey Jim,

I got a ROUNDTUIT if that will help.  I can bring it to Townsend and let you borrow. I would just give my ROUNDTUIT to you but what would I do then when the time comes for me to say "I will do it when I get a ROUNDTUIT", I will never get it done.

charles

[MGBV8]

I got him covered.  

[BlownMGB-V8]

Did I ask for a roundtuit? I don't think so. Used to have one I carried in my pocket and it made no difference at all. That ain't it. Nothing I can do will get Lance over the flu any quicker, and all the searching in the world won't turn up that spare brake switch/lamp for the dashboard until it's ready to be found. It's on the to-do list right along with about two dozen other things and a round tuit isn't going to knock even one of those things off the list. I am functioning at maximum efficiency. Today that means taxes. Yesterday it meant plumbing. Tomorrow it will mean something else. Maybe mowing if it is warm. Somewhere along the line the switch will be found, whenever it is ready to be found. I don't think it cares one bit whether I have a Round Tuit or not.  :-p

Jim

[DiDueColpi]

Agreed,
no roundtuit required in your case Jim.
What you need is my new book, The Procrastinators Guide to Tomorrow.
It should be ready soon.
Helps slow things down a little :-)

Fred