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Sat May 02, 2015 2:21 pm

The front license plate and bracket always seem to get more than their fair share of abuse, and always seem to be bent up. We used some heavy flat stock, threaded to accept the plate screws and welded it to some slightly overbent 2" angle to make a bracket:

We put a layer of heavy duty outdoor rated double-sided tape between the bracket and the chrome. That should keep it from rattling or daamaging the chrome:

It tucks up about as close as it could be to the bumper, without making cutouts in the rub strip:

Stainless button head M6 thread into the bracket:

Ready to avoid getting pulled over:

Sat May 02, 2015 2:31 pm

After a bit of a push to get the car road-legal, we drove it to the Dyno for a base line and some very basic measurements:

The Dyno use is part of a tuning class I'm taking (a nod here to Jeff of BadBug Racing, our instructor), one of the much more knowledgeable students helped me (he did the work, I watched) get some of the most basic full-throttle tuning correct.

The first shows a pretty bad dip at just over 3000 (lower traces), by the end of the class he had that smoothed out nicely (upper traces):

We had a problem with the throttle body butterflies on the right side sticking open after a run (that gets exciting) so we did not get as many runs in as we would have liked. Should be able to get back on the Dyno in a couple more weeks, and work through the table finding the optimal mixture, then the optimal timing.

Sat May 02, 2015 6:49 pm

What a great looking car! Your son is lucky! And I loved the photo of you with your 1302 Super in high school! Awesome!

Sat May 02, 2015 6:49 pm

What a great looking car! Your son is lucky! And I loved the photo of you with your 1302 Super in high school! Awesome!

Fri May 15, 2015 8:51 pm

After the first real fuel tuning pass on the dyno, this is the fuel curve we came up with:

We then did some quick timing optimization, here is the timing table result:

A chart of a full pull using the new tables and the original:

And a pretty scatter-plot of the drive home.

Here is a link to the MSQ, in case you want to see what we used:
http://baxsie.com/images/forum/bug/white_75/Dyno/Baxsie_2085cc_40mm_ITB_2015-05-14.msq

Sat May 16, 2015 11:27 am

Wow really cool to see it under its own power! I would have expected to see more power on the dyno though.

Thu Jun 04, 2015 4:07 pm

Took it for a drive, logging data shaking out problems. Stopped at a local butte for some glam shots:

at https://goo.gl/maps/H3HII

Thu Jun 04, 2015 5:49 pm

Man I really like the build, the creativity, and the results.

Sun Jun 07, 2015 9:09 pm

Getting the idle speed right is a bit problematic. Once we got the idle speed correct at warm conditions, we found that there simply was not enough air for the car to start when cold. We got the IAC kit from DIYAutoTune:

To filter the input, we used a little K&N 62-2480 Vent Filter. Cute, seems to work.

Originally we tired having it connected to feed air in to the same line that the measures MAP (Manifold Air Pressure). This actually worked, but when the IAC was open very far, the MAP was predictably very high, so the MegaSquirt thought that the throttle was almost wide open.

We needed two paths into the area of the throttle body and manifold below the throttle plates. The IAC path needs to have a pretty good flow, since the car will largely run from this path at idle. The MAP path just senses pressure without any flow, so a small tube is fine. I think the small tube can actually help damp and smooth the signal from the very noisy pressure signal between the a throttle plates and the intake valve before it gets to the MAP sensor.

First off we needed to drill through the unused injector bosses in the CB Performance Throttle Bodies. The bosses are unused, since our injectors are installed deep in the CB offset manifold, very close to the intake valves.

Here is the drilling, finally an excuse to use the angle drill vise!

The exit came out about exactly where you would hope:

We then tapped the holes for 1/8 NPT:

When adjusting dual carbs or dual throttle bodies, you must balance or synchronize the two sides to make the idle smooth. When the car is running mainly off the IAC, there is no control to balance the sides. We tried to make paths of both sides (4 paths total as exactly equal as we could to keep the motor balanced or synchronized when the IAC is activated. Really the IAC and its tubing act like a secondary manifold with the IAC acting like a single small throttle body:

Once the IAC is working, it is prettty fantastic, we set the idle goal to 900, and the MegaSquirt opens the IAC just enough to make the engine run at 900 RPM. It just works. As soon as you are off idle, MegaSquirt closes the IAC, so it does not interfere with the original tune.

To make all this work we got the engine warm and set the idle to ~700 RPM and balanced/synchronized the throttle bodies there. Once the IAC is enabled, the RPM jumps up to 900 RPM. At cold start the IAC opens farther, whatever is needed to maintain that 900 RPM.

During warm-up, the idle target is set higher so you get a nice fast idle. As the temperature approaches normal, the target tapers back down to to my default 900 RPM:

Here is a bit of a log file. showing that wonderful flat 900 RPM idle :)

We did all this work after the tune was complete, and I think that is the right sequence, but it did mean that this stuff was done as a retrofit. If you are going to do a MegaSquirt on a aircooled VW, I highly recommend including the IAC in your build.

Tue Jun 16, 2015 1:36 pm

What an incredible build... Congratulations on the work done and learned.

I have to ask about the color, do you have a paint code for it?

I'm tackling my 1973 1303 convertible and I'd love the same color.

Thanks

Tue Jun 16, 2015 2:03 pm

Thanks for the kind words.

The paint is Subaru WR Blue Pearl -- WR is "World Rallye".

https://www.google.com/search?q=Subaru+WR+Blue+Pearl&tbm=isch

Wed Jun 17, 2015 1:31 pm

cruise control = mind blown!!! :D

Great job!!

Wed Jun 17, 2015 10:51 pm

conrad1468 wrote: cruise control = mind blown!!! :D Great job!!
Thanks.

Yet to get the cruise actually going. We never got the clutch interlock working right, the way I made it every time you adjusted the free play the switch would have to move :(

Then we needed to replace the ignition switch and when the steering wheel popped off it yanked the wires and the flat tape ripped. So I need to find another spool thing and re-wind the steering column. And to do that, the tank needs to come out. But the tank needs to come out anyway because the new gauge, with new vibrator, and new sender still does not work worth a darn.

And the idle control was working perfect, but then stopped, so the MS3 has to go back to get fussed (again).

Never ending story ;)

He did just break 1000 mile son it though, and nothing major beyond the broken rocker arm stud.

Tue Aug 25, 2015 7:47 am

ok men..i saved your thread to my favorites in 2012. yes i am a procrasinator. With that being said i have been given a mandate by wife to get it going or get it out!!! Parts are rolling in but have one problem. Where did you get ALL the wiring looms to rewire your Car? I too have a 1974 SB Sun bug and the wiring is toast. I have caught up with your build and think the LED route is very cool. Any help with the wiring would be greatly appriciated.

Thu Oct 15, 2015 7:44 am

We were able to contact a fellow in Mexico who did a fantastic job of wrapping the modified dash.

Here is his playlist of the full videos of the operation:
https://www.youtube.com/playlist?list=PLoSIdv1C9uyQ5p0hYqlf1j-U2XiheZ_U0

Here are some pictures of the dash after we got it back.

Test fitting switches and gauges:

A view of the passenger side:

And what the driver sees, tach, speedo, AFR:

Thu Oct 15, 2015 7:52 am

Excellent dash. :)

Almost makes me wish I had a later Super.

Almost... :D

Tue Oct 20, 2015 7:27 pm

The car is a daily driver now for my son, he caught a nice sunset glam shot on the way home:

Wed Oct 21, 2015 4:17 am

wow, everything about this car is amazing.

Love the glam shots, looks like they came right out of an advertising brochure :D

Sun Nov 01, 2015 5:36 am

Great work here! 8)

Mon Jul 11, 2016 6:26 am

Amazing build and thread thanks. I upgraded my 1977 convertible to Megasquirt fuel a few years ago using the stock VW throttle body and plenum. I think I got the fuel table pretty close using Tunerstudio. Now I just upgraded to spark control and am using a generic ignition map. I hope to do some dyno tuning soon. Have you done any more dyno tuning of your spark table? Since our motors are identical i thought I might use your table for now.

As you know cold start and after start enrichment is very sensitive. I used a Bosch idle valve to control warmup idle speed. I have it setup so the car starts first try but the warm up idle always stumbles a little for a few seconds then settles into a smoother idle as it warms up. Have you succeeded in getting it to start and warm up well? What are your cold start and after start enrichment settings?

Thanks for the help.