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From first fire to dyno day









I spent most of 2014 installing the engine and trans, finishing and fine tuning the Megasquirt installation, and a bunch of other miscellaneous tasks to get it ready to turn the key for the first time. Also a million and one other "while I'm there" jobs like LED bulbs for the dash, securing the oversize spare wheel, fixing the hood support, etc., etc.,...


Then it was off to a local dyno shop for tuning with some great results for a first effort.


Installing Engine







The part I dislike the most. It's tedious and I suck at it. Wiring errors and "on the job learning" is perhaps the thing that slowed me down the most. And because I suck at it, it's all the more rewarding when I do get it right and stuff works as it should. The first pic is what caused me most grief - it's the VR sensor. I triple checked I had it wired up correctly, comparing dozens of posts online, and I still didn't. Yes, those are crimps for speed of mock up assembly, and yes they were insulated before use.



Megasquirt/TunerStudio would show cranking with the VR sensor polarity reversed, but never get a clean tach signal. I spent days trying to figure out why it would crank but not fire until I ripped it all apart and went back through it for a second time and flipped the polarity for giggles. Et voila. First fire.





I should add that at this point I changed course several times about how to fire the coil(s) and what coil(s) to use. I was originally going to use EDIS and a DIYAutotune four-post coil. See the EDIS and four plug wires in these early pictures.




...then I dropped EDIS and got the MS3X daughter card to fire smart coils directly for a cleaner install (less under the hood) and contemplated the "Yukon" LS coils.


There were no easy/clean ways to mount the Yukon coils with the stock GM bracket, and I don't have access to a shop to create my own, and there were none on the aftermarket that were suitable, so I started looking at coil on plugs with ignitors (aka "smart coils"). The VAG COP of choice seems the be the ones from early to mid VW Golfs and Jettas. Plenty of information out there in the Megasquirt documentation and forums about what to look for and how to wire them up. Be aware though that the part number revisions given in the documentation did not guarantee compatibility with Megasquirt. I burned out several coils before I learned that the only real check was to measure resistance across pins 2 &3... just like the documentation says to do ?

I did find it necessary to trim about 1cm off the lower part of the metal shroud on the coils (trim it back level with bottom of the rubber insulation beneath the metal shroud) to get a good fit on the top of the plugs. They are regular plugs for our cars. Can't remember which type exactly, except they are of the resistor variety with the bulbous tops instead of the threaded posts for connecting to the spark plug wires.





You can see the VAG COPs fitted and wired up in this pic.


So that's where the ignition landed. VR sensor feeding tach to MS, MS firing the VAG COPs directly using the MS3X daughter card. At this point It was time to fire it up.


Air intake

Due to limited room, I had to do some creative doodling about air filtration.



I bought some stubby air horns from a VW shop that are straight with no radius (so they aren't really air horns at all), some angled silicone hose, and a Ram Air filter and base plate. Here is one of the stubbies in situ:


Bolted them all together in the following order (except the thick spacer next to the real air horn - that was not needed):


I ended up with the following contraption:




With the thick spacer removed and all four attached with the actual filter, this is what it ended up like:







The hoses are now firmly secured using stainless t-bolt bands (not shown in the mock ups). I ran the car with no hood for several weeks because I was still spending a lot of time working under there tweaking stuff. When I reinstalled the hood, I found one of the support channels attached to the underside of the hood interfered with the filter when the hood was latched closed, so I had to trim another 2cm off the hose to lower the height of the filter.

Another problem, which I have yet to solve, is that the filter is too high for the strut bar I bought. If I don't fix the issue, look for the strut bar in the classifieds!


Throttle Cable

My first throttle mechanism was bodged together from whatever materials I could find in my garage plus some barrel adjusters from eBay and it was not pretty. It used the cable supplied with the Jenvey ITBs but the cable was incredibly sticky inside the outer sheath which made throttle modulation difficult. I think the first pic shows a piece of old carb linkage being recycled - like I said, it was a case of making do.




It worked well enough for a few weeks before two things happened:

  • the gas pedal fell off while driving
  • the throttle cable snapped

The "evil nubs" had not yet given up so I ordered a new pedal and a Lokar throttle cable kit. No pics of the new cable set up.


First drive

Here it is with a basic Megasquirt tune. There will still any things to complete before it was ready for the road.


Once it was ready, I took it out for it's maiden voyage in the computer age.



Wiring Revisited

The Megasquirt documentation is insistent on proper grounds. Here's what happens if you (inadvertently) get it wrong.


Again, I thought I had done it correctly, but the engine kept cutting out on drives over say 15 minutes. I would be powering along nicely, or just cruise steadily and then silence. RPMs would drop, no power, then nothing. Glide to the side of the road, switch the ignition off, switch the ignition back on again and it would instantly fire back up as if nothing had happened. Megasquirt logging several of these events showed the ECU saw voltage drop from +13.7V to 6V then nothing. Checking the relay/fuse holder and I saw the melted goey mess that used to be a fuse. Resistance was causing significant heat build up. Begin complete re-wire number three!


Hood Support

I broke the passenger side weld on the hood support torsion bar when removing the hood back in 2012, and my friend Kenny finally dusted off his gear for me.




Dyno day

While I had been able to get it to the point where it was drivable, I wanted an expert to take a look and tune it. My goals were twofold:

  • ensure a professional tunes it safely so I don't break anything with my basic tune
  • "more POWWWWAAAAAARRRRRR!!!!" (in your best Clarkson voice)


Got her all strapped in for her big day.



In the following videos, I am the very nervous looking guy in blue. Having never heard an M10 at full tilt (well, almost) from a few feet away, it was quite the experience for me. We agreed on an upper limit of 6400 RPMs but it sure sounded like it was going to grenade at about 6000. The operator didn't bat an eye though. One of the early dyno runs:


Nearing the end of the day:


The end result was a good 134rwhp (150ish at the crank?) and 129TQ with a really flat curve.


We finished up at about 7pm and the dyno operator, being the consummate salesman, said that there are two issues I need to fix and to "bring it back for another session, there's more in there!" The two issues (O2 sensor reading low, erratic CLT reading) have both since been fixed.


The Future

I tried most of the home brewed methods of getting the stock tach to work with Megasquirt and the COPs and gave up. The tach is now with North Hollywood Speedometers to be fitted with a custom PCB that will be driven directly by Megasquirt's tach output.

There may be forced induction in my future. There, I said it. I committed that thought to paper. It must be, like the EFI build, a "no cut" FI build though. I do not want to gut the front of the car or otherwise change the body work. Yes, that will force compromises, and I am absolutely ok with that. Here's my though process, and a failure on any one step below will cause the whole FI plan to be dropped:

  1. Move the alternator to the Tii position to make room for an airbox that can be pressurized
  2. Find an air box that will fit without moving the booster, etc.
  3. Find a place to mount an intercooler without cutting
  4. Find a turbo manifold and turbo that fits without cutting
  5. Run intake tubes everywhere

I am at this point today:




..and waiting for a XPZ962 fan belt to be delivered for Christmas.







Edited by stuff
remove spurious images

  • Like 3


Recommended Comments

Thanks ClarenceTE72. I've never cracked the engine open to confirm, but the specs I received with the car are as follows:

Korman stage 1 engine

2 liter

320i block

Piano top pistons

1.8i head

Head ported and polished

Ireland Engineering 292 cam



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