Megasquirt EFI (and EDIS) for the BMW 2002 - Part 1

[AustrianVespaGuy]

Hey for any followers, after reviewing some recent datalogs I've been surprised to discover that up at peak power, I'm starting to push 100% duty cycle on my 19# injectors and as such am going to replace them with 21# injectors instead.  My car has 9.5:1 pistons, and E12 head, and 284 cam.  I didn't really think this would be good for much more than 130HP but apparently the engine IS wanting that much fuel, so I'm obliging!  But a word to the wise for anyone else running the yellow-top injectors, you might want to see what your duty cycle looks like to make sure you're not running up against the same wall I am!

[vacca rabite]

That’s really cool. I live how you can look at logs and see what your engine wants. Have you had the car on a dyno?  Would be interesting to see before and after pulls to see what the new larger injectors get you (after tuning)

 

Zach

[C02]

Carl, thanks for the very useful details. Regarding your fuel return to the tank, you’re no longer using the original plastic tubing, so did you route new high pressure rubber tubing in place of this? If so, what size and did you any issues going through the cabin port holes?

/Martin

[AustrianVespaGuy]

11 minutes ago, C02 said:

Carl, thanks for the very useful details. Regarding your fuel return to the tank, you’re no longer using the original plastic tubing, so did you route new high pressure rubber tubing in place of this? If so, what size and did you any issues going through the cabin port holes?

/Martin

Hi Martin, Sorry if that was unclear, I AM using the original plastic supply line for the fuel return.  This is OK because the return is all low pressure after the fuel pressure regulator back to the tank.  The high pressure supply portion includes high pressure FI rated rubber line from the pump to the original steel (return) line, and another section of FI rate rubber hose from the steel line to the fuel rail.  Hope this helps!

[C02]

13 hours ago, AustrianVespaGuy said:

Hi Martin, Sorry if that was unclear, I AM using the original plastic supply line for the fuel return.  This is OK because the return is all low pressure after the fuel pressure regulator back to the tank.  The high pressure supply portion includes high pressure FI rated rubber line from the pump to the original steel (return) line, and another section of FI rate rubber hose from the steel line to the fuel rail.  Hope this helps!

Ah, thanks for that clarification Carl. I had been considering bending a parallel steel fuel line to the OEM thinking the original plastic could not support the 40-50 psi pressure. This makes it easier.

[AustrianVespaGuy]

7 hours ago, C02 said:

Ah, thanks for that clarification Carl. I had been considering bending a parallel steel fuel line to the OEM thinking the original plastic could not support the 40-50 psi pressure. This makes it easier.

Just to be clear, that's true, it can't, so don't get them mixed up! But the return pressure should be almost nothing (as it's just open into the tank at the back end), so maybe like 2 psi, which if fine as long as the plastic line is still in good condition.

[vacca rabite]

13 hours ago, AustrianVespaGuy said:

Just to be clear, that's true, it can't, so don't get them mixed up! But the return pressure should be almost nothing (as it's just open into the tank at the back end), so maybe like 2 psi, which if fine as long as the plastic line is still in good condition.

Did you run your high pressure line through the cabin like the stock line or run it under the car. I’m thinking of using nickel-cooper tubing and routing it under the floor pan instead of through the cabin. 
 

zach

[AustrianVespaGuy]

12 hours ago, vacca rabite said:

Did you run your high pressure line through the cabin like the stock line or run it under the car. I’m thinking of using nickel-cooper tubing and routing it under the floor pan instead of through the cabin. 

Hi Zach, for the high pressure supply I used the original steel hard line that runs underneath the car, with high pressure fuel injection hose running between it and the pump and the fuel rail.  In my opinion, any high pressure stuff is best kept outside the cabin

[germancarguy]

This is all very interesting, I am hoping to a phased approach to the EFI project but have some questions and would like the groups opinions. To start I have a stock 76 with a Weber 32/36. 

 My planned steps:

1. Install a OX sensor
2. Install the pulley sensor
3. Install the water divider and assorted cooling system upgrades
4. Select the Controller (Microsquirt or Megasquirt)
5. Move battery to the trunk.
6. Put it all together and test it all out with the Weber and get accustomed 

Thoughts ??

 

Thanks Everyone

Paul

 

 

 

[mike472]

Read a lot...  then read some more. You’ve got the right steps but the devils in the details. Go to the MS site and read posts here. Sounds simple but it’s not. A lot to consider. You will wind up with a smooth, powerful(if you do it right) and an economical fuel system if you can keep your foot out of it.  
Or, save yourself a lot of headaches and bolt on a 38/38 Weber instead of your 32/36 and a programmable distributor.  I have two cars one with each system and they’re both great in their own ways. One for its simplicity and the other for the ultimate tunable fuel/ignition system producing the most power and smoothness although with a steeper learning curve.  You need some electronic skills with MS.  Lots of wiring to do. 

[AustrianVespaGuy]

Everything Mike said is spot on for sure, so take all that to heart! The only thing I would add is that your plan for a 'phased approach' is indeed wise.  Start with putting in that wideband O2 sensor and see how that goes before committing to the next step(s).  Will give you a chance to feel wiring and tuning before you get fully committed!

[mike472]

That wide band O2 sensor is indeed a good way to begin. Even if you went the 38/38 route it will help you get the most out of your carburetor jetting.  Innovate makes a nice digital one that’s easy to install. 

[germancarguy]

I never thought of the 38/38 upgrade from my 32/36, would that give that much gain on a stock motor. The FI route was to give me flexible tuning.

 

Paul

[AustrianVespaGuy]

8 hours ago, mike472 said:

Innovate makes a nice digital one that’s easy to install.

While the Innovate kits are pretty friendly to get up and going, I personally have had repeated longevity issues with them.  Went through two LC1 controllers on the 2002 and also 2 MTXLs on the E30 track car.  Switched to a 14point7 Spartan2 for the 2002 about 2 years ago and have liked it better in every way. It's also cheaper, although the gauge is sold separately.  But it uses the better 4.9 LSU sensor, seems more responsive, and you can even calibrate the linearity to get a perfectly accurate output signal. I'm about to replace the second broken MTXL in the E30 with another Spartan2, so at this point I'm going to wholeheartedly recommend 14point7 stuff over Innovate products.

[AustrianVespaGuy]

52 minutes ago, germancarguy said:

I never thought of the 38/38 upgrade from my 32/36, would that give that much gain on a stock motor. The FI route was to give me flexible tuning.

38er is *sort of* an upgrade.  It FEELS more powerful, but that's mostly because it applies more throttle for less pedal input; you sorta get to full throttle by the time you only have the pedal pressed down half way.  It does breath a little better at the top end, but I think this only translates to an actual increase in horsepower if you have upgraded engine internals, and doesn't do much for a stock engine where a fully open 32/36 isn't really the breathing restriction.
FI is certainly more flexible, albeit a MUCH larger project!  I would reemphasize though, induction - other than ITBs or forced - isn't really where extra power is found.  Pistons and valvetrain is where power is made, and induction and exhaust tuning then allow you to make the most of and/or move the power band around for your given engine configuration.  But EFI and spark control definitely give you the MOST control and potential here for such optimizations!