Turbo Megasquirt EDIS 2.1L Forged M10 build-up. IT'S ALIVE!

[peteinjp]

Just a detail but you might look into replacing that driver side motor mount with the supposedly stronger rectangular type.

[CamB]

As long as it is carefully tuned, and you don't run the turbo too far outside its efficiency range (and it looks quite little, so I'd guess that would be in the 12psi range), then you should be fine.*

* Note - I gather this from what other people have done, rather than personal experience. It seems that with good tuning and moderate boost a 9:1 compression ratio is fine. I'm targetting more like 8.0-8.5:1 and 14psi +

[ThisIsTheRanger]

Thanks for the tips Cam and everybody. That's the reason I posted my build up.

As promised, the MS pics:

With the jumpers installed for running EDIS.

For those who have never seen the stimulator before:

Running for the first time

Finished!

Assembled the JAW wideband O2 board today...

and got the intake installed along with the 318i water neck and 318i alternator.

Ran into an unexpected delay when the throttle body linkage hit the brake booster line so I had to flip it upside down. You kinda can see how close the booster comes in this pic. I'll try to get a better one.

I need to figure how to run the MS on one of the 318i temp sensors. Does anybody have a resistance table?

[ThisIsTheRanger]

Oh and what do you guys think I should run for a throttle cable? As you can see I already have a cable bracket for the TB.

[alp]

check with Zenon on what he did to install his Megasquirt.

www.zeebuck.com

[ThisIsTheRanger]

Zeebuck was a little unclear of which cable he used, and it looks like people have pretty good luck with the Lokar cables, so I just bought one of these.

36" should do it. model number TC-1000HT36

[1669]

damn codester the build looks good

[Solive]

Looks awesome dude!

As far as using the stock temp senders, there's a program called "Easytherm" that allows you to run what ever temp senders you want. Because the temp senders are simple thermistors, you can "calibrate" the sender by measuring the resistance at three temperatures: ambient air, boiling water and an ice bath. Make sure you have a temp reading of each one . Im pretty sure easy therm allows you to choose what temperatures your resistance values are at.

[oz02]

Simply increasing the bore size from 89 - 91.4 increases the compression ratio by ~0.40:1, so I reckon you might be more like 9:1.

I don't exactly agree with this.

If bore size is increased, new pistons are needed, and these pistons will be made to a specific ratio - whatever you want really, so i would say in this case, you need to find info on the pistons and check if any metal has been removed from your head chamber (this will reduce cr) Also if your head deck surface has been machined flat as mine has been a couple of times this will increase your compression ratio (this can be remedied with a thicker copper gasket. The raised pistons i have seen are anywhere from 8.5 to 9.5 cr, i'm not sure on the bathtop ones as i have the piano top ones. of course special ordered ones can go to 12 cr etc.

Best of luck, looks good.

[CamB]

Well, **if** all you change is the bore size - same compression height, head unskimmed, block undecked, same size dome on the new pistons, then the compression ratio will increase.

Obviously changing other stuff will change the end result. I just wanted to point out that the c/r might be higher than the original poster expected - as you note yourself most of the changes are c/r increasing rather than decreasing.

[ThisIsTheRanger]

Simply increasing the bore size from 89 - 91.4 increases the compression ratio by ~0.40:1, so I reckon you might be more like 9:1.

I don't exactly agree with this.

If bore size is increased, new pistons are needed, and these pistons will be made to a specific ratio - whatever you want really, so i would say in this case, you need to find info on the pistons and check if any metal has been removed from your head chamber (this will reduce cr) Also if your head deck surface has been machined flat as mine has been a couple of times this will increase your compression ratio (this can be remedied with a thicker copper gasket. The raised pistons i have seen are anywhere from 8.5 to 9.5 cr, i'm not sure on the bathtop ones as i have the piano top ones. of course special ordered ones can go to 12 cr etc.

Best of luck, looks good.

That's exactly what I was thinking. I was told the compression ratio would be 8.5:1 with the new pistons. The head has been *lightly* resurfaced as well. With ｔｈｅ　protrusion on the piston as small as it is (~3mm), and the recessions for the valves，　８．５：１　ｌｏｏｋｓ　ａｂｏｕｔ　ｒｉｇｈｔ．　Ｉ　ｗｉｌｌ　ｔｒｙ　ｔｏ　ｇｅｔ　ｔｈｅ　ｓｐｅｃｓ　ｔｏ　ｂｅ　ｓｕｒｅ．

[ThisIsTheRanger]

Anyway, I have been making a lot of progress lately on the TurbO2. I have finished all of the wiring for the MS and EDIS systems, but will be running with a distributor just to get it fired. I will then hook up the coils and plug the dizzy hole. Also finished the JAW display and got the Bosch 4.2 LSU wideband O2 sensor. The only thing I really need to do now is fabricate the 318i exhaust manifold adapter for the T3 flange. Pics to come!

[ThisIsTheRanger]

It turns out the pistons were made to be 8.5:1 compression accounting for the bore and everything. I probably wouldn't make new larger bore pistons to be a certain compression ratio based on the old bore of the engine. Anyway, I have mostly configured the MS and the JAW, but the "Generate VE table" function just puts 0's in the boxes. Does anybody have a VE table for a turbo m10? I might make a post in general for that. Other than that, the car should be running within the next week here.

[CamB]

Almost there! I am definitely waiting to hear the result with interest, and more pics etc would be great.

What turbo and manifold BTW?

[Solive]

As long as it is carefully tuned, and you don't run the turbo too far outside its efficiency range (and it looks quite little, so I'd guess that would be in the 12psi range), then you should be fine.*

* Note - I gather this from what other people have done, rather than personal experience. It seems that with good tuning and moderate boost a 9:1 compression ratio is fine. I'm targetting more like 8.0-8.5:1 and 14psi +

Tuning is the major thing here. Technically with the same boost levels, you will make more power on a higher compression motor than a lower one. (if you can tune it)

And for my frankenstroker m50, i plan on building for an 8.8:1 CR. I also plan on pushing around 20psi boost!

Anyway, sounds awesome dude. Keep it up and take pictures!