1987 325e sedan M30B35 swap

[AWDBOB]

My cams lsa is 108, that Cat Cams 294 is 110. I think the stock B35 cam is 112. Most normal engines are around 114.

Yep, you definitely have too much overlap at idle. The Schrick along with that CatCams both have a 110 LSA. The new IE Billet cam is called the N21 and supposedly shares the same specs as the “legendary” Paul Burke N21. I think I have the cam sheet somewhere on my computer, I don’t remember what that LSA is offhand.

[LowR3V'in]

http://www.catcams.com/products/camshafts/datasheet.aspx?ENGINE_id=110&CAMSETUP_id=1428&Language=english

i don't have any cam knowledge what so ever keep that in mind
just got it because it was "turbo cam" and it didn't require springs, which it absolutely did. stock springs would float at 5.5k

looking back i should of got the big n/a cam.

[st.petebiodiesel]

ya that sounds super nasty i love it.

https://youtu.be/Kp6U8uPwrBs?t=26

my garbage cat cam stops making power past 6,200 wish i got something like urs.

when is the dyno i want to see that shit rip to 7k.

What are the cam specs?

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[st.petebiodiesel]

What are the cam specs?

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[st.petebiodiesel]

Time to finish detailing the Microsquirt install.
Microsquirt needs a variable TPS. If you have an automatic throttle body you can use the 6 pin tps already on the throttle body. You can use any variable TPS you like really. You just have to calibrate it on tunerstudio. I choose to use a M50/52/60/62 TPS. They are cheap and really easy to go to a junkyard and find half a dozen.
I bought a squared motorsports TPS adapter plate. I kinda wish I made my own, its clocked kinda weird. I think it's made for an M20 application.


I am not actually running a idle valve at all. My idle is controlled by a bleed valve from a euro m30 2 wire ICV.

The valve is just inserted to the hose where the ICV would normally go.

I may run a ICV later but this seems to work for now.

I used the open hole on the intake tube to insert the GM iat sensor. It fits pretty good.

You can use the stock motronic coolant temp sensor. In fact the calibrations are already pre loaded into tunerstudio.

I chose to leave my FPR un plugged to keep the fuel pressure stable at all ranges of rpm. Because my fuel table is infinitely variable I didn't think having the fuel pressure fluctuating would help with tuning.
Plus I need a intake manifold port for my map sensor. My map sensor lives below the relay box on the drivers side inner fender. I inserted a .030" might welder tip in the map line to smooth out the signal at low rpms.

After I had all my connections completed I began trying to wrap all those ugly wires. It's not the prettiest but better than nothing.

Here is how she looks right now.







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[LowR3V'in]

ya that sounds super nasty i love it.

https://youtu.be/Kp6U8uPwrBs?t=26

my garbage cat cam stops making power past 6,200 wish i got something like urs.
when is the dyno i want to see that shit rip to 7k.

[st.petebiodiesel]

Really good to know. Seems the Cat Cams 294 may be a nice compromise with a little less lift, a touch more duration and a wider LSA? http://www.catcams.com/products/cams...AMSETUP_id=257



Not worth changing at this point obviously. I read your thread once a week to remind myself of how bad I need an M30. Thanks for that.

My cams lsa is 108, that Cat Cams 294 is 110. I think the stock B35 cam is 112. Most normal engines are around 114.

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[AWDBOB]

If I had to do it again I would get a cam with a wider lobe separation angle. With this cam my engine is idling at 75-80 kpa. 102kpa is atmospheric pressure and most engines idle between 40-60 kpa.
Also it smells super rich at idle because both valves are open at the same time at the end of the exhaust stroke and beginning of the intake stroke.
Driving at low load, low rpm results in a bit of stumbling. At 45mph in 5th gear at 1500 rpm you can tell the cam overlap is making the engine less smooth. Anything above 1800 and you can't even tell. I didn't notice any loss of torque with this cam it pulls just as hard as it did below 3000 rpm.
You do get a lot of attention from other car enthusiasts when your engine sounds like the beginning of Van Halen's hot for teacher. Strangers ask me what is under the hood quite often.
Most non car people assume something is wrong with your car and your driving the most clapped out jalopy in town.
Above 3000 rpm this thing pulls as hard as a S52 all the way up to 6800. It's quite impressive compared to a stock M30 on motronic. I'm able to spin the tires going into second.
I'm still messing with the timing and tune trying to perfect the driveability.

Really good to know. Seems the Cat Cams 294 may be a nice compromise with a little less lift, a touch more duration and a wider LSA? http://www.catcams.com/products/cams...AMSETUP_id=257

Not worth changing at this point obviously. I read your thread once a week to remind myself of how bad I need an M30. Thanks for that.

[st.petebiodiesel]

Nice man! How does it feel off-idle/low RPM? Still snappy with the 292 since you've got 3.5l of fury?

If I had to do it again I would get a cam with a wider lobe separation angle. With this cam my engine is idling at 75-80 kpa. 102kpa is atmospheric pressure and most engines idle between 40-60 kpa.
Also it smells super rich at idle because both valves are open at the same time at the end of the exhaust stroke and beginning of the intake stroke.
Driving at low load, low rpm results in a bit of stumbling. At 45mph in 5th gear at 1500 rpm you can tell the cam overlap is making the engine less smooth. Anything above 1800 and you can't even tell. I didn't notice any loss of torque with this cam it pulls just as hard as it did below 3000 rpm.
You do get a lot of attention from other car enthusiasts when your engine sounds like the beginning of Van Halen's hot for teacher. Strangers ask me what is under the hood quite often.
Most non car people assume something is wrong with your car and your driving the most clapped out jalopy in town.
Above 3000 rpm this thing pulls as hard as a S52 all the way up to 6800. It's quite impressive compared to a stock M30 on motronic. I'm able to spin the tires going into second.
I'm still messing with the timing and tune trying to perfect the driveability.




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[gnmzl]

This is just great! Love your approach and have to admit, your thread made me look for an m30b35 to swap into my beat ass 325e.
Thank you for sharing the microsquirt install. Def super helpful

[st.petebiodiesel]

So microsquirt.
Its basically the same as megasquirt 2 extra. In fact if you buy a M20 or M30 pnp kit it contains a microsquirt unit.
Microsquirt is a very simplified version, it only contains 2 injector outputs and 2 ignition outputs. (You must provide the coil drivers as the microsquirt board does not contain them.
For a M10/20/30 this system will support the engine perfectly, even if boosted.
So let's begin the install.
Here is my microsquirt unit with 30" of harness wiring. It cost roughly $360.

Next you'll need a GM IAT and Map sensor.

Here is the wiring diagram I used to build the harness. It's very straight forward.

I had a spare motronic 1.3 harness that I hacked up to use the connectors.

Microsquirt units don't have coil drivers, only spark outputs. So you'll need an external coil driver. I picked one up at the junkyard from a Volvo 740.

Bosch P/N 0227 100124. It's a single channel coil driver. If you attempt to run a coil off the microsquirt spark output you will burn it up.

You will also need a wideband of your choice. It is super difficult to tune with a narrowband oxygen sensor. I'll post my fuel and ignition tables once they are perfected.

Here is where I mounted the microsquirt controller. I felt that under the drivers dash would be best.

There are extra provisions in the chassis grommet for the harness.

More to come.





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[e30RS]

Sounds fantastic! Impressive job sticking with it.

[AWDBOB]

Nice man! How does it feel off-idle/low RPM? Still snappy with the 292 since you've got 3.5l of fury?

[wworm]

thats a lovely sounding idle haha. glad to hear its back up and running! you move quick!

[st.petebiodiesel]

hell ya finally.
just saying i had a cat cam that floated the valves. it wouldn't make power past 5k
using the ie springs fixed that problem.

My logic to going with the IE springs was the steel rockers are much heavier and therefore would need more spring to keep the valves from floating.
Jeff responded to all my emails and recommended using his inner spring and a stock outer spring to reduce the spring force slightly.

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